ML20073H884

Monitoring Marine Environ of Long Island Sound at Millstone Nuclear Power Station 1990 Annual Rept

ML20073H884
Person / Time
Site:	Millstone
Issue date:	12/31/1990
From:	NORTHEAST UTILITIES
To:
Shared Package
ML20073H846	List: B13809, Forwards Annual Environ Protection Plan Operating Rept Jan - Dec 1990 & Monitoring Marine Environ of Long Island Sound at Millstone Nuclear Power Station Annual Rept 1990 ML20073H855 ML20073H884
References
NUDOCS 9105070296
Download: ML20073H884 (85)

Text

,

i Monitoring the Marine Environment of Long Island Sound at Millstone Nuclear Power Station Waterford, Connecticut o

A O o

p o o0 g 0 o0 0o g O o 0 ,a0 7(\.. O f$s,.

& ,t;} 3

%.!::(

. v. .

T i; 4 .y g[],i,. '.il'.:'

,,9 %d T%

h[h'i

'5j. :# 1 'l.'t .. g N ' ,WM ,

.. S.5' .Y'I- , . q. qq,gyili: ;q. , , ,,

e

. . . , ..; tv '.

w

5,

• yi': ; ;' ' ;

se e.:,s,.$.t. . ... ,

ANNUAL REPORT 1990 norenmnsrernurms

, m...--=~ NU ENVIRONMENTAL LAB l'".7007.0 % ~ ~~' APRIL 1991

- L L a C % C2.%"1? C 9105070296 910430 PDR ADOCK 05000423 R

PDR yf

4 Monitoring the Marine Environment 4

of Long Island Sound at: Millstone Nuclear Power Station

+

3 l -

'Waterford, Connecticut v

.O

'a 4 a 0

, # 'o :n g*,no 0:

3, 'o o0 0,0 a y ,

,2j I '. .

= a. .

. Q- -

. . .. s y

n r..

4 I-

~

9. .s l & ,, .

y.. ' m-

, - Q t; '

=6 g g .. .

..M..,_,,_ . y.,_.:. .m

'? * - .?. . Y',:;

.m...

, s, ,

.. g .

~. . m .

q

. 7^ . . g*; . . - . ..

. . ..w ,. . . m% . . . . ; ., y

.p..n.:-:

g- .. .

. , , e. . . : ,. . . .. .. .

w ,,

m, _

. :e i.'

... u-

,, ..;. . . . ~ g&g.;. e . . "p..3 ..a.m.y:.. . p,.: ., . . . -

. . . . . - l %p:'. .

~ .$ .. %,; @7 e. v.-:.y %._ .;..

,.; . . . . . . . . . . ;. .; : :;.g.

.m

.p ..y..

. .,y .

^3p * '

4.:F

• m. ..

y:,.... q .

W. -

5

V ANNU ALE REPORT:1990 NO8tTHIIASTIFt1tJTRS 1

• • = = w ~ => = - NU ENVIRONMENTAL LAB

- .,s. .u wu- ~ .,

u- APRIL 1991-g .

9105070296 910430 PDR ADOCK 05000/23 R PlJR

_ _ ____..______.___s _ _ _ _ _ _ _ _ _ _ _ _ _ . . .

Monitoring the Marine Environment of Long Island Sound '

at Millstone Nuclear Power Station  :

1990 Annual Report l Northeast Utilities Environmental = Laboratory April 19,1991 Waterford, Connecticut

+e , e - =~m--.s , e.u~-- -.---nm-.n -o , - ---

w

O O

O $ 00

[ o 0 0 O pc> r Q J l

' N- N I.  % ~%O 6 , .

.w f*: . . . >

Q,(MY .d

';L

N 7g; . A r- :

)

- - - - _ll===e ~ _ ,_,

9 -iR, f'

+-- g_d 2  %. .m  ; -m. / p fe 4 2- -

l

-.. ,, 4 l l $, M5[$$D1l

• lhe picture on the (tntt depicts a snull commumty of marint wtanjlvrcrs m a natural scilmg ,

of an old submerged log 'this commundy is compmed of; A) a shipworm, 'lcrrds twuchi, the '

one shown is orily partially cyward to sww [l= excurrent siphon, 2=)ullets, calcarrte )

i

' structures usni to seal oil the tute opcmng; 3*the calcareous tute which is necirted by the i

bivalve's mantle tnembrane; and,4avahrs, calcarcom shells uwd to tyre through the wood l prinidmg sustetun<c to shipworm],11) a lernnorid hopst I.inuuma hpmnnn, which is a irre j

l hsing crustaccars stui tunnch just twticath wooden surfacts; C) a tunicate, Sov/a (! ara, which l is not a wiswihorvr. but rather a filter feeding hemichordate slut can (cod on larsal shipvorms, D) a late stage vebger (pedneliger} of a long-term brtwhng shipworm, e g., I twtuhi; II) a juvenileshipworm iccentty set, characterued by two small siphons surrounded by digestest woix] l jfrauj.

)

1 I

l l

l

Preface Tius report was prepared by the Northeast Utilities Service Company Environmental Laboratory (NUEL) staff.

All contributors are acknowledged according to their respective disiplines.

Ilenthic Ecology: l'ish Ecologyt Statistical Support: ,

Dr. Milan Keser, Supervisor Dr. Linda Dircley, Supervisor Dr. Ernest lorda l

James F. Foerich John A Castleman

{

Raymond O. IIeller David P. Colby NUEL hlalling Address:

Donald F. Landers Donald J. Danila NU Environmental Laboratory ]

Richard A.Larsen Gregory C. Decker FO llox 128 Douglas E. Morgan David G. Dodge Waterford, CT 06385  !

Ilenty R. Paul Christine P. Gauthier John T. Swenarton JoAnne Konefal Joseph M. Vozarik J. Dale Miller Special appreciation is extended to our summer staff for their untiring efforts in field and laboratory support: Lisa Boulanger, Lydia Eichert, Miche!!c liodge, Ryan Lynch, Thuy Phan, IIcidi Seaton, and Dhclean Rivera Ubin:ts.

Critical _ reviews of this report were provided by Dr. William C. Renfro, Director of Northeast Utilities Service Company (NUSCO) Environmental Programs Department, Paul M. Jacobson, Manager of NUSCO Environmental Services Branch, and the following members of the Millstone Ecological Advisory Committee: Dr. John Tietjen (City University of New York), Dr. Nelson Marshall (emeritus, University of Rhode Island), Dr. Saul Saila (cmeritus, University of Rhode Island), Dr. William Pearcy (Oregon State University), Dr. Robert Wilce (University of Massachusetts), and Dr. Robert Whitlatch (University of Connecticut).

Preface iii

i Executive Summary I i

Winter Flotinder Studies consistent with previous findings. Annual abundance of larvae in the Niantic River during 1990 was near Operation of the Millstone Nuclear Power Station the 7 year median value. Densities in the bay have (MNPS) can potentially affect the local Niantic River been very similar during the past 5 years of sampling.

population of the winter Oosmder (Pseudopleuronectes No apparent relationship was found between annual americanus), particularly by the entrainment of !mae larval abundances in the river and the bay. This through the cooling water system. Consequently, suggested that either varying annual mortality intensive studies of the life 4 .aory and population occurred in the river prior to when many larvae were dynamics of this valuable sport and commercial flushed out or that the Niantic River was not the only species have been undertaken for as long as 15 years, source oflarvae for Niantic Bay.

Estimates of the abundance of adult winter flounder The annual abundance of yolk sac larvae (Stage 1) spawning in the river have been made since 1976, in the river was directly related to estimated egg The median trawl catch per unit. effort (CPUE) of fish deposition of spawning females. The temporal occur-larger than 15 cm during 1990 was 9.6, the smallest rence of each developmental stage in the river and bay CPUE in the time series. Although sampling this showed that most of the spawriing occurred in the year was hampered by the abundance of various algal river and that flushing of lariac from the river to the species, the low CPUE also reflected the relatively bay took place primarily during Stage 2 of larval poor year classes produced during the mid 1980s. development. Peak abundance for Stages I and 2 A mark and. recapture method used with the Jolly larvae occurred early during 1990 and was most likely stochastic model enabled estimation of the absolute related to the higher February water temperatures in abundance of the adult spawning population (winter that year, flounder larger than 20 cm, which includes some Larval gmwth was closely reinted to development immature fish). The most recent (1989 Larvey) in Niantic Day and both were positively correlated abundance estimate was about 34,000 fish, the lowest with spring water temperatures. Ilowever, these I of the past 6 years. Ilowever, an increase in the catch relationships were not as apparen'. in the lower river.

- of small (20 23 cm) winter nounder suggested that The slowest growth rates in the river coincided with abundance may also increase as these younger fish the highest densities of Stage 2 larvac, suggesting recruit into the spawning population. density dependent growth, which may have been Matur; females made up between one third and one- relawd tolevels of available prey, half of the annual catches of winter flounder in the The larval mortality was highest during Stage 2 of Niantic River during the February April spawning development (3. to 4 mm size, classes), wh -h is period. Estimates of the number of spawning females when first feeding occurs; larval abundance decibec and their resultant egg deposition were made by 94% during this stage in 1990. This stage may scaling annual standardized catch indices into absolute include a " critical period" for winter flounder; survival numbers. Using available information on sex, age, rates apparently improved progressively for larger size-and size composition, the annual female winter classes. The existence of density dependent mortality flounder parental stock size was estimated for use during larval development from hatching through the with the Ricker form of the stock recruitment 4. and 5 mm size classes was suggested by the relationship (SRR). Estirnated female spawner positive relationship between annual mor:ality rates

' abundance during the past 14 years was between 20 and c:"l production.

and 85 thousand and total egg production ranged from Demersal post larval juvenile wieter flounder have about 12 to 49 billion. been collected in the Niantic River since 19?3 arid in Estimates of larval winter flounder abundance at the Niantic Bay since 1988. Peak abundanca in the river MNPS discharge (entrainment sampling) have been during 1990 occurred late (late June to early July) calculated since 1976 from a station in Niantic Bay relative to previous years (generally early June).

since 1979, and at three stations in the Niantic River Maximum densities (atet 165 to 290 fish per 100 since 19fs3. Larval winter flounder abundance and m2 of bottom) in the river were the highest observed distribution at these stations during 1990 were in the 8 years of sampling. Peak dent i (about 85 1:xecutive Summary vii

l to 40 fish per 100 m2) in the bay, which occurred re-calculated this year, resulting in generally higher during the first icw weeks of sampling, were below annual estimates (154 ear range of 31.2 to 219.3 those in the river for the first time. Mortality was million) than those presented in previous reports.

apparently quite high in 1990, with few fish The potential impact of larval entrmnment on ll,e surviving in the bay and relatively few in the river, Niantic River stock depends upon the fraction of its given the high initial numbers. Because of the high pr Wuction entrained. To determine if the number of mortahty noted this year and the low mortahty found winter flounder lanae observed in Niantie Bay couki in 19n which resulted in the largest year-class of be maintained by the number found in the Niantie age-O fish seen since samphng began in 1983, year. River, mass-balance calculations were made lor the class strength may be atfected during the post-larval 1984 00 period. These calculations suggested that stage of hfe as well as during larval development, the Sound was an important source of larvae for No significant correlations have yet lun found Niantie Bay. An estimated 20 to 6W1 of the larvae between the indices of abundance for age O fish and entrained at MNpS appeared to have originated from those for adults in subsequent years. The lack of the Niantic River during the penad analyred.

relationships among these mwures of abundance Percentages of the river prtducuon that were entnuned meant that none of the cally hfe stages could be used annually ranged from about 6 to 199.

as a reliable index of year class strength. The ongoing samphng programs for winter Consequently, egg pmducuan estimates from annual 00ander prosided data for both short tenu assenments spawning surveys that were scaled to numbers of and for a computer simulation model for long term spawning females have been used as recruitment assessments, Data used by the Niantic River indices for the Niantic River winter flounder SRR. stochastic population dynamics nulel came from A three-parameter Ricker SRR was fitted to annual various basic life table parameters: the theoretical stock and recruitnwnt data and February water unfished spawning stock si/c and mean fecundity; the temperatures. The estimated value for n, the three parameter estimates of the SRR; February water compensatory reserve parameter, was 2.226. The temperature statistics; and simulation parameters temperature parameter c was 0.329, indicating a specific to each model run, meluding a random negative relationship between winter flounder vanabihty component Condinonal mortahty rates of recruitment and water temperatures in February. This 15,20, and 25% which corresponded to petulated month coincides with the period when most lanal entrainment rates at MNpS, and realistic spawning, egg incubation, and hatchtng occur, fishing rates were simulated accordmg to various Because fishing mortality has been increasing steadily scenarios. In addition, the winter flounder stock was during the past two decades, recent SRR-based simulated both as numbers of fish and as biomass estimates of ct greatly underestimate the true slope at (lbs). All model runs were stochastic and consisted of the origin. This occurred because the method of 100 replicates of each stock projection over a 100-calculaung recruitment already incorporated the cf fccts year period (1960 2060). A stochastic baseline was of exploitation on fish age 2 and alder as well as any generated that illustrated trends in abundance for MNPS larval entrainment effects. Therefore, indirect Niantic River winter flounder subjected to fishing, estimates of the true a parameter (i.e., when no but in the absence of any power plant effects. Using fishing murtality occurs) made by the Connecticut an initial stock si/c of 76,500 females (111J100 lbs),

Department of Environmental protection were used the actual mean stock site of the c>ploited stock for modeling purposes. The a value, re scaled to converged to a level of about 47,000 fish (52J100 lbs) units of fish numbers from biomass units, was by 1971, declined to 37,000 females (1 lb per fish) in estimated as 5.42 and describes the inherent potenual 1991, and then increased to about 43,500 spawners for mercase of this particular stock, through the end of the series as new fishing The number of larvac entrained through the regulations came into effect. Because larval entrain-condenser cooling water system at MNPS is the most ment eifects are magnified by current high fishing direct measure of potential impact on the winter mortality rates, larger mimmum site regulations will flounder stnck. Annual estimates of entrainment were substantially relieve fishing pressure on first time related to larval densities in Niantic Bay and plant spawners. Projections of stock sues were next made  :

operations. Tbc entrainment estin' ate for 1990 was unng three hypothesued levels of larval entrainment 138.9 milhon, one of the lowest since three unit l

mortality. The simulanons predicted a fmal 15% )

operation began in 1986. Entrainment estimates were stock reduction after sustained worst case (25%) larval viii Monitonng Studies,1990 1

entrainment during the entire h1NPS operational during the early hfe stages, w hich could help mitigate period (19712026). Probabilistic risk assessment, losses due to entrainment, howeser, predicted that one time stock reductions of Silversides dominated the shorcqone seme up to 30 409 could occur with probabihties of 0.21 collectioas and adults were abundant in wmter trawl for fish nurabers and 0.24 for biomass during the collections. There were no apparent changes in critical period of 19S9 9l w ben full h1NPS three-umt annual or seasonal abundance or dntribution of seined operation coincided with the hjghest fishing mortahty sihersides in Jordan Cove related to the three-unit rates. The possibihty of stock collapse due to secruit- thermal t31ume.

ment failure was investigated using a " recruitment Grubby larvae were present in ichthyoplankton overfishing" criterion. The probability of biomass samples and juseniles and adults were found in trawl reductions of 80-909c was only 0.03 for fishing plus samples. Grubby abundance i . both plankton and worst case entrainment and that of recruitment fadure trawI collections decreased i.1990, endmg a long Oeduction >409 ) was essennally zero. The spaw ni,g upward trend stock was pmjected to return to pre h1NPS levels The tautog is a commercially important fish and within 10 to 15 years after the tennination of Unit 3 the cunner is a numerically abundant species in the operation in 2026. Niillstone area. The greatest potential impact of h1NPS for both the t;wtog and the cunner is through

Fish Ecology Siudies egg entrainment. Over 801 of the eggs entrained are labrid (tautog and cunner) eggs. 1he results of an s The objective of the fish ecology monitoring entrainment mortahty study conducted this year programs at htNPS is to determine whether station indicated that almost half of the labrid eggs entrained operation has any cffect on local fish assemblages. survived the process. Although tautog larsac and These effects have tren defined as power ptml related adult abundances have declined, egg abundance, I changes in the occurrence, distribution and abundance probably our best measure of stock reproductive of fish species which would affect the coramunity capacity for this taxon. has increased. Abundances of structure. Fish assemblages in the area of AINPS most life stages of cunner collected near N1NPS have could be adversely affected by impingement on the declined. Part of the decline was probably a result of intake screens, entrainment through the cooling water removalof preferred habitats near the intakes. Young-E system or by changes in thermal regime or in of-the-year recruits accounted for a higher proportion

[ physical habitats.

To determine the impact of h1NPS on local fish of both lautog and cunner caught during three-unit operation. This shift could not be attributed to g

assemblages, trawl, seine, and ichthyoplankton increased entrainment, because if entrainment losses monitoring programs have tven established. Of the were affecting recruitment, juvenile abundance wouki one hundred and ciphteen fish taxa that have been be expected to decrease and the relative abundance of collected in these monitoring programs, six taxa were older fish increase. Commercial and recreational selected for detailed analysis due to their prevalence in fishing for tautog in LIS has increased during the last entrainment collections or their abundance in the decade and this may account for the shift in the length-shcreaone area of Jordan Cose, an area w hich may be frequency distnbution, However, a recent assessment I impacted by the thermal plume. Annual and long- of the population in LIS indicated a healthy stoco term trends in abundance of sarious life stages were Current values of fishing mortality for tautog were examined for caeh potentially impacted taxon. estimated to be alvut one. third of the level beyond The Amencan sand lance was primarily collected as which additional fishing effort would actually reduce l

larvac and was a dominant entrained taxon, Annual yield per recruit. At this rate, the equivalent adult sand lance abundance was hnked ia hlarch water population losses resulting from egg and larval temperature, even though annual larval abundance entrainment would have to amount to more than fluctuated substantially. twice the current annual catches in order to become Several life stages of anchovies were collected in entical. Because no fishery exists for cunner, there is the monitoring programs. Juveniles were caught by no published work assessing the present condition of trawl, and eggs and larvac were found in entrainment the LIS population, as there is for tautog. Because samples. In 1989, both egg and larval densities were the hfe span of the cunner is much shorter than that

=

low. Comparisons of annual egg and larval abun- of the tautog, conner may be more sensitive than dance indices suggested compensatory mortality tautog to increased mortality rates. llowever, the Executive Summary ix

) entire compensatory reserve of tir uninhed cunner females were f ublegal sired. This was within the stod should be available to conquate for losses targe of 3 unit studies (77 92% ) an i higher than the related to entrainment. range m 2 urut stushes (55 82G).

Lolnters that were close to molting comprised 1.obster Sitidles 3Ei of the total catch during 19W. Valoes during 3 unit nod 2 umt studies were 2.13.2% and 2.5 6 4% ,

'Ihe American lobster, llorum amerkurun,is the respatively. The average grow th lwr molt was 9.4 most econonucally important fishery resource in rnm (14.4%) during 1990, compared ta growth

! ohg Island Sound. The lolwter populauon in the between 8.4 and 9,4 mm durmg 3 umt, and 8.3 to 9.3 Millstone Point area was sampled using wire pots set inm during 2 unit operauon. Female growth was at three s uuons from May through October during higher (9.6 mm) than male grow th (0.3 nmi) during 1900. Potential effects of plant operations on the 1990 and higher than the range in 3.unn (8.5 9.3 local lobster populauon were taessed by comparing mm) and 2 unit studies (7.9-9.4 mmt the results of the 1990 study (catch per urut effort- Lobsters missing one or both (law s ((ulls) in 1090 CPUll, site distnbution, ses ratio,(haracienstics of comprised i1.9% of the total catch, which was within egg bearing females, molting and growth, lobster the range of salua reported in 3-unit (10.312.2%)

monment and larval enti 1meno to other 3. unit and 2 urut studies (10 615.5% ). Claw lou has been operational study years (19n6-1984) and to data lower (11.1% ) smce implemental on of es(ape sents collected during the period of 2 unit operation (1978- in 1984; before the regulanon was enf orced, claw lou 1985), as eraged 12.6% .

't he total number of lobsters caught during 1990 The number of lobsters tagged in 1990 (5,741) we was 7,106 the lowest value reported sinte the start of within the range of values reported in both 3 unit 3 unit operudon (7,211-8,871); the total number (5,680 6,837) and 2 unit studies when 20 wire pots taught durmg 2-unit studies w hen 20 wire pots were were used at each station (5,160 7,575). The used at each station ranged between 6,376 and 9,109 ivrceatage of tapped lobsters recaptured in our pots lobsters. Cakh vr I unit cifort during 1990 was 1.531 donng 1990 (18.6% ) was lowt r than that obsersed in lobsters per trap haut, compared to 1.585 1.920 3.uru'. studies 119.2 25.2%) but within the range of during 1986 89; and 0.004 2.006 during 2 unil 2 unit studies (14.4 23.9%). Commercial lobsteimen operation years (1978 85). The CPUE of lobsters s recaptured a smaller percentage during 1990 (16.8% )

82.6 mm, the 1990 legal size, was 0.076 (6 mean), than in prior 3 unit studies (18.4 20.4%) and 2 urut higher than the 1989 value of 0.065 ahen the studies (21.1-47.6% ). Lobstermen recaptured fewer minimum legal sire was 81.8 mm but lower than the lobsters since 1984 (19.8% vs. 38.0%), when the tange of values repor ed in other 3 unit (0.0740.086) escape vent regulation went into eIfect.

and 2 unit studies (0.098 0.173) w hen the minimum Nmety six percent of the tagged lobsters recaptured legal size was 810 mm. in our pots during 1990 were Umght at the stauon of

'the mean siec of lobsten caught during 1990(70.2 release, and 98% of all the tags returned by nun) was within the range of mean siics reported in 3 conunercial lobstermen were from 101 stm caught unit studies (69.5 70.2 inmi but smaller than those within 5 km of Millstone Point, The average reported during 2 unit studies (70.7 71.8 mm). 'ihe straight line distmee traveled by lobsters caught in female /ma!c sex raio of 0.7) in 1990 was the lowest commercial pots was 2.04 km during 1990, which since this study began in 1978 (0.79 0.97). For the was similar to the distance traveled in 3 unit (1.97-Tin.t time, Twotree catches contained more males than 3.16 km) and 2 unit studies (l.70 3.01 km). Since f(males (0.90 vs, 1.02 to 1.38 female / male). 1978,22 lobsters migrated 250 km ofishore where Fecuales began to sexually mature beiwoen 50 and 55 they were caught in deep water canyons on the edge of mm CL and all were mature at sires above 95 mm the conunental shelf.

CL ating 1990, as in previous years. The Stage IV lobster larvae predominated the collections percentage of berried females collected during 1990 during 1990 and 1986. In all other study years stage I (6.6%) was the highest percentage collected in this lanae were more aburulant. Significandy rmire larvae study (3.166). The mean CL of berried females were collected during night in 1990, similar to 1986 during 1900 was 78.1 mm compared to the velues and 1989; no sigruficant dif ference was found between reported in 3 unit (76.5 78.0 mm) and 2-unit studies day and nipht collections in other study years. The (77.0-8 L2 mm). During 1940,87% of the berried mean density of lobster larvae in 1990 was 0.748 per x Monitonng Studies,1990

m

,1 .

l i000 m iof coohng water and within the range of identined dunny the present rciert > car (Octoter 19h0-densities rs ported in 3 unit studies (0 7010 443) but September 199(b. Smcc Unit 3 began operanon higher than densities repined in 2 unit studies (0 409 (March 19hN,144 species were collected and the and 0.5N). The cotimate of total lotuter larsac overall total smvc the stuJ) began (1979) k l$h.

entrained, based on sample dennity and total MNpS Spaies that were identihed during 2 umt operation, unhng water demand. was 582,738 for 1"90 and w as but not during 3. unit operation to date, wcre not within the range of estimates rep 3rted during 3-unit consistent components of the flora. Of the two operation (394,518@0,573) but higher than values species collected sins l'mt 3 began operation, one repirted for 2 unit operations (77 AM and 12S,550). ( A niilh a m nio n sp has become a donunant The changes observed in the population camponent of the kul l ora This alpa ap; ears to be c haracterktin danng 3 unit vs. 2 unit operation (site newly introduced to the area trerhaps f rom the distribution, sex ratio, prepirdon of berried females, southwest pacihch a occurs at all our samphng sites growth and percent recapture! have been strongly and has been collected throughout the 3 car, and related to the implementation of an escape vent therefore its occurrence and persistence are hkely regulation in 1984 and the increase in minimum legal unrelated to power plant operation. Qualitative alpi site from h1.0 mm in 19S8 to 81.8 mm in 1959 and analyses allowed us to detennine floristic t hanges that 82.6 mm in 1990, increasing the minimu'n legal occurred, and continue to occur, at a thermally site is espected to result in increased proportions of unpacted site (FE), e.g., presence or estended grow mg berned females w hich will imprme the recruitment of season of algae with wann water allmity, and absence lobsters. The regulation to increase the mimmum or abbresiated season for species with cold water legal si/c appears to have been ef fective during the afhnity. At all other stations, similanty of species hrst two years of implementauon; the percentage of compo, tion betw een periods suggests that the overall berried females increased and the catch of legal. sited flora has ren ained relatisely consistent since our lobsters increased. The higher legal catches observed studies tegan.

in the past two > cars may, howescr, be due to Rocky intertidal sampling sites were aho recruitment of sublegal. sired lobsters from 1988, characterized in terms of abundance of dominant when th number of lobsters just telow the legal si/c organisms in undisturbed transects. For example, was unusually high. The effect of the increased high intertidal regions were predominantly bare rock, number of larvac entrained during 3 unit operation is and supported only small transient populations of dif ficult to assess at present, because lobsters require barnacles and ephemeral algae, w hile mid intertidal several years of growth to reach legal site. The surfaces were dommated by a fucmd canop) mer an effects,if any, of lobster larvae entrainment en f uture understory of barnacles. l.ow intertidal surfaces adult stock site will not be apparent until lobsters supputed extensive populations of Cnom/rus crispas, grow to a site vulnerable to capture in NUSCO and w hose surfaces in turn supponed populations of other commercial traps, algae (epiphytes) including Polysiphonia spp.,

Monostroma spp., and most recently, Antithamnion Rocky intertidal Studies sp. Dif ferences that esist among communities at our sampling sites were attributed to factors unique to The predominantly rocky coastline in close each site, such as degree of exposure to stonns and proximity to MNPS supports substantial and waves, and slope and stabdity of rock surfaces.

productive assemblages of plants and animals. An Differences between IT. (the station nearest to the ongoing environment;d monitoring program of these MNpS discharge) and all other stations were most ecologically important and potentially vulnerable extreme and were attributed to alteration of conditions communities was initiated in 1979, and continues to at that site by the thermal plume after the opening of assess the effects of construction and operation of the the second quarry cut. The low intertidal tone was power plant. Rocky interudal studies include cAposed to elevated water temperatures longer (910 qualitative algal sampling, abundance estimations of hours each tidal cycle) than were the higher two intertidal organisms that comprise rocky shore zones; these conditions prevented reestablishment of communities, recolonization studies, and studies of previously dominant populations climinated by the populations of Ascophyllam. opening of the second quarry cut (Chondnu, Monthly qualitative algal collections were used to Ascophyllumh and has allowed development of a characteri/c the kical intertidal flora; 128 species were community dominated by Codium, Ulva.

Executive Summary xi

Enteromorpha, and Polysiphonia, Populatiew et Fox island experimental site) has not recoscred since accies uruque to that site (Surgmsum), or of s[vcies in cUmination in 198.t, owing to the unfavorable i found elsewhere only .in the discharge quarry environmental conditions (water temperatures up to (Agardhirlia, Gracilaria) have also develojed nt i E. 7'C above ambient) caused by present 3 unit The mid and upper intertidal rones at FE were operating conditiont flowever, slighd) elevated exposed to elevated temperatures a shorter time, and water temperatures (2 3*C above ambieno at FN resembled the community that existed prior to the caused Ascophyllum to gruw longer and more rapidly opening of the second quarry cut, as well as those at this site, relative to stations farther away. Growth presendy observed at other sampiing sites. during 1989 9(1 was the second highest rccorded at Recolontration experiments, initiated by removal FN; it appears that degree of growth enhancement is of attached biota in September 1986, were continued dircedy related to the amount of thermal incursion during 1990; results of these experiments were (mkhtional heat hud) produced by the power plant. In compared to those of similar eywriments conducted other words, pl mts at FN prew longer when perials durmg 2 unit operation (initiated in Septernber 1981). of simuhaneous 3 unit operation were loncer or more Simple high intertidal communities (i.e., t arnacles, frequent, such as during 1988 89 (highest growth ephemeral algae) recovered in less than sit months year) and the present report year. As in previous durmg both 3 unit and 2 unit experiments. Rates of years, Ascophyllum mortality, or loss of tagged recoloni/ation of barnacle populations were similar in plants and tips, was not related to proximity to the both experiments (less than one year). liigh power plant but rather to degree of exposure to fecundity of adults and wide dispersal of larvae ensured prevailing winds and waves.

consistent and predictable recovery of ternoved barnacle populations. Recovery of Furus, the other Eclgrass mid intertidal dominant, occurred 5 10 anonths earlier during 3 unit operation than during 2 unit operation. Ecipass,70 stern marina, is a rnarine flowering Fucus recruitment was more variable because the plant, it provides a complex habitat for diserse I survival strategy for this alga is one of maintenance assemblages of rnatine organisms, stabilizes of tough,long lived individuals rather than high and se(hments,and raycles nutnents from sediments back predictable recruitment success as observed for to the water column, In addition, celgrass contnbutes barnacles. Reestablishment of the low intertidal significandy to the detrital food chain and serves as dominant, Chondrus crispus, involves vegetative food for waterfowl and other marine organisms.

Spread of nearby undisturbed plants rather than Ecigrass population characteristics (shoot density, recruitment of new individuals and therefore takes a length, dry weight standing stock and percentage of longer time. Rates of recovery of kical Chondrus reproductive shoots) were esamined during 1990 at populations were similar during 3 unit and 2 unit three stations (JC. Jordan Cove, NR Niantic River, experiments; however, intal recovery was not WP White Point) from June through September to observed at sites where Chondras had dominated assess whether any changes in celgrass populations before denuding, during both experiments (after t have resulted from 3 unit operation at MNPS In years and 5 years, respectively). Recovery of addition, sedimentary characteristics includmg mean Chondrus in the low intertidal zone at FE during the grain siec, percent silt / clay and organic content were 2 unit experimant, as well as that of bamt.cles and monitored at each site, Furus in upper tones at that site, was interrupted by - The shoot density of eclgrass significantly declined the opening of the second quarry eut and resuhed in from 1986 to 1990 at JC (by 53%) and from 1987 to-community changes similar to those observed in 1990 at NR (by 22%); no significant trend was undisturbed transects. Four years after the 3 unit ident ficd in the shoot density at WP, Similarly, autumn denuding, recolonization transects closely 'eclgrass standing stock significantly dechned from resemble undisturbed transects in terms of Codium 1986 to 1990 at JC (down 62%) and WP (down 31%)

abundance in the low intertidal, and of barnacle, and from 1987 to 1990 at NR (down 22%). Belgrass Fucus, and ephemeral algal abundances in the mid and - sampled at the NR site in 1985 and 1986 disappeared upper intertidal. in 1987; researchers attributed the sudden decline to a Ascophyllum populations at three stations in the disease and decline in water quality. The recolon-vicinity of MNPS continued to be monitored in iration of eclgrass to certain areas of the river began 1990. Ascophyllum at a fourth site (FO, the original in 1989 and continued during 1990. Recruitment of xii Monitoring Studies,1990

4..

new phants was attrib ited to gernunation of seeds 40 were similar to those seen in other bunit transierted hom heal.h) beds at the mouth of the operational y eart Total coserage by loulmg species rner. The 'ohl NR utt, was resampled during 1990 dunny 3 unit operation, relatise te 2-unit operational arkt results were compaed to those obtamed in carher leselt has increased at the Fox island ti h site, and studies (1985). In all i ases celgrau abundance and has decreased at the Efiluent (1 i ) and Giants Nesk growth m 1990 werc lower than those observed (G N ) sitet Denuties of some fouhng species during 19M5. (barnacles and muucts) hase generally des kned f rom

't he pera ntage of re stoductne shoots during 1990 2 unit to 3-unit operauonal penods at IT. At all at NR and WP were :omparable to those reported sites, abundance of fouhng speaes had lew ellect on smte 1985. liowever, :he ivrcentage of reproductive shipworm settlement than did phy ncal and hological slauts at JC in 1990 w is the lowest regurted to date, factors (e.g., sescre w mter condiuont as adaNhty of and for the hrst time, no reproductive shoots were wml substrata, varianon m the source impulanon h lound in the August samples The priinary focus of the esiusure panel study is While the abundance of celprass declined at all our on wood boring spectes because these are the stations smcc 1986, w hen Unit 3 began operatmp, organisms whose potential for property destruction is the dechne at Jordan Cose was most pronounced, highest, their populauon charactensties (e g , grow th he cause for the substanual dechne at JC, relative to rate, fecundity, recruitment succem are hLely to be the NR and WP site % is undetermined, although affec ted by clevated water temperaturet Abundances temperature increases of I 3eC, resulting from the 3 of I.4mnoru and Chrh4ra during 1989 00 conunued to unit thermal plume along with natural vanauons in be highly sariable, and continued to hase httle watcr ternperatures, may play some role m the relationship to esposure panel wood lou, or to pnk est shipworm tecruitment.

Abundance of 1rtrdo reahs in InX4 40 also Marine Woodborers conunued to be highly sariable, with lughesi densities occurring at the WP and GN sites.

h1arine woodlxucts in the vicinity of Ahlistone Abundances of this native shipworin in the 19S4 90 Nuclear Power Station (htNPS) melude two species Aug Feb panek were the highest yet recorded for that of mollusks (Irrrda ruruhs, a native shipwoim, and eximure period in hlapNov panels, densities and 7 bartscht, an immigrant) and two genera of wood loss hase signihcantly decreased at GN and crustaceans (lJmnoria, an isopal, and Chrlata, an mcreased at WP during Lunit operation. In the amphyxxh. Niarine woallerer studies at h1NpS were Distribution Study, a pattern of higher densities of conducted to evahiate w hether operation of the power this shipworm at a dist;mce of 500 m bom the quarry station has influenced the abundances, activity cuts has been observed sinse 14S6. De relanonship (amount of wootbloss) or distribuhon of wmidoring between shipworm reuuitment and distance trom the species in the vicinity of htNPS. quarry cuts, suplurts the supposition that settlement Comparisons between the two operational periods of L navalis is related to direct or indirect clicets of revealed that average weekly discharge water tem- the 3 unit thermal plume, peratures in the winter and spring (December June) 1rtrdo furtschi has been lound consistently and in tended to be 14'C wanner dunng Lunit operation large numbers within the hiillstone Quarry discharge than during 2 unit operation; further the discharge has waters since 1975. Increased wood less from panels been a more thermally stable ensironment smce Unit and densities of this immigrant shipworm at the 3 start up. Water temperatures at ambient sites Elfluent site since Unit 3 began operation were eshibited diumal variabihty, especially in summer attributed to the moderation of water temperature (time of masimum insolanon), mercasing to peak estremes m the quarry and to the increased availabihty temperatures of 2 3 'C above average. At White of food resulung from more frequent use of wood-Point (Wp; 1700 m from the h1illstone Quarry cuts), chips to plug small leaks in Unit I condenser tubes.

an additional elevation of up to 2*C is noted around in November 1989, one individual of 7eredi the time of maximum tidal ebb, attributed to the barrAchi was collected at GN. Ilowever, due to the htNPS plume produced by 3 unit operation. great distance between hlNPS and GN (7 km), the Fouling species on esposure panels are monitored occunence of Teredo bartschi at Giants Neck indicates to assess their effect on settlement and growth of that small populations of this shipworm may esist in woodborers. In general, fouling patterns dunng l989- other areas of 1.ong Island Sound. Continued l

nsecuuve Summary siii l

1 l

I 1

l l

l monitoring at this site will establish whether the most of the previously dominant organisms, and occurrence in 1989 was a unique event, or the first particularly in the abundance of oligochactes and occurrence of a new population at this site. thynchocoels. Ilecause the changes in the WP community in 1990 were ako evident at the GN llenihle litfauna reference statkm, some natural factor was most hLely responsible for the infaunal community shanges During 1990, intertidal communities at two observed at WP in 1990 and not operations of the  !

poientially impacted areas in jordan Cove, (JC and Millstone facility. Ilowever, the declines in WP) and one reference station at Giants Neck,(GN) abundance of tasa obwrved at WP were greater than were sampled and described in terms of sediment those at GN. Although the slight temperature characteristics, community comgwilion, abundance, inercases that occur at WP (during certain tidal stages) numbers of species and dondnance. These parameters during 3 unit nperations are unlikely to produce were used to identify spatial and temporal diffct nces impacts, the pouibility can not be discounted at this at the p>tentially impacted and reference communities time.

relative to previous 2 and 3 unit operational years. Al JC, patterns of infaunal community structure l Sediment characteristics at intertidal stations were and abundance in 1990 continued to exhibit categorized as medium (GN,WP) to cmtse (JC) sands dif ferences from those observed during the 2 unit with low silt clay content. During 1990, sediments period. The temporal fluctuations in the JC at GN and WP were not significantly different from community are believed related to changes in the previous years, while those at JC were significantly sedimentary environment w hich began in 1986 and different (finer) than thosc obtained during thc 2. unit which coincided with an observed decline in op rational perkd abundance and sumding stock of an offshore eclgrass During 1990, intertidal collecthms contained a total bed. These shifts also coincided with start up of 3-of 38 species and 5,111 individuals. At all sampling unit operations at Millstone; however, a direct link sites, total nembers of species and individuals in has not been established to date. Given the disumcc 1990 was lower than those observed during the 2 unit of our JC station from the Millstone facility, direct (19801985), but only the WP community has shown impacts (e.g., related to scour, large water ternperature a significant change (decline) between the 2 and 3 increases) on the infaunal community are unlikely.

unit operational periods. Ai GN and WP, pilychactes llowever, the possible influence of slight water

- and thynchocoels were the numerically dominant temperature incremes (13*C) due to 3 unit operations organisms while oligochaetes daminated at JC. The on the JC infaunal community are at present, ON and WP communities shared 3 of the top 4 unknown. Indirect piwer plant impacts on local dominant tasa (Leitoscoloplos fragilis, oligochactes intertidal infaunal communities are more likely than and rhynchocoels). In addition to these tata, the direct effects. The changes in the sedimentary amphipod Nrohaustorius biorticulatus, and the environment and infaunal community in JC observed polychacte faraon/sfulgens were skiminant at GN and since 1980 would be considered an indirect offcct WP, respectively. As in all previous sampling years should the decline in the Jordan Cove eclgrass bed be at JC, oligochaetes were the most abundant taxon subsequently attributed to 3 unit operations of the during 1990; abundances of other organisms (i.e., Milhtone facility.

Scolccolepidcs viridis and //cdure diversicolor), which Subtidal communities at three potentially impacted were previously among the dominant tata, remained areas (EF Efiluent, JC Jord.m Cove, IN intale) and low, . No significant long term changes in the one reference station (GN Giants Neck) were sampled abundance of individual ina were evident at JC, while -during 1990, Sediment-grain site was fine to at GN and WP the abundance of the polychaete medium sand at JC, GN and IN and medium to coarse Paroonis fulgens and the umphipod Neohamtorius sand at EF. Silt clay values ranged from 0.40 biarticulatus sign!!1cantly increased in 1990. 24.0%; values were lowest at EF and highest at JC, infaunal communities at the potentially impacted infounal samples yicided 185 species and 29,547 WP and the GN reference station remained similar to individuals. The major tasonomic groups exhibited each other in 1990 in terms of community abunimec, lower total numbers of species and individuals in number of species and in the kinds of tasa which 1990 relative to 2 and 3 unit years. Polychaetes

. numerically dominated the community. At both were the most abundant group in terms of species and stations, however, there were decreased abundances of individuals at JC, GN and IN. As in previous 3 unit 4

xiv Monitoring Studies,1990

i I operational years (1986 89), oligochaetes were the followmg the initial impacts awriated with start up most abundant group at EF. Since 1980, there w ere of 3 unit operations can be eqveted in future 3 cars.

e no significant long term trends in community The JC community also showed signs of recovery abundance or nurnbers of species at JC, EF or GN. f rom the estensive sihation w hich occurred after Unit However, regression analysis indicated a significant 3 start up. Although the silt < lay content of the

increasing trend at IN lot both numbers of individuals sediments has decreased, sediments wcre stdl arxl species, significantly different from those observed dunng 2-During 1990, ohgochaetes wcre the numencal unit orvrational years. As at IN, recm cry is espected dominants at EF, JC and GN Codominants at these to be a long term process at JC because the stations included, /'olycirrus rtimiut Tellina agilis mechanisms that will promote the change (i.e.

and I'rotodorvillra gasfernsis at EF: Aricidra inlaunal sediment reworking and storm related radu rinae mkl Afediomastus ambiseta ut jct Aricidea sediment transport) are inherently slow.

ratherinar and '/hary spp, at GN. The numerical dominants at IN during 1990 were TrIlina orilis and Ichth)opluliktoll l'ntraltittlellt frogone hches. The community dominance structure IU tintation at 2 of the 4 subtidal stations showed some substantial differences w hen compared to other 3 unit The number of orgamuns entrained through the perkxls, but marked similarity to the structure during condenwr cooling water system of Mdklone Nuclear the 2 unit perimi. At EP the relative abundance of Fower Station is onc of the mmt direct measures of Polycirrus eximius and oligochaetes was similar to potential plant impact on marine populations. Of the percent contribution during the 2 unit period. particular concern is the number of fnh eggs and Ohgochaetes and Aricidra ratherinar abundances larvae (ichthyoplankton) entrained. Annual enttain-increased during 1990 at JC and were ruore similar to ment estimates hase been calculated using several

, abundances established during the 2 unit period. different methals. Estimates based on the arithmetic Regression analysis revealed that there were long term mean density were ustd through 19M1, those based increasing trends in oligochaetes at EF; Polyrirrus on the median denuty (m~h ' ased) from 1982 eximiut and Protodorvillra gaspernsis at EF and GN; through 1989, and estimates based on daily denuly Lumbrineris temds at GN and JC; Nucula proxima at estimates from the Gompert/ density function JC Decreasing trends in the abundance of Aricidra (Gompertebased) were introduced in 1990. The catherinar and oligochaetes were noted at EF and JC, arithmetic mean methal was discontinued because the respectively, Cumulative species curves, species s easonal hequency distributions of sample densities diversity and numerical classification reflected the were skewed and this resulted in overestimation of shif ts observed at the EP, JC and IN stations. entrainment, Comparisons were made between Subtidal communities sampled during 1990 estimates from the Gompertnbased and median based continued to show temporal and spatial shifts in toth methods for seven dominant ichthyoplankton tasa the sedimentary environments and infaunal (cunner, lautog, and anchovy eggs; anchovy, winter communines within the areas influenced by 3 unit flounder, grubby, and- sand lance latvac) The operations at MNFS, The IN station in 1990 Gempertobased estimates were consistently greater, exhibited continued signs at reco cry from the even though the estimated daily densities from the impacts related to dredging associated with Gomperty function were similar to actual sample construction of the Millstone Unit 3 intale, an event densities. The median based method apparently which significantly changed the sedimentary underestimated entrainment because it dhi not include characteristics and infaunal community at this station. organisms entrained dunny the early and later portions in 199(), wdimentary characteristics closely remembled of their season of occurrence. Therefore, the those prior to construction activities; however, the Gompertabased methat will continue to be used, but wide variation in the infaunal community suggests the accuracy of estimation methods should be that recovery is still proceedmg. At the EF station, continually evaluated.

sediments in 1990 remained coarser with lower sill, clay content; certain rpecies that had disappeared after start up were abundant during 1990. Given its location EF will continuously be impacted during phnt operations; however, recovery of some tasa Esecutive Summary xv

I Contents introduction ............... ..... .......................... I Winter Flounder Studies ............. ....................... 9 Fis h E colo gy S t u d ies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 89 1 obst e r S t u d ies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ... 129 1(ocky Intertidal Studies ...................................... 153 Eelgrass .............................. ................... 189 Marine Woodborer Studies . . . ................... ............. 201 llenthic Infauna . .. .. .... ... ... ..... .............. ... 223 lehthyoplankton Entrainment Estlination . . . . . . . . ..... . .. ..,, .. 261 l

l

w i

1111 rod tic t1011 Ikporting itequirements No. 4 Cenificate of Ensironmental Companbihty and Public Need for un Electric Generating Facthly ident-The following report summarites results of ongomg dial as 'Milktone Nuclear Power Station, Unit 3,'

environmental rnonitoring programs conducted by North.

hvakd in the Town of Waterford, Connecticut" and cast Utilities Service Company (NUSCO) in relation to the operation of the three unit Millstone Nuclear Power dakd Manh 22,1% This report satisfies the kquiknwnts of the NPDES permit and of the Connect.

Stauon (MNPS). MNPS can affect kval manne biota icut Siting Council by updating and sumtnari/ing in several ways: large organisms may be impinged on varie studies conducted at MNPS that were presented the traveling screens that protect the condenser coohng and service watcr pumps; smaller ones may be entrained

• "*I '"""II Y 5" NUbCU (IWUL through the condenser coohng water sy em, w hit h sub-jects them to various mechanical, thermal, and chernical NIk El effects; and marine communities in the discharge area MNPS is located about 8 km west muthwest of New may be sul9ected to thermal, chemical, and mechanical nho on dw Connecncut show of IJS Wig. It The cifects resulting from the outflow of the cooling water.

nati n is situated on Millstone Point and covers an area in addition, occasiond maintenance dredging is done in of about M ha. The propeny is bounded to the west the vicmit) of the intale structures. The basis for the by Ntantic Bay, to the cast by Jordan Cove, and to de studies is the National Pollutant Discharge Elimination System (NPDES) permit (CTO(XG26) issued by the wuM h lwWrW Nand Channel. The MNPS moni.

tonng IWgrann sample a study area of approximately Connecticut Department of Ensironmental Protection to Un? mat exknds inun de nonhern ponie of the Nonheast Nuclear Energy Company (NNECO), on Niantic River and Jordan Cmc to Giants Ne(L,2 km whose behalf NUSCO has undertaken this work. The soum Twoun Nand, and 2 kni cast of White Point.

regulations in the permit allow the MNPS cooling ork takes phice from the shorchne into areas as deep water to be discharged into Long bland Sound (LIS)in as 20in wuthwest of Twotree kland.

accordance with Section 221430 of Chapter 446L of the Strong tidal currents predominate in the vicinity of Connecticut General Statoles and Section 402b of the Mdistone Point and in0uence the physical charac-Federal Water Pollution Control Act. Paragraph 5 of teristics of the area. Average tidal flow through Two-the MNPS NPDES pennit states that:

lice Island Channel is apprmimately 3,400 mi sec 1 anl 7he pctmitter shall conduct or continue to conduct biological studies of the supplying and ",' **U"""" IS *b0Ut W m' hec (NUSCO 1983).

unent ve &s are about I to 1.8 kn in the channel, receiving waters, entrainment studies, and intale impingement monitorinx. The studies g y Im 0 to I.5 Ln) near the plant and in Niantic Hay, and telatively weak in Jordan Cove and in the shall include studtes of intertidal and subtidal Upper Niantic River. The currents are drisen by semi-benthic conununitics,finAsh conununifics and umal GM that have a mean and maximum range of entrained plankton und shallinclude detailed studies of lobster populations and winter and U m, wslutively. Thermal and salinity-induecd stratification may occur in regions unaf fected by founder pojelations.

Mrong ikktl currents. The greatest temperature variation in addition, paragraph 13 of the permit requires that:

On or before April 30, 1986 and annually has ken asened in nearshore areas where water kinpaature can vary from -3 to 25'C; salinity varies therca/tcr, submitfor review and approval of much im and ranges from 26 to 3W The bouom is the Conunissioner a detailed rc; wit of the on.

goinx biological studies required by paragraph E'"""U Y ***W' sed of fine to medium sand throughout S and m approved underparagrmh /2.

de ama, but aim includes some nick outcrops and Funhermore, a decision and order of the Connecticut inuddy sand. especially near shore. Strong winds, trtie-ulady from the southwest, can at times result in locally Siting Council requires that NNECO inform the Coun-heavy seas (up to 1.5 m or greater) near Millstone cil of results of MNPS cndronmental impact moni-Point. Additional infonnation on local hydrography and toring studies and any modifications made to these nwkelogy can be found in NUSCO (1983).

studies (ptragraph 6 of the proceeding entitled

• Docket Introduction 1

d*/&'ap, 6 9 ##

tat 4 N y Da {

O 1 m;

?..

N r

J urn 02, Md t G;cnts so

$(%n y ca e u te WP Se:We j  ;

No.. ,1 - inctree Ctenel  !

\ 'Inmno 0 tre e o % reat D artett m Long Islarid Sound

_-.c-.

see4 1y i. t he cea in which biologial nmmionng swdica are being conduaed to auen the effedt of the opetauon ni the

%D i me Nos Icar l'owet bnon Millstone Nticlear l'ower Slution plants from debris. Units I and 2 have 9.5.mm mesh traveling screens nnd Unit 3 has a combination of 9.5 The h1NPS complex consists of three olwrating and 4.8 mm mesh screens. A fish return system nuclear power units; a detailed description of the (sluiceway) was installed at Unit I in December 1983 station was given in NUSCO (1983). A chronology and one at Unit 3 during its construction to return of significant events associated with AINPS con- aquatic organistus washed off the traveling screens struction and operation, including installation of back to 1,15. The installation and olvration of these devices designed to mitigate environmental eflecis and sluiceways have minimized the impact of impinge-unit operational shutdowns exceeding 2 weeks are ment on fish and macroinvertebrates at h1NPS.

found in Table 1. Unit 1, a 6(ohtWe boiling water The cooling water is nominally heated in Units 1, reactor, began commercial operation on November 2, and 3 Irom ambient temperature to a maximum of 29,1970; Unit 2 is an 870 htWe pressuri/cd water 13.9,12.7, and 9.5'C, respectively. Each unit has reactor that began commercial operation in ikccmber separate discharge structures that release the ef 0uent 1975; and Unit 3 (1150 htWe pressurized water into an chandoned granite quarry (ca. 3.5 ha surface reactor) commenced commercial operation on April area, maximum depth of approximately 30 m). The 23,1986. All three units use once through condenser thermal discharge (about i1*C warmer than ambient cooling water systems w ith rated circulating flows of under typical three-unit operation) exits the quarry 26.5,34.6, and 56.6 m3 sec-1 for Units I through 3, through two channels (cuts), whereupon the thermal respectively, Cooling water is drawn from depths of cluuent mises with 1.lS water (Fig,2). The cuts are about I m below mean sea level by separate shoreline equipped with fish barriers consisting of 19 mm intakes located on Niantic Bay (Fig. 2). The intake rnetal grates, which serve to keep larger fish out of structures, typical of rnany coast:d power plants, have the quarry. The thermal plume is warmest in the coarse bar racks (6.4 cm on center, 5.1 cm pap) immediate vicmity of the cuts and within about 1,100 preceding vertical traveling screens to protect the m of the quarry the surface oriented plume cools to i

2 hionitoring Studies,1990

- . . - . . . . . . _ - - _ . ~ - - - ---.-- - --..~ ---- - - - - - . . - .~

TAllt.l? 1. Chronology of ensjur constructhm and operation events at the Milliume Nuclear Power Statmn (MNPS) through 1990.

Date Artimy Refer-nte r lhember 19M Corntrusum for MNPS 1 kgan NUSCO 1973 Novemkr 1969 Constnxino for MNPS 2 kgan NUSCO 1973 October 26,1970 MNPS I imtint criticahty; produted first thennat einuent INilf November 29,1970 MNPS 1 initial phane to gnd (NL

' Decemter 28,1970 - MNPS I hcgan nunmenial opctathm IN11.

January 15,1971 to ichruary 22,1971 MNPS 1 shuidown [NL August Desemkr 1972 Surface tuvn at htNPS 1 NUNCO 1978 November 1972 l'iih hamer installed at quarry cut NUID September 3,1972 to March 20,1973 MNPS 1 shuiamn INII, Mvember 1972 MNPS 2 (offer dam ternoved NUSCV 1973 April lh to July 28,1973 MNPS I shutkun . INL August-Denmkr 1973 Surfa6e taman at MNPS l NUSCO IV7k July thember 1974 Surface turn at htNPS 1 NUSCO 1978 September i to November 3,1974 MNPS I shutdow n INIL July-October 1973 Surface lush at MNPS 1 NUSCO l978 July 1975- llouum tusn innelkd at MNPS 1. Nt'SCO 1978 August 5,1975 .

. MNPS 3 coffer dam mentrucike legan NUl2, September 10 to October 20,1975 MNPS 1 shutdown [NL 1 October 7,197$ MNPS 2 pnstuced fint efnuent .

InW ,

j . November 7,1975 MNPS 2 initial entkahiy; pnxluced hrst thermal efnuent 12MN November 13,1973 MNPS 2 initial phne to grid INL Ikcemkr 1075 ' MNPS 2 began wenmercial operatum Null March 19,1976 MNPS 3 coffer darn tonitructam firiinhed Nt12.

, June October 1976 2 Surfan tusn at MNPS 2 NUSCO 1971:

October 1 to December 2,1976 - MNPS I shutkun INH.

December 20,1976 to January 20,1977 MNPS 2 shutAen (Nil May 6 in June 25,1977 MNPS 2 shutAm n INil Junc4khher 1977 Surfue tusn at MNPS 2 NUSCO 1976 1

November 20,1977 to May 1,1978. MNPS 2 shutkwn INil.

March 10 to Af'll 13,1978 MNPS 1 shutkun [NL '

4 March 10 to May 21,1979 MNPS 2 shutdown (Nil.

April 28 to June 71,1979 MNPS 1 shutdown INL August 10 to 25,1979 MNPS 2 shunkmn (NL November I to DecemNr 5,1979 MNPS 2 shuidow n INIL May 7 to June '19,1980 . MNPS 2 shutdown INil 4 -

June I to June 18,1980 MNPS 1 shuikun ~ INil.

August l$ to October 19,1980 MNPS 2 shutdown INIL (ktober 3,1980 to June 16,1981 MNPS I shutdown INil January 2 to 19,1981 . MNPS 2 shutdow n INL Deecmher 5,1981 to March 15,1982 MNPS 2 shutdown INE <

March 1981. .. Thuiorn hawn removed at MNPS I NUI2, September 10 to November IN,1982 MNPS I shutdown INL March 2 to 18,1983 MNPS 2 shutdown . .

INIL April September 1983 MNPS 3 coffer dam removed, intake maintenance dredging . ht12.

May 28,1983 to January 12, 1964 MNPS 2 shutdown INil December 1983 1ith retum system installcJ at MNPS 1 intake . hLlli

August 1983 = . Second quarry cui qwned NU13; April 1 3to June 29,1984 MNPS 1 shutdown INL

. I chruary 15 to July 4,1985 - MNPS 2 shutaan - lNL June 1985 . Intake maintenance dredging NUlj, September 28 to Novemter 7,1985 MNPS 2 shutdown INil Oetcher 25 to December 22,1985 MNPS I shut Amn INIL November 1985 - MNPS 3 prukned first effluent 11RN February 12,19k6 MNPS 3 produced first thennal effuent IDAN April 23,19M - MNPS 3 began unnmercial operation INL Lluly 25 to August 17;19% . MNPS 3 shutdown - INL Sentember 20 to necember iR lom MNPS 2 shuidown - DNdt Iftlf0(ltlClioll 3 1- . . - , . ~ , ~ . a 2.~ __ _ . - . _ _ _ _ -.u. __u.______.._

1 Altlf.1. hmt 1 I Asembre i to 15, tvk6 SINPS 1 shuta.wn [ N il .

January 30 to I ebruar) 16,1987 MNPS 2 shuiaiw n INil Marth 14 to April 1 0, 19167 htNPS 3 shuia w n I Nil.

Jime 5 to August 17.1987 MNPS I shutaiw n (Nil Nncmher 1,1957 to lebruary 17, Ivak MNPS 3 shuiaio n ( N il .

lkternher 31,1987 to l ebruary 20. IVh% 5tNPS 2 shutAiwii (N il .

Apnl 14 to May 1,1988 MNPS 3 thutaswn I Nil May 7 22,19*8 MN Us 2 shotaiwn ( N il .

( Atoter 21 to %nender k.14hh htNPS 3 shutdow n INil i ebruary 4 to April 29,19K9 MNPS 2 shut Aiwn ( N il.

Apnl A to lune 4,19M9 MNPS 16 hut A>wn (Nil .

Mn 12 to June 12,19H MNPS 3 shuiaiu n iN il,

( Atober 21 to Nncmher 24, IvW MNPS 2 shunk wn INil.

hth D in Apeil 20,1990 MNPh 3 shunlown. instaurion el unc 9 9 non miske utren pantle (Nil, May h to Jute l$,1990 MNPS 2 shuikw n ( N il .

Septemhr 14 to Nntrnhi r 4. I't'ni MNPS 2 shunlown (N il,

' IIN(11 tefcrs to the chily nd gevieranon log

' '.tti,l. Niers to NL:5CO I.nuronrnental 14haatory es cords

'%\N rtfen ta the emirmnrot I data esquianon istwerk

, Millstone fUnit 3 "l -

\

Nuclear Poser 5 tat;on [

i /

f '

U 2 Jordon C ,22 6 2 discharges Con

/ Unli -11 Niantic / 3 Bay intakes c __.-

b{ '

I f,

200 -

A L O N

0- / qua rryN( , -

1 ]s'o c ond tut "i ln N S I cut Twotree i

, Channel Fir. 2. Tir MNPS site siming the intue and disdurge of each unit, the quury, and the two quarry dinhuge cuts.

)

4 Monitoring Studies, IWO

within 2.2*C above ambient. Eleyond this distance ally were evaluated using best available method.

the plume is highly dynamic and varies with tidal ologies. The programs discussed below include currents (Fig. 3). liydrothermal surveys conducted at Winter Flounder Studies, Fish Ecology Studies, MNPS were described in NUSCO (1988). Lobster Studies, Benthic infauna RosLy intertidal Studies, Marine Woulborer Studies, and Ecigrass. In Monitoritig Prograttl$ addition, a special section is presented this year on Ichthyoplankton Entrainment Estimation, Regorting This report contains a separate section for each [vriods for each section vary and are predicated on monitoring program, some of them ongoing since biological considerations and prosessing time neces.

1968. These long term studies have provided tlw rep. sary for samples, as well as on regulatory require.

resentative data and scientific bases necessary to ments. In cases where the seasonal abundance of assess potential biological impacts as a result of organisms differed from arbitrary annual reporting MNPS construction and operation. The significance periods, the periods chosen were adjusted to test of changes found for various communities and popu. define its season of interest f or a particular species or lations tryond those that were expected to occur natur. community.

m ,t - ~ . , / i

[ ~(, G

. b(/ P '~A n ' ) ..kdf~ 4 ,

( , , . . . .e , ,d..,EQ w. . ex L. . [T!.Na t .

l . ?j ~  ; 3;,,

s.,, ,>

'J~? Q 'n: t-

, s. ,, .

. 6'3 mMT' n ' N ' '

• i "N .

e5' ,"' -

\ g. .i... ( .

. i.4.. ,

..m .~ -~

ml r . ,e

%e i,..

t'.i

• e-I g *

...~ m j i l L

f ,.

c ,, -, --

\l .

( ) ,. *  %.., O  ?

{ > y * % C

s. , _ , < t';' t .

, - , . . . , _ m . ' 'M i

/ Es k .7., ._,, g

{ p ,; ,_- L .,,4, j :_ . , u s~ m ,j., _' _

w..,..

%,e xj ,_f;g <o i,,.,

( si s s r. .\.. . .

sc4 gyg kJ 444

, . , l,

n. <>

bg. 3. Locations of selected three. unit thermal plume isotherms for various tidal (ondaions. Clockwise from upper left the plume is shown at low slack, rnnimum ebb, maimum fkul. and high slack.

Introduction $

.._. ~. - - . . - __-- _ _ _ _ _ _ _ - _ _ . _ - . _ _ _ _ _ _ _ _ _ _ _ - _ _ _ _ _ _ _ _ _ . _ .

lieferences Ciled NllSCO. (Northeast litilities Service Company).

1973. linvironinental ef fects of site preparation arki construction. Pages 4.41 to 4.51 in Millstone Nuclear Power Station, linit 3, Ensironinental relutt. Construction pennit stage, NilSCO. 1978. Impingement studies, Millmone linits I and 2,1977. Pages 1-1 to 4 2 rn Annual report, ceological and hydrographie studies,1977.

Millstone Nuclear Powet Station.

NUSCO. l983. Millstone Nuclear Power Station linit 3 environmental regurt. Operating lic< nse stage. Vol.1-4 l NilSCO.198N. llydrothermal xtudies. Pages 323 ,

3$$ rn Monitoring the marine crivirontnent of l 1.ong Island Sound at Millstone Nuelcar Power l

Station. Three-unit operational studies, 1986 1987.

NUSCO.1990._ Monitoring the marine ensironment of 1.ong Island Sound at Millstone Ntwlear Power Station. Annual report 1989. 258 pp.

1 6 ' Monitoring Studies.1990

_- . _ - .-=.-.- - .- - - . - -_- - - .- - _- -

i

)

I Contents Winter Flounder Studies . . . . . . . . . . . . . . . . . . . . . . . . . .................. 9 Introduction . . . . . . . . . . . ............ ................... 9 Materials and Methods . . . . . . . . . . .. .........................10 Sampling programs . . . . . ................ . . . . . . . . . . . 10 Adull winter flounder . . ...........................10 Larval winter flounder . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 l Juvenile winter 0cunder . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 Indices of abundance . . . . . . . . . . . . . . ................,...14 Relative annual abundance of adults . . . . . . . . . . . . . . . . . . . . . . 14

- Absolute abundance estimates . . . . . . . . . . . . . . . . . . . . . . . . . 14 '

Spawning stock size and egg production . . . . . . . . . . . . . . . . . , , .14 Abundance, development and growth, and mortality oflarvae . . . . . . 15 Abundance, growth, and mortality ofjuveniles in summer . . . . . . . . 16 Abundance ofjuveniles in fall and winter . . . . . . . . . . . . . . . , . . 17 Stock and recruitment relationship . . . . . . . . . . . . . . . . . . . . . . 17 Assessment of MNPS operation on local winter Dounder . . . . . . . . . . . . 19 Estimates oflarval entrainment at MNPS . . . . . . . . . . . . . . . . . . 20 Mass balance calculations . . . . .......................20 Stochastic simulation of winter Dounder stock dynamics . . . . . . . . . 22 Results and Discussion . . . . . . ... ...........................28 Adult winter flounder . . . . . . . . . . ........................28 Relative annual abundance . . . . . . . . . . . . . . , . . .........28 Absolute abundance estimates ........................30 Spawning stock size and egg prcxluction . . . . . . . . . . . . . . . . . . . 32 Larval winter nountler . . . . . , ...........................34 Abundance and distribution . . . .... ................34 Development and growth . . . . . . . . ................,,.38 Mortality . . . . . . . . . . . . ... ...................42 Juvenile winter Counder . ............... ..............44' Age Ojuveniles during summer _ . . . ..................44 Age-0 juveniles during late fall and earl winter . . . . . . . . . . . . . . 52 Age-1 juveniles during the adult spawn ng season . . . . . . . . . . . . . 54 Comparisons among life stages of winter Counder year-classes , . . . . . . . 56 Stock recruitment relationship (SRR) . ....... ...............59 MNPS impact assessment - ..... '.. .....................63 Estimates oflarval entrainment et MNPS . . . . . . . . . . . . , . . . . . 63 Mass-balance calculations . . . . . . ...... , , . . . . . . . . . . 64 Effect of entrainment on the year class . . . . . . . . . . . . . . . . . . . . 66 Stochastic simulation of the Niantic River winter Counder stock . . . . 66

Conclusions . . ..... ........ . ... ......... ...........78 References Cited . .. ........... ........................80 Appendix . . . . . . . . . . . . ... .............................85 l

~

l

_ _ - . _ . _ _ __ . _ . _ _ _ _ _ __ ___ . _ _ , ____u_. . _ _ _

q .

Winter Flounder Situlles introduellon but many of the dkpiacca lanae are iunner aspeisea an a) f rom the area 1.arger larvac inamt.nu some s on-The winter lloundet (Bruhplcamnn tr3 amon uol over their pouuon by sertwal nuncmenh arul c4PmA)Ibn received Inuih (Wiention in erhironnlCrilal also may sperid colhlderahle time on the l%5ttoni.

impact studies conducted by Northeast l'lihties I:ollowing metamorphosis, inost of the demersal Service Company (NUSCO) at the hidtstone Nuclear )oung of the-) ear wmter lloutuler are lound in Power Station (h1NPS) breause of its importance to shallow mshore watert knmature yearhngs (ape 1) the sport und commercial fisheries of Connecticut beanne photonegative ami most of them are usually (Smith et ad 1989) and its numerical dominance of lound m deeger waters than arc-0 inh (pearty 196?;

the hval demersal fish commumty (NUSCO 1990). hhCrac ken 1963L Some adult bsh stay m estuaries Potential impacts at htNi S intlude the impingen.cnt f ollowing spawning, wlule others disterse mto deeper of juvenile tind aduk winter flounder on the travehng waters of fshore. lly suminer, most lish icase the screerl% of the cooling water intale% and the w armer shallow waters lh lheir prelerled teni[Ntalule entrainment on tarvae through the coolmp water range n 12 INC (hkCraiten 10M). Ne s er thele ss, system. The impact of impingement has been some remain in the estuaries and otten asoid mitigated by the installation and operation of fah temperalmes ahose 22SC by bury mg thennehes in return sluiceways at AINPS Units I and 3. The uoler oottom sedm.cnts (Olla et al 1900). Pic) mg consequences of plant indused mortahty of larval on a wide vanety of benthic invenebrates and algae, winter flounder are potentially of greater signit'icance winter flounder are sight Iceders usually active only than for most other species allected by htNPS durmg the day, operation. This is because the winter flounder, unhke NUSCOaponsored stuaes of the winter llounder most marine fishes, is a product of hval spawning started in 1973 to obtain data needed for a long tenn with geographically isolated stocks associated with assewment of hlNPS operauon ef fects on the Niantic indnidual estuaries (lmbell 1939; Perhautter 1947; River stock. Although understandmg annual vana-Saila 1961). In particular, the population of winter hihty n important for assewing short term imp.wls llounder spawidng in the nearby Niantic Riser has the most significant changes in inheries tend to ot cut been the focus of much of the research ef forts to on longer time scales (Cushing 1977; Steele et al.

awess the loag term effect of larval entrainment 10kO). Therefore, the desetopment of long term through the htNPS cooling water system. awessment capahhties has remamed the ultimate hiany aspects of winter flounder life history h,nc researth goal of the NUSCO winter flounder stuaes.

been summari/ed by Klein htacPhee (1978) lirielly, The general approach has consisted of a combination the species ranges from Labrador to Georgia, but is of sampling programs and analytical methods most common in the central part of its distribution designed to panide a preliminary short term assess-(Scott and Scott 1988), which includes Long Island ment capability and, ultimately, a long tenn awess.

Sound (LIS). Most aduh fish enter estuaries in late ment tool in the form of a comprehensisc computer fall and early winter before spawning in late winter simulation model, and ently spring. In castern LIS, females begin to This section summari/cs and uph hndings mature at age 3 and 4 and males at are 2. The reported previously (NUSCO 19% new userage fecundity of females is about $60,000 eggs mformation from work completea -

Also per fish. Eggs are demersal, hatch in about 15 d1ys, included are the presentation of a nas method Of and larval development takes about 2 momhs, with calculating larval entrainment estimates and a method both processes being temperature dependent, Small for estimating the pmportion of entrained larvae that larvae are planktonic and although many remain in originated from the Niantic River. The NUSCO their natal estuary, numerous individuals are swept winter flounder stwhastic population dynamics model into coastal waters by tidal currents (Smith et ah (SPDM) was used to simulate the long term cifects of 1975; NUSCO 1989). Some of these lanae may be htNPS operation. The simulation scenario used returned to the estuary on subsequent incoming tides, historical and projected rates of fishing mortality and Winter 171ounder 9

l l

plant operahon schedule with three hypothetical of the winter flournier prior to the operation of Urut IcVels of entrait rDent at MNpS. Although some .l Sarnpling progrann that (oritributed data to the samphng progrann 3i cided data not dirc6tly used in Nianut Rn cr w mter flounder stu,hes are show n in this simulabon, they prouded mlormation useful for Figure 1, w hieh mctudes the seasonal duration of understarnlmg winter 00unJer hfe history. These data samphng and uming relative to the annual hic c3cle nuy also be used for sun L awcument purpwes at a of Nunne Rner winter flounder. liriel descripuons later date. 01 lictd inethodologies taed in these prograrrn are gn'en below.

Staterials and Slethods Mult winterflowuler Sampling programs liasic s.unphng in.*thods used for the adult winter Data needed in the awcurnent of MNpS impvet on llounder spaw ning s arsep in the Nmnue Riser base the w mter flounder are prouded by ongomp samphng remained relatively constant smce 1976 (NUSCO programs. Several of these (e.g., Niantic Roer mlult IW7L 1:at h sursey smcc 1982 staned in i ebruary or and lanal surveys, age O sorsey) were deugned to c.aly March alter most ice uner dnappeared in the owesugate specific ble history stages of winter toer and toramued through early April. Sursep flounder. Some informahon comn from year round teased when the proportion of repnkluctively active samphng of the entire local hsh tommumty, such as females sleereased to less than IOS of all females from the trawl tuonitoring program and is hthy- esanoned for 2 conseculise weeks, whnh was an oplankton monitoring programs at MNPS and m indieahon that most spaw ning had been completed.

Niantie Day. Much of the information used in I or caeh surve), the Niantic Rher was divided into a various auessments was presented in NUSCO number of stations mg. 2); since 1979 no sarnples (1987), which summari/cd various hfe history stuJics have been taken outside of the navigatiorul thannelin 5 { Trawl Monttonng,6 stations '

+ Q 4 [> 'a m ] Age 0 Juvenito Survey 3 I l'P ' N'" 2 ' 1 lehthyoplank1on Monitonng 2 stations I 2 [ 9m n m x h ij Nianne River Larval Survey 3 pmA1 Niantic River Winter Flounder Survey I FIMIA IM I J lJ lA IS IO IN ID IJ lF IM IAI y _,

Year O g Year 1

1. February Apnl sampling for adutts and juveniles throughout the Niantic River

2. February June lar.'al sampling at three stabons in the Niantic River

3. Year round monitoring of allichthyoplankton at MNPS discharge and in Niantic Bay

4. May September sampling of Age O juvendes at two stations each in Niantic River and Bay S. Year round monitoring of all benthic fishes at six stations near MNPS (juvenile data come from two stations in November, four in December and six in January through Apn')

Fig.1. Current sampling programs comribuhng data for computanon of win r flounder abundance mdices (hatched area show nonths from which data were um! in tha remnt 10 Monitoring Studies,1990

winter flounder were measured to the nearest mm in loud length during each week and, since 1983, all 8

N specimens larger than 20 cm were measured and sesed. Fuh that were not incasured were classified into various length and ses groupings; at minimum, all winter flounder cuunined were classified as smaller or larger than l$ cm. The ses and reproductive Niantic condiuon of larger winter flounder was detennined Rive r either by observing cygs or mitt or, as suggested by n 34 Smigielski (1975), outing the prewnce (males) or absence (females) of tiemi on the caudal peduncle scales of the left tide, liefore releasing, each healthy j

fish larger than l$ cm (1977 82) or 20 cm (1983 and after) was marked in a specifie kwation with a number N

[ or letter made by a brass brand cooled in liquid nitrogen. The marks and brand location were satied g

l in a manner such that the year of marking would be 7

North i 62 .

apparent in f uture collections.

o 1km y (Atrval winiciflotmcict Winter flounder larvae have been collected in 6 Niantic llay at station Nil since 1979 and in the Q Niantic River at stations A,11, and C since 1983 9 4 (Fig. 3). The 60 cm bongo plankton sampler med was weighted with a 28.24g oceanographic depressor and was fitted with 3.3 m long nets with mesh si/c of 202 pm in February and March and 333 pm during the remainder of the season Volume of water filtered

- was determined using a single General Oceanie (GO) flowmeter (Model 2030) mounted in the center of each bongo opening. The sampler was towed at approximately 2 knots using a stepwise oblique low pattern, with equal sampling time at surface, mid depth, and near bottom. The length of tow line necessary to sample the mid water and bottom strata

[

/ q was determined by water depth and tow-line angle measured with an inclinometer. Tow duration was 6 min at stations A, II, and C (filtering about 120 m3) and 15 min at station Nil (filtering about 300 m3).

Fig. 2. Location of stations sampled for adult winter One of the duplicate samples from the bongo sampler flounder during the spawning season in the Niamic River during 1990. was retained for laboratory processing.

From the start of larval sampling (usually mid-the lower portion of the river Decause of an agreement February) through the end of March, single daytime made with the East Lyme Waterford Shellfish tows at each station were made twice weekly within 1 Commission to protect habitat of the bay scallop hour of low slack tide. During the remainder of the (Argcyecten irradians). Winter (hundet were collected season, until the disappearance of larvae at each on at least 2 days of each survey week using a 9.1 m station, tews were made twiec a week only at night otter trawl with a 6.4 mm bar mesh codend liner, duting the second half of a flood tide. Jellyfish The fish caught in each tow were held in water-filled medusae, at the three river stations, were sieved (1 cm containers aboard the survey vessel before processing, mesh) from the sample and measured volumetrically For all survey years, at least 200 randomly selected to the nearest 100 mL At Nil, single day and night WinterFlounder 11

l l

( T u N 1KM g } .__ L, (i s1-(T(

i 1 Mi s

\

V NlANilC  ?

I,' RlyLR Y U l>/ Y t,

(,p) $

,a :4 f

/ \f 4 r l

J, [5 NIANilo"(,,k(

(

UAY (s '

!( EN ND Mii.LS' lone PT \- ,_ _s

,J 4[jy (

)

DLACIK PT.

IV 3. laation of Hanons samNed for bral w mter Bournier m IWO.

lows were made Overy two weeks during February arki tollected during lxith daylight arid at niyht on(c grf at least once a week from March through the end of weet in February and June, and during 4 days and the larval winter flounder season. The annual nights per week from March through May. All sampimg schedule was based on knowledge gained ichthyoplankton samples, including those described dutieg previous ) cars and itas designed to increase bbove, were preserved using 10% formahn.

efficiency in data collection and to redum "rbus sempling biases (NUSCO l981). Juvenile winterflolvuler lintrainment samples for winter flounder larvac have hen taken at MNPS (station EN,1:ig. 3) since Information on Juvenile (age O and age l) winter 194. Collections usually alternated between the flounder has been obtained from three f,ources. One is discharges of Units I and L dependmg uPon plant a special samphng program targeting put larval operation arxl water flow, l.arvae were collected using soung of theycar, the sceond H the trawl monitoring a gantry system to deploy a 1.0 x 3 6-m plankton nei program (1 MP), and the thir.! is the catch of juveniles of 333-pm mesh. Four 00 flowmeten weie taken incidentally during the adult spawning positioned in the mouth of the net to account for abundance surveyt in the Niantic f(iver. Because data horisontal and vertical flow variation; sample volume on juvemle fish abundance were available from about was determined by averaging the four volume esti. May of their birth year into April of the following mates from the flowmeters. Generally, the net was year,,iuvenile indices were referred to as a;e O or deployed for 5 to 6 min (filtering about 400 m3), but age-1, depending upon the ome period and wur(e of this varied depending umm the numkr of circulating the data. Following larval inctamorphmk, the pumps in operation and tidal stage. A sample was abumkince of post L4rval age O winter nounder bus 1

12 Monitoring Studies,1990 l

l 1

s k 1 KM /

Of L J~

1 MI NIANTIC

RIVER I

(/--g LR RM [

}1

/{ r NIAml0 k

/ BAY B s T p ),

kg ,

/

Fig. 4. Laetion of stations sampicd for op.o winter Counder from May through September in 1990, been monitored at suitions in the Niantic River since . of successively larger mesh have been used during 1983 (LR) or late 1984 (WA), and in Niantic Ilay each sampling trip. A change to the next larger mesh (RM and IIP) since 1988 (Fig. 4). Stations in the in the four net sequence war. made when fish had river were sampled weekly from the third week of grown enough to become susceptible to it, as the May through the end of Septernber during daylight larger meshes reduced the amount of detritus and algae frorn about 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> before to I hour after high tide. retained. At each station, two replicate tows were Stations in the bay were sampled before or after those made with each of the two nets in use, which were in the river, depending upon the time of high tide in deployed in a random order. Tow distance was relation to r.unrise or sunset and, thus, were occupied estimated by letting out a measured line attached to a at various tidal stages, During each year, sampling at lead weight as the net was hauled at about 25 m tw:r the toy stations ceased in August or September when min. The length of each low was increased from 50 few or no young were taken for 2 consecutive weeks. to 75 to 100 m at a station as fish abundance The young winter flounder werc captured with a 1 m (hmmt beam trawl, the efficiency of which was discussed in Catches from the TMP (see the Fish Leology NUSCO (1990). This trawl was used with inter- section of this report for methods) were uwd to changeable nets of 0.8 ,1.6., 3.2., and 6.4 mm har follow the abundance of age-O winter flournier during mesh. In late June of 1983, two tickler chains were fall and winter, in addition to the TMP, juvenile added to increase catch efficiency, as older and larger winter flounder smaller than 15 cm in length (mostly fish apparently were able to avoid the net without . age 1) were caught along with adults in the annual them (NUSCO 1987). In 1983, triplicate tows were Niantic River spawning stock surveys. Fish were made at LR using nets of increasing larger mesh as processed similarly as adults, although none were the season progressed. Ileginning in 1984, two nets sexed or branded. When these juveniles were Winter Flounder 13

p . - _ - - .. - .-..-. _ . - _ . - - _ .~ _ . _ _ . _ _ _ . - _ - _ - -

i i-

?

f l' libundant, a subsample_ of at lent 200 fish was were excloued from the analyses. Catches of winter measured each survey week, otherwise, all were 11ounder larger than 15 cm in tows made throughout treutut the 1,gvwning surveys were standardind to cither l$. min tows at stations 1 and 2 or 12-min tows at au L Indien of abundance other stations. The minimum length of 15 cm used for CpUE calculauan we srnaller than the 20 cm

! The data resulting from the field sampling used for mark and recaixote estimates descriled telow prograrm previously described were used to calculate because of data limitations from the 1977 82 surveys.

annual and seasonal indices of relative abundance. Effort we staadantired within each ) ear by replicating

%ese indices were computed for various hfe-stages of die median CpUE et,timate in a given week as needed winter hounder, from newly hatched latvae to adult so that cffort (number of tows) wns the same for each spawners, and also included estimates of egg weck sampled. A 95% confidence interval (Cl) was pnxluction. Indices were calculated using various calculated for each annual median CpVE using e 3 sampling sudsnes. These depended upon the slucific distribution free method based on ordct statistics i stage of life, surnpling cIfort, and suitability of the (Snedecar and Co&an 19M).

l datat a detailed description of each follows. Thc A second relath c index of abundance we based on j indices enabled timely asenmtnts to be made the size and sei distribution of the fish hem catches regarding the current status of the Niarlic Rivet stantiardized by variable weekly and yearl / cffort.

- winter flounder population and many of these data Tnis index was used to calculate anm.nl recruitment -

were used with the SpDM for long term prr,Jictims and egg production. Additional adjustments of catch L of MNpS impact. were made using samphng effort to insure that cach sire and sex group of fish was given equal weight Relativr annualahmulance of adults within each survey week, ntnong weeks in each survey year, and to adjust for varying effort among The relative annual abumlance of winter flounder in years. Detailed methals of calculating these values the Niantic River daring the late February.carly April wers given in NUSCO (1989). To avoid confusion spawning senon has bere described using a trawl with the CPUE index, this measure is referred to as catch.per unit.cffort (CpVE). An annual CpUE was  ? annual standardized catch

• throughout the remainder calculated using the median catch following data of this report.

, standardiration. Components of standardiration 4

included low length, low daration, weekly cf for,, and Absolute almndance estimates fish length and ses categories. Tow distance (with cxceptians noted below) was lhed in 1983 because Absolute abundance estimates of iruer flounder using the same tow length at all stations was - spawning in the Niantic River were ootained using expected to reduce varbbility in CpUE. Treviously, mart.and recapture medniology and the folly (1965) ,

tows of variable length had been taken et all saticns. model Since 1954, brands from previous years of ,

A distance of 0.55 km was selected as the standard sampling have been recorded, thus enabling the because it represemed the maximum length of a low estimation of annual population site (N) for the entire that was possible at station I, Since 1987, tows spawning population in the river. Other estimated ~

one half or two thkds 01' this length were (niquently _ model parameters include survival ($), recruitment taken in the upper rivet to avoid overlooding the imwl (B), and sampling intensity (p). These estimates were -

with macroalgae and detritus: this was especially true obtained using the compulcr program ' JOLLY ,

~

e during 1990. P,ccause catch data from station 2 were (polkxk et at 1990).

used also in the trawl monitoring program, hauls thete were made over 0.69 km. the statulard for thtt - Spawning stock si:e and egg productica particular sampling program..

Duratk n of tows varied and wu usually longer in The proportion of mature females for each 0.5.cm

-the _ lower than in the upper river because of length increment beginning at 20 cm vas estimated differenees in tidal currents, wind, and amounts of from qualitative observations on reproductive extraneous mMerial collected in the trawl To lessen condition made from 1981 through the present, error in : the calculation _ ol" CPUE, data from Dese estimates of gercent maturity by site. class were exceptionally long or brief tows made prior to .1983 adimted to give a srnooth progression of maturity up 1

14 Monitoring Studieu,1990

U_ sg 7 .- ~=

b -

ft , $ 5 The f ecutshiy (annual epp produs lion per f emak i w as frequen,ies s aned among some stauons. llata f rom esumated tot each 0.54 m u/c class by usmg the day hpht s.unples af ter hl.us h, w hh h w ere colles ted al follow mg relanornhip deternuned for Nianne Rner uauons I N and Nil, were culuded f rom abundatue w mter flounder (NUSCO 1987r (alculanons, ewept for estimatmg lanal enu.unment fecunthly = 0.0M'40:ngth m emr4 % (1) at hlNP5, because older lanae apparently rem uned

't his relationship was used with the a 'nual near the botton, during the day and were not sundardved catch of mature lemales and their length sus,epuble to the bongo sampler.

compmioon to takulae egg proJuetion. Annual I anal abuthlance data oser ome att usually 4 ewed, mean f ecumht) was determined by daidmg the sum hasing a rapal increase to a onumum dernoy of all inJaidual egg production eqimates by the followed by a siower dalme. A tumulatne derna) standatdved t atc h ol lemales gu nmg 1*.r >can mer tune from this type ul dntobuuon results in a Abwlute estunates of spaw ou.g femak:, and urmoulohape, w here the ume of peak abundanse wrrespondmp annual cre pmJu(oon estimates for neun at the mnemon poim of the urmoid the 1977 through 1990 were determmed by anuniing that Gomiert/ f uneuon (tiraper and Smah IONI) w as us J the relanie values tepresemed 3M of the absolute to desenbe the cumulatne dianbunon of the tan al values hee Absolute abundance cuimates in Results w mter llounder abundance data because the miln uon and Discussioni. Annual e=stimates et the number of pomt of this fum tion is not wnstramcd to be the icolatf spaw ners w ere aIwo thCd in the denvanon (?i a (entral p6Nnt ol the sipinoid (une, 'IhJ infni of the stosk tcuuitroen; relanonship for Nianne Rner Gompert/ fuistion used was a uuei Dounder. C, x u(espHiespb Krl D Cl w here C, e tumulatn e densny at tune i

" " I" " "% *Y\"W '"*"U t

• C U n *\ >

A butulatu t, tjeccloptnettt anil yron ;)t, atuf mottality of larvae' 0" """" Y#"* U "

w = shale parameter

' "' """" ""'E khthyoplankton sampics were sphi to at least -

" '""' ""'"I'" '"#Y I ene half solume in the laborator). Wmter flounder w hich was w ben wmter Oounder lavae gem rM1 3 fun lanae removed from the samples were counted ining "

" ""N""*

• a dnsectmg microscope. Up to $0 randomly selected a Man ard enon and asyniptone m (onM m e lanac wcre measur(d to the nearest 01 nun in standard length (snout tip to notothord tip). The

" # "" #'*"# ""I"A h I"""f a uahon to the cuinulanvc abundance data developmental stage of each measured larva win " """ # " "" "* I""U"k recorded tning the foHowing identification uiteria: UW uunu na wue o uned as de Stage 1. The yo!L aae was present or the eyes fun were not pigmented (yolk.sae larvae) " "" "E""SUHM " o"'f"a' wWW geonwtrie nu'ans of the

" E"'"'"d " "I Ih" '"'""I"U VC Stage 2, The eyes were pigmented, no )olk. sac curve was used as an indet to nimpare annual was PNsent, fio fin ray deselopment, g g and no liexion of the notochoid A den W ,, l.unch,on was mnsuuekd by Stage 3. Fm rays were present and nexion of "" "#""ve of the Omnpeni "E

the notoehold had starte't, but the leh " "* "'E#" """# .""**"'"Y""C"""' I cyc had not nuerated to the mid ime a nd.un e mu Stage 4. The left ese had read ed the mid.bne' ume (abund.mee eune), has the fomr' but juvemte characteristics were not N * (7"I *.)IIC'PIO "PII * '#h (3) pNwm whae 4 = &nWy at Unie Stage 5. Transformation ta juvenile stage was mmplete and intense pigmentahon was and all the other parameters are as descdbed in present near the caudal fin tme Equation 2, except for u, which was rescaled by a Larval data analyses were based on densities faam of 7 because the cumulative densities were standardized per 500 m3 of water sampled. A based on weekly peomeuie means and, thus, ceometric mean of weekly densities was used in amunted for a 7 day perint. Tune of leak abundance analyses because the data generally followed a m numated as the date to cortexponding to the Wmter Moun&r 15

1 l

l I

l f inflection point of the cumulative Gornperte curve abunimce indcit of the large larvac(7 mrn si/c<lau) l- (Eq. 2) given by: ,

to that on the smaller larvae (3 mm and smaller si/c-i t,=(logMD/K (4) claues L i During 1% the Comperti function could not be '!he prewnee of density delvndent mortality was satkfurtority fit to abundance data for Slage 1 and 2 determined by relatmg annual lar al abundance in the larvae in the river (all three stations combinedt For 7 mm and larger site-claues from station EN to the

, these data, the date of peak abundance was estimated annual total ci'g production indes for the Niantic ,

directly from the data by selecting the weck with the Rucr using the ic! low mg relationship (Ricker 1975):

largest geometric mean for each developmental stage h%-(L / E) . a + bE (5) and using the mid point of the week as the date of where L = annual larval abundance of larvac 7-mm t eak abundance. Further, an annual abundance indes and larger at liN t.< estimated by n (see l in place of the n parameter was estimated from the 14 2) total cun.ulative abundance. Linear regression was E = annual egg production estimate l

used to compare prestous total cumulative annual a = intenept ,

- abundance estimates to the a parameter for Stage I b = rate of dendly dependent mortahty

-and 2 larvae in the ther. The slope was not Since the ratio 1/E represems the fraction of fish ugnificantly different from 1 and had u 95% surviving from eggs to 7 mrn in si/c, density.

conndence interval of 0,9951.024, which indicated dependent mortahty may be auumed w ben the slope

. that cumulative abundance wa(n gml estimator of (b) is sigtnficantly different from /cro. This mortal.

the a parameter, . ity is compensatory when b is negathe and degen-

' Larval mortality rates were estimated from data satory otherwhe, collected at the three Niantle River stauonatata from +

1983 were excluded us smaller larvae were 6bmn/ance, growt/t. and mortality of

- undersampled because of net extrusion (NUSCO jueenllesin Aulnmer ,

1987). The abundance of lar ae in the 3 mm and smaller sire classes (by 1 mm the< lanes) was used for data analysis and calculation of CPUE, the as an index of newly-hatched larvac because 3 mm canh of young of the. year winter nounder in each of was the approsimate length at hatching. The decline the four replicated 1 m beam trawl town was ,

in the frequency of larvae in progressively larger standardi/cd to a f(C m low distance before taking a site-classes was attributed to both natural mortality mean, resulting in a density for 100 m2 of lottom. 7 and tidal flushing from the river, liess et al. (1975) For some comparisons among years, a moving ,

estimated the loss of larvae from the entire twer as average of three weekly density estimates was used to 4% per tidal cycle and also determined that the loss - smooth trends in abundance, from the lower portion of the river was about 28% Nearly all of the ape O winter flounder collected per tidal cycle ~ Compensating for the 28% decline were meawred fresh in cilher the Geld or laboratory to lur tidal cycle with two cycles per day, the daily the nearest 0,5 mm in total length (TL). During the

.- - abundance estimates of larvac in the 3.tnm and first few wecks of study, standard length (St.) was I smaller siic claues at station C in the lower portion also measured because many of the specimens had of the river were rescaled by a factor of 1,93. The damaged caudal fin rays and loud length could not le

- abundance of larvae in the 7 mm sire daw was used taken. A relationship between the two lengths '

- as an index of larval abundance just prior to juvenile determined by a functional regression was used to

, _ metamorphosis. Scir abundance at station C was convert SL to TL wienever necewary; not adjusted for tidal flushing because previous TL in mm = 0,2 + 1.212(SL in mm) (6) studies (NUSCO 1987.- 1989). have shown a nel Growth of age >0 winter flounder at cach station was.

3: - import of larvae of this site into the Niantic River. examined by following weekly mean lengths For the mortality calculations, abundance indices for throughout the sampling season. Mean lengths of newly hatched larvae (after adjusting - for tidal - young taken at the Niimtic River stations LR and WA -

Dushing) and for larvac in the 7 mm size class were from late July through September for 1983 90 were -

!- determined by summing the mean weekly abundance compared using an analysis of variance; significant

, (three stations combined) during each larval season. diff(rences among means were determined with Survival rates' from- hatching throur,h larval Duncan's multiple range test (SAS Institute Ine, development were estimated es the ratio of the 198$).

a

- 16 : Monitoring Studies,1990 re-,- +- --.,eF w-,-,_,s 3-- c re ew w -,- , , ,e-, y v ,om,.., . , , , - m-- .r .mem--.io.m4,w._., u_.-.-.- . ~--- _ _ - - _ _ _ - - __.- - -

To calculate a mortality rate, all young were from the catch at age of winter flounder because the assumed to comprir.c a single cohort. A catch curve spawning stock is made up of many year classes and was constructed with the naturallegarithm of density the true recruitment consk.ts of the reproductive plotted against time in weeks. The slope of the contribution over the life of each individual (Garral descending partion of the curve provided an estimate and Jones 1974; Cushing and flotwood 1977),

of the weekly rate of instantaneous mortality (Z). Therefore, annual parrntal sta k was based on denml Once Z was determined, weekly survival rate (5) was egg production and the resulting year class of recruits estimated as exp( Z) and the monthly rate as on their own egg praluction accumulated over their l c'p(1 ZJ[30.4 / 71L life time. This acemmted for variations in year class  !

strength and in fecundity by site and age. The l Abundance offureniles infall and winter assurnplions and rnethals used to age Niantic River winter flounder and to calculate a recruitment index in fall and r srly winter, age 0 winter flounder expressed as equivalent numbers of female spawners gradually dispersed from areas near the shoreline to were described in detail in NUSCO (1989,1990). I deeper waters. The catch of these fish during this For completeness, a brief summary of diose methods time period at the trawl monitoring program stations is given below.

(see the Fish Ecology section elsem here in this report Stock and recrullment Indices. Methods for methods) was also used as an index of relative uwd to calculate the annual standardited catch index abundance. The data used from inshore stations (NR and total egg production of the parental smck were and JC) began in November, nearshore Niantic Ilay given previously. The recruitment index was stations (IN and Nil) were added in Decernber, and determined by applying an age length Ley (described offshore stations (TT and !!R) were added in January in NUSCO 1989) to the annual standardized catches arid continued through February for each station of females partitioned into length categories. This grouping. These catches were used to calculate year. allowed the determination of the number of females j class abimdance using a 6 mean CPUE (NUSCO from the same year class present at ages 3,4, $, and ,

1988b.) This index of abundance is the best N during successive spawning seasono The age M estimator of the population mean w hen the data come group was furdier subdivided into the numbers of fish from a distribution that contains numerous rero expected to sursive to a terminal age of 15 by values and is approximately lognonnal (liennemuth assuming various annual instantaneous mortality et a!.1980; pennington 1983,1986), rates (Z). This represented a change frorn NUSCO The annual median CPUE for juveniles smaller (1990) and was an attempt to make mortality rates than 15 cm (mostly age l fish) taken during the adult more realistic because fishing pressure increased from winter flounder spawning surveys was determined as the 1970s through the 1980s. The value of Z used described previously for the fish larger than 15 cm. for each of the year classes from 1977 through 1986 Median values were calculated for stations in the was increased from 0.80 to 0.9$ by increments of iower Niantic River navigational channel (I and 2) as 0.025 every other year. To follow each year-class well as for all river stations combined, when after 1990 to its terminal age (to 2001 for the 1986 sufficient data were available. For comparati e y ear class), a Z of 1.00 was used, llated on observed purposes, an annual 5-mean iibundance index for abundanet by age, a large fraction of age 3 females, juvenile fish of similar sl ct was also determined considerable numbers of age 4 fish, and even some using catch data from the five truwt monitoring age-5 females were apparently immature, with many prograin stations outside of the Niantic River during not present in the Niantic River during the spawning the period of January through April, which season (NUSCO 1989), Thus, the total number of temperally overlapped the adult spawning surveys, females was reduced to mature females (i.e.,

spaw ners) using length specific proportions of mature Stock and recruitmenf relationship fish estimated from annual catches in the Niantic River for fish age 3 to 5; all females age 6 and older

= A stock recruitment relationship (SRR), as were assumed to be mature.11ecause the estimates of described in NUSCO (1989.1990), was the basis of age.3 fish were thought to be unreliable, this the life cycle algorithm that drives the stochastic estimation pmeess was only carried through the 1986 population dynamics model for Niantic River winter year class (age-4 females taken in 1990). The final flounder. The stock and recruitment data were derived adjustments for mature fish provided an index of the WinterFlounder 17

fully recruited year class espressed as the aggregated temperatures in the month or period selected were number of female spawners paulng through each age- used as an esplanatory variable in adjusung the two.

class. An implied assumption was that catches in the parameter SRR for temperature ef fects to help reduce Niantic River were representative of the population, fccruitment variability and obtain more reliable except for the immature fish that did not enter the parameter estimates for the SRR. 'I h n river until fully secruited. Ahhough this recruitment ternperature dependern SRR tud de fonn:

index could be used together with the annual number R, = nP, esp ( DPi )cy4Tr ad (8) of female spawners to derive an SRR, this would where the secon,l esponentul descrites the effect of ignore sire composition differences that affected February water temperature on recruitment and the annual egg prouuetion. Therefore, the above indch new lutameter o represents the strength of that clicct.

was adjusted for differerwes in fecundity among Osh This eff ect can le either a reduction or un increase in using the length fecundity relationshin for Niantic the numhcr of recruit &per sonvnet produced each year Riser winter flounder phen above (E4 1). FinMiy, because

• temperature" was defined here tu the desi-annual egg production was summed up over the ation (Tt m) of a particular mean February ternperature lifetime of each year clou to determine the from a long term (1977 86) average of February water recruitment index as epp and, then, converted to temp ratures. When the February mean water temin-

" equivalent" fernale spawners at the rate of one female ature is equM to de long term uverage, the deviation spawrrt for each 561, fit 0 eggs (the mean fecumhty).

(Ts) in Equation 8 becomes reto and the essmen.

Sill parameters und biologleal reference points, {the SRR described by Ricker (1954,1975)

HW equals unity (i.e., no temperaim effect),

appeared best kuited for use bere because the TM l@ son 8 de m b iMdW Ma % 't) relationship between wanter flounder recruitment and ph M mim cedidon NoMid regten on inethods (SAS Imtitute Inc.1985) were spawmng stock indices resulted in a dome shaped W for estimating the patameter6 in the abme curve with subsumdat decline in recruitment w hen the stock was larger than average (NUSCO 1989), in addition, this particular form of a SRR has been nual instantaneous rute of fhhing (F), also upphed to other New England flounder stocks (Gibson referred to as inhing inortahty or fishing rate. is an impsrtant fuetor afIceting the growth potential of the 19N9). The mathematical espression describing this bO E sto(L (Goodyear 1977) and, thus, relevant for R, a uPg exp( DI,,) asseuing other impacts. Because fishing and natural (7) anortality of winter flounder take place concurrently where R, is the recruitment index for the progeny of through die year, the actual fraction of the stock the spawning stoel P, in year i and o and p are removed by the fishery each year (l.c., the parameters esdmated from the data. The a parameter exploitation rate)is obtamed at describts the growth pmential of the stock and log, u u =(F/Z)(1 expbZl) (9)

(the slope of the spawners recruit curve at the origin) where Z = M + F,and M is the instanumcous rate of in equivalent to the intrinsic natural rate of increase natural mortality (estimated as 0.35 for the winter (Roughgarden 1979) when the stock is not exploited. flounder).

The p parameter is the instantaneous rate at which Stock recruiunent theory and the interpretation of recrullment declines at large stock sites due to some several biological reference points (DRPs) derived form of density dependent mortality, The natural from Ricker's SHR model were discuued in detail in logarithm of winter flounder recruitment was found NUSCO (1989). Three of those BRPs that were correlated with mean water temperature during useful for stock assessment, plus a fourth one derived February at the intales of MNPS, which is when for thk study, are given below The equihbrium or most spawning and early larval development occurs sustainabic stock site of an exploited stock (i.e.,

(NUSCO 1988a,1989). Therefore, the parameters a w hen F20) is given by: -

and were estimated initially by fitting Equadon 7 to Pt:(F)= (logeln) F)/ p -(10) the data and then re estimated under the assumption For F=0 this becomes the equihbrium or rcplxement that there was a significant temperature effect. This level of the unfished stock:

was accomplished by adding a temperature effect P,9 = (loge (al)/ D (11) component to Equation 7. Similar to Lorda and The fishing rate for " recruitment overfishing" was-Crecco (1987) and Gibson (1987), annual mean water defined by Siwenwine and Shepherd (1987) as:

l' 8 Monitcring Studie's,1990

d 1

1 1

4 l

i l lho = 0.40(logtl uD (12) floun&r becau e many immature hsh (agee2 and 3)

! w here a was scaled for a quwtung siwk espreswd in are vulnerste to Mong pat Mnipson M i reponed that aluut 72% of 1 IS winter nounder landed biomau units. This fhhing rate was replaced into j I?quauon 10 (with all parameters re. scaled for biomass t y the i ,mmercial fishery were betwcen 2N and 32 1

unitO to obtain the threshold sto.k biomaw or "stak (nu many of Hoe Ni would hase ban aged

? overfishmg" at w hich recruitment failure becomes a Additional problems ariw from the appliumon of real concern. This new IIRp can tv calculated directly deterministic rnodels (i.e., auuming stead). state I

usmg the equation: condnbne 10 fie e w how e$odahon nun am pm . (0.10(logd ulD / D (13) not stable and, especi ll,, w hen they are increasing as

'the crMical stwk w.e P3o is equivalent to 10% of the m the case of the winter flounder smcc the late 1970s steady-state unfished stosk biornai.s (by 11) and, g ,, gg g thus it corresponds to an equibbrmm point of the muhs in ps teem veion of natural tuottality rates f urther weakening the results of deterministic

! spawner recruit function with slope loge (R/P), w hkh ements.

{ k 90% of the slope at the origin.

A more realii. tic approach to sink aweument that can incorporate enviromnental variability and all 3 Assessment of MNPS operau,on on types of mortalny, both con 4 ant and vanaMe, local winter flounder involves the computer sunulation of the hsh e

population dynamics using a shople model rf The problem of managing fish wwks has been the i population renewal with spawning stock feed back object of much work by fishenes scientists since the (e.g a stwk recruitment relationshipt Two uAan.

carly 1930s (Thompson and itell 1934) through the tapes of this approach are that assumphorn of l present. Talay there are several welbestablished equilibrium are no longer needed and that conddions methods and analyucal tools available for stock or " scenarios" according to which the fo.h population

aswssment (Smith 1988), However, most of these changes through time can be generally hnplemented i i methods rely on stock recruitment theory and need to with almost any degree of detail desned. An addo assume constant fishing rates and populations with 2

tional advantage is that Alonie Carlo methods can

stable age structure, which result in equilibrium or readily provide the stochastic (as opposed to steady. state stmLs that rep 1xe themselves year after deterministic) framework needed for probabilistic risk year, Some of these tmalytical melbods are based on 1

assessment (PRA) and for testing hypotheses atout equilibrium equations (such as Eqt 10 through 13h the probaMe site of the stwk at some future point in which have been modifled to incorporate cHects of 1

time. This simulation approach was already applied fish mortality caused by other activities in addition to in NUSCO (1900) to assestthe impact of larval fishing; This type of siwk assessment was discussed entrainment under a very simple scenario. *lhe pres-by Savidge et al. (1988) for the case of mortality ent study used the same approach to re assess the caused by the entrainment of larval fish through the impact of h1NPS operations on the hical winter cooling water intakes of power plants and it was Hounder niore realistically by using various apphed in NUSCO (1989) to the impact auenment combinations of historic and projected fishing and of winter floundet larval entrainment at h1NPS.

luval entrainment rates The four basic steps leading There are, however, several problems with this SRR*

to the final impact assessment using this simulation

, based . approach to impact assessment at blNPS, .

apprmch are: direct estimation of annuallarval entrain, itecatise stock recruitment theory (Ricker 1954) was ment rates at MNPS; mass balance calculations to develoivd for semelparous fish (i.e., those which estimate the fracuan of Niantic River annual flounder spawn only once in their lifetime), Equation 11 may production lost through larval cotrainment at MNPS; provide unreliable estimates of equilibrium stock stochastle simulation of the winter flounder stock to sites for iteroparous fish (muhbaged spawninE project std s tes for selected levels of entrainment ,

stocks), such as the winter flounder. Although the and fishing rates; and probabilistic analyses of -

parameter a in Equation 10 could be adjusted for the s mutation results leading to a hat estimate of the effect of repeat spawning, this equation also assumes probability of recruitment failu'e under simulated that no fishing mortality occurs pnor to maturahon. conditions.

This auumption cannot be met in the case of winter Winter Flounder 19

i i

1 Stimales oflatwil enthlinment at MN/'S unkn%n numben (.!ianae Dushe<' to and from Lls

' were combined as an untaown in the calculation The estimated number of larvae entrained in the Thus, the forni o' de mau tulance equation was

s. MNpS (ondenser cooling water system each year is Nil, 4 5 m (N; i - (Ent) - (Mart) + (RomNR) -

4 the most dircel measure of inipact on the local winter (ToNR)1 (Source / Sink) (14)

Hounder stock 1hese values were obtairwd usir.g the w here r = time in dap i Oomperti density Iunction (Eq. 3) fit to data co!!ccted Nit,. 3 = numlet of larvac in Niantic llay at $

at station LN (Fig. 3). Daily densities (number per

' days after day i (instantaneous daily

$00 m3) were calculated and daily entrainment esd M d

c>timates determined after adjusting for the daily Nil, e initial number of Ianae m Niantie Bay condenser cooling water volunw, An annual estinwie was determined by summiag all daily estimates on 4 i Onumcous ddy emmme) 3 during the larval season, This method of esumaung Ent = numbi A larvae loi.t from Niantic Bay L entrainment differs from previous years (NUSCO d- hmnent in Ow coderwr 1990), for which entrainment was estimated from codmg wmer sptem (over a $. day seasonal median densities; annual entrainment esth

,g y , ,,,.At of larva: lost from Nian0e Day -

, mates determined by each method are compaled in a separate section of this report (see Ichthyoplankton do natural nmrtahty (over a $ day Entrainment Estirnatiout y_. y homNR = wmber of invw ilueed from the MaAs-balance en/m/a. llons Niantic River (over u 5 day period)

ToNR = nunAr of lavw entering the Niantic  ;

i The number of wimer Hounder la vae entrai m' is River (over a $4Liy lvrital) dependent ulwi lanul densities in Niantic !!ur. Source / Sink = unknown number of larvac in ,

Potential impact to the Niantic River stock front g;,gg pq gg gg gg g3 g, egg 7 L the bay from LlS (o,er a 5. day period) lanti entrainment should be related to thc number of larvae that originated imm the river, Mau balance S@i br dw wknou Source /Sid htm, the calculations were used to investigate whether the r dE i- %ource/Smk = (ND, ,5)- (Nu,) + (Ent) 4 (Mort) .

number of w inter flounder larvae enteong Niantic Ila)

L hom the Niamic River could sustain the number of

,g g larvae obsened in the bay during the winter Counder anw 3ecause diese manMana cakuladons wm larval season each year (19M 90). There were three based on the change in the number of larvae in Imtential tarvat inputs to Niantic Ilay: eggs hatching Nbnk Day over a Hay idd W

2 in the bay, lanae Dushed from the Niantic River, una M ,b w = M 4 & M,)

larvae entering the bay from LIS across the boundary 'lherefs between Millstone Point aml Black Point (Fig,3). So . e ($4tay Change) + (Ent) + (Mort) -

Due to the low numbers of volk sae larvac collected (FromNR) 4(ToNH) (17) annually in Niantle Bay, minimal spawninr und Daily abundance estimates were derived imm the subsequent hatching was thought to occur in the bay Gomp rte density equation (Eq; 3). The daily esti-and, therefore, it was considered a negligibic L-aal mates for Niantle Bay at two pomis in time (Nil,ami source. Larvac were known to be Oushed from the Nil, . 3) for each 5< day periml were cateuhited from river to the hay and the number ent, ring can be data collected at stations Nil and EN combined, which estimated from available data, flowever, the number represcated an instant;mcous daily standing stock after

of larvac entering Niantle Bay from LIS was not adjusting for the volume of Niantie Ilay (about 50 x known. Four potential losses of larvae from Niantic 106 m3; E. Adams, Mauachusetts institute of Tech-Day included larvac that entered the Nhnlie River nology, Cambridge, M A., persi comm.). The differ.

during a Good tide, those lost to natural mortahiy, ence telween these two estimates (N!!iand NBi , g) those entrained by MNPS, and larvae that were was the term called 54Liy Change. The sele; tion of 5 Rushed from the bay into LIS. Larvac entering the days as the perimi of change was arbitrary and.a Niantic River and lost by natural mortality and ~

entrainment were estimated, but little was known cursory examination of results based on 10 day L

periods did not aher conclusions made from the mass-about the. number of larvae flushed to LIS, The 20 Monitoring Studies,1990

1 balance t,akulations mmg the Oday Ivrnkh. Dady entramment estunates w oe teed on data coliccted at station I N ami the ai tual dady solume of condenser g' ,

0B0 ,,

toohng water us:d at slNpS.1he dady entrainment cstunates were sumined user each $ day Ivrul ti un.

p33 /i Annual stage 4pesihe snortahn rain for 19SJ h4

/

were deterrmnul ty neuo and llow cli (lW D und for

, (,:0 ,

/

Q f Iwo (V, Creu o. C T DI P. WatirlorJ, C'i, pers F @-

comm ). Thoe annual rates acre imiifed to (Lah * /,' 18- ON stage specibe mortahty rain in auuming Hbday k2* j'  ;

stage dmatmns for Stages 1,3. und 4 lan ae, and 20 days lor Stage 2 lanae, Ihe proportion of each stage qg h

_rY_,

,gg, 0 M0 iNO 1500 2000 udlected at station 1.N duritig each $-day gerux! *a, 8 apphed to the daily standay stosk for Niantic Ilay $ YA #' W SW'M C M

• W M **b (ND,) to estiinate the number of ian ae in eat h da el-opmental stage for stagcape(ihe mortahty takula. y E-  ;.ggg uont The dady loss due to natural inortality was y!

sumned f or each 5 da) letal t Moro. 2 300 -

'!he 5 day input of lanx to Niantie Bay from the 8 '

rner (1:ron,NR) w as based on daily density estunales  % g ,, , ,

for ination C in the river auer admsting for the rate of d a ljushmg between station C and th" fnouth of the rivtr i tiig $). To determine the relationship between the

• estunated dady densit) at station C and the m erage , ,

density of larvae leaving the river on an chb tide, the b m r- T , r geometric mean denuty of samples collet;ted during 0 W Mc 1M 200 OM XO an ebb tide for 10 impori nport studies conducted at MANiic bay Density (No/20 m ) S the mouth ci the Niantic River during 1984, 1985, and 1988 (NUSCO 19h5,1986,1989) were t ompared y to the estimated daily densitics at station C. It

, g. m r h n M W at &nudo 4 eta & %

un ebb tide at mouh of the Niantic River cornpared to appeared that less than $09 of the larvac estiinated to cortnpon<hng daily dennly eshrnates at stadon C, und be at station C were llushed from the ther. wHected duong a bd tide at the rnouth of the Nianac Therefore, the merage dendly of larvae Oushed from Rher compacd m cortnpmding daily dermty cr.thnato the Niantic her was estimated by the regreoion in Niarnic Hay.

equation:

Average density 18.k28 + 0 4% (Dady denuty at station C) (18) rio apparent systematic bias in this relauonship and This merage densuy, the overage tidal priun of 2.7 x for lack of better information, the estimated daily 106 m3 (Kolhneyer 1972), and about 1.9 tidal priuns densities for Niantie Hay from the Gompertz equauon per day were used to estimate the dady flushmg of were used to estimate daily loss aher adjusting for the larvae from the river to Niantic Hay, 'thn daily input average tidal prism and the . number of tidal piisms per to the bay was summed for each 5 day perm! to day, 'lhese daily estimates of the number of larvae calculate the term FromNR in the masebalance entenng the river during a Good tide were summed equation. The loss of larvae from Niantic Bay to the iner cas b $-day rerial to calculate the term ToNH in river during a fkel tide (ToNR) was based on the the mawbalance cquation, daily density estimates for Niantic liay (stations NB The Source / Sink term represents the net lov, from i and f;N combined). A comparison between the daily or gain to Niantic Day of larvae from LlS during a $-

esumated density for Niantic Bay and the geometric day period that is required to balance the calculation. l mean density of the samples collected during a Ibl For a net loss this terrn would be negative and for a  !

tide for the 10 import-nport studies indicated no net gam the term would be positive.

significant relationship (Fig. $). Because there was Winter Floornier 21

SlDC/hlAf/C Alttild(lfioti c 7[ Willld]70l#!dt7 Chitstensen 1964), in the present winter llounder stod dytuurlirA [vpulation inodel, adult Inh dy namics were linpleinented espheill) by grouping fish into dntinct llackground and inodeling strateg). 1 he age-classes and by carrying out the sunple stochastic populanon dy nannes model (Si DM) computations needed (rnostly adJilions and develqA'd for i.he Nianti, Riser winter flounder stot t multiplicationG iterainely user the age indes (I w as based on the Ris ker f orm of SRR desershed in through 15) and act the onnder of years qveified hit NilSCO (1959) Although the specific SRR cach snnulabon. Ihn approach was algebraically equation (Eq. 8) filled to the data does not appear identical to the !.eshe ruatris forniulation and esplicitly irl the intklel forniulation, the ina hanisnn simphlied the toniputer uxle when describing the fish tinderlying the Ricker lorm of recluitment are pepulation eith,I as biomaw (allowing for si/c incorporated in the set of equations that the inodel comlwnition within each age < law) or numbers of uses la calculate rnortaht) through the first year of fish. A silnitar implena:htation of adult population life lleyond that [kiint in the life Cycle smiulatiori dy namies simulat!on w as recenll) used by Creno arkl u .c 4 age-1), the population nuxlel simply describes Saso) (19871 in their model of Connecticut Riser the annual redu; tion of each ) car 4 law through natural American shad Mlma sapidumu).

mortahty and inhing together with armg and M mlel compont nts 't he simphfied flow chrt ic produt tlon. 'lhe latter occurs at the beginnmg OI show n Ui l'igure h represents the i,omponents of the cach tuod.:l tune step ol length eqiut to l ycar. Thev: computer progr un used f or the NUSCO St' int.

piocesses correqwmdirig to the dy nannes of the adult Conyxmenu depi,ted by solid line botes constituted population hase been implemented in inany presious the fluxlel presently in use Components depicted by Inh populanon nuxlels by means of 1.eshe inatris imes with d.nhed hnes denote p.uts of the matel that cquations (e p., liess et al.1975; Vauphan 1981; were not used in the prewnt appheation and will not Spauhhng et al.1983; Reed et al. l%t; hlycar and he dncuwed here. lion s er, these conqunents, inpui un and . . . . . . . . . . . . . . . . . . . . . ,

simdaien psame!es  ;

Y H.ee

,.....Y.....,

, rotDN A tused ,

g....... w ats enimmment l

e e

tempm alar e .i .r.h.rk

.. p.

c.omps. .on ;,

'e i Y...... r . . . . .T . . . . . ,

,r.....Haicrung chintiuhon ,, e Mit nW ,

............ ...%s in.1 w.... . . . . . . . . . . . . . p t wv at dwai i l l l avval cohcris l and entramnerd j

, ............., ......e.....,

a I t 9 Y i l c.am;+nw on. 4 l f-> l ninwment and 4=a*.=..=*********.*=====**==*=..=.=*

r Acta 1 (ohort y Ilahikpn hoe.t:

4 j

& Y I Aduit cohoq cauahons Annuaiadue Pr ceah,In.hc and  % fopuMbon - --- % n%k NannW and icNno rnoq Aty comats a sessmeni Y Y l' smnam sucs we

__ and OUTPUT l og pohnnn esamamo

-' i k

MNPS hiel componenh m iih dehcd imes and aww s hn e not been med m the present apphc anon.

22 Monitoring Studies,1040

~

i including the MIT larval dispersal and entrainment females from the same year class that survive to model and the results of ongoing mitochondrial DNA spawn year after year during the lifetime of the fish.

(mtDNA) larval stock identification studies, may be The algebraic form of this multiplier is identical to used in future applications as they become available. the numerator of Equation A 4 in Christenacr. and The functionality of some model components should Goodyear (1988).

be clear from the figure and no further details will be Random varlability. Stochasticity in the winter Counder model (Fig. 6) has two annual com-provided, llowever, critical components, such as the one labeled age 1 cohort, the two random input ponents: a random term that represents uncertainties boxes, and the component that performs the associated with the estimate of Ricker's a parameter; and annual environmental variability in the form of probabilistic risk assessments are described below. A list of the actual input data used in the application of random deviations from the long term mean Februa y the model to the Niantic River stock will be given water temperature, w hich occurs during the period of later in the Results and Discussion section. larval development. Wsc two components of annual Calculation of fish surviving to a ge.1, variability are incorporated into the calculation of Tbc most critical aspect m the formulation of a stock- each new year class via the mortality from egg to age-recruitment based population model is the specific 1. The term n, in Equaticn 19 is the random " noise" equation and parameters used to calculate total simulated as independent random variates from a rior-mortality during the first year (i.e., from egg through mal distribution with zero mean and variance equr.1 to age 1). The equation used for this purpose in the a2. The value of a is estimated during the model cali-winter flounder model was derived from Ricker's bration runs as the amount of variance required to equilibrium equation for Zo (total instantaneous mer- generate a values within the 95% confidence interval tality from egg through maturation age) and involved of the estimate of a used in the model. Similarly, the extension of stock-recruitment theory, which was the term 4WT,in Equation 19 represents the effect of developed for fish that spawn only once, to itero- annual environmental variability of February water parous Osh with multi-age spawning stocks. The temperatures on larval survival. This effect becomes form of this equation as used in the present model random when the February water temperatures are was: themselves sim lated as irglependent random variates Zo,, = loge (FEC) + log,(ASF) loge (n) + ns - from n norma, distribution with mean and variance

$ W T, - Z3 ,2 + P, (19) equal to the mean and variance of February water temperatees at the MNPS intakes during 1977-85.

where the subscript I denotes the time step or simu.

Probabilistic risk assessment (PRA), The lation year and implies that non subscripted terms stochastic simulation of fish population dynamics remair mnstant from year to year; a, , and & are the provides a convenient framework for probabilistic three parame'ers in the SRR (Eq. 8) estimated from the stock and recruitment data; FEC is the constant assessment using PRA methodology. This type of mean fecundity of the stock expressed as the number assessment is based on Monte Carlo methods (Rubin-stein 1981), whcre many independent random repli-of female eggs produced by each female spawner; cates of the stock time-series are generated so that the ASF is a scaling factor to adjust a for the effect of a multi age spawning stock; n, and WT, are independent mean stock size and its standard error can be esti-m ted. Alternatively, the Monte Carlo replications random variates from two specified normr.1 distrib.

can be used to derive either the sample distribution utions described later; Z12 is the instantaneous "

mortality through the immature age classes; and the f"n" wn*st tistical distribution, or the probability den-last term ( P,)is the feed back mechanism simulating y

sity function under the arumption of a lognormally stock dependent compensatory mortality, which varies distributed stock size (Tuljapurkar and Orzack 1980),

according to the size of the annual spawning stock P,. Both methods can be used to calculate the proba-The complete derivation of the above equation was bilities of postulated outcomes, such as stock size given in NUSCO (1990: appendix to the winter reductions. PRA methodology was used to asseu the flounder section). The scaling factor ASF is simply a risk of stock reduction resulting from three different multiplier that converts age 3 female recruits into the levels of larval entrainment at MNPS simulated in potential recruitment of the year class. This recruit- this report.

ment is denned as the cumulative number of mahre Winter Flounder 23 1

Model assumptions and limitations, The that this number of replicates was sufficient given the major model assumptions relate to the underlying amount of variability present. The complete simu-form of the SRR used and the reliability of the SRR !ation consisted of four model runs, which provided a parameter estimates. First, because tne model incor- set of four time series generated under the same potated the Ricker form of SRR,it was assumed that scenario t. ' with different larval entrainment rates stock dependent ampensation and the postulated (termed "ENT"). These rates were chosen to simulate effect of water temperature on tarval survival (Eqs. 8 no plant effects (i.e., /ero entrainment rate) and plant and 19) applied reasonably well to the Niantic River effects correspcmding to low, medium, and high winter flounder sto k. Secondly,it was assumed that entrainment rates under hlNPS three unit operation.

the three parameters of the SRR were correctly The first time series with no plant effects was always estimated and that a, in particular, was a reliable the baseline series or reference against which the estimate. Thirdly, although the population was not effect of the entrainment rates simulated in the other assumed to be at steady state, the average fecundity three series were compared, Although the term and survival rates fer fish age l and older were " conditional mortality rate" was introduced in recent assumed to remain fairly stable over the period litcrature (e.g., Goodyear 1977; Savidge et al.1988) correspomhng to the time-series data used to estimate to deal with fish mortality caused by plant operauons, the SRR parameters. Although the last assumption its precise meaning is not obvious and may create may generally apply to fecundity rates and adult confusion when used in conjunction with fishing and natural mortality, fishing mortality rates are less natual mortahty rates usually given as instantaneous stable. Changes in exploitation rates from year to rates on a logarithmic scale. In this study, condi.

year should not cause estimation problems as long as tional mortality rate refers to the fraelion of the the changes are not systematic (i.e., change in the annual production of a fish stock that is removed and same direction yea, after year), Because these assump- lost from power plant operation. Therefore, the Lions are seldom completely met, applications of the above three conditional mortality rates describe year-model included calibration runs to validate predictions class reductions of ENT equalling 15%,20% and under both deterministic had stochastic modes by 25%. These hypothetical year class losses were comparing model results to recent series of stock chosen to represent low, medium, and high abundance data. Finally,it shoukt be noted that the entrainment rates, respectively, at hlNPS and were stochastic simulations assumed a random envir- based on the latest estimates of winter flounder larvae onmental variability about some mean water entrainment. The "high" rate resulting in a 25% loss temperature value. In other words, no temperature was very likely an overestimate of the actual annual trend or large scale environmental changes (e.g., losses since the start up of Unit 3 in 1986. This rate global warming) are assumed to occur during the was intended as a worst case scenario to compensate years simulated in a population projection, for the low precision of current estimates based on the Model application to simulation of mass balance model and other uncertainties still MNPS entrainment, The output from a run of associated with that particular analysis. The other the SPDM consists, in general, of a time series of two rates were in agreement with the conditional annual stock sizes generated under some specified set mortality rates of 0.149 and 0.204 derived by Crecco of population parameters and other conditions which (1990: Table 3) using the geometric mean of " mass-constitute the scenario being simulated. These baiance" model estimates of Niantic River larvae parameters include the fishing and larval entrainment entrained during 1986 89 (three unit operation period) rates, their schedule of changes when r,ot assumed and its upper 95% confidence limit, respectively, constant, and the length of the time-series in years. Because the ability of a fish stock to withstand The output series, also called a population projection, additional stress is reduced by fishing mortolity is the result of averaging several replicate time series (Goodyear 1980), the long-term effects of entraining identically generated except for the random com- winter flounder larvae were si:nulated while ponents used to compute ennual fish survival rates subst:mtial exploitation of the stock was taking place.

(NUSCO 1990). The number of replicate series (i.e., in addition, the simulation scenario included frequent the hinnte Carlo sample size) wm rt to 100 changes in fishing and entrainraent rates caused by throughout this study and the " aver.,ges" were always fishing trends and size limit regulations and by the geometric means. Although tr.al simulations with start up of MNPS generating units in different years.

larger replication were conducted,it was concluded Therefore, the dynamics of the Niantic River winter 24 Monitoring Studies,1990

TAllLE 1. Coohng mater requirements and dates of opeianon for each unit of Millstone Nuclear Power Station assuming an expected hfe-time of 40 years.

Coohng water flow Fracuan of MNPS Fint year of Projected Ian year Unit knhsec) total flow Stan up date entrainment of operation

~

1 26.5 0.225 November 1970 1971 2n10 2 34.6 0.294 thcember 1975 1976 2015 3 56.6 0.481 April 1986 1986 2026 MNPS total i17.7 1.000 flounder stock was simulated under a realistic real- of total (three unit) cooling water used in periods time scenario running from 1960, well before the when fewer units were in operation. These calcu-start up of Unit 1, to 2060, long after the projected lations and the final schedule of conditional mortality shutdown date for Unit 3 in 2026 (Table 1). rates used to simulate larval entrainment were Concurrently with the power plant effects based on summarized in Table 2. The derivation of the actual generating units in operation each year, the schedule of fishing mortalities was based on the scenario used estimates of fishing mortality according estimated nominal fist.ing rates for winter flounder to historic and projected rates of commercial since 1960, and the length limit regulations since exploitation and sport fishing for winter flounder in 1982 (Table 3), Because the commercial length Connecticut. This scenario with time dependent limits changed three times during 1983-84, the entrainment and fishing rates was implemented by average length limit of 10 inches was adopted for providing the population model with a detailed look- simulatic'i purposes for those two years. These regu-up table or schedule of annual rates. Rese rates were lations were expressed in terms of the age groups that derived from MNPS operational data and from DEP were fully or partially vulnerable to the sport and estimates of nominal fishing mortalities for winter commercial fisheries, by converting the lengths in flounder and length limit regulations in effect since Table 3 into approximated ages (Fig. 7) based on tbc 1982 for eastern Long Island Sound winter flounder age-length key developed for the Niantic River winter (P. Howell, Connecticut DEP, Waterford, CT, pers. flounder stock (NUSCO 1989). De vulnerability of comm.). carly age classes to the fisheries was first calculated The simulation period (1960-2060) was partitioned without taking into account discard mortality of into bhicks of years corresponding to periods of none, undersired fish (Table 4) and was then adjusted for one, two, or three unit operation, accordmg to start- discard mortality to obtain the final vulnerability up dates (Table 1) and assumed a 40, year period of estimates (Table 5). These estimates are only age-uninterrupted operation for each unit. Next, the nom- specific " vulnerability factors"t actual fishing rates inal year class reductions for three-unit operation at were calculated by scaling the nominal fishing rate for low (15%), medium (20%), and high (25%) entrain- a given year by the corresponding vulnerability ment rates were scaled proportio.nally to the fraction factors. Finally, the look up table (Appendix I) used TAllLE 2. Simulation schedule of year class reductims for three different rates of larval entrainment and auual power plant units in epradon during the period of 1960 through 2060.

Number of Percentages of year class reduction at three entrainment !cvels:

Period Operating units yean tow Meda a liigh 1960 1970 Nme 11 0 0 0 1971 1975 1 5 3.375 4 500 5.625 1976 1985 1&2 10 7.785 10.380 12.975 1986 2010 1,2 & 3 25 15.000 20.000 25.000 2011 2015 2&3 5 11.625 15.500 19 375 2016 2025 3 10 7.215 9.620 12.025 2026-2060 &ne 35 0 0 0 Total simuladon period 101 Winter Flounder 25

l TAllt I; 3 1.adem 1.ung Island Samd wmter flounaer length hmit regulanons' in eficci for the cornmercial and spon In'.cnes tin (e 1982 t.cngth uma in inshes t ength hmn in rnm IVnal Ccmmeraal Inher) Sport hiber) Comme reisl inher) Spon hshery 6

19K2 R k 203 203 19'O Oan-hls)) 8 8 203 201 lux 3 (Jun ikt) 11 K 279 20!

19x4 dan. Aug) 11 h 279 203 195-l (sep IM) 10 h 254 2ni 19 b5 1986 10 10 254 234 1987 Dan Aug) 10 10 254 254 1987 (Sep Dec) 11 10 279 254 1958 1990 11 in 279 254

• P. Ilaell, Cl Dl'P, Waterford, CT, jot. comm y

Pnor to 1982 there were no size regulathms, but n u at suumed th4t fish between b inches (152 nun) emi k inches (201 mm) w cre mbectcJ to shiut one half of the nominal fishmg monalay for cash > car. Inh larger than 6 inthet (ahmt 2 8 )can old) were fun 3

1. !cd to the fisher).

l .cngth in cm 15.2 20.3 25,4 27.9 1.cngth in inches b 8 10 11

? e e 2 3 4 Age in years 1,9 2.8 3.5 fig. 7. Cmersion of minimum lengths for the sturt and commercial fisheries to approsimme age according to NtJSCO age-length data for the Ni,sntic River winter flounder stock us input for the population model was obtained by about 28% when natural mortality of M=0.35 was wmbining the data from Tables 2 and 5 with the nuumed, nominal fishing rates since 1960 (see column labeled The simulation results later discussed include:

" Nominal F" in Appendix 1). The criticalinteraction graphical displays of the four time series (one base-between fishing and entrainment rates is shown by line and three impacted) population projections from the oming of MNPS operations relative to increasing the simulation; tabulated results in terms of projected nominal fishing rates since 1970 and by the winter flounder stock reductions at selected points in magmtude of conditional mortality at low, medium, time; and PRA for the stock reductions of interest.

and high entrainment rates (scaled as instantaneous All the stock projections were reported both as

ato > relative to nominal fishing rates (Fig. 8). The number of female spawners and as spawning biomass, notul size of the spawning stock used to start the Biomass was used because overfishing criteria often lupulauon projections was 57,900 female spawners rely on measurements of biomass and because fishing ui all four series of this simulation This stock 6.c and larval entrainment effects result in long-term was derived from the parameters of the SRR as the stock reductions which can be quite different depend.

replacement level of the exploited stock (Ricker ing on whether the stock is expressed as fish numbers 1954), or equilibrium si/c, to which the stock would or as biomass. The probabilitics of stock reductions eventually converge when exploited at a constant for PRA were empirically derived from Monte Carlo Oshing rate of F=0A (see Eq. I1). This fishing rate replicates of the time-series of impacted stocks, both corresponded to a moderate annual exploitation rate of as numbers and as biomass.

I 26 Monitoring Studies,1990

~l Allt.E 4 1: astern lamg Island Sound wmter ibunder age groups panully and fuM) sulnerable to Inhmg and derned hactional fahing rates correspodmg to commerdal (60% of total landtrys) and spirt (44 ) Inheries accordmg to lengtlvlumt regulat'3dl in eI(ed durmg the periods listed.

Age groups vulnerable and derived frastional futung rates' l.cngth imuu (mshes) Commersial Sport 'l otal inher)

Pernal Commercial Sport 1 2 3 4, 1 2 3 4+ 1 2 3 4+

Defore 1982 Sw None 0 03 036 0 60 0.00 0 02 0.24 0 40 0.40 0 05 0 60 1 00 1 00 1982  % h 0 0.12 0 60 0 60 0 0 Oh 0 40 0 40 0 0 20 1 00 1.00 1983 44 10 h 0 0 0 60 0 60 0 0 On 0 40 0.40 0 0 Oh 1.00 1 00 19li5 87 10 10 0 0 0 60 0.f 3 0 0 0 40 0 40 0 0 1 00 1.00 1988 40 11 10 0 0 0 30 0 60 0 0 0 J0 0.40 0 0 0 70 1 00

• %>te that Inhmg "raics" are not il salues, but the scalmg fators that when applied to tbc nonunal F valae m eash year would gne the adual mstantancous fahing rate that applies to each age gnmp The notatiim 4 refers to inh that are age 4 and older TARI.lii Vulnerahihty factors from 'lable 4, adpntot for dmard monahty of underwed Inh vulnerable to inhing geart correard f raa.on.d fahmg raies by age grmp' Commeraal Sport 'l ot al inher)

Penod 1 2 3 4+ 1 2 3 4. I 2 3 4+

Before 1982 0 01 0.36 0 60 0 60 0 06 0.24 0.40 0 40 0.09 0 60 1.00 1 00 1982 0 0 36 0 60 0.60 0 06 0.13 0.40 0.40 0 06 0 49 1.00 1.00 19M L 84 0 0.30 0 60 0.60 0.06 0 13 0.40 0.40 0 06 0 43 1.00 1.00 1985-87 0 0.30 0 60 0 60 0 06 0.u6 0.40 0.40 0 06 0 36 1.00 1.00 1988 90 0 0.30 0.45 0.60 0 06 0 06 0.40 0 40 0.06 0 36 0.85 1.00

• 'lha correctum assumes dinard mortably at h.aif the nonunal I rate for age-2 and older Inh caught by commerual year and at 15".- of the nominal F rate for all undersued inh caught by anglers (Cf DLP enimates; P, llowell, Waterford, CT, pers. comm ).

6 'the notauon 4+ refers to fish that are age-4 and ohler.

O.7'  : 3-unit  :

r) {. operation j a '

- Or

@ i 1 I 0.s "  :  :

l H  : i, cr. F ,

o 04  :  :

i  :  :

o of I 2Sx ENT I td 20xENT  :

h, 0.2 ~ 15x ENT  :

= , .

bZ 0.1 -  !,

i l  ;

0.0 ' i. - ,,

• i- + . < - ..t.. r- << 'i- i- - - -

1960 1970 1980 1990 2000 2010 2020 2030 2040 2050 2060 YEAR Hg. 8. Ihstoric and projected annual mortality rates due to tuth fishing (F) and larval entrainment (three rates) at MNI'S as implemented during the model sirnulation.

l Winter Flounder 27

ReStills atid Dihetahslon in many areas.11y mid. March,large amounts of the latter two macroalgae were observed entering the river Adult winter flounder on flood tides, much of which settled in the naviya.

tional channel. The macroalgal loading was alleviated Relatirc annualahimdance in many instances by reducing the standardimi tow distance by one half or one third.

Winter flounder spawning in the Niantic River has The numerous short tows made in 1990 resulted in been followed during late winter and early sprmg the highest total number (320) of tows for all the sinec 1976 (Table 6). Trawl catches from these surveys (Table 7). The median CpUE of winter surveys were used to calculate two relative indices of flounder larger than 15 cm was 9.6, the smallest alxmdance: trawl CPUE and annual standardized catch. index of the l$ > car series (Fig. 9), although this The standardiecd catches were also used with length value was apparently not significandy dilferent from and reproductive information to estimate annual the CPUE of 10.2 for 1986. The coctficient of female spawning stock size, which is discussed skewness of 3.N was relatively high, illustrating a below, 'These two indices are highly correlated patchy distribution of fish. Tryughout the survey, (NUSCO 1989,1990), which supports the reliability fish were more abundant in the upper river during the of methals used in data standardi/ations. carly weeks and more common in the tower river navigational channel after mid-March, The overall l

'l AHt.li ft Annual Mantic River winter flmmder

• population decrease in abundanen was not uneApected as relatively  !

surveys durmg the spawning season from 1976 thnmgh 19% por year-classes produced in the mid.1980s resulted l g in low recruitment to the present adult spawning Year Dales sampled wecks sampled stoek; most females are fully recruited to the Niantic River spawning stock as 5 year olds (NUSCO 1989, 1976 March 1 - April 1.1 7 1990), llowever, when sites of fish caught during 1977 March 7 Aptd 12 6 the past 5 years were compared, an increase was seen l 197s March 6, Aprit 25 s '

this year in bcth the number and percentage of smab

) It h I r ler (20-23 Cm) winter flounder (Fig.10), These smab 1981 March 2, April 14 7 ler fish % ere most likCly from the 1987 and 1988 year-1982 l'chruary 22 - April 6 7 classes. Monitoring of age-Ojuvenile winter flounder 1983 February 21, Apnt 6 7 showed that production of these fish was greater E

ry 27 A (luring th se 2 years (particularly in 1988) than for the i 10 1986 February 24 Apnl N 7 1983 86 year classes (NUSCO 1990), llowever, the 1987 . March 9 m Apra 9 3 relationship between juvenile abundance indices and 1988 March 1. April 5 6 Niantic River adult spawners remains unclear.

1989 l'ebruary 2l April 5 7*

1990 l'ebruary 20 Apnl 4 7 g 70 CPUE (115 cin)

• Mmimum sisc for marking wat 15 cm dunng 197682 and o 60

- 20 cm thercaner. -

• 1.imited sarnpimg during scand week due to ice formation. $0 The 1990 population abundance survey began on 54 /

February 29 Sampling during the first 2 weeks was . @ 30 affected by high winds, ice, and cold temperatures and 5 20 resulted in low catches of adult winter flounder.

Macroalgae abundance hampered sampling throughout l

y ,g the study and about a do/en tows had to be discarded - - -

because the trawl calends were too heavy to be taken 76 77 78 79 80 81 82 84 85 86 87 88 89 90 in over die stern of the research vessel. In some areas of the river abundant Ectocarpus and Desmarestia clogged the nel meshes, thereby increasing drag and N Annual nmhan a2 stamfard ernd for

. . . Niantic River winter flounder larger than 15 cm from weight by reducing water flow. Gracilaria, Lamm. -

1976 through 1990.

aria,and Ulva were commonly retained by the trawl 28 Momtoring Stadics,:1990

TAltt.17 Annual c l m oiict irawl adjustni rnedian cPul:a of winice fhamder larger it.n 15 cm* taken throughout the Niania kner donna the 1976 thnmgh 1990 aduti population abundance nunc>i lowi Adjuued Coeffatent So.vey Weeks au cpiable number ol Median 9M tonfideme ol year nampled fw CPUl? tow t usc# (WI , ' inte rs al akt w net /

1976 7 141 231 37.0 342396 3.01 1977 6 Ih4 22 tl 23 1 20.4264 1.95 1978 6 137 159 21.0 186270 t k 'i .

1979 5 122 145 33 6 25539.5 1.52 19hD 5 112 145 36 0 30043.2 1 rik 1981 7 lk? 231 Si_.6 456564 3 50 1982 5 115 150 42 6 426460 1,14 1983 7 232 23R 30.2 26211.8 0 85 1984 7 245 2M7 16 h 15 15-18 0 1,17 19h5 7 267 280 14 h 14 21$ 4 133 1986 7 310 336 to 2 9.7 11.1 1.47 1987 5 233 270 14.8 141-162 1.46 19hh 6 293 312 16 8 15 7 17.5 0 50 1989 6 277 318 12 2 11.1 13.3 1.08 1990 7 320 343 96 k 7410 3 3 04

• Catch per Han64rdned tow (see Materials and Methah).

6 Mastly age-2 and older fish.

Only towi of standard time or dMante were Wnudered d liffort equalued ammg weeks.

7.cro for symmetrically dauntaned d.ua e1 5*

U, ,A i

• f I D \ / 1 a

iu 4'

v' , t i

E E 90' i

(

o 3 z .'

b 85 f, i\ ! '\' '

g ji

$. 2 c r>

, \;l \

\ -

ld ,/\1 ,

sl u

o

~ ' vs-37 [N s~ (

l'

,ON./\,/ ,

89 g

~%

0*,

20 25 30 35 40 4b LENGTH (cm)

Fig.10. l.cngth-frequency distribution for winter flounder .er than 20 cm taken in the Niantic P.iver during adult population surveys in 1985.1987,1989, and 1990.

Winter Flounder 29

l Absolute abundance estbmurs 34 thousand (Table 9), Although this estimate Mark and recapture methods are frequently used to should be regarded as preliminary, it was the lowest estimate absolute fish abundance. The Jolly (1965) total of the 6 years and paralleled the decrease seen in stochastic model used with the Niantic River adult CPUE from 1988 to 1989. Additional recapture data winter flounder mark and recapture data has been from 1990 resuhed in some changes to parameter considered among the most useful in providing estimates reported in NUSCO (1990). The most abundance estimates for open populations as long as important change was in the abundance estimate for basic assumptions are approximately met (Cormack 1988, which inereased from 53 to 61 thousand as a 1968; Southwood 1978; llegon 1979; Pollock et al. resuh of a second year of recapture data.

1990). First given in NUSCO (1989), absolute llecause of the particular form of Jolly's sariance annual abundance estimates for Niantic River winter fonnula, the standard errors of N are correlated with 00under larger than 20 cm have been calculated by N, makmg the 959i confidente intervals generally pooling together all fish marked and released over a unreliabic as a measure of sampling error, except at particular survey and obserymg recaptures in very high sampling intensities (Manly 1971; Roll subsequent years. llecause of uncertainty in data 1973; Pollock et al.1990). Sampling intensity (p),

records and ambiguity in brands used during the early or the probability that a fish will be captured, was surveys, absolute abundance estimates are not estimated to range between 0 03 and 0.08 (Table 9),

possible prior to 1984, As a minimum of 3 years of Such low proportions may result in pmr estimates of data is required by the Jolly model to produce an abundance (llishop and Sheppard 1973). Sampling estimate, fish branded in 19u0 and joining the marked intensities of about 0.10 are recommended to obtain population of winter flounder will enable the reliable and precise estimates of population size and estimation of their population site beginning in survival rates with the Jolly model (llishop and 1991, Sheppard 1973; Nichols et al.1981), Lower s;un.

The scarcity of adult winter flounder in 1990 pling intensities may gise acceptable estimates if resulted in the smallest number (2,275) of winter population size is relatively large and the numtwr of flounder 20 cm and larger that were branded since marked animals is also relatively high Obghtower and 1983 (Table 8), A total of 162 previously marked Gilbert 1984). llowever, Gilbert (1973) and Car-winter flounder was recaptured, including at least one others (1973) reported that N was underestimated and fish from each of the seven previous surveys. These of low accuracy when sampling intensitics were low data were used with the Jolly (1965) model to (5 9%), Any loss of marks because of tag loss and primarily provide absolute abundance estimates (N); mortality, how ever, w ould require increased sampling estimates of survival ($), recruitment (B), and intensities. Other sampling errors, model assump.

sampling intensity (p) were also determined. The tions, and biases inherent in the Jolly model that 1989 abundance estimate of winter flounder larger could have affected these estimates were discussed in than 20 cm in the Niantic River was approximately NUSCO (1989) and Polkxl et al. (1990).

TAllt.I; 8. Mad and recapture data trom 19%3 through 199u used for estunating abundance or wmter riounder larger than 20 cm n the Nimuc Rher dunng the spanning scam Tual Total not Numtrr Reapture s Survey nusnbe+ preunusly nuded and Total (year m nked)

> car ehse rved maded rcleased reuptured 1943 1984 1985 1986 1987 1988 1989 1983 5,615 5.615 5,6 t 5 n 1984 4,10) 3,973 4,n s3 13n 13n 1985 1,49 t 3,3 5 n 1,407 141 47 94 1986 3,031 2, Alt 7 3,010 141 23 45 76 1987 2,578 2,463 2,573 115 2 13 27 73 19A8 4,33.3 4,106 4,3n9 227 7 22 31 61 I n-1 1989 2,821 2,589 2,752 232 2 11 9 33 32 145 1990 2,297 2,135 2,275 162 1 7 4 15 14 3x 83 30 Monitoring Studies,1990

TAHl.119 Fsomated abundance' of winter nounder larger thai. '") cm taken during the spawning season in the Niantic Rner in>m 1984 through 1989 as determined by the Jony (1965) rnark and recapture model.

Atmiance Standard Probabilit) Standed estimale error of 95% Cl of nurmal error 95% Cl Year (N) N for N (4) of $ for 4 1983 0.332 0 040 0.253 0 411 1984 58,433 8,533 41,709 75,156 0.550 0.066 0 421-0 678 1955 78,781 10,h79 57,459 100,104 0.363 0.043 0279 0.447 1986 49,296 6,394 36,763 61,R29 0690 0 077 0539.o.h40 1987 80,249 10,h4 3 58,998 101,501 0.530 0 064 0 40b0 656 1988 61,308 7,484 46,639-75,977 0 385 00% 0 272 0.499 1989 34.16! $287 23.406-44 MQ, _

Mean 60,373 3,471 53,570 67,176 0.475 0 0t5 0.445 0.505 Sampling Swderd Annual Standard intensity error of 95% Cl recruitinent e rrur 953 Cl Year (p) p for p (B) d# for B 1984 0.070 0.0102 0.050 0 090 46,606 9,04h 2K,932 64,190 1985 0.044 0.0061 0.032 0.056 20,707 5,271 10,375 31,019 19h6 0.061 0 0080 0 045 0.077 46,273 9,197 28,246 64,300 1987 0.032 0.0043 0.023 0 040 18,807 6,022 7,003 30,611 1988 0.070 0.c386 0.053 0 087 10,559 3,769 4,151 16.967 1912 0.032 0OQ 0 n57-0.107 Mean 0.060 LOO 36 0.053 0.067 28,602 1,768 25,137-32,067

• Figures vary frms those reponed in NUSCO (1990) because of de. added as a result of the 1990 winter flounder populaine surve).

The Jolly model also a 'ost always overestimates then total numbers of winter flounder larger than 20 the survival parameter (P (Bishop and Sheppard cm in the Niantic River may have been as large as 1973), Loss of brands or failure to record them also 200,000 fish during their peak abundance in 1981, results in bias and loss of precision for this estimate The generally good correspondence between the (Arnason and Mills 1981), llowever,the mean of the median trawl CPUli index and the Jolly abundance somewhat variable annual survival estimates was estimate led to further comparisons among abundance 0,475 (Table 9), which compared invorably to an indices. The annual standardized catches of all fish estimate of 0.453 made using independently collected brger than 20 cm for 1984-88 were compared to the age frequency data from 1981-83 with a catch curve total abundance estimates from the Jolly model. The (NUSCO 1987). The estimates of recruitment (B) 1989 value was not used because it was based on provided by the Jolly model are generally considered recaptures from only 1 year and was subject to greater to be unreliable (Arnason and Mills 1981; ilightower bias than the other estimates For the five Jolly esti-and Gilbert 1984) Nevertheless, the low estimates of mates used, the annual standardized catch indices made B for 1987 and 1988 reflected the low recruitment up 2,7 to 3,9% of each annual total population, and from the 1983 86 year classes, had a geometric mean of 3.23%, This differed from The total population abundance estimates for 1984- the similarly calcu!ated value reported in NUSCO 89 generally corresponded with the median CPUE (1990) by only 0.01, Therefore, relative numbers of indices (Table 7), Each index decreased by about a iemales and eggs produced each year were assumed to third from 1985 to 1986 and both increased again in represent, conservatively, about 3.24% of the abso-1987 to values similar to those found in 1985. The lute values and a multiplier of 30.8(>l (100 / 3.24) decline in absolute abundance from 1988 to 1989 was was used to scale abundance indices to absolute num-greater than the corresponding decrease in CPUE, but bers for assessments discussed below, This assumed this Jolly estimate will likely change as recaptures are that the ratios of annual standardized catch to absolute made in following years, if the relationship between abundance for 1977 through 1983 would have been absolute population estimates and CPUE is reliable, similar if estimates of the latter had been available, Winter Flounder 31

Spawning stock size and egg producthm The sir.c of the Niantic River winter flounder recent years, as few gravid fish were seen throughout female spawning stock is used in various assessments these surveys. The percentage of gravid females each of hlNPS impact,- The annual standardized catch of week in 1990 was somewhat greater than in 1989

- female spawners (an index of spawning stock site) but the rates of decrease were rdmilar. Spawning and their pmduction of eggs were determined from appeared to have been correlated with water available data on sex ratios, sciual maturity, and fish temperature and in relatively cold years (e.g.,1977 length frequencies. The sex ratio of winter Mounder and 1978) proportionately fewer females spawned larger than 20 cm during the 1990 spawning season during the earlier portion of the survey, whereas in

~ in the Niantic River was 1.24 females for each male warmer years (e.g.,1983 and 1987) more were spent (Tabic 10). Only in 1986 and 1987 were more males at the beginning of sampling (NUSCO 1987),

than females taken. The geometric mean over the The pmportion of females considered to be mature pmt 14 years was 13-1 and ratios of 1.50 to 233 in for each 0.5 cm length increment was used with each favor of females were regorted by Saila (1962a, annual standardned catch of females to obtain relative 1962b) and by 139 we and Coates (1975) for other annualindices of female spawners. Mature females populations in southern New England, comprised apprmimately one. third to one half of each yearly total, with relative numbers of female TAntt m. Fenute to mak wm ruhn of winar nounder i.iken spawners ranging from 655 in 1956 to 2,752 in 1982 during the slwning scawn in the Niantic River from 1977 through 19'K).

(Tabic 11). Due to an error in calculation, the values g

hured were in error and are corrected here. The annual Year AH fith capored Inh > 20 cm standardized catches of females differed somewhat from the median CPUE of all winter flounder larger 1977. 1.03 1.26 than 15 cm (Table 7), llowever, this was not ino

[f7 246

's i

2.n3 unexpected because of annually varying sex ratios aed differences in percent maturity due to changes in 1981 1,42 1.61 length-frequency distributions. Average fecundity was 1982 t 16 1.50 low during thc' late 1970s, when smaller fish were in] 1.52 i 52

' more abundant, but in recent years it has been greater .

'$3 i I,$ . t$ because the spawning stock had increased proportions in6 0.92 032 of older and larger fish. The relative index of total 1987 0.78 c.78 egg producdoa reflected female stock abundance and -

19ss-. 1.5 0 c -1.50 length distribution and was greatest from 1981 fj2 [] through 1983 because of peak population abundance and moderate average fecundity, fowmenioncan ' t.3 3 1.34 As noted above, absolute estimates of spawning female stock site and egg pnxtuction were made by multiplying corresponding relative numbers by 30.864. Female spawners, ranging in number from Weekly changes in the percentage of gravid females about.20 to 85 thousand, and total annual egg -

Liarger than 26 cm, the size at which about half of all production (range of about 12 to 49. billion) was

observed females were mature (NUSCO 1988a), were greatest in the early - 1980s -(Table 11), Egg noted tolietermine the rate of spawning. Generally, pnxluction was relatively high in 1988 (26.8 billion) most spawning was completed by late March or early - and 1989.(22,l' billion) as proportionately older and -

April airelatively few gravid females were found in larger females dominated the reproductive stock, the river afterwards (Fig.11), in most years, ice in However, egg production decreased to about 13.3 the river prevented the start of population surveys in . billion in 1990 because of a decrease in female January or early February, so approximately Iwo- abundance and in their average size. The total number thirds of the females examined during late February of female spawners was used as one of the bases for-and early March had spawned before sampling began. the SRR, which will be discussed later in this report.

Apparendy, most females spawned relatively early in 321 hionit'oring Studies,1990

40-1986 o

n 30-

@ 1987 s s

1990 / 's 5 '

1989 ' s d 20- 5,,'- N a

c;; .,s..........., Ns N \

W s  %

o 1988 ~

%', N N, ,

r- ,% .

'N,

• b o

10- ,~~

- s x +

..,'~,

o-FEBRUARY MARCH APRIL Fig.11. Weekly percentage of Niantic River female winter Counder larger than 26 cm that were gravid during ilu 1986 through 1990 adult population abundance surseys.

TAltl.l'.11. Relaii<c and absoluie annual standardised caich of female winter flounder spawners and egg prodocuon in the Nianne kner innn 1977 through 1990.

Relative index Relative index Surs ey of spawning  % mature Average of total Toial female Tot.tlegg year females' females' fecunihty' egg product'on d std site' prmluction (X10')*

1971 884 36 446,336 394 6 27,287 12.179 1978 ;412 51 508.096 717.5 43,587 22.147 1979 1120 37 478.108 $351 34.556 16.521 1980 9tO 31 469,976 424 3 27.863 13.095 1981 2669 44 518,275 1383.1 K2,366 42.688 1982 2752 49 580,227 1596.8 84,938 49.284 19x3 1869 46 578,845 1082.0 57,691 33.394 1986 871 *) 575,822 5016 26,883 15 480 1985' 92x 41 609,215 565 2 28,636 17.445 19s6 655 42 667,065 436.7 20,205 13.478 1957 852 39 621,085 531.6 26,292 16.409 19:48 1279 53 677,910 866.9 39.471 26.758 19M9 984 52 72 M,042 716.2 30,364 22.106 IWO 676 42 630,527 432.1 20.852 13.335

• llated en prop >rtion of the relative annual standardited catches of winter flounder that were mature females h

At a pnportion of all winter flounder 20 cm or luger.

• Toul egg pnwhmtion divided by the number of spawmng femalet d A relative index for year to year comparimns and not an absoluie estunate of pnxiucton.

• Cakulated on the assumption that the relative annual stanJardued c.nches were approsimately 3.24% of absolute values

' V41ues for 1985 conected In n those re;urted in NUSCO (1994 Winter Flounder 33

Larval winter flottnder opmental stages a't the five stations (Fig.12); the abundance and distribution of Stage 5 larvac were not

' Ahumlance anddistribution examined because so few were collected.

The abundance of Stage I larvac in the river for

'The a parumeter of the Gompert/ func tion (Eq. 2) 1990 was about average for the 8 year series with a Lwas used as an index of abundance for both temporal similar abundance found at all three stations. A r (year to year) and spatial (Niantic River and Bay) comparison of Stage I abundance among years abundances of winter flounder larvae,12trval abun- showed a similar relative ranking, with 1988 the dance in 1990 in the river was moderate in highest and 1983 the lowest. The low abundance in comparison to the previous 7 years and similar to 1983 was attributed, in part, to undersampling 1984 and 1987 (Table 12h Abundance in the bay because of net extrusion (NUSCO 1987), but this during 1990 was similar to the preceding 5 years and was rectified in 19M when a smaller mesh (202 pm) less year to year fluctuations were seen than for the net was used during the early portion of the larval river. No apparent relationship was found between season. Stage I larvac were rarely collec!cd in the annual abundance in the river and bay (Spearman's Niantie Bay at stations EN and NB, indicating that  !

- rankerder correladan coef0cient=0,07; p=0.87). This little, if any, spawning meurred in the bay, Except lack of sciationship suggests at least two hypotheses. for a slightly greater abundance at station A in some First,if many of the larvae in the bay originated from years, annual abundances at the three river stations the river, then varying annual larval mortality rates were similar, This indicated a somewhat homogen-

- occurred prior to the period w hen tarvac were Gushed cous distribution of Stage i larvae throughout the ifrom the river to the bay, Second, the Niantic River river, Because winter flounder eggs are demersal and may not be the only source of larvac entering the bay, adhesive and the duration of Stage I is short (about The cumulative density or sum of the weekly 10 days), this distribution suggested that spawning geometrie means may be used as an approximation of was not isolated to a specibe area of the river, the a parameter from the Gompertt. function to Stage 2 larvac were found predominantly in the compare abundances in instances where this function river, but were more prevalent in the bay in

- cannot be satisfactorily 6t to the data, This usually comparison _ to Stage 1, in 1990, relatively few Stage occurs when the developmental stage was rarely 2 hirvae were collected at all stations. In general, the collected at a station (e.g., Stage I at stations EN and relative annual ranking of Stage 2 abundance at the Nil or Stage 4 at station A). A previous comparis(m three river stations was shnihir to Stage 1. - This between cumulative _ weekly geometric means and the implied a similar rate of larval loss (mortality and

. corresponding a parameters showed them to be flushing)-from year to year during the period of

. highly correlated (Speannan's rank-order correlation transition from Stage I to 2.

_ coefficient of 0,999; p<0.001) and that the cumu- _ Larvac in Stages 3 and 4_of development were lative weekly geometric mean was a good approxi. generally most abundant at Station C and their mation of the a parameter (NUSCO 1989), The abundance at the two bay stations (EN-and NB) cumulative weekly geometric means were used to increased to levels similar to or greater than stations s compare the annual abundances of the first four devel- A and B. During these later stages of development,

' tam.I! 12. Lmat winter flounder almndmes and 95% confidence inieruts for the Niantic Rner and liay as.esumated in the a parameter

- fran_the Gwnperu function.

LYear- Mantic Raer - Ndniic lby

.1953 1,863 (1,798,1,929) 3,730 .(3,67n.3,79 t) 1984' 5,017 (4,884 5,152)- 2,200 - (2,n88 2,311) 1985 11,924 (l l,773, t 2,075) 1,801 - (1,7171 h8t.) =

1%6. .1,798 -(1,725 1,871) 1,035 (979 1,091) 19t47 = 5,381 (5,172-5,590 1,30) (1,240-1,363)

.19h8 - 24,nni (23,644-24,364) t,785 (1,708 1,861) 1989- I h.,5 87 (17,966 19,208) 1,750 (1,701 1,801)

,990 5,544 (5,378,5,710) 1,512 (1,474-1,589) 34 Monitoring Stuilies,1990

-_ . - . . - .~ , . . . ~ . . .- - . _ . . _ _ - _ ~ _ . .- . - -

25000 -

STAGE 1

~

w

@ 20000'-

5 ~

h15000.--

w ~

$10000.- _

w0o - _

_~ -- - ~

~

~

~ ~

g_ f~E' ._ -

83 ft 8586 87 88 89 90 i e3 84 85 86 87 88 89 90 I 83 84 85E 67 68 Ba 90T 83 84 tis 86 si 88 89 90F85 84 85 86 er 88 89 tel YEAR 7 STAGE 2  :

, 18000 -

~

9 16000-140001 10000-

[100002 380m - -

• • i

,4000 -

~

~

gg_

r~f_-.

' I~ I 0 ~ '-1~ -f- rm.-,-. f~}-1-~1 r b f~ ...

m YEAR 83 84 C5 86 87 88 89 90 I 83 84 85 86 87 88 09 9D0 83 b4 85 86 8188 09 901 83 84 85 86 8188 89 001 83 84 85 86 87 88N

~

STAGE 3 l w 3500- ~

Q L, a 3000-l Q -

g 2500- _ .

20m . _

~

2 ' ~~

1500 - -

~~ ~

100'1 2 - -

500-0 -

R A .

YEAR 83 848586878889901 83 848586878889901 83 848586818889901 83 84 8586 87 88 89 90I 83 84 8586 81 88 69 sol STAGE 4 m 900 - -

M 800-Q 700 --

$ W- -

$ : 600l .

3 ' 400 E -

300 - _

~

~~-

g; -

~

'7 4r a@

_ r, rh,.T ~1' . . l YEAR 83 84 8586 8 / 88 89 901 83 84 85 86 8/ 88 80 001 83 84 85 86 8/ 88 89 001 83 84 8b 8t2 87 88 89 901 83 84 85 86 8188 89 901 STATION A B. C EN NO

. Fig.12. Cumulative density by developmental stage for larval winter Counder at each station from 1983 through 1990.

Winter Flounder 35

_ _ _ - - _ . _ - _ _ _ _ . _ . _ _ _ _ ~ _ . _ . _ _ . - _ _ _ _ . _ _ .

winter nounder larvac were no longer homogeneously Ahhough the precision in estimating the abundance distributed throughout the river. The decline in of Stage i larvae in the Niantic River appeared to be abundance at the upper river stations (A and B) may good, the results from a simulation with a Niantic

' have represented a gradual Hushing to the lower River larval dispersal model (Dimou and Adams portion of river and into the bay. For Stage 3, a 1989) indicated that the estimated abundance of Stage similar pattern in the annual abundance was evident at I larme in the river w as not sutficient (by a factor of the two bay stations (EN and NB). The consistency 50 to 100 times) to support the number of larvae of the relative ranking of years for Stages 1 and 2 at entrained by MNPS. This discrepancy could be the three river stations and for Stage 3 at the two bay explained by the hypothesis that Stage I larwe were stations suggested good precision in the estimation of more abundant near the bottom and the bongo nets larval abundance. Also, the similar abundance of undersampled them. To examine this, nine paired

- Stage 3 larvae at EN and NB cach year suggestcd that tows of near-bottom versus the standard oblique low the different sampling techniques at the two stations were made during March of 1990 in the Niantic were comparaNe. River. For the lowermost tow the bongo sampler <

- The previously reported (NUSCO 1990) positive remained near the bottom for the entire 6 min tow, I l

relationship between total egg production (Table 1I) except during deployment and retrieval. Larval den-and the number of newly hatched Stage I larvae was siues were greater in the near. bottom tows for seven still evident in 1990 (Fig.13). The measure of Stage of tne nine comparisons and the geometrie mean was larval abundamce was the a parameter from the 311 per 500 m3for near luttom tows compared to Gompert/ function for the Niantic River (stations A, 171 per 500 m3 for the oblique tows. - A tentative B, and C combined), except for 1990, w hen Stage I conclusion was that Stage I larvae were more abundance was based on the cumulative weekly abundant near the bottom than in the remaining water 1 lgeometrie mean. A linear regression indicated a column. but sdll not in sufficient numbers to explain strong relationship between egg production and Stage the discrepancy between the results of the larval I abundance, with a significant (p=0.0016) positive dispersal model and actual collection densities. The slope utst_a good fit (r2=0.88). The abundance of possibility remains that Stage I larvae were even newly hatched larvac was directly related to the a hilt more abundant very close to the bottom at the reproductive capaCty under the assumption that egg sediment water interface, which the bongo sampler hatchability was similar among years. The consis- cannot sample effectively, tency of this relationship implied good precision in The dates of peak abundance, estimated from the the sampling of Stage I larvae and, additionally, that inflection point (Erl. 4) of the Gompertz function, egg production estimates were a reliable measure of were compared to examine the temporal occurrence in annuai reproductive capacity, the river (station A, B, and C combined) and bay (stations EN and NB combined) for each develop-mental stage (Tabic 13). Because Stage I larvae were 2" " *

,2 0.88 rarely collected in the bay, the dates of peak ~

p p = 0 0016 abundance could not be estimated for this area. The z 0000- dates of peak abundance for Stages I and 2 for the

-h; af 88 river in 1990 were estimated direcdy from the data

- a - uxg because the Gompertz function could not be i1 85 satisfact tily fit. Approximately 50% of the seasonal y y abundance for both developmental stages occurred 5- x87 during the week of February 21 (Fig.11). With a few 0-- fese me%m,A d # sunhee h M heb i i i i

_opmental stages by location have been consistent m a 20 25 - 30 gyg,; the 8-year period. Stage I larvac in the river 8

EGG PRODUCTION (X 10 ) generally peaked in late February to early March.

Fig. l3. The relationship between annual Stage 1 Based on water temperatures of 2 to 3'C during abundance in the Niantic River, estimated from the a February, and egg incubation times reported by parameter of the Gomperu function, and egg production Buckley (1982), peak spawning probably occurred in from 19&l through 1990. early to mid. February, w hich corresponded to obser.

36 Monitoring Studies,1990-

. ____ ___ = _ _

TAllt.l! 13, thumated dates or peak abundance or lanal winter flmnder for each devetgment nage in the Nantic Rarr and 114 Year Stage 1 Stage 2 Stage 3 Stage 4 Swtuiht 1983 Manh 5 March 15 Apnt18 May 2 19M Marsh 7 Manh 9 Apnl24 May 19 1985 March 11 March 16 Apol25 May l ti 1986 f ebruir) 26 March 11 April 2n Mi> 12 1987 Marsh to March 17 Apol20 May9 1988 lebruary 29 Marth 9 Apid 7 Ma> l 1989 Marsh 8 Marthl2 April 14 May 11 199u Ichruary 21 i ebruai) 21 Apnt21 Mo9 henc un 1983 Aptd 7 April 21 Me 10 1981 April 8 May 4 M.n 25 1985 Apnl1 Apnl29 May IM 1086 April 5 April 28 Me 11 1987 Apnl6 Apul28 Mayth 1988 March 2 4 Apnl 22 May9 1989 Apni 13 April 23 Mg 17 109n Apol3 Apnl 23 May 7

1. 2500 valions of spawning adult females. Except for 1990, STAGE 1 Stage 2 larvac in the river peaked during mid N1 arch 2000- and in the bay during early April. For Stages 3 and g

z 4, the timing of peak abundance was similar in the

[ 'S O' river and bay with peaks occurring during late April y 3939; for Stage 3 and during mid hlay for Stage 4. Dates of 8 peak abundance for older larvac were similar in both

> soo. the river and bay and because those for Stage 2 hirvae n 0 r#\

rrrrT rr7*r*T*T+r+r +r r*i a differed considerably, this suggested that most larvae were probably flushed from the river during Stage 2 FEB FEB MAR APR MAY MAY of development.

7 28 21 u 2 23 The early peaks of Stage I and 2 larvae in the river y during 1990 could have been related to water E GTAGE 2 temperatures at the time of spawning, The mean February water temperature in the bay (determined d 150- from a continuous recorder in the intakes of Units 1 7 and 2) in 1990 was 4.3*C (95% CI of 4.14.5'C), the g 100- highest of the preceding 14 years (197649h which 5 had a mean of 2.5'C (95% Cl of 2.4-2.7'C).

Q so. . Although spawning apparently does not occur in the e b /\ bay, these water temperatures should have been Ni:iiii+r*i indicative of those in the river. Buckley et al. (1990) h 0-i i i i rrT FEB FEB MAR APR t

MAY MAY found that the length of time for egg incubation prior 7 28 21 11 2 23 to hatching was inversely related to water temperature DATE during oocyte maturation and egg incubation. The higher February water temperatures in 1990 may have Fig.14. Weekly geometric mean density (noJ500 m3 ) increased the rate of egg development in the gonads in the Niantic River Ohree stations combined) for Stage and embryonic descloprnent after spawning. Either or I and 2 winter flounder lan ae in 1990. both of these re3ponses would have caused earlier Winter Flounder 37

l l

l peaks in abundance of the first two larval develop- and developmental rates (Chambers and Leggett 1987; l mental stages. Ilowever, these early peaks in 1990 Chambers et al.1988), Since deiermination of '

did not persist for the later developmental stages, developmental stages began in 1983, the lengtle Medusae of the lion's mane jellyfish (Cyanca sp.) frequency distribution for each stage has remained have been prevalent in collections at station A and fairly consistent (NUSCO 1987.1988a.1989,1990).

there are numerous accounts of jclhfish preying ulon Stage specific length frequency distributions in 1990 and affecting the abundance of fish larvac. Several showed a separation in modal lengths for the first species of hydromedukac and the sc)phomedusan three developmental stages by 0.5 mm si/e classes Aurelia aurita prey upon herring (Clupca harrngus) (Fig.15). Stage 1 larvac were primarily in the 2.5 to larvae (Arai and Hay l982; Moller 1984), and 3.5 mm size classes (97G), Stage 2 were 3,0 to laboratory studies with Atlantic cm!(Gadus morhua), 4.0 mm (88%), Stage 3 were 4.5 to 8.0 mm (86%).

plaice (Plcuronectcs platessa), and herring have shown Predominant size classes for Stage 4 were 6.5 to that the capture success by A. aurita increased with 8.5 mm (85%), showing some overlap with Stage 3.

medu;al size (Bailey and Batty 1984). Evidence of a These consistent results from year to year indicated causal predator. prey relationship on larvae of plaice that developmental stage and length of larval winter and European flounder (Platichthysf7csus) by A flounder were closely related. At least for the first aurita and the etenophore fleurobrachia pilcus was three developmental stages, this relationship allowed reported by van der Veer (1985),~ Pearcy (1962) stated for the estimation of developmental stage from length-that Sarsia tubulosa medusac were important predators . frequency data.

of larval winter flounder in the Mystic River, CT, and Length frequency distributmns (all stages had. greatest impact on younger, less mobile combined)in the Niantic River (stations A, B, and C

. individuals. Crawford and Carey (1985) reported large combined) and Niantic Bay (stations EN and Nil numbers of the moon jelly ( A. aurata) in Point Judith combined) in 1990 were quite different (Fig.16). The Pond, RI and felt that they were a significant predator differences in size-class distribution between the two oflarval winter flounder, Marshall and Hicks (1%2) areas were similar to previous findings (NUSCO also reported that jellyfish were most abundant in the 1987,1988a,1989,1990) and consistent with the upper river, in addition, lateratory studies have spatial distribution of developmental stages (Fig.12),

shown that winter flounder larscc contacting the Sm211er si/c classes predominated in the river during temacles of the lion's manejellyfish were stunned and 1990, with about 80% of the larvae in the 3.5 mm ultimately died, even if not consumed by the medusa and smaller si/c-classes, in contrast, over 65% of the (NUSCO 1988a). At station A in 5 of the 8 years larvae in the bay during 1990 were in the 5,0-mm and sampled, weekly mean larval abundance was . larger site-classes. These differences in length-significantly negatively correlated (ps0.05; Spearman frequency distribution provided additional evidence  !

L rank correlation) to_ weekly mean jellyfish volume that a majority of the larvac hatched in the Niantic.

L 1 during die period when medusac were collected. But River and some of those that survived early

(. ' for the same years no relationship was found between

. development were flushed into the bay, The slight p annuallarval abundance at station A and annutd mean . increase in frequency for the larger size-classes in the l jellyfish volume : The decline in larval abundance river has been apparent in some previous years may not be wlated to an increase in jcilyfish abun. -(NUSCO 1987,1988a,1989)and was atuibuted to an dance. -The decrease in larval abundance may have import of older larvac into the river, .

o resulted from a gradual flushing out of the upper . Length frequency data from entrainment collections proportion,of the river or as a result of natural (station EN) were used to estimate larval winter R - mortality (excluding predation . by Jellyfish). flounder growth rates for Niantic Bay; these data were l Although there are numerous reports of predation by - examined beenuse of the 15 year time-series available.

.jcllyfish on larval fish, the potential impact of Weekly mean lengths during a season form a sigmoid-jellyfish predatior; on larval winter flounder in the shaped curve (NUSCO 1988a); The linear portion of Niantic Riv~cr is not yet clear, the sigmoid curve usually occurs during the middle of the larval scason and growth rates were estimated by

Development andgrowth fitting a linear model to individual larval length ,

measurements during that period. This model Laboratory studies on larval winter flounder showed -adequately described growth and all slopes (growth that there werc lusitive ' correlations between growth rate as mm per day) were highly significantly 38 Monitoring Studies,1990

.~ , -

l 60 STAGE 1 (Ed' I) I#'#"I I** ##* " ^""""

_ growth rates for station I!N were variable and ranged

, from 0.055 to 0.100 mm per day. In mklition, most QA0- of the intercepts of the linear regression were about 3, b 30 - the approximate si/c at larval hatching. To validate d this estimation technique, grow th rates were est imated

^

$ 20 - from length data collected at station NB from 1979 through 1989 (NUSCO 1990); annual growth rates 0-were highly correlated (pc0.89; lx0.001) with those 0 A rTl -T- er- rr t i 1 r T r- t,m from station liN.

20 30 40 50 60 70 00 90 in taloratory studies, water temperature aficcled the growth rate of winter nounder larvae tLaurence 1975; 50 - Ub # To exanune k ch of Rmp-S'i AGE 2 .

erature on the estimated annual growth rates, mean 40- water tenyieratures for Niantie Ilay determined from

$ continuous recorders in the Units 1 and 2 intales, f 30 - were calculated for a 40 day period starting at the U

beginning of the week when the fit.t < larval length 20 -

$ 1 measurements were used to estiinate the annual to- growth rate (Table 14). A positive relationship (slope =0.0197; p=0.(X)2) was found between growth 0-97 "TTT iUi i ri i7 T rim rate and water tem]erature (Fig.17). As concluded 20 30 4.0 50 60 70 80 90 16 - 4 -

STAGE 3 RIVER w 12- " "

w 30 -

0 - .

G ~

$ g ,. "

~

b 20 u

a u-a E $

] 10 -

4 0- ,- 0- n rT T' T O r"r" r"TUUU T T r UW- 'i

, , , 3. 7 - 7 7 7 7 . 7 , - t 79 2.0 30 4.0 50 60 7.0 80 90 20 30 40 50 60 7.0 80 90

~

STAGE 4 bay 25- 12-w

[ w 0 20 - 0 -

< 4 n 9-w I5- w

~

g 6- -

g 10 - -

g

- 3' 5- -

0 - '- T i i i r- T-- r"T T T - r T "r r T 1 0 3 ~r T " T T T' 7'"r '"1 ~ T T '"r 7 M 2.0 30 40 5.0 60 70 60 90 20 30 40 5.0 60 7.0 80 90 LENGTH (mm) LENGTH (mm)

Fig.15. Length frequency distribution of larval winter flounder by developmental stage for all stations com. Fig. Iri. Length frequency distobution of larval winter bined in the Niantic River ed Bay during 1940. flounder in the Niantic River and Bay during 1990.

Winter Flounder 39

'l Allt.li 14 i;stimated l4rs al wiriter flounder grow th rates iri Rantie Ilay f rom data toilevinl at stauon IN based on bncar regrn non, with 95% tietfalence intervals and mean m4ter temperatun+s during the first 40 day of the ume perwd Ttrne penal GroMh ute 95% umhdenic Mcan water Ycu incimled ' mnelay intm al temper aiuv e' 1976 Marsh 21 May 2 0.100 0 09 h -010 2 70 1977 Apni 3&ne 5 0 O?h 0 071 0 010 67 Marsh 2fv June 11 0 035 0 052 0 0%h 4h 1978 l979 March 25 Juncl0 0 05h 0 05tnD cou 59 19ko Mar,h 21 June f6 0 060 0 058 0.062 5u 19hi Apnl 5 May 31 0 064 0 061 0 067 73 1962 Marsh 2h-M4) 30 0 061 0 0604 0t a 5h 195) March twMay 22 0 n56 0 054 0 05h 52 19 ti4 March 25 May 13 0 069 0 066-0 072 64 19h5 Mar <h 17 lune 2 0 059 0 05 L O 06) b0 19M6 Marsh 30 May 11 0 044 0 Uhlo 101 16 19h7 March 22-May 17 0 019 0075-000 7.0 198n March 2LMay B 0 01: 0 Os 10 09 $ 7.1 19h9 Marsh 26-M4) 7 0 069 0 060 0 On 7o 1990 March 4 May 1.) 0 071 0 066-0 076 59

• Tune proat of the werkly mean lengths used to clitrnaic g owth rate.

• Mean donng a 40 day penod starting at the beBmmng ur the med that the fitu wreMy encan length w at ut:,d in crianng growth rate O ll, 8 M.W 25 - Qs 77

r , . 0 5,6 76 z $ x g 010] p = 0 002 x 86 $ \

ion B8 p

4 UAY n' ~

\n g us y 003- 77 y 37f {ua MAY5 - N x

a I u.07.,

90 x

V h 82 NA84 X x 86

• N

• t 62/ g'8 f APR 25 -

50 9 89 x Na 87 hOh 0

78 [,,.s'79 80 (x85 B1

'd g

. rV - 0 73 A 63 d0 g 05 - . [ 83 g 7- - - , m APR15-p , o col esx 3'6 r m 4 5 6 7 8 3 4 5 6 7 MARCH APRIL WUER TEMPERATURE MEAN WATER TEMPERATURE (*C)

Fig. 17. The relationship between meun water Fig . 18. The relationship between March-April mean temperature (*C) and the estimated growth rates of winter w ater temperature ('C) and the anmial date of peak nounder larvae at station EN from 1976 through 1990. abundance (estimated from the u param ter of the Gomperit function) of winter rounder larm at station previously from comparisons of annud length

• EN from 1976 through IWO.

frequency distribution and developmental stage, growth and larval development were found to be found that winter flounder lame metamorphosed 31 closely related. Therefore,if water temperature affects days earlier at WC than a' 5L Amiual dates of peak growth rates, it should also affect larval develop' abundance varied by 37 days deng the 15 3 car mentil time. T he timing of peak larval abundance period, mou likely beca;se of a 3'C diffuence in the should be related to the rates of recruitment and loss hlarch. April water temperature between the caliest (including mortality and juvenile metamorphosis), (April 16,1976) and latest (May 23,1971) dates of Annual dates of peak abundance of larval winter peak abundance (Fig.18). Dopite the , vide range in flounder collected at EN were highly correlated to the annual growth rates, a consicern rdationship was mean water temperature in March and April (Fig.18)- found between length frequency ilistribution and stage This agreed with the resuh3 of Laurence (1975), who of development (Fig.15). This was consistent with 40 Monitoring Studies,1990

(-

laloratory observations for larval winter flounder as 0 12 -

Chambers et al. (1988) found that at metamorphosis, *

. age was more variable than length and larval age and f 0ti. 86 length were independent. E a90 Growth rates were also estimated for Niantic River W 4 sh larvac using length data from station C with the if g 4 )7 N

• methods given above for the bay (Table .15), An g0*

annual metm water temperature was determined for 2

r. 066 P = 0 014

• N l data continuously recorded at a dock near the mouth of h 89 1 81i the river during a 6 week period starting the same 0.08 , , r .

l week that the first length measurements were used in o toon 200n 30to 40tn 5000 the growth rate calculationi Station C was selected STAGE 2 ABUNDANCE for this analysis because all developmental stages were collected there in abundance (Fig.12). Again, a Fig.19. The relationship between annual Stage 2 abun-linear model fit well and slopes (growth rates as mm dance, estimated from the a parameter of the Gomperti per day) were highly significantly- (ps0.0001) function. and the estimated smwth rate of winter flounder different from zero. The estimated growth rates for larvac collected at station C from 1983 thmugh 1990.

~ larvac from the river were generally greater than for .

larvae from the bay and in'1990 were the second apparent relationship between Stage 2 abundance and  ;

highest since 1983. The growth rates for larvac in annual growth rate indicated density dependent growth the river were similar to taloratory growth rates of for larval winter flounder in the Niantic River.

0.104 and 0,101 mm per day at mean water Laurence (1977), in a laboratory growth study of temperatures of 6.9 and 7.5'C, respectively (NUSCO larval winter flounder held at 8'C, reported a decrease 1988a). .No positive relationship was apparent in growth rate as prey densities decreased, The

. between growth rates and water temperature, as was laboratory study, along with the apparent density-found for larvac in the bay. The possibility of dependent growth in the Niantic River, suggested that density dependent growth was examined because the as the number of feeding larvae increased, the lowest growth rates occurred in 1985,1988, and numbers of available prey declined to levels less than 1989, which welc coincident with the highest larval optimum for growth, ,

abundance in the river and the highest growth rate was Slight declines in growth rate caused by less than in 1986 when tarvac were least abundant (Table 12), - optimum food, unfavorable temperatures, disease, or

~ The at parametcr from the Gompertz function for pollution can lead to longer developmental times, Stage 2 larvac in the river was plotted against during which.high. rates of mortality can have a estimated annual growth rates (Fig,19). The abun. profound effect on recruitment (lloude 1987); Buck.

dance of Stage 2 larvac was used because during this . ley (1982) stated that food availability and water

. developmental stage larvac begin to feed. An temperature appeared to be the two most iniportant TABLE 15, intimated larval winter flounder growth rates in Niantic River from data collected at station C based on linear regrtuion, with the 95% confidence intervals and mean water temperatures dunng the first 40 days of the time period.

Time period _Grumth rate 95% mnfidence Mean w ater Year included

• 6 mm/ day interval temperature 1983. March 204tay 1 0.100 0.096 0.104 7.6 1984 March 254tay 6 0.100 0.094 0.105 6.8 1985 Mitch 31.May 26 0.084- 0.080 0.088 9.6 1986 March 2341ay4 0.109 0.103 0.I15 7.7 1987 March 224 fay 10 . 0.099 0 095 0.103 7.3 '

1988 Mar,h 2041ay 21 0.099 - 0 094 0.104 1989 0.087 0.082 0.092 9.9 .[

March 26 M4 21 9.1 -

-1990- March 25.May 13 0.106 0.099 0.I13 7.9

' Time period or the weekly mean lengths used to estimate growth rate.

• Mean dunng a r> week perkxlit.ining the week or the rirst weekly rnean length used in estimanng growth nie.

Winter Flounder 41 l

l 1

factors controlling taival growth. Although laurence abundance of 7 nun and larger larsae collected (1975) demonstrated that the metaNilic demaads of annually at station EN was used as an estimate of larval winter Oounder increased at higher temp- larval recruitment. The 7-nun and larger site classes cratures, the growth rate also increased if sufficient were selected as a measure of lanal recruitment food resources were available, and other laboratory because they would soon metamorphose into studies (Laurence 1977; Ituckley 1980) have shown juveniles and collections at station EN were used that larval winter flounder growth rates depend upon because 15 years of data wcre available. A larval prey availability, in Niantic llay, growth and recruitment mdex was calculated by taking the development correlated with water tem;vrature, but in logaritlun of the ratio of the a parameter for 7-mm the Niantic River growth appeared to be density- and larger larvae to the egg production estimates.

dependent, perhaps because of prey availability. This was plotted against egg production esumates and the slo;w of the linear relationship was tested (Fig.

Mortality 20h Although there was some scatter around the relahonship, the negative slope was signilicantly Based on length frequency distributions in the river (pw0.009) different than vero, indicating that for 1990 (Fig.16) and previous years, it appeared that compensatory mortality was occurring dunng the most winter flounder larval mortably occurred winter llounder larval period.

between the 3.0, to 4.0-mm si/c classes. About a 94% decline in frequency occurred in 1990 Ivtween 5*

these two size-classes, which included yolk sac (Stage s l) and first feeding Stage 2 larvae, This initial large 9 r#- 0 45 decline was followed by smaller decreases for p eu p. o o09 8d progressively larger size classes, indicating a h 83 reduction in the monality rate after larvae reached the 4.5.mm siie-class. Pearcy (1962) reported a greater

))"7[ '79

~

U

• 8 x

mortality for young winter flounder larvae (20.7% per h 3-5 x,

g 89 day) compared to okler individuals (9.1% per day). In B7 5 j 3a r.%ef a laboratory sttdy on winter nounder larvac, g et Chambers et al. (1986.pned that larval mortality 3 2-- 1 - ,- i -r i was concentrated dunng the first 2 weeks after 10 20 30 40 50 hatching. Laurence (1977) found that winter 00under EGG PRODUCTION (X 10 )

S larvac had a low energy conversion efficiency at first feeding compared to later development,and that this Fig. 20. The rebuionship between the annual winter stage of development was probably a " critical period" flounder egg produchon in the Niantic l(iser and the for mortaiity, lijorleifsson (1989) showed that the larsal recruhment index 00garithm of the rado of the ratio between RNA and DNA, an index of conthlion annual abundance of 7 mm and larger larvae to the egg and growth rate, was lowest at the time of first produnon) at station 1:N fmm 1976 thmugh 1990 feeding of winter Counder (about 4 mm in length) and that these ratios were affected by food availability.

The " critical period" concept was first hypothesized Because the egg production estimate was used in by Hjort (1926) and was discussed by May (1974) for calculating the larval recruitment index, a possibility marine fishes. In many cases, the strength of a existed of introducing correlation between the year class is thought to be determined by the independent (egg prmluction) and dependent (recruit-availability of sufficient food after completion of yolk ment index) variables. A better approach to identify absorption. the presence of density dependent mortality wns to The possibdity of density dependent mortality for compare annual larval mort.dity rates with estimates winter flounder larvae was examined using a function of spawning stock si/c (i.e., egg production). Total (Eq. 5) provided by Ricker (1975) and estimates of larval mortality for 1984 90 ranged from 82.4 to annual spawning stock size were compared to larval 97.9% , with a mean instantaneous rate (Z) of 2.86 recruitment. Each annual egg production estimate (Table 16). To determine if density dependent wa.s used as a measure of spawning suick size and the nmnahty in the larval stage could be identified, these ct parameter from the Gompertz function fit to the annual instantaneous mortahty rates were compared to 42 Monitoring Studies,1990

T Allt.li 164 I:sumated luval winter nounder hital monaluy hsicJ im ddferences m ebundance from from hauhing to the 7.mm site dau.

Mu ly 7mm 'lutal mitaniencous Yew hatched suedau Monald) (%) monatuy rate 1984 6.500 t54 89.9 2 3u 198$ 13,773 452 96.7 3 42 1986 2,4 h 3 4.48 62 4 1.73 1987 6.480 474 92.7 2.62 19 4 24.561 67 ti 97.2 3 59 19W 19,192 394 97.9 3 hk 199C 7.015 65) 91.7  ;,,13

- . . _ _ . _ . . _ mun r 2 M 4 ,, 89 3 to 4 mm

x. / ,

_ $$ / 3 00 M ' $8 gg 1 g -

w M 3- /y,/ u 3

e6 05 N 00 [$ t e. -

x / 3 b /x w D4 h2- f / 64 h'~ 8,0 og a

o's $~u-et 1_. , , __,__ r - - i

'"*"~f-"~~~f" F~" '

m a M 25 10 10 15 2n 25 u 0

EGG PRODUCTION (X 10 )

3 to 6 mm 4 (L Fig. 21. The relationship between the anmi.il winter rl0 85 gg Dounder egg production and instantaneous larval mor.

Lality rate in the Niantic Riser from 1984 through 1900.

S b'

E >

3' egg production estimates (Fig. 21). A strong relation. E 87 ship was apparent, for when egg production increased, $ ,

a larval mortahty also increased. This relationship may have resulted from either density dependent hatching

~

g, 2m ,. ,

rates (i.e., egg viability), or from density dependent , , , ,

i u a 25 to larval mortality rates. Because it was shown earlier (Fig.13) that annual egg hatching rates were very consistent, the negative relationship between egg S to 6 mm production and subsequent larval survival provided 40- ,

further support to the hypothesis of compensatory g g 80 g

Ci 3 5 - x mortality during larval development. -  ;,o /

To determine when the larial density dependent & x y/

mortality was occurring, instantaneous mortality rates @ 3o- /

were calculated for newly hatched larvae (3 mm and g ,s . o g smaller size classes) to each successive i<mm si/.e- g n- / , / 87 e

g," p= 0 052 class. These rates were then plotted against total egg ac production estimates (Fig. 22). No apparent relation- 2o , r- , ,

ship existed between egg production and mortality to 15 20 25 30 rates for the 3 mm and smaller si/.e-class a the 4 mm EGG PRODUC rlON (X 10')

and to the 5 mm si/c classes. By the 6-mm si/c class Fip 22. A compatise i of the instantaneous mortality a stronger relationship was found and the slope was i L" IN'" fE8 production to the 3 4.mm site. class, the 3 5 mm site. class, and the 3 6-mm site. class for Niantic nearly significant (p=0.052), suggesting that density.

nr winter nwnder larvae during 1984 through 1990.

dependent monality or compensation occurred during Winter Flounder 43 l

I iI k. h 1 ( ( (

si,e.s asses, a d,w u m p w id, die o m e of n ,s u ecain g peated on stay 0,w h u , was aboui die midpoio, a and supporting the " critical period" concept the range of dates determined for l083<89 (Table l3).

previously discussed. Thus, de difference in peak abundance letween these two indices was about 2 months in 1990. The reason Juvenile winter flounder for this delay in the peak of post larval young in 1990 was not b now n.

Age-Djurenl/rs during Smn/in'r The initial densities of newly metamorphosed young of theqear winter flounder in 1090 were qmte A b u n tla nce. The peak abundance of demers.d high for the Niantic itiver stations. These densities post larval agc-0 winter nounder in the Niantic Risers occuaed despite die low abundarwe of adult spaw nas usually occurs in mid June, wben larval recruitment found in the river the presious winter. At WA peak to shallow water habitats n greatest and just before densities were about 165 per m2and at 1.R were about abundance begins to be reduced by mortality, in 290 per 100 m2 (Fig. 23); these were the highest 1990, however, leak abundance occurred in late June densines noted dunng de 8 yean M mp% for ut station WA and in early July at LR (Fig. 23). each of the past 3 years, numbers at the Niantic Ilay Differences between the observed dates of peak unons (up and Rhl) were greatest (S$ 90 per 100 abundance for Stage 4 lanae in die Niantic Ris er and ,

" I."' """E * * '# "I 0# "'d'""

demersal age-O juseniles at station LH luring 1983-in law ay amicadyj unt N ym niaded de laq 87 ranged between 25 and 38 day s, but mercased to 44 unwlotw ieli n a abundana of young was greata and 48 days for 198S and 19S9, respeedvely (NUSCO n da' wn r a dian in du' bay, w @ a mannuun 3 1990) 'lbese differences probably reflected both vari-week mosing aserage density of 250 per 100 m' at able developmental line and the amount of um en m LR (Hg. 24L Following the abundance peaks ic 'norphosed young required to mose to shoreline V w-M 'M u sw w ., j C,1) /

I hC <m'~ - . .

h, ns lO ,s

} ed , } 103 Sm ald 8

7b i

'[\ N x W 1 -

'm}_ ,

dM 3

D

@s 4

3'P4y da

'e , .

}1 kAf vai <JNE sda AUGUST ;>EP i MM JJNE JJu AJG EI SEPD;M 3

'P [w . i ng 'id' Op -in3 100 iOO b

f 7S

.\ , a k $

g 15

\ ,

J . /!  ! \ )

r to I , n -

1 i 0 N j"

s, Ri t j,. "

\ wi

%% .. 0

.m 44 JUNE JULY AUGUGT SEPrEMM MAY JUNE JULY AUGUST SEPTEMBi R l'ig. 21 Weckh mean CI'tT ti2 st.uutard crmre of : p 1 u w " iader taken m ihe Nianne River and liay during 1990.

44 N1onitoring Studies,1990

l sw g ad ib O .n

n 13

!c w ' E , 7, M

bb

n. o

" '3 n c j h! ? . .. /

Lh ' [

,4 . .

a3 4

t.

8-w /v%% \

fM h ,?,$ ,3. s a s

~~=

p, , ,

Mnf odNd r

<! k i AdW I4[ . 612l vip Lii Fig. 24. Moving everage of weekly mean CPUE of age.0 wimer flounder taken in the Niantic River and Day during 1990.

in cach area, a fairly steady decline in numbers ences in mean growth between the river stations were occurred throughout the summer. Although densities not very large during the past 5 years, although in at the Niantic River stations increased as those in the some cases even small differences in means were-bay decreased,it was unlikely that many fish entered significant (Table 18). Greatest differences between the river from the bay. Tlus was suggested by differ- mean length at river stations occurred in 1984 and ences in growth observed between the two areas 1985.

(discussed below). . Similar to 1988 and 1989, num- As in both 1988 and 1989 (NUSCO 1989,' 1990),

bers of young in Niantic Bay declined to near zero by most fish taken in the bay were smaller than those August and sampling ceased (Tabie 17; Figs. 23 and collected in the Niantic River, especially early in the 24). . Densities at the two river stations fell to about- season (Fig. 28). Cencrally, weekly mean lengths 13.5 to 20 young per 100 m2 by the end of Septem, increased throughout the season at RM ond BP, More

[. ber. These values were approximately equal to those variability in lengths was seen during July as sample =

l: for 1987 and below the abundance levels found at the size decreased because of declining abundance in the cnd of the 1988 scason (Figs. 25 and 26), bay. As in 1989, the few fish remaining at RM in l

Growth. Growth of young was examined by late August and early September (not shown on the i observing changes in weekly mean length.: A rela, figure because of the small weekly sample sizes) were L . tively rapid increase in weekly means was seen in the particularly large (up to 75 mm) relative to those in -

l .Niantic River from May through the beginning of the river, Orowth of fish'was less in the bay than in.

- July (Fig. 27). However, little change occurred from the river and length variability for bot t areas was rela-then until mid September, when increases in mean. tively small until late summer. Therefon based on

!!cngth were again noted. Growth was less variable observed weekly length-frequency distribut.ons,it was than abundance as the weekly means had relatively unlikely that appreciable numbers of young entered small confidence intervals. fixcept for 1989,-differ. the river from the bay. Movements of many smaller Winter Flounder 45

_a 2. _ _ _- ,

1 Allt.li 17, Scaumal 1 rn ham trawI mrJian CPUl'. Oiumber per 100 m3 ) of age 4P wintet fl.amdet at t*o staums in the lower Nanut River (1.R and WA) from 1941 thmugt 1990 an<l two statiom in knin llay (RM and RPiirom 194 thros.gh 194#u Corf fiornt Suney ' lows uwd Medun 957. tonfidente cf year

• St ain m Sra wn* for CPUI. CPUI' ime n al sk e w nen' 1943 1R l arly 30 32 7 200507 2 24 LR I. ate 27 10 0 110133 0 49 19M4 1R l'arly 40 18. It 167,250 a 63 IR late 36 63 3.h 7.5 0 $4

% -\ late 32 11.3 k 017 5 0 94 1%5 1R I .arly 40 13.3 10 0-16.3 0 91 lR l aic 32 70 60R0 0 97

%A l arly 40 15 0 100200 0 kl

%A l ate 32 90 80100 0 70 19h6 [R lady 39 14 M 23.3400 0 31 (R l ate 36 11.5 12 5 17.5 0 50 WA 16:13 40 21.7 12 5-26.7 1 49 W\ late 36 18 t l5 0 20 0 2 03 1987 1R lurly 40 59.2 5.13-7.13 -0 12 IR l ate 36 17 9 IL5-26 7 0 70 WA l'.arly 40 28 ) 21.7-3 0 0 27 i WA l ate 36 10 6 6 011 k 0 K .)

19 sit IR lirly 40 61.3 52.5 72.5 0 37 1R 1 ate 36 60.0 50 0-70.0 1 17 '

%A 1.arly 40 40 0 32.5517 0.11 W\ late 36 38 3 3.1 3 5!.7 0 22 RM liarly 39 47.5 30.0725 3 68 RM late 36 7.0 6 0 8.0 0 20 Itt' thely 40 71,3 32.5-107.5 1.17 llP late 32 16 1.0 3 0 0,99 1989 lR l'arly 40 17.5 11.7 217 0.09 IR l ate 36 88 7.0 113 0.54 WA 12rly 40 10.0 8.313 R I.]o WA late 34 55 4.0 10.0 0.66 RM Early 40 50.8 26.7 75.0 0 64 RM l ate 3;. 00 0 0-1.3 1.79 llP F. arty 39 20 0 6.3 32.5 1 78 llP 1 ate 12 00 0.0 0.0 1.46 1990 IR Ijrly 40 156.? 137.5 187.5 1 05 LR late 36 20 0 15 0-52.5 1.10 WA thrly 40 f. s . 3 50095.0 0.62 WA late 36 13 5 10019.0 1.20 RN1 I:.ady 40 40 0 17.5 55.0 0.8 i RM late 24 0.0 00-1.0 2.40 llP Iktly 40 32.5 12.5500 0 it 9 llP late 24 1.0 0 0 2.0 0 89

• 1 or age-O fish, Lt.e year dass is ibe same as the survey year.

' 1:arly season cor~ipon l< to laie May thnsugh July and late to August thr(algh kptendwer

• Zern for symrnetrically diwibuted data 45 Monitoring Studies,1990 ,

t 1

i 3

Statiori LR - 1983 ,

.f 7 3.j --

.s4

- 3 100' aw-($'5 td .

4 (*7

'$.c$

' 7d '

s-O . i' _

Id dp a ,,

- $-y bd' ', +

Lz j'~ h *

+ ,

c

> l 2,5 '

9 i, * ' ,

-.o. tb. ...... .,,

=

u. ,

s O ...

3 ,a.- ,.s -,

,- 4 ~ ~ ~ ~ ~ ~ - -

.> nb, . . . . . - - '_-

0, , d f) .- -

M/u adNi-: JdtY AdGU5T 2CP fEMiaCh

.?

4di 5tution LR .- -10 2.7--00 ,,

F t

. -- a ,

> Js son' .

l <

a to.-

170 j ',

a <,t- , *

, y

.o -, ,

- h 160 l ,

i- e ,_. ' .. .,

a ag - ,. ,

-Q  : l g b ',

"4*

.s q @; *. - ga d ' 's i

• e-100-i: . ::; -  :

s,..-...s

. . g. , _

.< O 10 - . 31 ,, -

.s

_N s.-

4' ,

. j o.- 33

.n20

/ ,

,1 f.- :s d 88 +';

N -

4 ab- ,,

g . ,-80 , ,

mat - c s>JN E - - sdLY Ad60si hCFiEMbEn 4

ll

. Fig. 25. Moving average of weekly rnean CPUli of age.0 winter flounder taken at station 1.R in the Niantic River from 1983 through 1986 and 1987 through 1990_(note differing vertical seales between graphs).

i Winter Flounder 47

1

. Stot.cn WA .- 1987 -00 1.:b ' "

.f l '

(b} l ',<

}fU

,, Ti i n l l 's

'\

J td '

e ,e  ;

d,;:'f3n 3d s ,

to di .,,. ,

j  ; '

.5 E ,

,f

/ ,

() -  %

so sa

'3 ~,

.f.y y3- ;

' ~

%i " .

', ~

. .t . -

^b i b 1

'b ~ 'A- '

Q] .. - m, ',

10 .a-~

..) * , -

mar ." lH i,' %10 A h alJi O IEMd'* i

' Hg. 26. Moving average of weekly mean CPUE of age O winter flounder taken ut station WA in the Niantic River from .

1987 through 1990.

- fish from the bay into the river would have resulted in and river stations, particularly in spring and early

- bimodal length distributions and greater variability in summer when growth was most rapid and probably weekly means, which did not occur.- . accounted for some of die differences noted in growdi.

Water temperature most likely affected growth of. Water temperature was usually 0.5 to 1.0'C cooler at

-; young and faster growth was expected in warmer LR than WA, probably from the tidal influx of waters imless the optimum temperature for growth Niantic Ilay water, Sampling took place at LR

was exceeded. Water temperature differed among bay during de second half of flood tide and at WA near TAllLE 18. Me'an lengIh of age-O wintes nounder taken at stadons 1.R and WA in the %ntic River during late July through Septemhr of

- 1983 through 1990. L

. Mean length in rnm' L4 $ 11 57 il 51 - 50 g 46 45 l-n 43 C 42 .42 Stauon ~ -lR 3 IR 1R . IR 1R WA WA WA1 l1R 1R 1R WA W4 WA WA

' Year 83 84 : 89 . 85 - 88 88 - 89 87 . 86 87 90 S4 85 - 90 86

~

~

- Difference ktween late scawnal mean at LR and WA:

Year 8i 85 86 87 88 - b9- 90 I

- Thfierence in mrn 16 15 4 2. 0 8 1

• Means underhned not signifiantly different (p 5 0.05).

' 48 Monitoring Studies,1990

_ __ . . _-_ . . - . ~ . _ , . . -

1 Niantic Bay stations - 1990 60 53-

i 3

B /

2- /

'3 33 ,

"/

h d}/

s /F 1 3 20'

\e pp.g q}6 sg&t 10'- 8 hM---

0' -

MAY JUNE JULY AUGUST SEPIEMBER 60 Niontic River stations - 1990 LR A

~

50- ,

i y 4 0 '- N,Il fd 30- /

t?,

W A - - --

b x

20' /

ff d

3 10-0v -r ,

MAY JUNE JULY AUGUST SEPTEMBER

(%. 27. Weekly rnean length (12 standard errors) of age-0 winter nounder taken in Niantic River and })ay during 1990.

I Winter Flounder 49

_ y _

l l'

among > cars at station 1.R is density dependent growth, w hich has been regularly observed in juvenile

• fishes (Cushing and llarns '973; Ware 1980, Poston 3 g et al.1983; van der Veer 1986). Significantly larger M %P means were found for 1983 85 and 1989 Clable 18)

$e / f9 '. w hen annual densities were lowest (Teble 17). Little

// niortality of young appparently occurred in the river

-@M g

/ during 1988. When this anomalous year was jg g e

' excluded, a significant inverse relationship was found between mean length and abundance at L.R dunng dis gp j y to pg latter half of sununer, w ben both densities and growth were relatively stable (Fig. 29). 'Ihe relationship was AUv0ST LEPTt statt not ai t lear at M, howmr.

uAi sonc seu Eg. 28. Comparison of weekly mean lengths of age O ,c n Me 4A winter flounder taken in Niantie River and llay dunny Q 1990, '

4 < et i 50 +80 3

high tide or during the first part of the ebb. Water j ,g temperatures have been consistently 1.5 to 2.0'C ,r; cooler at 11P than LR. As the temperature at BP 'l 4 d

(average depth of about 7 m) was measured at the ec surface, the difference between this station and the shallow water LR station would likely have been h

,0 85* 93' '86

{] g 0

even greater at the bottom, , here young fish resided. Mwj ceuc (A JST- 5EPT DER)

The difference between int and LR varied between about 1.5 to +1.5'C; this probably reflected varying water masses originating in the river or bay, depend-ing upon the tidal stag" sampled at RM.

Other factors which could have affected growth, y mmy such as benthic food production and availability, most i t

. ea likely also differed among areas and from year to year. Ye Saucerman (1989) found significant differences in y abundance, mean length, and length weight relation- j 8p, a9 ships for young winter flounder among different ga habitats in Waquoit Ilay, M A. Areas adjacent to ,A *ea 50 celgrass (Zostera marina) were particularly conducive g to greater growth. Sogard and Able (1990) also 86 reported variable growth among different habitats in New Jersey estuaries. Changes in eclgrass beds with

h. 40

"\ 30 [ [],

C '

accompanying sediment changes were also yEDtAN cF uc (Au$vsr twofe) qualitatively noicd at and near station LR during the years of study (see helgrass section elsewhere in this report for additional information). Both food Hg 24 Rehtionship between annual mean length and preferences and rates of feeding were considered densay (median CI'tm) of . ige.0 winter nounder for the important factors in the growth of young plaice penud of August September from 1983 through 1990 at (Steele and Edwards 1970; Poxton et al.1983). A stations t R and WA. The data for 1988 were excluded tentative exphtnation for growth differences obwrved Innu the regrmion.

50 Monitoring Studies,1990 l

l l

Apparetit changes iri prow th inay also hase been nificantly dilferent fro.ii zero blorithly survival esti-caused by dilkrential nioveraent of 1 ;er young aw ay rnales in 1990 for the Niantic Riser stations IJ(

from a station, Ahich also would hase increased the (0.247) and WA (0,3NJ) were considerably Niow apparent (nortahiy rate (dheussed below). Ilowever, almost all estimain inade in previous years (Table few )oung hase beer) tuleu durmg tht surnmel at 19), Estimated monthly suhhal rates lor young trawl monitoring program stations and it is unblely wanter nounder in the Niantic River we'e less than that large-seat rnovemerits oa uried throughout riiost the value of 0.69 reported by Pearcy (1062) for the of the suturner. Neverthelew, soine off station inove- hnystic Rivi;r cituary, but were smiilar to estiniates ments in the river followed by a later return were made for young phice in British coastal otobavments sugge5ted by % mall tip' urns irl abundalice seen in late of about $09 per fnooth (Lockwood 1980; Poston el September during sescral years of study (Fin 25 and al.1982; Poston and Nasir 1985).

26). Some inh may have moved into shghtly deeper Frem the decline seen in weekly catches, mortahiy water to avoid peak summer tonperatures at the 01 young wtu apparently much greater m the bay than shallow alongshore stationt flowever, few of these in the river. 13 cept for Rhl in 1987, no fish Ibh have been taken irl suntriler by otter trawl at sla- remairled at the two hay stations by the end of tion NR in the navigational channel Ahernatively, sununer and it is likely that the disappeerance of fish sorne fish that settled in slightly deeper water in the there was actually due to mortalit:. As mentioned liser could hase inoved lowards shore til the end ol previously, sigriificant liiosernents of young froin summer. Niantic Hay into Niantic River were not apparent, Nlortality. Instantaneous tr.ortality (Z) and based on observed patteins of abundance and length weekly and monthly survival rates (S) by year and distributions during each of the past 3 years. Young station were determined from catch eurves of wectly probably thd not emigrate f rom the bay stations to abundancv data. Using thn method. however, requires other areas Of LIS cither. Rela!!vely few young an auuinption that )oling comprised a siliple age winter Counder were taken 4tt five seine sampling u,hort throughout the seasor., The catch curves had stations along the shoreline of Niantic Bay or LlS relatively good fils to the data, with r2values ranging from 1969 to 1981 (NUSCO 198?), a period during from 0.67 to 0.93, escept for 1985 at WA that had an which the winter 00under w as more abundant than at 2

r of 0.51. No survival estimates could be determined prmnt. Furthennon', few young have been collected for LR and WA during the high abundance year o; at two of these stations UC and WP)in in&ue areas 1988 as the slope of these catch curves wcre not sig- of hudan Cm that have ken sunpkd through the T Allt.l! 19. Monthly survnst taic estimairs an determined from (atch curves Ier ege <0' wintcr flounder taken at two stathm in the lower Nianth River O.R and WA) frem 19kl thn. ugh tWO and two stathm in Manuc tlay (KM and OP) from 19EM through IWO.

e agium a bihh mn n al rate N at staus b rve) year' tR WA Rst 10' 1910 0 552 19h4 0 171 1983 0 $99 0.694 19k6 0.576 0 356 (car 13 )

0.440 (l Alf) 19K7 0626 0 541 19h8 NN ' hY 0. 4 nu O179 19h9 0 $kt 0576 O l t,6 O t:2 1990 0 247 0 %0 0 10.1 0 167 Awrage survival rate d 0516 n 461 0,19n 0 154

' 1:or age D fish, the year < lait a uic same at the suncy ) tar

• Data partitaned becaine of tru rt ase in atwindanic at statu.n m rmd stammer, ciumates ruiy be unreliable.

Shyc not sigi,iricantly thf t: rent from nro d

Iktermmed from the ascrage of the conettsmomg ciumates or mstar,laneoul rnonahy r 410 [

Winter Flounder $1 l 1

l i

k i-  : present (see Fish IIcology section). Therefore, sub. newly metamorphosed winter flounder (Whitehouw 1 . itantial ruovement of fish into the shore yone of the 1989) and Jeffries et al. (1989) suggcHed that it 4 bay was tmlikely during the summer, Few young preyed upon both larval and metamorphosed winter have been taken by otter trawI in Nbntic Itas 3ther nounder in Narragansett llay. Malhn (1976) returted offshore waters until late fall or winter, w' :n many that aduh p40 mm) sand shrimp in the Mystic of thesc small fish have withdrawn from the river in River, CT rnoved into shallow (<l m) water during response to decreasing water tem;wrature. Winter their ApribJune repuxluctive perimi. Densities of floundet as small as 30 mm nre taken by puer trawl adult sand shrimp there were about 4.6 to 6.5 per m 2 d Jring this perial and also in the Niantic River during during these months but abundance rapidly decreawd

the mlult population surveys. If young were present when water temperature nue alme 18'C, The perial

) . at deeper stationn in the bay or LIS in mid summer, of greatest adult sand shrimp abundance coincided L thtm they should have been available to capture by with highest mortality of age O wimer flounder in the this gear. The apparent lack of common off station

. Nientic River. Similar to the plaice and other movements implies that natural mortality of young Gatinhes (Rolf 1981), the largest year. classes of in Niantic Ilay is high following metamorphosts and winter flounder in the Niantic River (NUSCO 1990),

settl ement to the bottom. Greater mortality in the Narragansen llay (Jef fries and 'lereciro 1985; Uibson L bay may be related to the generally smaller sim of 1987; Jeffries et al 1989h and in southern New young and the greater numbers of fish available to Jersey (Danda 1978) were awociated with estremely prey upon them in these deeper arcat This is cold w nuers. The extent to which predation by sand analogous to the case of age-O plaice tr3 liurope, shrimp affats young winter nounder numbern is yet w here mortality in the shallow inland Wadden Sea of unknown, althouph Moote (1978) noted larp The Netherlands was less than that found for plaice reductions in the number of sand shrimp in llarnegat inhabiting the more open and deeper liritish bays, llay, NJ as a result of the sescre winter of 1976 77; whkh had more fish predators (llergman et al.19N3). this winter coincided with the pro 1uction of the

j. Ilowever, as noted above, some )oung at the two strong 1977 year class of winter Hounder in luth New ,

1 river stations couki have emigrated off station during Jersey and Southern New lingland.

the season, resulting in remew hat greater estimates of Mortality in 1990 was particularly high throughout rnortality than actually ocurred. the r.cason. Although larger young are probably Adult recruitment for many fishes is great l) alfccted picyed upon by pise:vorous fish and birds, one by density dependent processes occurring uuring the possible explanation for the inercased mortality seen first year of hfe following the larval stage (Dannkter in the river during 1990 is disease. The particularly et al 19741 Cushing 1974; Sissenwine 1984). A high densities of young in mid sununct coupled with conclusion in NUSG9 (199@ was that no sustained water temperatures above 20*C couki have density dependent mortality d posi. larval Niantic facilitated transmission of the mierusporidian parasue River winter flounder existed, as ar;tarent survival Glurca.ucphant among the population (Dr. A. Call, rates were highest in 1987 and 1988, when densities Rutgers UnScrsity, Newark, NJ., pers. comm ).

were greatest. Dannister et al. (1974), Lockwood This parasite can cause high mortalky in infected (1980)l and van der Veer (1986) all reported winter nounder (Stunkard 1969; Weidner 1973; Cali density dependent mortality for young p'aice, et al.1986), Furthermore, rates of infection can vary although examination of their findings indicated that greatly from year to year and from locality to kicalhy greatest rates of mcitality occurred only when (Stunkard and Lux 1965), which could have extremely large year classes of plaiec were produced accounted, in part, for the large differences in (three to more than-five times larger than the mortality noted between 1988 (relatively low) and average), A similar situation may exist in the 1990 (relatively high), despite generally similar water Niantic River as the peak densities in 1990 were temperatures and relatively high densities of young

.about three times gret ter than in any other year since winter flounder in comparison to other years.

1983 and mortality was greater than in any previous

. year of study, Age-Ojuveniles during latefall Much of the mortality on newly metamorphosed arulcarly winter young carly in the season may have been a result of predation by the sand shrimp (Crangon scpicm- Young winter flounder disperse from shallow

. spinosa). This speeles has the ability to feed on waters near the shoreline to deeper waters as water

$2 Monitoring Studies.1990 1

_ ~. _ - _ , ~ . . . . . . _ _ _ _ _ _ _ . - - - _ _ - - - - - - - - - - - - - " - - - - - - - - - - - - - -

temperatures decrease in fall, thereby becoming the Niantic River during the subsequent late February-available to the otter trawl used in the year round early April adult wint;r nounder Aurvey (F ig. 31).

trawl monitoring program. Young were usually first Although similar trends were seen among these three captured by trawl at the shallow mshore stations (NR catch indices, none of them wcre significantly and JC) adjacent to the nursery g ounds in Octoler or correlated (see Table 25 telow).

November, the near shore Niantic Ilay stations (IN Relation 6ips among abundance indices of jusenile and Nil)in December, and at the dee[vr wyter static.ns winter nounder may have teen obscured by sampling in LIS (TT and DR) in January. Using trawl variabilitv. The selectivity or fishing gear is a major monitoring program catch data beginning with these months and continuing to the end of February, a 6-rnean (NUSCO 1988b) indes of relative abundance was developed for these age O fish. The October- u a February period occurrt.d during the transition j g following the summer beam trawl sampling and p m ovu mm ywa ( .. y preceding the catch of these fish as age 1 juseniles jD during the intensive adult winter noutukt surveys that ga thke place in the Nientic Riser from late February e through emly Aptd. Ile(ause of the timing of this y" # d report, th: most recent abundance index reported here ja is for the 1989 year < lass, The 6 mean for the 1989- a y- ) \

S 4to H 9 -t' N [

t ]

90 sampling was Il.9, a considerable decrease f. rom the value of 294 for 1988 89, but nevertheless was

) io n n > n onnaneroo the fourth highest mdex of the 11 year series (Table gu 20). Since 1983, when comparable data were available, the fall carly winter 6 ineans generally

. I ig. 30. C,omparison between the 1976 49 inte falb corresponded with the precedig late summer 1 m beam trawl densities at stations LR and WA in the ' "' IY

• i"' ""'nal 6 mean CPUL of are-O w inter nounder for the uswl nionnoring pnymn Wh caich Niantic River (Fig,30), llowever, little correspon-per standardized low of 0.69 km) and the 1983 89 late dence was seen between the 6 means and median bs b 0 W M mh CPW CPUE of winter 00under smaller than 15 cm taken in ph Fr 100 m 2 L TAltt120. The laic fal1<arly winter neaumal' 6 moinCPUl: of6 age 0* winter flounder taken at the sin. trawl monitoririg sininmi in the viunity of MNPS fngn 1976 77 ihtough 1%9 9n.

Suney) car

• Nmnber of a mpics Non nro observations 6 mean

• 95% umfidente inienal

~

1976 77 /2 36 61 2 0-10.3 1977 75 42 38 5.1 2379 197h 7'l 42 36 42 2064 1979 80 42 38 42 226.2 19 AO 81 40 37 10.7 4.2 17.2 1981 82 4n 3M f( l 2,9-13.3 1982 4 3 3R 36 21.8 100436 1983 84 4n 37 6.7 3.3 In 2 1984 ES 36 32 69 2.0-15 6 1985 46 36 36 86 5.7 11.6 1986 87 36 33 13 4 2.0248 1987 88 36 35 49 1.6 R.2 198 R 49 42 41 29.6 ll.k 47.3 1989 90 36 36 11.9 6.2 17.7

' Data scamnally restriaed to November i ebruary for NR and JC,ikccmkr4chruary for IN anJ Nit, and January 1:chrua9 for TI and itR,

• Catch per standard.ted tow of 0 69 km (ice Matenah anJ Methods of I oh tkology scumn).

For age O feh, the year <lm is the same at the first year pven Winter Flounder 53

-mi.--- - - - -

Agr ljucenilts riuring the ahdi Apawning Acawn NE erd MGdN (--)

id

• Each ) car dunny the February April aduh winter ilounder surveys in the Niantic River small wi ter hM sn 0~*n.a en hmnmnyapm,ed xn annuai

@M median CPUE was calculated for winter Counder DM smalla than 15 crn; this st/c group indudes mostly age 1 fish from the year < taw spawned dunng the hO mo i, e,eseus ym adjuumems maa,io d,m.h dma b,,

i f .0 yio y }

g[1U. _._.q,/ ;\y

} '

the calculation of CPUE were smular to those previousiy diwussea for aaduta por some annuai

1. ' MM : . _ . . , _ _ . _

compari,ons, data were restricted to stations I and 2

., a . s e n r. o H 6 4 h "

• e because smau winter Counder were pencraHy len

'W

• abundant than adult fish in the upper river, where no "k Inun M Wough UmR V 31. Comparimn betw een the late lau-eto3 w mter I""fuues

• • "i o w, on f or sman wimer Counder aabic se.nonal 5 mean (.l,UI.. of arc 0 mimer nounder hit the mm min b W M Md M

?O trawl monitoring program (TMP; t at b per standaniacd tow oI 0.69 kno and the Niantic Rher surves median CI M 7h hdm NM M M M M o u low n 1he value of 7A in CPUli tWI N t akh per standardved low) $r wint(t UNO (W year < law was shndat to the CoUE of nounder smaner than t$ cm Imm 1976 through 1989 7.0 from the previous ymr. This occurred despite the apparent large dliference in the hund,er of )oung source of bias in abundance estimation,intluding si/e pnxtuecd in the Niantic Riser between 19M8 (high) scleethity of the gear, spatial distribution of indn- and 19S9 (low), as tellected in catches made by beam iduak in relation to the gear, and behavior of fish in trawl during summer and otter trawl during late f all-the vicinity of the gear (Parnsh 10M). hiean lengths early winter. l.ow juvenile abundance indices in the of age O winter Dounder taken by otter trawl in fall Nianta River during recent years seemingly implied were about 15 to 25 mm larger than those taken poor reproducine success, llowever, because the during preceding months by 1-m beam trawl. This behavior of juvenile winter Dounder largely innuences slic difference was greater than would have been their availability to sampling, this particular espected by growth alone and most likely biased abundance index ha not been considered a reliable CPUE indices as smaller individuals were likely measure of year clau strength (NUSCO 1988a, excluded from the catch. The fised kications of the 1989). The magnitude of the CPUE index and trends otter trawl samphng stations in relation to the habitat in abundance for these fish 'dso depended upon the available to juveniles may also have af fected catches. particular data used to calculate the index, For hlovements of str,all juveniles were alfected by example, it was shown previously (NUSCO 1988a, factors such as water temperature and tide, and their 1089) that combining catches of age.1 winter llounder availability to the sampling gear in fall and winter f rom tows made throughout the river with those made varied from week to week and year to year, dependmp only in the lower river navigational channel changed upon conditions. Relatively large confidence inter, the comparability of annual median CPUE values, vals around the &means were probably un indication The median CPUR of 2.0 calculated for the entire of this variation. This was in contrast to the stunmer liver w as a record low for this time series (Table 22).

sampling by the relatively efficient beam trawl that Conversely,the coefficient of skewness of 5.0 was rel-took place during a fixed tidal stage in areas known to alively high as several very large catches of juveniles be preferred habitat for young winter flounder. were made near the n'outh of the river during the last Finally, a mixture of juveniles from a nundier of week of the survey, whereas scry Icw were taken in different source areas most likely occurred throughout the many trawl hauls made in the upper river.

LlS during the winter, and this could also have biased Ddlerences between the two juvenile median CPUE the measure of abundance, depending upon the inde- probably reflected fish distribution, which variable contribution of the different stocks. varied both inside and outside of the river. Nearly all 54 Monitoring Studies,1990

'I Allt.I' 21. Anima 19 l m otter trsal a.huited rnedian CPUl'8 of u mit t th*under ima!!ct than 15 (n? takin m the r,sug aininal thannel of the low er hiantit kner dunrig Die 1976 through IMI adult g.yulatum abundanic sunt):

'l ow s Ad omed Um fi n ient hunry Wtdt ad rpiable numhcr of Mnhan VW. conhdem t of

) t a r' tamphd for CpUl? tow i u..t J' (yUl'. intr n al skrwnen' 1976 7 4h 154 20 0 190200 2 77 1977 6 166 229 13 5 120170 1 50 197h 6 129 156 21 6 150450 1. 5 v 1979 5 107 136 41 0 2706r 3 2 h2 1940 $ 110 145 49 3 34 5 r4 6 1,30 19kl 7 91 140 Ti.) 55.0 k t k o 79 19ti2 4 50 70 34 4 132525 1.46 IVR3 1 77 77 41 0 11 (1 S k h o 55 1964 7 72 77 1k 5 14 2 ;0 h 2 23 19k5 7 k2 64 23 6 Ik44h2 1 27 19kh 7 72 l15 41 2753 l 37 19h7 5 41 50 50 4.367 2 0h 10kN 6 49 54 11.2 77147 1 38 1989 7 50 54 7.9 40119 1.19 1990 ~1 65 91 74 5 k 13 3 2 06

• Cauh per staml.irdved tow (see Materir.h ed Methmh)

• Mostly age I inh, so prrdon man egc4 ein w as pn=luitd 1 3rar hlore the survey yest (hdy tows of standard tune or datame ma le in the nasiganonal thannel of the lower ener were oinudered d Lffort equah/ed among werk t.

' Zero for symmeintally dntrdoted data.

T AllL!! 22 Companion of annual 91 m otter trawl adjusted rnedian CPUl;' of w mttr flounder unellri than 15 s m* taken in the navigatumal channel of the lowcr Nianuc River with thoic caught throughout the enute samphng ern of the ener dur i,g the 1976 thnogh 1990 adult poptdatam abundance surveys.

Suis.muldarmel teh: Luutt._ ansa'Imt.f ma ktL Adjusted Adjusted Survey number of Median Coefhcient of number of Median Nf huent o' d

year" tow i umed' CIUl'.a skewnein tow s used' CPt T ' sk c u nrid 1976 154 20.0 2 77 211 14.4 2.84 1977 229 13.5 1 50 Insulhuent town rnade m upper rwer 1978 156 21.6 1.59 Intuff nicnt now n inade m upper rner 1979 136 41.0 2,k2 InsuIhnent town rnade in upper mer 19ko 145 49 3 1.30 Insuffinent town made m upper r:ver 191tl 140 71.1 0 79 th? 14 0 114 1982 70 34.4 1.46 118 87 2 40 1983 77 43.0 0 $$ 238 11.5 1.80 19k4 77 iK.5 2.23 2k7 64 4 08 19A5 64 23 6 1.27 2hD 13.3 236 1986 lik 41 1.57 336 40 1.47 1987 50 50 2 08 270 32 2.46 1088 54 11.2 1.35 312 37 3.03 19H9 54 79 1.19 3th 6I , 1 64 1990 91 7.4 2,06 320 00 ,

5 00

• Catch per standardved low (ice Mairnals and Mcthah)

• Mosdy age-l fuh. no predominant age 4 tats was prtuluted I > car before the nuncy year.

• Effort equahred among weeks.

d Zero for s)mmetncally datnluted data.

Wi0ter Flounder $$

4 adult winter Counder were in the Niantic River during 1 the spawning season, with relatively few individuals found in Niantic Bay, but this was not the case for age 1 juveniles. A 5 mean abundance index for winter Counder smaller than 15 cm taken by the trawl

{[ NR m McMN ' (-- -)

ej

! monitoring program from January through April at g '

4 stations outside of the Niantic River was computed and compared to the CPUE median for fish found

. within the river (Fig. 32). A longer time sp,m was

)4

• 0

'O -

chosen for the trawl monitoring program data to -

\

increase sampic site and to overlap the spawning period. Overall, the catch of these mostly age.1 N+0 k0

's;

}-+-h,62 l' }]

i.

4 hh!

winter flounder in the winter and early spring

• 8 ~ WEAN .

fluctuated less outside than inside the Niantic River.

As the numkr of small fish in the river declined to 76"""ly y Q]"""*

low levels in recent years, the relative number outside

the river has increased. In 1988, however, catch H n empr%n mn uu una mmMin within the river increased as catch outside the tiver decreased. This trend reversed in 1989 as catch in the O'M Nr k mt umamW mem N'; *

[ e pr arm

• d ww d o+9 W md k M c j bay was the hecond highest of that series and showed hn survey median d'titi(%TS; nuh tier mndardired

.that most juveniles did not remain within or re. enter W br wimo nounder smalin Nn 15 on hom 194

) the Niantic River during the 1989 spawning season- through 1990 Although catch in the bay decreased in 1990, the bay CPUE remained greater than that f or the river. Thus, iles to a density.degrndent regulatory mechanism that a small CPUE index in the riser may not necessarily operated during and shortly alter larval settlement,

, indicate a continued decline in abundance, because Rothschild and DiNardo (1987) reported a median CV even a relatively small increase in catch for the much for recruitment indices of various marine fishes of larger geographical area of Niantic Bay would account 70% with those for various flatfish species being .

for the low abundance in the tiver. As a result of the mostly less than 75%. For Niantic River winter differential distribution and abundance of agc+1 Houmler, variability in numbers of spawning females ,

juveni l es per haps as a result of variable environ-(CV=54%) and eggs produced (52%) was relatively mental conditions innuencing their khavior and a' vail- low (Table 24). For the first three mlutt female age-ability to sampling, their abundance indices remain a classes, variability decreased from age.3 (80%)

generally unreliable predictor of future adult popu- through age 5 (65%), which not only reDected vari.

lation size, ation in recruitment of year classes, but most likely variation in numbers of immature 3. and 4 year olds Comparisons among life stages of winter present in the river each year. Variability among flounder year classes larval stages was greatest for Stage 2 larvac (93%),

which was expected as much of the compensatory - ,^

Previously discussed abundance indices for various mortality is believed to occur during this stage of

- life. stages of the 1976 through 1990 year classes of development. -llowever, inclusion of the data from . ,

winter flounder are summarized in Table 23 Varia- _

1988 made this finding less certain because of the -

bility in annual abundance indices were examined by unusually high densities of Stage 4 larvac found that -

- comparing the coefficients of variation (CV). ian der .

year. Deleting the 1988 data reduced the variability Vcer (1986) noted that the highest CV for yearly ~ - for Stages 3 (65 to 49%) and 4 (82 to 34%). As for abundance estimates of different life stages of plaice plaice, variability in abundance increased at larval

- occurred during larval development in late winter metamorphosis and settling. The carly juvenilo index

- (n=4, CV=95%) and at first settlement of pelagic had a CV of 96% over all years. Similar to the larval juveniles in spring (9,62%). Less variation was data,1988 was an unusual year for age 0 young as found for post larval young during mid summer (9 little mortality apparently occurred throughout >

30%) and for age 2 recruits (9,35%), lie attributed summer and high densities were found in September, the decline in variation of abun Lmcc of older juven

• Deleting 1988 reduced the. late summer CV by more 4

- 56 Monitoring Studies,1990 t

yv- -\-v-wn,w..--w.m . ,t-,-w,. -.-,m.,,w ~.,#,,, --.-mm.,-+ w,..,r.,.rw-r.wr.w,e.I.e-.,_.r.m,.-.w.m.-c .nw.

.,w% . .,_.,.n. ...--w. , . - . - m

4 l --

q.

! 'I Allti 21 Csunparitiet Of in.hteg of shtmdame for urious Ide 6ups or einter fhiundre fut the 1976 through the IWO yeargloses I

4-lars al abunhn&ddlutsf luvenur ahmhMs Age 1 Nianlit lover sutumi MNPS int.Le laer lower Rner/ bay fish l emale Year. I gg Sugel huge? $tge l Sup 4 (lN) nver nver 6,mr an (nver) I j spaw ners class prodocutm (;1 rnm) (3 $ mm) (6 mm) (7.$ mm) (74 mm) (MayJuf) (Aug Ap)(Nm Ith)(l'ch- Apt) l 76 . . 634 + .

6.1 13.3

$lt4 77 M46 $67 31 21.6 7 1,412 7A 717.$ 4 734 . . 4.2 41.0 l 1,120 79 $33.3 4,2 49,3 641

901 no 424.3 .

643 . 10.7 71,1 2,669 El 1,383 I . . .

$61 A] 34 4 2,7!2 62 1,$u6 h -

610 +

21.8 43.0 1.h69 8l 1,082 0 -

749 40R $6 1.21 $ 32M 10 0 6.7 18.3 k?! A4 $016 2/01 1,$01 $73 67 917 16 A 6.3 ft R 23 6 92i. $5 $69 2 b,2N) 4,676 $84 31 312 13,3 70 $6 4.1 M5 kh 43rt7 1,279 176 301 24 $10 33.8 13.k 13,4 $o 852 87 $11.6 3,218- 629 1,016 48 313 $9.2 17.9 4.0 11.2

.1,279 k8 kh6.9 14,491 4,469 1,531 210 419 61,3 60 0 29 6 7,9 984 $9 71ro2 12,463 3,976 $N9 73- 327 17,$ k.8 l 1,9 74 676 90 432 1 4.817 365 25k $7 $08 136.3 20 0 .

' Alllarval abundanse indwes given are the ta parameter from the Gungrti funttkm, except for $wge I and 2 for 1990, where the

. cumulative weekly geometrie incan denuty was used 1

]

• i than half to 45% Similar levels of variability in age. 'Ihc unusual and apparently high survival of larvae  ;

0 abundance were seen during fall and early winter as i and. age O young in 1988 also suggested that the 4 - young left the shallow inshore waters. The increase success of a year class may le detennined over several in CV for age I juveniles in the Niantic River during life stages when particular conditions are met, the adult surveys was probably related to the _ Alternatively, the large settlement of young in 1990 previously discussed annual differences in distribution was apparently ofIset by high m0rtality during 4 (clated to their behavior as well as from actual summer. For the Niantic River winter flounder,1988 l

variation in year class strength, was the strongest year class praluced since the current TAlllI 24 Ctefficiems of tenation (CV) for abundance indnes' of various life stages of Nianuc IUver uinter ihmnder.

Numhet of W W 1)fe suge Ahundarne indes used - . observations (all yrars) (deleting 1988) female spawners Annual standardiud tatth . 14 $4% $6%

- Age 3 females Annual standardited catch 12 80 %

Age 4 remales Annual standardited taith 11 63 % -

Age $ females Annual standardixd catch 10 60 %

I?ggs .ligg praluctkm indes 14 . $2% $5%

Stage i larvae is parameter of Gm! pent functam 7= 79 4 78 %

f Stage 2 larvae (4 prameter or Gunperti functum 8 93 % 104 %

Suge 3 Imae t (wrameter of Genperts functkm 8 65 % 40%

Suge 4 Imae (* (wrameter of Genpite functhm .R 82 % 34 %

J Age-O ymms Median CPUl; al stathm (R (May July) R 96% . 107%

Age O ymms Median CPUI! at station IR (Augusi Sept) - 8 98 % 45 %

' Age 0 ymmg Fall

• inter 6 mean at trawl statkes 14 71 % $6%

Age 1 juveniles . Medon CPUli of fish <l5 cm in Niantic IUver = 14 Ru% 76%

Indeces used correspond to those given on Table 23, escept for age-3 through age.$ females.

Winter Flournier 57 1

l 1

-e,- w,E.m..m-..,n-.-,-...-.-.m..,-.#.w..r.---wc m -4r.w r . w ------.w-m---.m.,,... .-.- e -.- .c, w. ---m m m -e -v., .,,w.o __.w---,w,--.ea- - -

larval and jusenile sarnphng began in 1%3. 'lhis tonipensatory pracwes sceilied an unlikely explan.

resulted in abundance indices 'or several hie stages ation. Sotne laLL of correlation was probably related that were (ensiderably above those of other ) cars to sainphng, because lited locations and tilne of (Table 23), sarnpling did not take into consideration environ-Ideidly, II indices for all life 4tage', w ere accurately ruental ellet,Is and behavior of winter flounder that und precisel) incasured cas h y ear, then they should be could have introduced (onsiderable s ariation.

correlated after upplying appropriatc time laf % eMept Although negatisc correlations were found between w hen processes such as density dependent inottality or the abundance of b inin larsae at station EN with sucaelectise fishing result in a latL of linearity ca,h of the first three larsal stages, none of thern were between two Con 5,ccutise hie stages. llow es er, the signif u ar'. This is consistent with the esistence of abundance indices by )carglaw were sigruficant l y cor. densit). dependent effe(ts during the larval stages related for only a few life stages. 1hese included dncuwed previously. Relationships arnong abun-feinale spawners cgg production, and )olk sac (Stage dance indices of winter llounder for the saine

1) larvae; and early season and late season age O year 41aw are of interest for impact auessment.

young at station LR in the Niantic Rher (Tables 25 Knowing the cathest poulble incasure of relatise and 26). Correlations were nearly sigmlicant between year-claw strength is desirable because it would Stage I and Stage 2 larvae and for Stage 2 and Stage enable predictions of future recruitment to the adult 3 larvae in niost instantes, however, no correlations stotL and, thus, provide an early warning of were found between sumssise stages because of rectumnent ladore.

inconsistent changes in annual abundance for w hit b

'I Allt.l; 25 Wro or Soninun i rei-o#Jcr wrrelsom among s anom w inier rieuna s sierg sus k and lan at abunhe inJuri Siantit Rnn Nanta Ratt Nania Rner Nianta R ntt Nianta R ner SINi'S intake slati g g Stc.ge i Sigt 2  ? tqt i Sige 4 ta n se Indn

• pvudu( non lan se tan ac lan ac lan ne (h mm)

Nient Hntt O 8 f 41 Oh571 05714 04762 0521k 0 2li79 fein41c OlkiOI ** 0 0111

• Oin)NS 023N NS 01%27 NS 01182 NS spa w ne n 14 7 R h k 14 Nianut Rher n 7k57 0.523h 0.5714 0.357] 0 0191:

edult egg 0042' 0 1s27 NN O l >>0 N S 0 MSI NS 0 94f>5 NN prmluction 7 8 k h I4 Nunne Rnce 07500 0 6071 0 67k$ 05357 Sup 1 0 0522 NS O 1442 NS 009M NS 0.2152 NS

!arvac 7 7 7 7 Niantk River n7M1 0 4048 05432 Stage 2 0 03r ri

• O 3199 NS 01105 NS lanne h h h Nbnuc River 04266 0.5714 Stap 3 OW)4 NS 0 IWa NS lanne h h Nunne River 00052 Stap 4 0 h:25NS lan ne 8

?

' Indnet used cortespirut to those gnen on Table 21 6

Shown for each Spearnan rek order wnvianon torrelation coeffiornt, pnibabilay level (NS - not signinant.

• sigmfkani at p 5 0 M " 6pmf n 4nt at p <. 0 01). and number or annual obsen sieoru (sample irie)

$8 Monitoring Studies,1990

i 4

'IAlltI 26 Ma'rts of Sprarmani ranL+rder correlau os among sarious lan al and juvenile minier ikwmder abundan c andnes Nianus River tower nver low er river f all earl.v omter Nianuc River Slagt 4 cany age.0 tate age.0 nver bay u mte r 4pnng Imle t ' tan ae juveniles juvendes juteniles age-1 juveniles MNPS inW e 0.0952' O 1905 0 0714 02244 0 60 fit

, larvae 0 h225 NS 0 6514 NS 0 hMS NS 0 4404 NS 0 0209

• _ (74 mm) $ R R 14 14 Nianne River 01667 0.1667 0 3571 0.42 kr Stage 4 06932 NS 0 6032 NS 0 4)l6 NS o.3374 NS larvae 5 8 7 7

)

tow er nver 0 9048 02143 0]k57 early age-O 0 0020 ** 0 6415 NS 0.5245 NS I juveniles A 7 7 temet tiver U.214) On714 late age O 06445 NS 0 879n Ns '

juveniles 7 7

!!all carly winter .n2OB river bay 01254 NS agm ? juveniles 14

• Indwea vied currespond to ihnic given on Table 23,

• Shown for each Spearman rank 4orrelation:

torrelauon coefficien',

pruhability level (NS nor signira ant,

• signiinant at p 5 0.n5, " signirwani at p 5 0 01), and numhet of annu41 observathms (sample site)

Assuming that catch indices w cre representative of possibility is variabl2 discard mort..lity of juveniles annual relative abundances, Niantic River winter in the commercial fishery, Meanwhile, none of these flounder wrre found to be fully recruited only at atout life stages can presently be used as a reliable measure age 5 (NUSCO 1990). - Thus, age 3 or age-4 fish of year class strength, probably should not be used as an index of) car class strength because it is likely that only a fraction of Stock reentitment relationship (SRR) these fish are found on the spawning grounds each year. Furthermore, this fraction may vary from year . Because the abundance of early life stages could not to year, Correlation coerficients calculated between be reliably correlated with that of adult spawners, egg various indices of larvae and juveniles and the production estimates from annual spawning were used abtmdance of female spawners at ages 3,4, and 5 did to determine recruitment. Calculation of the recruit-not reveal any consistent significant correlations ment index was described in the Materials and (Table 27), Several of the significant correlations Methods section and this index, as well as the annual found were negative (e.g., between age-4 females and spawning stock index, were scaled to absolute popu-tha age 0 full winter 6 mean) - The weakest of the lation sire, These values were used as stock and negative correlations (not significant) was found recruitment data for the Ricker SRR model (Table between age-$ spawners and the fall carly winter -28). Recruitment numbers shown here differ from juveniles ,which should have been one of the most _ those rep)rted in NUSCO (1990) because of differing reliable, as females should have been fully recruited - total instantaneous mortality rates (Z = 0.80 to 1.00) by this age. If the negative correlations persist in applied to particular year classes to agree with the future years, they could be interpreted as an indication increasing exploitation rates, as opposed to a Z of of unknown processes operating after winter flounder 0.85 used for all year classes last year. Also, the become 1 year old that result in fewer adults being addition of new catch data from the 1990 adult winter recruited in spite of larger numbers of juveniles. One flounder survey resulted in improved estimates of '

Winter Flounder 59 l

j

a TAllLli 2?. Mains of Speannan's rankcdct corrtlatum among inrious winter flounder tanal and female sp-uner abanJance irniken MN PS intake t.ow er ver t.oect river IaH early minter Nianbe Rnct lan ac early age o tale age 0 river tg winter opnng Indca ' (henm) juvenden juveniles Jugernles age l juvenden Age.3 01259' O 0000 0.1000 03919 0.5 a 74 remale 0 6967 NS I RN10 NS 0 4729 NS 0 N26

• O M46

• spawnett' 12 3 $ 12 12 Age.4 0J09) 0.4000 0 8000 0 7 bit 2 0 2nIs female 03550 NS 0 6000 NS 0.2000 NS D ONU *

• 0 401i NS apa n ne rs* 11 4 4 11 11 l

Age $ 04546 A J -04kO3 -02242 female 0 th69 NS 0 trint NS 05D4 NR s paw nets" 10 10 10

' f.arly hre history indeces owd wrresporal toihose gnen on Table 21

• TkierrnmeA by applying an age length key (NUSCO 19W) to the tength dninbunon or annual standardi/ed female shundantri.

.c Shown for each Spearman tankqorrelainan correlath,n coeffnunt, probabthty lesel (NS rnd signifwant.

• nigtufu ant at p 5 0 05, * * - segmraans at p 5 0 01), and immbef or annual observatkine (sample ti/c)

Not rewwgh towervauoni mudahle (n 51).

recruitment for the rnost recent year classes. For and three parameter match were lower than the earlier year-classes, differences in estimates between corresponding values (2.972, 2h46) reported in this year and in NUSCO (IWO) for the recruit index NUSCO (1990). The lower estimates this yeat were ranged from -l% (1977 year class) to .107, (190 year, the result of generally lower recruitment indices as a claw). The index this year inetcased 3% for the 1984 result of their re calculation as well as from the addi-year class, but decreased 25% for the 1985 year class, tion of the 1986 data point, which was a poor as fewer age.S fish were found in 1990 than expected, recruitment year. The estimate of Ricker's J par.

Ricker's two parameter model (Eq. 7) was initially ameter, which .. describes the annual rate of fit to the spawner and recruit data and a was estimated compensatory mortality as a function of the stock as 2.422 with a standard error of 0.785, or about 32% sire, was 0.(X)00214, 7his value was essentially of the parameter value. A second fit to the data using imchanged (0.(XXK.'223 in NUSCO 1990), confirming the three parameter model with temperature effects the consistency of this parameter since 1988.

~ (Eq. 8) provided a lower estimate for a of 2.226 and a The absolute value for 6 ( 0.329) increased from reduced standard error of 0.518, or about 23% of the the value of 0.259 reported last yetir. Mechamsms parameter value (Table 29). For this model, the that result in the negative relationship between winter parameter $, corresponding to the effect of February flounder recruitment and February temperatures temperature deviations (Tres) from the 1977 86 rnean - remain unknown, bol February coincides with most of 2.3'C was negative (-0.329) and significant. Iloth . spawning, egg incubation, and hatching. These pro.

of the SRR's are shown in Figure 33 as follows: the cesses as well as larval growth,, ire all temperature-unadjusted SRR (two parameter model: Eq. 7) is dependent. In aildition, the effect of temperature on shown as the central broken line curve drawn near the potential prey or predators (e.g., sand shrimp) of solid-line curve that represents the three parameter larvac and newly metamorphosed juveniles may be an curve (taljusted SRR for the 1977 86 mean February additione means for control of population abundance.

temperature of 2.3'CL Finally, the two dashed line The three parameter SRR explained $8% of the curves included in the same' figure describe low variability associated with the recruitment index, an recruitment in the warmest year (1984; Treh = + 1.72)_

increase fre n the R2 of 47% reported last year and high recruitment in the coklest year (1977: Tren = M.E M4 hdng m N m, die M &

1.94). The a values determined for both the two- last two recruitment indices calculated (1985 and 1986 60 Monitoring Studies,1990

l i

l l 1 Allt.l 21 Annual Niantic River winter thunder siat rnruitment data based un imh6cs of egg pralunam for the 1977 thniugh the 19166 l year.(laises e uh mean i thruary w aict innp rature and dev6atums (I nd inen the mean.

I

Mean f ebruary idiaine from i

Indes of female imica of female R!P ' u ater nican 3 etwu,iry water Year 4tais sponets(P)* rnru e(R f' ratio temlerature ('C) tenywrature (thd 1977 21,710 70,17 k 3.23 0,36 l 94 j 1978 39,474 49,520 1.25 1.09 1,21 1

1979 29,450 39,94 R I.36 1.48 0 k2 19k0 23l144 31,66$ 1.36 2 't k 0 0h '

1981 76,093 31,333 0,41 2 to 0.33 19h2 k7.R 50 36,717 0 42 1 56 n 74

19R3 59,524 3 8,81 R 0 65 3 74 1 44 1984 27,$ 96 30361 1.10 4,02 1,72 19h5 31,097' 19,362 0 62 2 36 0.06 1986 24,n25 15,677 0 65 3.11i 1 OR j Mean 42,017 36,360 0 ti7 2.30

• Stnied munker of female spa nen and retruni rnen npened egg pn=luuunt kahng iaaon used une 561p eggi per innaici and I multipher ol 30 $64 to bong knalimmberi up to an absoluir pipulatum sisc.

• 1ren of female rectuus differs fnwu that repmed m NUSCO (1990) because of a change m the method of talculatnsi oce int).

• Value of female spwner indo for 19M$ torrected (nwn that repated in NUSCO (194r).

year-cittsses) were less than crpected, given parenuti feliance placed on obsened catches and less on stock sites and prevailing February water temp-projections of future egg pnxtuction, cratures in those years, llowever, both of these esti- Ilecause fishing mortality has been rising steadily

. mates may te regarded as preliminary, because their since 1978 (Smith ct al,1989), the Niantic River values relied on only one or two age gt,ups to which winter flounder population has undergone considerable annual estimates of survival, maturity, and fecundity reduction in stock hi/c and its present fishing were applied to project expected fecruitment in exploitation rate is believed to be approaching the subsequent years, For incompletely fecruited age- critical value for recruitment overfishing, Gibson classes, this procedure rnay have resulted in (1989) reported SRR u values for several other considerable error. For oldef, fully recruited year. Southern New England winter flounder stocks that classes, calculations were more reliable because the ranged from 2,22 to 2,59 when scaled for biomass index w.,4 based on the observed abundance of units of the stock, These estimates were not signif.

spawners over a number of years. Dus, data from icantly different from the n value of 3,74 obtained for

- futurc surveys should result in improved recruitment Connecticut winter flounder by Crecco and flowell estimates for the must recent yeariclasses with more (1990) with methods that did not rely on stock and TAllLli 29. parameten of the f(i6ker sto6k recruiiment matel rated to Nientic rner winact thunder data nen r 1977 through 1986 and mne l derived points of reference.

Mtal parameters and reference pomts hhidel parameter Standard error t' a parameter (cornpensatory reserve) 2,226 0,3111 4,30 "

l.

j- l} parameter 2. I 40s 104 4.6 I a 10

• 4,64 " '

$ parameter o.329 0.09144 3.34 "

Ik l uilibrium sim;k (P ) 37J96 -

Fuhing raic (I'po) for " recruitment over6 thing

• 0.695

-

• t stausue ice perameter estimate s 0 with d.f. = n 3 = 7

• As derined by Sissenwine and Shepherd (1987).

Winter Flounder 61

_ . . . i BO' 3

• 17 (O M)

~a 70-o 6

2 60^

g , e n U x,

.a

$; /> U 4?A - . _. _ P3 (3 74W 40' t-L . ~ _ . , p ,, g m 0 ,' 4 e ~

1 30- f., g ug eu u as n;

D i O' -

'?.b (i .RW h,l .

?t>(3JPW 6 10' x

d ,

n: 3., ., , ., , _ , . - - , - - ,

a 10 20 30 40 b0 t> 0 70 80 90 600 i~i: mad: WAMDb IN TH00%Db l'ig. 31 The Rk ker SkRa for Niantic fliser winter flounder w nh I chru.uy encan temperature ('C) shown f or c.w h par.clau (see teu for esplanation of the four turves plottedt recruitment data. Recent shsk-recruitment tused esti4 (Cushing 1971; Cushing and llartis 1973; Longhurst mates of u for the Niantic River winter flounder 1983; lloenig et al.1987; lloudreau and Dickie 1989) greatly undere.stimated the true slope at the origin for based on diflerent life history parameters. Because this stock bec4iuse the method of calculating annual these methods do not depend upon direct estimates of icouitment already incorporated the cifcct 01 ( Aploi- recruitm nt, they avoid biases caused by changing tation on fish of age 2 and older in addition to any fishing rates and provide independent means of vali-larval entrainment effects. Therefore, direct estimates dating SRR-based estimates. The present study used of a provide values corresponding to a compensatory a Ricker model u parameter estimate derived from the resene diminished by prevalent entrainment and value of 3.74 in biomass units reported by Crecco and exploitation rates. Goodyear (1977) discussed the flowell (1990: Tuble 2) by re scaling it for stock concept of compensatory reserve in thhing stocks and units of numbers of fish. 'Ihis scaling was based on the effect of exploitation on the shape of the the relationship:

reproduction curve when the recruitment index is o g, = a / (mean weight per mature female based on the exploited stmL (Goodyear 1977: Fig.1).

Ish) (20)

This implied that as entrainment and fishing rates where the mean weight is calculated for a population increase, the estimates of recruitment will decrease at equihbrium and assuming only natural mortality and so will the estimates of n (i.e., the

• remaining" ( .c., the unfished population). The calculation of a compensatory reserve),

incan weight of 1.45 lbs per female spawner for the The possibility of using indirect methods to Niantic River unfished winter flounder stock is shown estimate the true a parameter (i.e., for the virgin in Table 30 usine population data pieviously reported stock when F=0) was investigated by Crecco and in NUSCO (19d0). Using this mean weight, the re-llowell (14)0). They used four indirect methods g.ded u paracter for 'his uudy a obtained m 62 Monitoring Studies,1990

TAllt.l. 30 Dnunau utuilanoni for the hnnc Riut o mtri nonnao remale irawnmg ins k tiaird on an inuaniancoui naioral mortahn este of M s0 3$ and an mitaniantout Inhmg monaho , sic of I mo (g npn om i)

I emale bids i of we 9,hi of Iggs p r spaw meg noiL lh p.pulahon i ras uon maiore maiore lemales enaturr buim a n pr alsu non Art nur mahnt female' Chi ptinb) femalt Obo omunmi) 2 1000 0 " ha 00 00 1 7D4 69 0 Oli $6 lh 0 $$4 2217)$ 31.2 4 12 bij 4 496 $9 0.16 17k 77 0 kli 174 9 ) 141ok 67 6ku

$ 34444 0 92 121 94 i Okk St.k 2 41 MO 2 I tk2 942 0 246 60 1,0() 2 4 t t.0 1377 7k$ko t .119 8,6 19 ) KOO 7 17177 1 09 171 77 1 g,4 4 3 004 7 / g. ;kt p, 174 6al k 122 46 1 00 12246 i k73 1201123 2N % 147 Dx6 9 h6 29 1.00 k6 29 2 037 136n9si 17 t 5 t 117 vty to 60 kl 1 00 60 kl 2 201 1502$s7 lit y r 91.17 l 11 42 n$ 1 00 42 h5 2 104 ISyk397 9A 74 6k tot 12 30 20 1.00 30 20 2 390 I t.k 2 204 72 17 50 7ok li 21.2 k i 00 21.? N 2 161 17$4kno 52 37 17 142 14 l $ .00 1.00 15 00 2 516 ikO9000 '. 7. 71 27.12/

15 10 57 i.00 10 $7 2 s$2 Ikl$kuu 2 t, 9 7 lo.$o$

'l otal 1T61 ni 1366 91 tuhu 71 i tol 1N Mran weight nr maiore femaic fnh e (1 %0 lbi + 1.47 mature frmalco = 145 lhi o / 6 t m hsh)

Mean letunday (vngm sus L) . N 7),54k (gp pet f emale spawin-t in NUSCO (1990). Using this mean weight, the ie. MNI'S impact assessment scaled a parameter for this study w as obtamed as u = (obioman)(mean weight) = (3.74)(1.45 lbs) lhtiituites oflarwilentniinmerit at A/N/'S a: $.42 (21)

This parameter describes the siwk's inherent gutential The number of w mier Hounder larvae entrained in for increase becaue the naturallogarithm of u is the the condenser coohng water of MNPS is the most slope of the SR curve at the migin for the unfished direct measure of potential impact on the winter floun.

stock (Ricker 1954) and that slope, in turn, der stoi.k. The annual total entrained was related to corresponds to the intrinsic rate of natural increase of larval densities in Niantic Itay and plant operations the population (Roughgarden 1979). Since the slope (cooling water volume). Generally larvae were of the SR curve at the origin decreases with coHected at :itation EN trom i ebruary through June, increasing exploitation rates, it is usclul to think of with a majority (greater than 409) occmring in April u as the " remaining growth potential" or " growth and May. The entrainment estimate for 1990 (138.9 reserve" of the stock. Consequently, the large million) was one of the lowest since the start of three.

difference between the value of a derised aNwe and unit operations in 1986 (Table 31). 'Ibc lower the direct regression estimate of ux2.226 (Table 29) entrainment estimate in 1990 can be attributed to low simply reflects the dif ferent growth reserves of the larval abundance, as the cooling water volume was unfished and exploited stwks of that species when the about average, Entrainment estimates for this report fishing rates are relatively high. The choice of an were based on the Gomperu density function (Eq. 3) unfished stock as the starting point for the simulation and were generally greater than those previously had also advantages for the particular simulation re[orted (NUSCO 1990), w hich were calculated from scenario selected for this studys which included the seasonal median density. A comparison of initially moderate fishing rates much lower than those estimates using the median and Gomperu function is affecting the data on which the regression estimate of provided in a separate section of this report (see a was based. Estimates of the other two SR Ichthyoplankton Entrainment Estimation).

parameters, p and c, for the population model were as As in previous years, larvae in Stage 3 of reported in Table 29. development predominated in entrainment collections.

Winter Flounder 63

. . _ . _ _ _ - _ _ . _ _ _ . _ . - - _ _ . - - - . , . . _ _ - - - - - ~. ._ - -

TAltt5 31. Annual stundance indes (a parameter of the Gomgwns runtum) v 6ih 95% umridence snietsel of omier noun.ict tanac in entrainment narnples and total annual entraminent estimates danng the lanal traton or ouurtente, and the udume of seamaict entrained at MNPS cas year during an is day p rat from 1:chruar) l$ throgh he 30.

Numtwr entmned Scan ater solume a Year a turameter VM sontalence inter $al in rnilliunt entrained (m X 10 )

3 6 i 1976 1,636 1,$ $ $ .1,724 107 6 t>62.A 1977 751 630 832 31.2 $65 6 1978 1,947 1,2n8 2,666 87 4 49u 9 1979 1,296 1,121 1,470 47.7 474.1 1980 2,$ 53 2.47$ 2,632 175.7 6R3 194t 1,163 1,113 1,213 47,7 4$5.2 lub2 2,239 2,1 A4 2.334 170 4 674l 1983 2,9 ti6 2.921 3,012 219.3 644.0 1984 1,*40 1,74l-1.919 A8.3 $73J 198$ 1,$ h $ l.4 0 l.6k6 13.4 $2h 1 19k6 9m $_i7 M 130II 13R 4 1987. 1,194 1,14$ 1.242 172.2 1323 6

. 1988 t.404 1,31 $ . ),4 93 193 4 13kl 7 1989 1,677 1,65n.1,704 114 7 101$ 9 1990 1,073 1,021 1,12$ 138 9 13077 s

In'1990, the percentage of each developmental stage loss of lanae from Niantic Bay occurred during the entrained was 2% for Stage 1,13c4 for Stage 2,74% first part of the larval season, Starting in early April, _

for Stage 3, and i1% for Stage 4. This was similar the Source / Sink term tecame positive, indicating that to the proportions found overall during 1983 89, larvae from other sources (i.e., LIS) were required to which included 2% in Stage 1,27% in Stage 2,60% support the c hange in larval abundance to balance the in Stage 3, and 11% in Stage 4 of development. equation. Dur ng peak entrainment (mid April), more larvac were imported from LlS than were entrained, Mass balance calculations suggesting that this was an important larval source for Niantic Ilay, These patterns in the mass. balance

'The pole'ntiid impact of entrainment on the Niantic results were similar for the other years examined. For Riwr winter flounder stock depends on how many of each 5 day period the proportion of entrainment the entrained larvae originated from this stock, A attributed to the Niantic River was estimated from the .

recent evaloalinn of this effect awumed that all winter . ratio.of larvac entering the bay from the river Counder larvac entrained were from the Niantic River (FromNR) to the total input from both sources .

stock (Crecco and flowell 1990), ilut the possibility (FromNR + Source / Sink). This proportion was

exists that some winter nounder larvac enter Niantic. applied to the total number entrained to estimate the llay from LIS because spawning stocks occur both to number entrained from the Niantic River, For $ day the cast and west of the bay. .To determine if the periods when there was a net loss (negative number of winter 00under larvac entering the Niantic Source / Sink term) or when the proportion from the Day from the river could support the number of Invae river was greater than one, all larvac entrained were observed in the bay each year, rnass balance assumed to have originated from the Niantic River, calculations were made for 1984 through 1990: 5 of listimates of annual total entrainment and the annual these years (1986 90)' occurred during 3 unit number entrained from the' Niantic River were operation.- The results of calculations for each 5 day -detennined by summing over all 5. day periods. Based period in 1990 are provided as an example (Table 32). on mass-balance calculations for data collected in During the season the'value of the-term (5. day 1984 90, alout 29 to 68% of winter flounder larvac Change) went from positive to negative when the entrained by MNPS originated from the Niantic River estimated number of larvac in Niantic Bay started to (Table 33),

decline during a 5. day period beginning on April 21, The potential impact of larval entrain;nent depends As indicated by a negative Source / Sink term, a net upon the age of each larva at the time it is entrained, 64 - Monitoring Studies,1990 u _._._ . . .ua_. _. _.__. _ _ __ _._ _ _ . _ _ _ _ . _ -. - - .-

i l 1

l

'I Allt.E 32. Results of menshlann cakulanons for each 5 day permiin ivv0.

Start of 54ay Nundrr IAsidue Numhet frorn Nurater to .hreeSink '

5. day change e ntraincd to mortality Niantic River Niantit Rivet te nn perimi (X10 *) - (X 10) (X10*) (X 10*) (X10') (X 10*)

2 15 00 8 00' O. 0 8

17.5 0.0 ' 17.5 2 20 0.0 0. 0 0.0 18.4 0.0 18 4 2 25 0.0 0.0 0.0 t il,9 00 l69

.. 3 02 0.0 0.0 0.0 19.1 00 -19 1 1

3 07 0.t 0.0 0.0 Iil 9 00 1E R 3 12 0.5 00 0. I I E.6 0.1 17.9 3 17 1,5 00 03 Ik10 05 15 6 1 3 22 3.1 0.5 07 17.2 1.6 .I13 3 27 45 2.5 1.1 16.3 -36 46 4 01 4.9 5.5 2.2 15,4 6.1 33 4 06 4.1 9.0 2.9 14.4 8.5 10.2 4 11 2,4 15.1 2.0 13.3 10 3 16 5 4 16 0.6 19.2- 2.7 l2.3 11.2 21.3

-4 21 .l 0 19,6 2.6 - 11.3 11.2 21.0 4 26 2.0 17.5 1.7 10.4 10.4 17.3 5 01 2.5 14.3 1.4 9.5 93 13 0 5 06 -2.6 11.0 1.2 8.7 7. 9 6.8 5 11 2.5 6.9 0.9 7.9 66 4.1 5 16 2.2 5.2 0.8 7.2 5.4 1.9 5 21 l<9 3.7 0.6 6.5 43 03 5 26 .l.5 2.7 0.5 6.0 3.4 0.9 5 31 41.2 2.0 0.4 5.4 27 - l .6 6 05 41.0 1.4 0.3 49 2.1 2.1 '

6 10 08 1.1 02 4.5 1.6 2.3 6 15 0.6 08 0.2 4.1 1.2 -2.5 6 20 0.5 0.5 0.I 3.7 0.9 ,2.6

, 6 25 0,4 0.3 0.I 3.4 0.7 <- 2.6

+

a Due to toimding zero salues represent numbers under 50#Ki tarvae.

TAD 1.E 33.1. anal u.tcr f1wnder en! mates of total entrainment, number of larvae emreined fr~n the Niwne 14ver. and the [wrcenage of total entrainment attributed to the Niantic River for 1984 90.

N! antic River  % enirninment

. Tuial entrainment larval entrainment etinhuted to Year (X10') (X106 ) the Niantic River 1984 84.3 59.8 67.7 1985 83.4 44.7 53.6 1986 130.8 '53.7 41,1 1987 172.2 '70.7 41.1 ,

1988 193.4 63.6 32.9 1989 174.7 51.2 29,3 .

1990 138.9 72.5 52.2 l

Winter Flournier - 65

..w..-.-,--.__.--,, ..--.-e-.m,.w-.e.-..e.,.m.,.-.r-,.,,w., +,w ,v

4 because an older individual has a greatei protubility to Niantic River (see Fig. 5). Estimated daily entrain-

. contribute to year class strength than a younger one, ment was based on data taken with high sampling 1herefore, the estimated number entrained during each frequency; eight samples wcre collected per weck at 5 day perial for each developmental stage was based station EN in March and April when entrainment was on the proportion of each stage collected at station greatest. Even though estimates for the parameters EN. Ily applying the proportion of ertrainment Mort and ToNR had probably the least precision, attributed to the Niantic River (FrornSR / E of results of the sensitivity analyses indicated that even FromNR and Source / Sink), the number o* larvae in large errors in their estimates w ould not have appreci, each stage was allocated to each of the two tources for ably changed the estimated number of larvac entrained every 5 day period. The annual numbet of larvae from the Niantic River stm k. The change in prmlue-entrained by stage from each source was estimated by tion losses due to varying the above input parameters summing over all 5 day periods (Fig. 34). Escept for can be determined 1 y direcdy .y plying the increased 1984 and 1990, rnost of the Stage 3 larvae (the or decreaed percentage of larvac entniined to the esti-predominant stage entrained) originated from sources mated praluction losses in Table 34.

other than the Niantic River. Some of the larger larvae from other sources rnay have entered the lifkrt ofentralnment on a year class s

Niantic River during a flomi tide and could have caused the increased frequency noted in larger sire- Annual entraintuent estimates were tompared to classes (Fig.16). The estimated number of larvac indices of aburulance for ages 0 and i juvenile winter entrained by stage from the river was compared to the flounder (Table 36). Although none of these post.

annual abundance estimates for each larval stage in entrainment life stages was significantly correlated the Niantic Rive' (Table 34). The estimated with total larval entrainment, sample sites oI avail-percentage of the Niantic River winter flounder able data were relatively small(713). Nevertheless, prmluction that was entrained annually since 1984 the correlation coefficients were all positive (i.e., no ranged from about 6 to 1991. These (sthnates of yeas apparent effect), except for the index of age 1 fish.

class strength reductions can le used in further impact flowever, the reliability of the age I abundance indes assessment work using the SPDM. Based on avaib as a true menture of year class strength is able data, the empirical mas + balance calculations indi- questionable, as discutted previously in this report, cated that a large number of entrained larvac werc 'Ide negative correlation between the apparent from a source or sources other than the Niantic Wver. survival of 7+ mm larvae through age l and total The estimated nun,ber of winter floundo larvac entra inment could te interpreted as an adverse effect of entrained from the Niantic River stock, sa based on er.tratnment on year class strength. Ilowever, that mass ixdance calculations, depended upon the accuracy negative correlallon was not significant and, of the input parameters. To determine the impli- furthennere, the group of age 1 fish did not appear cations of inaccurate input data, sensitivity analyses correlated with adult spawners (Table 27). In general, were conducted on the mass balance calculations for negauve e irrelations between annual entrainment and four parameters: Mort, FromNR, ToNR, and Entrain. survival of early life history stages do not necessarily The number of larvac entrained from the Niantic imply an entrainment impact unless positive River was recomputed with each of the four correlations between those early life history stages parameters doubled (X 2) or reduced by half (X 0.5), and mature female fish can also le demonstrated.

w hile the remaining three parameters were unchanged.

Ilased on the percent change from the original Stochaffic simulallon of thc NiantiC Nlrrr estimates, the larval mortality rate (Mort) and the winterflounder stock number of larvac entering the Niantic River (ToNR) were the least sensitive of the four parameters (Table Model - Input dala, The input data used to 35)? The most sensitive parameters were the numtcr initialite the SPDM for the Niantic River winter of larvae entering the bay from the river (FromNR) flounder shock included basic life table parameters for and the number entrained, but these two parameters the adult population (e.g., number of age-classes, age-were probably the most precisely estimated as well. specific rates of maturation, natural rnortality and A good relationship was found letween the estimated fishing, and average weight and fecundity at age); the daily abundance at station C (used to estimate irutially unfished or virgin spawning stock size and FromNR) and the actual density at the mouth of the its mean fecundity; the three parameter estimates of 66 Monitoring Studies,1990

- - .- ,- ..= - -. - .

f i P

]

1 30 h 3934 j939 __,

- { e- $- 26 *-

E02 20 '

t: .

~ 16_ -

y.> 16 -

10 -

~

h 10-

~~~"

0- -

1-2

-j 3

3 4

3 0- UL.T 1 2 i ~~ 7 3

t-I 1

1.

60 - --

I 1006 1987 70 -

S* 40 "

, --4 c" 60 -

• ~

E E -

$0 p 30- -

$ 7 ~ ~ '

9 QI 40

~ -*

' 2 30 _

h 20- .

1-

$10--

~~'

-- $ g,-

w w 10-N 0- r-'* n, 7 7 ,

0- --

-; j  ;  ;

1 2 3 4 1 2 3 4

-120 - 60 -

1988 '

1989 -

ro100 - -

c 70 -- .

e o.* 60 -

6 80 - 5 y 60 - >

g 60- # 40_ _

4g. . 30 - -

20 -

g g

20 - -

w 10 -

" P 0:

1 i

2

~~',

3 g

4 j 0 N*~'

1 2

3

"U -)

4 60 - '

1990 r so ~~

S. .

E 40.-

t; O

~ ['] NIANTIC RIVER l 30-w 10-20 -

[] OTHER SOURCES

~

0- i I- -1 1 1 2 3 4 5 STAGE-Fig,34; Estimated numbe: of winter fimub larvao entrained at MNPS by developmental stage (rorn the Mantic River and other sourecs, based on mass balance calculatioe for 1984 through 1990, Winter Flounder 67

..- . . _ . . - . - . _ . . _ . . .__.__,;____.___. . _ , _ _ . _ . _ _ _ _ _ . . . _ _ , - ~ . - ~ _ . . . _

4 J

1 Altli 34 Estimated stamJanse 64 wmter flouneer lanac in the Nientar imer and the numtwt and terstninge 4 the prmlattain enirainett

! fawn the Nienuc kner by denlopmental stage for 1%M0 The numter uf lanet fran the Niantu knet was Nwd on mais blance j - < eleplathms.

Nint ta Rsver* 1.ntramment (som Ibelnpmemal als,ntante Manik River 4 of .he stage (X10*) (A ID*) sumla,tiim a

, . _ .m -,-.m-.- m........ _. .

I hl4

!- Stage i Mwb 03 dii Stage 2 743 23.2 34

! htage 3 364 27.7 7.6 j l Stage 4 253 6.ti 26 '

i Tinal 3Y.k' 13 7 1V1.9 l- Slage 1 4071 41 0.1 l_ Suge 2 977 22.7 2.3 i Stage 3 479 15.3 L2 i buge 4 33$ 26 06 l lin al - 41.7 64 l l'!M Stage i 2696 11 .r u l 7 l- Siege 2 755 12,I l.6 l Stage 3 392 29.9 7.6 l stagt .i 275 10 6 3.9 heal 53 A 13.2 l ]

i .

hh2 Stage 1 32N1 1.1 < 0.1 ,

l Since 2 919 22.I 24 i Slage 3 478 42.5 80

Stage 4 334 1,5 5.0 lival 70 8 12.9 M5 hinge I $352 4.7 0.1 Stage 2 - 803 12.7 1.6 Stage 3 - 289 40.8 14.1 Stage 4 208 5.5 26-Tuial t0.7 i n ,4 MB.2 ,

Stage 1. 4421 _ 3.7 0.1 Stage 2 _619~ 16 1 16 .

Stage 3 204 28 9 I42 l Stage 4 137 2.4 l.8 lidal 51.1 18.7

. . - h2D

' Siage 1 -.

2667 1.5 - 0.1 Stage 2 1095 10.1 0.9 Siege 3 301 52.1 17,3 Stage 4 -259 14 . 9 -U3 l

Tttal 12.b 18.6 8

I. Alumdance citimates for 1964,ho were (rorn Crrno amilloweu (1%0) and for 1990 were cakulated by NUSCO staff.

• S nne entrainment estimates atmhed to the Niantk River me dJfer slighdy frun thme m Table 33 because of rounding error; M . Monitoring Studies 1990

1 AB1135. *lhe estm nie : nun,ber of w mu r fLionarr 1,in ac entra.orJ leed on nim balante tahulatuen compaul to the tnulu of sentiinil) analy sts w ith the (wittniap intnair (+ ) of darrec ( ) f rom the ongmal enumair Iur 19A4 thr+gh IVWI 1954 19h$ IVh6 IVh7 Ivhh low 1990 Ytar (Xif) (N 10$ s\ 10 % (\ 10 6; (K lO% (N lgh gy gghj I'surnate' $9 h 44 7 31 7 70 7 t,1 6 s1 ; 7; 3 (Maru X 0 5 f> 4 2 47 7 S t. ; 73 9 or, 4 sa ; 74 7

% chanp +7.4 6.7 44 7 4$ ,44 4$9 .3g (Mort) X 2 $2 4 40 4 49.3 64 h $h O 4n 6 (,7 9

'r e thang -12 4 96 42 63 hh 90 63 (I nimNH) X 0 4 32.7 29 3 30 7 37.3 3 r. 4 :A0 19.3

% <hangt -4$ 3 14 5 -4; y 47 ; 4; 8 45 1 4g 3 (f rornNR)N 2 hh.) f 17 k N (, 125 (, 104 3 y, 9 Ign 7

% tharte .47 3 .42 5 .fA 0 .77 7 . f ,1 0 , g,y 7 ,p g floSR) X O 5 73 6 $15 61 8 n; 3 73 1 $n g g6 ;

4 thang 423 1 + 19.7 ,13 l , l t, 7 ,l4 o . 10 3 .jg9 floNR)X 2 41.5 3% 1 4; 4 $5.3 50 1 41 7 31.9

% chang 30 to .;l 5 -;l o .;] .R 21j . n e, q$7 (lentrain) X 0 5 34 2 23.2 34 6 4x 9 39 9 3i 7 46 9

% shange 42 h 43 6 15 f. 00k 37 3 3h l 33 3 ti mram) X 2 95.1 75,3 74 4 9.18 90 6 74 0 tot n

% chanur + 39 0 + 6N.5 63h $ e 32.7 -,4 2 $ 444.5 ,39 3

• lbumatcd numhet (X lif') of winter Ibun.lcr lariac cni'aowd then the Nianta Knct (see 1able 31) the SRR: st.itistics from actual water teinperature d.ita Carlo replications desired, mnditional tuottality in February during 1977 86 (e.g., nican, standard (ENTO l5,20, or 259 ) wtresponding to the particular deviation.and temperature range); and sitnulat;an para. larval entrainment at MNPS to be simulated. and meters specific to each Innlel run, such as nuilder of whether fishing rates initially input were to be years for the population projection, number of Monte changed during the simulation (Table 37). In the T Altl136. Mains of S wamuni s rank. order corniatiam twiween the annual csumates of lanat wmier nounder enuamment at MNPS amt several pnt entramment early IJe hi* tory siapt l Uwf r rner I,0wCr rnrr l all-carly w irlier hianlR NNrr Apparent larval carly ap.0 1Mc ap 0 rner bay wirer sprmg sury n al inde s ' ju v emics juveniles pn enile s ap.) jusemici rate Annual 0.35716 0.3000 0 5121 0.lk48 02354 esumate of 0 3851 NS 0.2070 NS 0 0612 NS 0$270 NS 0 417s NS entrainment h > l4 l4 14

• In4hces used corre<pwul to th ,e given iv. iehle 23, eu rpt for the appart nt sunn al rate, whi;h is the age.1 indes onided h the mdn of 7 rum and larpr 14n me in Nianuc 11i>.

" Shown for each Spearman rank terrelation.

orrelation mffiaent, pftbabdlly lcs cl (NS . thd glgmiff tent, *

• bigni[h Rnl at p 5 0 05, * * . sigriificant at p 5 0 01), arul numhet of annual (&tvauons ', enple sve)

Winter Flounder 69

1 Allt.l! 37 Data, was. and wher inlwie uu d with the %anu6 kner u min flutact pyulatusi d>*umiu a simulatum nulel _

Malet inpit Yahw used or suitable Number of age-clators in prolanon 15 l'athest age at u hn b an feniales arv niaturr 6 l tastuvi rnaiutt, rue m wt ilNL ami tot an troun.hty b ap AFr I femalci O O Ol1 0 Aye 2 fnnakt 0 0 125 0 0 08 0 554 2D//15 Age-3 femaki Age 4 fernalci 0 36 O bil 37,5 A4 Age 5 fernales 0 92 l Oh9 56h,2 4.1 Age 4 fernalci  ! 00 1377 7k$,V87 Age 7 femalct 1 00 1 645 1,004,776 Age h femalci 1 00 1 b73 1,201.125 Age-9 females 1.0h 20%7 1 J 66,u t i Ag e.10 f ettistes 1 00 2 201 1,50 2 ,':57 Age 11 females 1 00 2 104 1,59%,597 ._-_

Agr.12 females 1 00 2 390 1,fi h 2,2 n h Age 13 lemaici 1 00 2 461 1,754 MD --

A ge -14 lemale, 1 00 2 516 1, h D9,000 Age .15 females 1 00 2 552 1.5 4 5,h 00 Age af trr w hn h unertahty rername tomtant 3 Imtantannwt mort.ibiy rates M and l at age-1 0 90 0' Imtanianeous monahty take M and l at age 2 0 45 0 Instantaneous monahiy raies M and l- si av 3 + 0 15 0 Imual lemale spawtung simk sur 7tWKP Mean fesundy of the sim k feggt/femaic spaw ner) 171,060' a inen Ridet i three parameter SKR 5 42' D f rom Rider's ibire p.iramcies SRR 2.140510 '

o f rom Rider's three paramcier NRR 0 329 Mean I chru. ry (1977 M) w aa r irmperaturr (T) 2 30 ltafklard dC%lathili 1,19 imnunum temn rature 0 36 ma6 mum temp raunt 4 02 Number of spsuntng cples (years)to simulate 100 Number of simulainm rephsaiti per run 100 1:racuon of age-O group entrained at MNPS (i.e , unpaa) 0 00'

• Values are entered here ml) when enonahues ermAin 11, int dunn$ all the Epa %mng (plci of ) Cart $lmulalCd [Cro Talues direct the snakl to get a detailed schedule of tuonahues frien en audhar) ,nput fil: net up at a liaOup table (sce Appenda Is

• Cottespmds to the unf nhed umL

• A sero simulates a non impaaed st<n k; other+ ne the mndinonal monabi3 due to cmramment is used latter case the model used a secondary input file to 1960 to 206(0. Annual February temperatures were read the fishing und larval entrainment rates for each random variates from a truncated normal distribution year of the simulation (App:ndit I), All the model with the range, mean and standard deviation specified runs in this study were stochastie and consisted of a-s input (Table 37). A second form of random 100 rephrates of each imyear stak projection (from variability (the " noise" component n, in Eq,19) was 70 Monitorirg, Studies,1990

~ _ _ _ - - , _ . _ - . - - -- .

- _ ~ - - - - - - ~ _ - _ - - - --.- -

j l

4 3

also present in the pencration of all the stochastic recovered only partially mer the nest 6 to 7 years, block projections. The amouilt of viuiabihty needed and finally (onverged to a new sustainable stock that

. for this noise conyonent was determined during the fluctuated alvut a mean sue of 43,5(Mi spanners

) initial cahbration of the model described in NllSCO through the end of the series, The stott recovery 1

(1990). starting in 1991 could be attributed to the new length 1 Simulation results, The sitxhastic baschne limits of 1I atal 10 in for the commercial and stort generated for impact assentuent pur)mses (Fig. 35) fisheries, respectively, and to a slight reduction in illustrated the trends in abundance 01 Niantic River overall fishing rates from 0.65 to OR). The mean winter flounder since 1960, wien only fishing ef fects weight per female spawner, w hich was i,10 lbs in were cornidered, This MmL projection awumed no 1971 ($2,000 lbs und 47,(KR) spawners), dechned to '

power plant effects and was taler used as a standard about I lb per spawner by 1991 as a result of upainst which the three impacted stock projections increasing esploitation rates. This caused the stock were compMed Therclore,it was imprtant for the projection lines plotted for fish numbers and biomass st wk trajectory described by the bascime to be a fair after 1991 (Fig, 35) to be almost identical as the represcritation of past pad prqjected trends of the hical reduction in the Hierage weight of female spawners winter flounder abundance, Although the unfished made Osh numbers and biomass equivaleni.

J stock site used to initiative the simulation was For the simulation, the top line (dashed) in Figure 76,500 female spawners (or about lil A10 lbs), the 36 is the baseline time seties from Figure 3$ dis-actual mean sire _to which the esploited stock cussed abme, The other threc hnes (solid) corres[onJ converged by 1971 under the starting nominal fishing to the prqjections of the same initial stock as in the rate of Fa0,40 was about 47MXi female spawners or baseline, but with annual larval lones at low

$2,000 lbs (Table 3h Accordmg to the simulation (ENT= l 59 ), medimn (20%), and high (25's ) entrain.

schedule (App ndis !), nominal fishing rates started at rnen] rates, as listed in Appendis 1. In all thtee impac.

- Fw0,40 and_ remained stable through 1970, increased led lopulation projections, the stock began to decline gradually to a maximum rate of 0.65 by 19X9 90, 4 years after the start up of Unit I in 1971, reached a 4

declined back to 0.60 by 1995, and remained stable minimum in 1991 for numbers (i.e.,4 years after the thereafter, The baseline in Figure 35 agreed fairly start of Unit 3) and in 1992 for Homass, and then well with the above scenario as the initial slock began a slow recovery that accelerated after the end of averaged (thout 47,000 female spawners through three unit operation in 2010, The impacted stocks, ,

1971, then steadily declined to about 37,000 by 1991, however, did not return to baseline levels until about

'l Allt.fi 38. lisputed omndiers and bbnais or trmale wintet n,under trawners ai rior (ntaal minis i dunng the simulation (ec lburc 36) 1 tpected sawk sieci are the geomeine mean or 1n0 Monte Perlo rephemies Perantagri helmeen parenthews indaate ihr propoed atmk trduemm relaiNC 10 thC hMbnC Hmk U/C Ior thf namC Kaf.

Start or Smalleti l' tant impact on: Uno 1 start up: 3 urdi operanon: ilm k siis Unii 3 thui down:

Numteri 197l 1986 1991 202h llawhne (Inia 0) 4 7,n5 7 39,20h 36,927 41,524 t ow imput (l'.N*li 15%) 47,047 35,916 (ht) 31,394 (IS%) 39,456 ol%)

Medmm tmpact (INii20%) 47,057 34/!90 (11 %) 29,52) (20% ) 38,f 10 (ll%)

- t hgh impact O'.NTt:5%) 47,057 33 A51 (14% ) 27Al7 (25%) _ 37,221 (15 % )-

liioman _ 1971 1986 1992. -2026 11awlme 0:NT=0) 5 l ,971 40,ita 37,253 43,794 low impact (13NTal5%) $ 1,971 37,n t ? (8% ) 31.416 (16 %) 40,08N (8% )

Medmm imgvet ONT=20%) 51,971 35,867 til%) 29.473 (21% ) 38,744 (119-)

liigh impact ONii2%) 51,971 34,709 (14% ) 27,$n6 (2h'O. 37,2h9 (tS%)

Winter Flounder ' 71

7b. Maximo en 9 70- .

o e i

f" 65; o, o, o ,, o o, o

,o o .

• o ** = e * **

• f * *yl

• o*w,o ***

o,*S *,$s en e

• o%t o <<> *o~,

g SS- ** *o , o, *, o *, .

p 5& ** Mean and 9br U

1. ggy44g{g{ \g9 4 t

tgHyd"U MHHHHinHHHi!HhgggHHHHHHftH9H l

.t 40' t I A

• o y'N 00 - 3$- o*o g % *o co* o, o o o 30

• • *oo *o o e

3 *

• %*o

-id 2S' is.

'3;

., Minirna 1960 1970 '1980 1990 2000 2010 2020 2030 2040 20b0 2060 2 YEAR d

o 75 - Mox rhu

' ru O e

-70' *mq%*

^ o o o th Db^ , o- o S o **o

• e , o o e*f e- *a. o%,

• a g* *cm ,,o /* ,*%"=,

W 9tH4fitHHHi **# **

• s$j 50'  % Mean and 95x Cl i

S:'

go a, o*

o '"\ y gv """""""*""""""""H " o "" nt""" a n" 4,*

o ,o eo * 'o,% / %" %o"ccrPooj o'o,ed id *

• W @

d 15 '

Minima-hs 20 19 t>0 1970 '1980 fl900 - 2000 2010 2020 2030 2040 2050 2060 YEAR l'ig,35. Stochastic baseline of the Niantic River wintet Dounder stock espressed as numbers (top) and biomass doisom) with the annual simrt and comrnercial fishing rates sirnulated as folows: a nominal fishing rate of F=0.40 remained constant -

until 1970, then gradually increased to F=0 65 in 1989 90, declined to 140.60 by 1995, and remained constant at that rate thereafter (see Appendis i for detailed schedule). Each solid line describes the average and 95% CI (100 Mora Carlo replicatioris) of the stock sire trajectory. The open circles cortesiend to the largest and the smallest stocks among the 100 4 - replicates generated for each year, 72 Monitoring Studies,1990

. u. - _ _ _ _ , _ _ _ _ _ _ _ . _ , , . . _ _ _ . _ . - _ . - _ . _ . _ _ _ . . _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ . . _ _ _ _ _ _ _ - _ _ _ _ _ _ _ .

1 SS: l  ; l l to l l o , , , ,

z bo- l l l l N AI  !  ! l D .

ENTt= 0  : .

o p~ .

T y

'l 7  ; ~ -

y*%e

'{' ,

r

-Z sl '

4 3'

43'  ; / -/

[2 i' 'h / 15x ENT :

AN ,.s/, A w , , l .

2 33- l N /'2 0n ENT, ~'lf 4-l 1

e[' av

{N 33- l l M.j2bx ENT/"f f"I'#  !

W  : /'" l l j '

, l

j w  :

!  ; i L No [1,2-unit ! 3- u nit ;1.2-utut : Reto.ery period

',mpact l._,-%_ops vperation  ; ops .

(no unitt. on .Ene) , . _ _

23- .+ .~._ _

1960 1970 1980 1990 2000 2010 2020 2030 2040 20b0 2060 TEAR o' ba  ; l ,

O ,

, 50-  ! j i  !

n  :  ; l l l o l \  ; ENT = 0 l l O 45- N, .a A '.'

/ ';s -.N-l  !

U)

{ -%

d Ii 40-

,\, /

l "a _

i \ ,j'10*[N f}

sZ 35 i

2o*>(

25x NTr & f ! l 30-v) , , , ,

l u  :

g 25-, l l

!1,2-unit !

l y No il,2-unit ! 3-unit '

Recovery period impact l ops  ; operation l ops (no units on line)

W ,,0.

1960 1970 1980 1990 2000 2010 2020 2030 2040 2050 2060 YEAR fig. 36. Results of the simulation showing the combined effects of fishing and duce different larval entrainment rates on the numbers (top) and biornass (bottom) of the Niantic River winter flounder stock Entrainment rates changed annually according to the number of MNI S units in operation and fishing rates were also variable (see Appendix 1 for detailed schedule). The dashed hne at the top of each graph is the beeline with fishing effects only. All stock sites are averages of 100 Monte Carlo replicates.

1 Winter Flounder 73

10 years af ter the terminanon el MNPS operations m due to entrainment elletts alone Shange from the 2026. The nctual sta L sves projected for cash IM d,nhed line to the sohd line) ia eswntially the same of larval entraininelit at four selected 4imts 1 in tiene for both in whhhon, ligure 37 pros ales tiie rocarn are given m lable 38. Stal louci. relatne to the to aucu the relative cIIctts of hshing and lanal correspondmg luseline u/es are aho show n as percen- entrmnment oser time by tomparmy the inhed and tapes nest to the numbers of inh (or pounds of impa,ted skw L projechon lines to those (orrespond-biornaw). The hrst (olumn m lable 3h gnes the mg to the hshed but ununpacted stosk, and the latter common stmL si/e hir cash ;iroicction m 1071.just to those of the unfhhed and undaturbed sta L.

before the operation of MNpS had any (llect; the Probabilktic risk autument (Pit A) of second colutun corresponsh to 19% and shows larsal entrainment ellects. T he simhasne moderate stm L reductions of h,11, urul 149 resulting sariabihty awociated with shwk projettions for from 15 years of one. and twwunit MNPS operation; lishmg ell" cts alone and ender sunuhaneous Inhing and the llurd (olutan torrnponds to the most critical and lanal entrainment are illustrated in figure 3$ for reference point m the simulanon inauw it predicts the ba cline (i.e., only inhmp) and in i igure 38 for the greatest slmi redus uon that would likely result the worst <ase unpact simulated O.e., f or the 254 under the worst-case conditiom umulated Tins cnti- I NT hoe plotted in Figure 36). 't hn variabihty cal point occurs as a result of a combination of peat forms the basis for probabiksue anal > ws, whkh tale exploiulion rates (FuG 65) and full MNPS three unit into annunt not only the mean stal size predNted operation, which causes maumum suvt reductions f or ead > car, but also the range of prednoons both equivalent hi the direct, unwompensated production smaller and larger than the mean. 'ihe results of the lowes attnbuted to larval enir,umnent. Since thew pR A for stm L projechons made f or 1991 (time of masimum stmL loues are not sustained, the real greatest hshing and larval entrainment rates') and 2006 uwiulnew of the above t ritical point is in aswaing (cod ol l! nit 3 operat on) are sununarized in lables 39 the risk of stott collapse by means of PR A. l> mall), and 40, rc<pectisely. Becauw the run of proba, the fourth und last column (onesponds to the simL bilities in these tables were normaheed to unity, each projc(tions at the end of thut 3 operauon in 2026 single probabihty represents the proportion of 1he predicted stock reductions of 8. Il, and 159 at predicted stod lowes that fell in a given category this refereme point w ere nmderate and short hved, O.e., a specihed range of lowes). The hrst row in since the stml fully recovered in about 10 years, both tables gises the probabdities auociated with returning to baseline levels by 2036 (Fig. 36h simL vanabilii) in the baschne (no plant effects Because conditional manably due to larval entrain- sitnulatedh For imtance, simL instabihty due to ment, unlike fishing tuottality, does not allect the age changing Inhing rates caused d6% of the baseline structure of the stocL. relative loues due to plant stowL (as fish numbers) tephcates for 1991 (Table 39) operation are enentially nientical for both fish to be larger than their mean of 36,927 spawners given nundiers and biomass. Suitt t iomau loues in 1992 in Table 38. Of the 514 that were smaller,27%

were shghdy larger than corresponding loues in fhh were in the 0104 cange, th% were 10-20% smaller numbers for 1991; Ihhing rates increawd during 1971 than the mean, and so forth. The other three rows of 89 and caused a decline in userage spawner weigl t both tables contain similar probabdities, but were from 1.1 lbs in 1971 to about i Ib by 1990. derived f rom the impacted stm L projections instead of Tre dif ferent nature of stm L reductions caused from the baseline. Nesertheless, the stock redueuons directly by fishing and those resuhing from larval were sull relative to the mean size of the baseline loues through entrainment at MNPS is illustrated in stock and, thus, they represented losses caused by Figure 37, Fishing reduces the stml biomass at a larval entrainment. As another example, the proba-greater rate than the number of spawners because it bihty of numeri$al stock reductions of less than 10%

tends to remove larger fish first and, thus, reduces the by 1991 w as 0.22 at low entrainment rates, but only average weight of the spawners tcmammg in the 0.19 and 0.09 at medium arut high entrainment rates, stock l. owes due to tan al entraimnent, on the other res[rctively (Table 39). Similarly, stock losses of 20-hand, remove the same proportion of [kh from each 30% at high entrainment rates had a probability of age group or year class. Therefore, w hile the sto(L O.36, but lowes greater than 409 were scry unlikely reduction due to fishing hhfference between the top (p=0.05). Probabilities obtained for stock losses solid line and the dashed line in Figure 37) is far exprewed as biomau (bottom of Table 39) were very greatet for biomass than for fish numbers, the loss similar to those for simL losses as fish numbers, 74 Momtoring Stuches,1990

i 7b- Moomo

$ 70*

2 o bb' c, O O 99, e n 4,o ee o 5 00 c, , , o ,4,*g ec?o E- 6b- e*

e* o

., e, w,c, 6 U L,

'l e o

Oto *

(n pHtfttt} ggt e, , yean an g 95y, t y i e

~35 * *

• N b ,o ** eo# 4;H4tHHtHttHlHit!HmH j 40- h co s *e*

o ,f #e

• h4 d o*e eff*# b c *e iggHf ct 3b- e, e

^ \ dguyH N t gi " t o

• e * #e4* e*e**%*

• 0 e, '% hpHfHt e,gp*,' p &

~ ~- o & c d go.

• ,*,,5cg '* o 4*'" #

Minimo 1 b __

1960 1970 1980 1990 2000 2010 2020 2030 2040 20b0 20b0 YEAR E2 7S'  % Maximo o

0 70'

• coq %#

• e X 6b' .

60-gno ** 'o *

, o o* *,ow

• o, l n

• en bb' *

$) }Nfyffft}+ a 'o 2 * *47%o

• 60' * *

        $                                                                                                   Mean and 9b> Lt 8e g ep                                           b (t'         40     o     ,e o o g eo                /}}}}gj-}}{}kN}fik fk@,IIN 4

o# , o o**e ,4, g gHW y;! 35: o f o

                                                           \                                                      m                              4

• dI "i

         .d-                                                                      dg499 tut                o We* "## f#coe%P e, #e

• g 30- , n, 4g gtH&p gf

{[* p'- Minima

                                                                  \ ,j         ,,****va e*
                                                                    -r~~r------~                            ~~~~r-~~'~~ -

15 --~~- - - 1960 1970 1960 1990 2000 2010 2020 2030 2040 20$0 2060 YEAR Fig. 37. Illustration of the effects of fishing (twin 0 Ime) and MNPS operation under worst case !arsal entrainment (257 ENT line) relative to the theoretical (SR. based estirnate) uninhed stock espressed as fish numbers (top) and bioman (bottom). All stock sites are aserages of 100 Monte Carlo repbcates. I Winter Flounder 75

't 120-v1 ca 110-k n 100-3 93-o.h.

                         .                                                                                       Unfished Stock Z      B0-            m s v \ p % -                                                                                                 % --- __---                       -

f 70-e a 60-

                        .$        30-                                                                                     ENT = 0 y        40'
                                                                              \. - '. .. ,                    ,...e-~~-.-~m                                 /
                                                                                                                                                                                            - - ~ - -

s/ 25x ENT - (a W"J, d 30-20 * - - 1960 1970 1980 1990 2000 2010 z0/0 2030 i'040 20hD .;' 066 YEAR

                          ,,   i s.O                                                                             Untibbed Stock
                         '] 110, -%,~K,                                                                                 P --           ~/y =-                                                           -

u, 100- , a O 93

                           .1 h., - bo '
                        .M        70-l                          03     '

z

                                 '50-                                                                                     ENT = 0 M

n.

                                                                                   -s j'                       .f        40-                                                               k/       '

25x ENT . ,. J

                           .      30*
                                                                                                   \

W~/ l l.5

                             "     20-1960.'1970 1980' 1990 -2000 2010 2020 -2030 -2040 -2050- 2060 YEAR Fig. 38. Stochastic variability associated with the projected Niantic River winter flounder stock expressed as nomewrs (top) and biornass (lottom) for simulated sinri and commercial fishing rates and worst case larval entrainment at h1NPS (25%

ENT line plotted in Figure 36). Each solid line describes the average and 95% CI(100 Monte Carlo replications) of the stock size trajectory. The open circles correspond to the largest and the smallest stocks among the 100 replicates generated for each year. 76 - Monitoring Studies,1990 L

    ..           . _ .           . . , . . _ ~ _ . . , _ _ _ . _ . . _ _ _ - _ . _ _ . . . . - _
                                                                                                                                  .  ._-_-.______.~___ ._._ _ _ ___ __ __ _ ____ _.______ _             -  -

TAllt E 39 Proteh$ltsik risk usammer-4 ed skak site reductams at the time of peak effects fcw luth fi.hing and tarsal tiritraitiment (1991 for sembers ar,J 1992 ror hiamst IN et. lated ndatims au telatwe to the ene an sin of the bastime stak (mly fuhing effects) for the same yar. IWbibths St.re base 4 sm Idn Mcuite Carlo rephesticms for the sirnulations Ifdbahdily Numbers: Simuleed of stAl -- - 1;mpincal twohabil.nes of pistulated stak reductions by 1991 - --- plau impa tuvase 0 10% 10 20% 2040% 30-4 % 40 5 % >575 Nmc ' O.46 0.27 0 15 0 09 0 0 0 15 % 0.12 0.22 0.34 0.23 0.09 0 0 20% 0.05 0.19 0.24 0.33 0.13 0 01 0 25% 0 03 0.09 0.26 0.36 0.21 0 05 0 Probability thomo ss:

   '                     Simulated           of stak                .- - - thpincal ;wobabihties of posiutated stwk reductims by 1992- -

plant impact inc re ase 010% 1D20% 20 30% 3040% 40 50% >$0% Nme ' O.38 0.27 0.25 0.09 0.01 0 0 15 % 0.12 0.18 0.33 0.28 0.09 0 0 20% 0.05 0.16 0.37 0.30 0.11 0 nn 0 25% 0.05 0.07 0.24 0.37 0,24 0.03 0

               ' Cornspwids to the beschne and illustrates the varahthly associsted with the espected stmk size afwe 30 years, hen no plant effects are simulated TAllLE 40, Probabilistic not assessment of stak sin reductions at the end of the pentui of plant operation (2026 for both tiumbers and bicwness). Postulated reductions are relative to the man site of the basehne stak (only Yishing effects) for the same year. Probabihties were based on 100 Monte Carlo replications for the nimulations.

Probabihty Nun hers: Simulated of sicx k -- Empneal prabsbihthi of postulated simi reduuons by 2026- - plant irnpact incrt ase 010% 10 20% 2040% 30M% 4040's > $M

                                                                                                                                                              ~

Nanc' OA6 0.30 0.15 0 37 0 0 0 15% 0.28 0 36 0.26 n.10 0 0 0 20% 0 25 0.34 0.30 0.10 0.01 0 0 25 % 0.22 0 31 0.32 0.14 0 01 0 0 Probability liioi uns Simulated of stak -- Empincal prteabihtie e of postulated stock reductions by 2026- -- plant impact increase 0-101 10-20% 2060% 30 40% 4050% >50% Nme ' O.50 0 27 0.20 0.33 0 0 0 15 % 0.24 0.37 0.30 0.)9 0 0 0 20% 0.22 0.37 0.31 0. l 0 0 0 0 25% 0.17 0.34 0.34 0.14 0.01 0 0

• Corruponds to the beschne and illustrates the vanabihty associated mth the espec d stock sin after 70 years, when no plant effects are simulated.

There was only a slight tendency for higher rnost likely reductions for wofst case entrainment probabilities of biomass stock reductions in the range (last row in the table) would be 10% or less (p=0.31 of 20 to 40% losses for the worst case entrainment. and 0.34) and between 10 and 20% (p=0.32 and 0.34) Probabilit ies of projected stock losses by the end of fo losses both in terms of numbers and biomass. MNPS operation in 2026 (Table 40) indicated that the The probabilities of stock reductions of 3040% were Winter Flounder 77

                                                                                                                                             ------..---m__.____.____.___-.-

l....... negligible in both cases and were rero for reductions Conclusions greater than 40%. No risk analysis w as conducted for stock projections beyond 2026 because 10 to 15 years ne Niantic River winter nounder spawning stock - after the end of MNpS operation no measurable abundance during the past few years was low as I differences were found between the baseline stock and relatively ;mr year classes produced during the mid-the impacted stocks (Fig. 36). 1980s entered the population. Generally poor Finally, the probabilities of stwk collapse due to recruitment was probably the result of greater than recruitment failure were calculated on the basis of optimal initial number of eggs spawned early with stock biomass losses relative to the unfished sicv,k generally warmer than average winter water temp-biomass usit t the criterion of " recruitment over- eratures that Ncurred during most of the 1980s. In fishing" (Sissenwine and Shepherd 1987). This addition, fishing rates were high during the period, criterion assumes that recruitment failure beccaes a which decisively contributed to reducing the larger real concern when the stock biomass falls bel w a stock sires present at the beginning of the decade. A threshold value equivalent to 10% of the ini.ial possible recent upturn in spawner abundance was unfished stock biomass. The probability of the Nian- indicated by more abundant smaller (2423 cm) w inter tic River winter flounder stock falling below this 00under during the adult survey this year. These fish critical biomass was calculated for the baseline were mostly from the relatively large 1988 year. class. projections with only fishing effccts (Fig. 35) and fm The simulation modeling, however, predicted that the stock projections with both fishing and worst case lowest stock sires would be found in 1991 for entrainment (Fig. 36). The PRA indicated that the numbers and in 1992 for biomass. probability of stock biomass reduction of 70-80% The results from sampling winter nounder larwe in increased frotn 0.32, for fishing effects alone. to 0.83 1990 were consistent with previous findings, liased lor fishing plus worst case entrainment effect:(Table on the temporal and spatial abundance of newly 41). The probability of biomass reductions greater hatched larvac, peak spawning occurred during early to than 80% but less than 90% was only 0.03 for mid February with little, if any, spawnMg in 'bc bay, fishing plus worst case entrainment and the The annual abundance of yolk sac larvac in the probabihty of recruitment failure (biomass reduction Niantic River was directly related to total egg pro-greater than 90%) was rero in all the cases (iA., it duelion. Most larvae were Bushed from the river to never happened during the hundreds of simulations the bay during Stage 2 of deveiopment< luvat length that were conducted), and developmental stage were closely related. Larval growth rates in the bay were positively correlated to water temperature and in the river were density. dependent, pouibly due to prey limitations. Density-dependent larval mortality was apparent and a TAllt.t! 41. Probabihitic risk asuisment of stak biomass reductions at the time of peak effects for toth fishmg and larval entrainment (1992) relnuve to the average unfuhed stock bhwnan 1he *rscruit overfahmg* cetterwn of Suses.atne and Shepherd (1987) was used to estess the ruk of recrui; ment fattore 4 c., when biomais reducthm w as greater than 90%). Probabilities were based on 10n Mmte Carlo replicathms for the simulauoni. 1992 mtan PreJicted for 1992. Simulated stock biomans 12.mpmcal proh.nhihues for 4 teductmn of unfished sloth twmais - stock condition 0 50% 50 60% (670% 70-80% 80 90% >90% (lbs) IJnfished and 110.628 0 43' 0 0 0 0 0 unimpacted habe 1, but ummpacted (banchne) 37.253 0 0.05 0 63 0.32 0 0 Both fished ar,d trnpacted ONT = 2M) 27,5m 0 0 0.14 0 83 0 03 0

• 57% uf the Monte Carlo rephcotes mere larger than the mean for the unfahed and ummpacted stc.cl 78 Monitoring Studies,1990

maiority of the mortality occurred at the time ol last history paramelsis unnputed by Crecus am llov cli lecilmg, supporting the "cntical peiitxP concept. (1990) was re-scaled into umts of luomass h r ose in Although adult sjuwner abundance in 1900 win the mijnict assessment. 'I h b value and a' u o ml.uwe low est foural since 1976 ; mil densuies of las vae m the estimates f or a thcoteta ally unhshed w mter 11 umdei Niantic Rner were only imxterate, the densities of population were used m the SI'DM lot the Nantie newis inctamorphosed young-of-ttv-> car m the riser Rner w mter llounder sial. w ere the lughest seen ui S Sears of study. In a1Lhtion, A ducet measure ol potential uniuct on the Nianor the uuttal tiensities ol ihn ble stage were higher in Riser w mter (hiuntler is simply the number oi larvae the rivei th.m m the bay, whh h was unhke presiois cruramed at h1NPS cat h year. Silice the beguinisit: of S mim gs. As dunng the p,ht 3 yean, lew young three unit operation, amuul entramment estimates icinamed at the luy stations alter mid summer with luve cuceded 100 milhon lanac, Stage 3 larvae were no esidence of them moung to o '.cr areas of the bay pretlomisunt. The masvlulance anal)sn suggested or mio tho mer. Thus, appaiently lugh inostably ol tlut inany of these older hirvae did not ongiiwe f rom young acun in the luy. Tlus 3 car the niortality rate the Niantic Riser. Since 14S-1, the percentages of for young was aho rel.uisch high m the riser and larvae entramed that were attnbuted to the Niantic was pedups related to deibuy depelulent ellects. The Riser stock ranged from a%out 30 to 6SG ami the mihally high numlers 01 youne were te lueed to an repsesented au estunated annual puxhietain loss f rom aserage sved year <l.ns by September. In wntrast, the rner of appioumately 6 to 10G. Ilowes er, no large numbers el young were pnxtuced m 14SS with esidence was fomul that the abund.mce of post-httle mortably noted in the river. 'Ihus, considerable entrauunent lite stages w as associateil with the aQustments to year <l.bs strength can apparcoti) number of latute emrained at NINPS cach year. occur dunng the tint sununer of hk followmg the Assessment of MNPS impact was based on lanal sure. computer simulations carned out to cunnine potentul To date, no strong correlations base been found long-term elfects of Nuntic River w mter flounde tooong the abumlances of sanous hfe hotory stages larval entramment while the stock was undergoing beyond those of female spaw ner, egg, and yolk sac exploitation at present listung rates. The sunnlanon larvac. Il is aho possible that ether pnvesses operate predicted a linal 15% stock reduction attei sustained aher age-I to set year < lass strength as the abundance worst <ase larval entramment dunng the entire MNI'S unhees 01 aged througa $ lemale spawners were not operation period (1471-2020). Iloweser, one-time conelated with those lor early life lustory stages. stock reductions of up to 30-10% couhl occur with Furthennore, the couelations were of ten negatise, protubdities of 0.21 Gar lish numl ers) aml 0.21 (lor although not signiheant. lish biomau) during the cot cal period (1980 01) As a msalt of new data f rom this year and a change when tull three unit operation began to allect the m the manod of calculanon, new estimates of the spawning stock and fishing rates were the highest, in SRR parameters were made. Compared to estunates spite of these potentially large stock losses, it was repoited in NilSCO (1440h the u paramelcr was concluded imm the resuhs of pR A and on the basis of smaller ihn Scar and the absolute value of Q was the " recruitment overfishing" cnterion that the proba-larger; however,little change was seen in p. These bihty of stock co!! apse was essentially /cro once a parameters were to be used in the NllSCO SP!n1 lor gradual recosery of the stock got underway alter 1991. unluct assessment. llecause 01 the present high rates it was also concluded that the suwk would return to of lishing, the Nuntic Rner wmter flounder popu- projected pre MNPS lesels wahm 10 to 15 years after lation has been reduced considerably in sue. the termination of linit 3 operation in 2026. Furthennore, present exploitation rates may be large Finally, thmugh the comparison of stock projee-enough such that recru;nuent overkshing, delined as tions at various punts in time during the simulation 0.00ti orylal) by Sisselmine and Shepherd 10S7, is a study, it w as concluded that present lan al entrainment posnility. Ilowever, the SRR lused salue of a was effects under MNPS three-unit operation were magni-an underestimate of the true slope at the ongm fied by the concurrent high fishing rates in the because the method of calculation could not esclude commercial amt sport lishenes. lloweser, the simu-the ef fects af esploitation. This estinute of u also lation results also supported the notion that larger w as a s ahie correspond'ng to a com,s nsatory resene miniumm si/c regulations recently adopted will base reduced t y current entrainen:nt and fishing rates. substantial effect in reliesing lishing pressure from Therelore, an estunate of o based on various ble the unportant lint tune spawners. Winter ilounder 70

References Clied American winter Bounder (Pseudoplcuronectes americanus) s ith Glugea srephani (M wrosporidia). Arai, M.N., and D.E. Hay. IR2. Predation by J. Fish. Biol. 28:109 206. medusac on Pacific herring (Clapra harengus) Carothers, A.D. 1973. The effects of unequal hirvac. Can. J. Fish. Aquat. Sci. 39:1537 1540. catchability on Jolly Seber estimates. Biometrics Aniason, A.N., and K.ll. Mills.1981. Bias and loss 29:79 100. of precir, ion due to tag loss in Jolly-Seber Chamla:rs, Rf., and V'.C. Leggett. 1987. Sue and l estimates for mark recapture experiments. Can. J. age at metan orob. sis in marine fishes: an analysis - l Fish. Aquat. Sci. 38:1077 1095. of laboratory reared winter flounder (Pseudo- l Bailey, K.M., and R.S. Batty, 1984 Laboratory pleuronectes americanus) with a review of study of predation by Aurelia aurclia on larvae of variation in other species. Can. J. Fish. Aquat. cod, flounder, plaice and herring: development at d Sci. 44:19361947 vulnerability to capture. Mar. Biol. (Berl.) Chambers, R.C., W.C. Leggett, and J.A. Brown. 83:287 291, 1988. Variation in and among early life history Bannister, R.C.A., D. Harding, and SJ. I ockwmxi traits of laboratory-reared winter nounder Pacudm 1974. Larval mortality and subsequent year class pleuronectes americanus. Mar. licol. Prog. Ser. strength in the plaice (Plcuronccles platessa I-), 47:1 15. Pages 2138 in J.ll.S. Blaster, ed. The early hfe Cl.ristensen, S.W., and C.P. Goodyear. 1988, history of fish Springer.Verlag, New York. Iccing the validity of stock recruitment curve fits. Begon, M.1979. Investigatmg animal abundan:e: Am. Fish. Soe. Monogr. 4:219 23 L capture recapture for biologists. University Park Cormack, R.M. 1968. The statistics of mark. Press, Baltimore 97 pp. recapture methmis. Oceanogr. Mar. Biol. Ann. Bergman, M.J.N., H.W. van der Veer, and JJ. Rev 0:455 506. Zijlstra. 1988, Plaice nurseries: effects on Crawford. R.E., and C.G. Carey. 1985. Retention recruitment. J. Fish Biol 33 (Suppl. A): 210 218. of wimer Counder larvac within a Rhode Island Bishop, J.A., and P.M. Sheppard. 1973. An salt pond. Estuaries 8:217 227. evaluation of two capture recapture models using Crecco, V.A.1990. Evaluation of the mass balance the technique of computer simulation. Pages matel and the estimation of current entrainment 235 253 in M.S. Bartlett and R.W. Hiorns, eds. rates at MNPS Connecticut Dept. Envir, Prot,, The mathematical theor) of the dynamics of Bu. Fish., Spec Pub. 9 pp, biological populations. Academic Press, London. Crecco, V.A., and P. Howell 1990. Potential Boudreau, P.R., and L.M. Dickie.1989. _ Biological effects of current lan al entrainment mortality from model of production based on physiological and the Millstone Nuclear Power Station on the winter ecological scaling of body size. Can. L Fish. flounder, Pscudopleuronectes americanus, spawn. Aquat. Sci. 46:614 623, ing population in the Niantic River. Connecticut Buckley, LJ. 1980. Changes in ribonucleic acid, Dept. Envir. Prot., Bu. Fi.sh., Spec Pub. 37 pp, deoxyribonucicie acid, and prolcin content during Crecco, V.A., and T. Savoy. 1987. Fishery ontogenesis in winter flounder, PscudopIrur. management plan for the American shad in the onectes americanus, and effect of starvation. Fish. Connecticut River. Connecticut Dept. Ewir. Bull., U.S. 77:703-708. __ Prol., Bu. Fish., Spec. Pub. 140 pp. Buckley, LJ.. 1982. Effects of temperature on Cushirig. D.H.1971. The dependence of recruitment growth and biochemical composition of larva! on parent stock in different groups of fish. J. winter flounder Pseudopleuronectes americanus. Cons. int. Explor. Mer 33:340 362 Mar. Ecol Prog. Ser. 8:181 186. Cushing, D.ll.. 1974. The possible density-Buckley, LJ., A.S. Smigiciski, T.A. Halavik, and dependence of larval mortality and adult mortality G.C. Laurence. 1990. Effects of water temper. in fishes, Pages 10311I in J.H.S. Blaxter, ed. ature on size and biochemical composition of The early life history of fish. Springer-Verlag, winter nounder Fscudopleuronectes americanus at New York.

    - hatching and feeding initiation, Fish Bull., U.S. Cushing, DJI.. 1977. The problems of stock and 88:419 428.                                           recruitment. Pages i16133 in J.A. Gulland, ed.

Cali, A., P.M. Takvorian, J.J. Ziskowski, and T.K. Fish population dynamics. John Wiley and Sons, Sawyer. 1986. Experimental infection of New York. 80 Monitoring Studies,1990

Cushing, D.ll., and J.G.K. Harris 1973. Stock and chastic variation in survival of the young. Trans. recruitment and the problem of density dependence. Am. Fish. Soc. I13:627 632. 14pp. P. v. Reun. Cons, int. Explot. Mer llennemuth, R.C., J.E. Palmer, and B.E. Brown. 164:142 155. 1980. A statistical description of recruitment in Cushing, D.ll., and J.W. llorwood.1977. Devel. eighteen selected fish stocks. J. Northwest Atl. opment of a model of stock and recruitment. Fish.1:101 111. Pages 2135 in J.ll. Steele, ed. Fisheries liess, K.W., M.P. Sissenwine, and S.B. Salla, mathematics. Academic Press, New York. 1975. Simulating the impact of entrainment of Danila, DJ.1978. Age, growth, and other aspects winter flounder larvae, Pages 130 in S.B. Saila, of the life history of the winter flounder, ed. Fisheries and energy production: a sympos-Pseudopleuronectes americanus (Walbaum), in ium. D.C. Heath and Co., Lexington, MA. southern New Jersey. M.S. Thesis, Rutgers Hightower, J.E., and RJ, Gilbert. 1984. Using the University, New Brunswick, NJ. 79 pp. Jolly Seber model to estimate population size, Dimou, N.K., and E.E. Adams. 1989. Application mortality, and recruitment for a reservoir fish of a 2 D particle tracking model to simulate population. Trans. Am. Fish. So.. Il3:633 MI. entrainment of winter flounder larvae at the Mill- Hjorleifsson, E. 1989. (Abstr.). Condition of stone Nuclear Power Station. Encigy Laboratory winter flounder larvae in Narragannett Bay as Report No, MIT EL 89 002. Massachusetts measured by RNA/DNA ratio. Workti.op on win-Institute of Technology, Cambridge, MA. 73 pp. ter flounder biology, Mystic, CT, December 5-6, Draper, N., and H. Smith.1981. Applied regression 1989, analysis. John Wiley and Sons, New York. 709 Hjort, J.1926. Fluctuations in the year classes of pp, important food fishes. J. Cons. int. Exp or Mer Garrod, DJ., and B.W. Jones. 1974. Stock and 1:5 38. (not seen, cited by May 1974), recruitment relationships in the Northeast Arctic Hoenig, J.M., D.M. Heisey, W.D. Lawing, and H.D. Y cod stock and the implications for the manage. Schupp. 1981. An indirect rapid methods ment of the stock. J. Cons. int. Explor. Mer appicach to assessment. Can. J. Fish. Aquat. Sci. 36:35-41. 44 (Suppl 2):324 338. Gibson, M.R. 1987. Preliminary assessment of Houde, E.D.1987. Fish early life history cynamics winter flounder (Pseudopleuronectes americanm) and recruitment variability. Am. Fish. Soc. Sym-stocks in Rhode Island waters. Rhode Island Div. posium 2:17 29. Fish Wildl., Res. Ref. Doc. 87n. 51 pp. Howe, A.B., and P.G. Coates. 1975. Winter Gibson, 'M.R.. 1989. Stock recruitment relation- flounder movements, growth and mortality off ships for winter flounder in the S. New England Massachusetts. Trans. Am. Fish. Soc. IN:13 29. area and revised fishery reference points. Rhode Jeffries, H.P., and M. Terceiro. 1985. Cycle of Island Div. Fish Wildl., Res. Ref. Doc. 89/9. 10 changing abundances in the fishes of the pp + 5 fig. Narragansett Bay area. Mar. Ecol. Prog. Ser. Gilbert, R.O.1973. Approximations of the bias in 25:239 244. the Jolly Sc3er capture recapture model. Jeffries, ll.P., A. Keller, and ? Hale. 1989. Biometrics 29:501-526. Predicting winter flounder (Pseado;4euronectes Goodyear, C.P. 1977. Assessing the impact of americanus) catches by time series analgis. Can, power plant mortality on the compensatory reserve J. Fish. Aquat Sci. 46:650-659. of fish populations. Pages 186 195 in W. Van Jolly, G.M. 1965. Explicit estimates from Winkle, ed. Proceedings of the conference on capture-recapture data with death and immigration assessing the effects of power plant induced stochastic model. Biometrika 52:225-247, mortality on fish populations. Pergamon Press, Klein-MacPhee, G.1978. Synopsis of biological New York. data for the winter flounder, Pseudopleuronectes

     ,                               Goodyear, C.P. 1980. Compensation in fish                     americanus (Walbaum). NOAA Tech. Rep.
     ;                                   populations. Pages 253 280 in C.H. Hocutt and             NMFS Cire. 414, 43 pp.

J.R. Stauffer, eds. Biological monitoring of fish. Ko%ncyct, R.C. 1972. A study of the Niantic Lexington Books, Lexington, MA. River estuary, Niantic, Connecticut. Final report Goodyear, C.P. and S.W. Christensen. 1%, Bias- phases I and II, physical aspects of the Niantic elimination in fish population models with sto- River estuary. Rep. No. RDCG A 18. U.S. Coast

     !                                                                                                                                   Winter Flounder 81 1                                                                                                                                                      l 1                                                                                                                          --- --

Guard Academy,New London,CT. 78 pp. and Associates. Ecological studies for the Oyster Laurence, G.C. 1975. Lateratory growth ard Creek Generating Station. Progress report for the metabolism of the winter flounder Pseudopleur- period September 1976 August 1977. Vol.1. Fin-onectes americanus from hatching through and shellfish. Ichthyological Associates, Inc., metamorphosis at three temperatures. Mar. Biol. Ithaca, NY. (Berl.) 32:223-229. Nichols, J.D., B.R. Noon, S.L. Stokes, and J.E, Laurence, G.C. 1977. A bioenergetic model for the H Mes. 1981. Remarks on the use of capture-analysis of feeding and survival potential of winter recLpture methodology in estimating avian popu-Counder, Pseudopleuronectes americanus, larvae lation size. Studies in Avian Biol. 6:121 136. during f.ae period from hatching through (not seen, cited by liightower and Gilbert 1984). metamorphosis. Fl.h. Bull., U.S. 75:529 546. NUSCO (Northeast Utilities Service Company). Lobell, M.J 1939. A biological survey of the salt 1983. Fish ec logy: trawl and seine evaluation, waters of Long Island,1938. Report on certain in Monitonng the marine environment of Long fishes. Winter flounder (Pseudopleuronectes Island Sound at Millstone Nuclear Power Station, americanus). Suppl. 28th Ann. Rep., N.Y. Cons. Waterford, Connecticut. Resume, 1968 81. 78 Dep., Pt.1:63 96. pp. Lockwood, SJ,1980. Density dependent mortality NUSCO. i985. Winter ficunder studies. In Moni-in 0-group plaice (P!curonectes platessa L.) popu- toring the marine environment of Long Island lations. J. Cons. int. 7.xplot. Mer 39:148 153. Sound at Millsinne Nuclear Power Station. Longhurst, A.1983. Benthic pelagic (;upling and Annual report, 1984. 74 pp. export of organic caroon from a tropical Atlantic NUSCO.1986. Winter nounder studies. In Moni-cmtinental shelf, Sierra Leone, Est. Coast. Shelf toring the marine environment of Long Island Sci.17:261285. Sound at Millstone Nuclear Power Station. Lorda, E.C., and V.A. Crecco 1987. Stock recruit. Annual report, 1985. 69 pp. ment iciationship and compensatory mortality of NUSCO.1987. Winter flounder studies. In Moni. American shad in the Connecticut River. Am. toring the marine environment of Long Island Fish. Soc. Symposium 1:469 482. Scund at Millstone Nuclear Power Station. Manly. B.J.F. 1971. A simulation of Jolly's Summary of studies prior to Unit 3 operation, method for analy.,ing capture recapture data. 151 pp. Biometriss '7:415-424. NUSCO. 1988a. Winter flounder studies. Pages Marshall, N., and S.D. Hicks. 1962. Drift of 149 224 in Monitoring the marine environment of medusae and their distribution .. relation to the Long Island Sound at Millstone Nuclear Power hydrography of the Niantic River, Connecticct. Station. Three unit operational studies, Limnol. Oceanogr. 7:268 269, 1986-1987. May, R.C.1974. Larval mortality in marine fishes NUSCO. 1988b. The usage and estimation of and the critical period concept. Pages 3 20 in DELTA means. Pages 311320 in Monitoring the J.H.S. Blaxter, ed. The early life history of fish, marine environment of Long Island Sound at Spruger Verlag. New York. Millstone Nuclear Power Station. Three unit McCracken U.D.1963. 9asenal movements of the operational studies. 1986-1987. winter Counder, Pseudopleuro-ectv americama NUSCO.1989. Winter flounder studies. Pages 239-(Walbaum), on the Atlantic coast. J. Fish. Res. 316 in Monitoring the marine environment of Board Can. 20:551586. Long Island Sound at Millstone Nuclear Power Modlir' R.F. 1916. Life history, ecology, and Station. Annual report 1988. population dynamics of Crangon septemspinosa NUSCO.1990. Winter flounder studies. Pages 9 (Say) (Decapoda: Caridae) in the Mystic River 77 in Monitoring the marine environment of Long estuary, Connecticut. Ph.D. Thesis, University of Island Sound at Millstone Nuclear Power Station. Connecticut, Storrs, CT, 91 pp. Annual report 1989. Moller, H. 1984. Reduction of a larval herring Olla, D.L., R. Wicklund, and S. Wilk. 1969, population by jellyfish predator. Science (Wash., Behavior of winter nounder in a natural habitat. D.C.) 224.621 622. Trans. Am. Fish. Soc. 98:717-720. Mcore, D.W.1978. Sand shrimp. Pages 242-250 Panish, B.B.1963. Some remarks on the selection in T.R. Tatham, D.J. Danila, and D.L. Thomas, processes in fishing operations. Int. Comm. 82 Monitoring Studies,1990

l= l Northwest Atl. Fish. Spec. Pub. 5:166 170. mous and catadromous fishes. Am. Fish. Soc. Pearcy, W.G. 1962. Ecology of an estuarine Sym.1. population of wmter flounder Pseudopleuronectes Roughgarden. J. 1979 Evolutionary ecology of americanus (Walbaum). Bull. Bingham Oceanogr. single populations. Pages 295 408 in The theory Coll.18(1):1-78. of population geneties and evolutionary ecology: Pennington, M. 1983. Elficient estimators of an introduction. MacMillan Publishing Com-abundance for fish plankton surveys. Biometries pany, ine., New York. 39:281-286. Rubinstein, R.Y. 1981. Simulation and the Monte Pennington, M. 1986. Some statistical techniques Carlo method, John Wdey and Sons, New York. for estimating abundance indices from trawl 278 pp. surveys. Fish. Bull., U.S. S4:519 525. Saita, S.B. 1961. A study of winter flounder Perlmutter, A.1947. The blackback flounder and its movements. Limnol. Oceanogr. 6:292-298. fishery in New England and New York. Bull. Saila, S.B. 1962a. The contribution of estuaries to Bingham Oecanogr. Coll. I1:1-92. the offshore winter flounder fishery in Rhode Pollock, K.ll., J.D. Nichols, C. Brownie, and J.E. Island. Proc. Gulf Caribb. Fish, inst.14th Annu. Itines. 1990. Statistical inference for capture. Sess.1961:95 109. recapture experiments. Wildl. Monogr.107. 97 Saila, S.B. 1962b. Proposed hurricane barriers pp. related to winter flounder movements in Poxton, M.G., A. Eleftheriou, and A.D. McIntyre. Narrugansett Bay. Trans. Am. Fish. Soc 1982. The population dynamics of 0 group flat- 91:189 195. fish in the Clyde Sea area. Est. Coast. Shelf Sci. SAS institute Inc. 1985. S AS user's guide: 14:265 282. statistics. Version 5 edition. SAS Institute Inc., Poxton, M.G., A. Eleftheriou, and A.D. McIntyre. Cary, NC. 956 pp. 1983. The focxl and growth of 0-group flatfish on Savidge, J.R., J.B. Gladden, K.P. Campbell, and nursery grounds in the Clyde Sea area. Est. Coast. J.S. Ziesenis. 1988. Development and sensi. Shelf Sci. 17:319 337. livity analysis of impact assessme::t equations Poxton, M.G., and N. A. Nasir. 1985. The based on stock recruitment theory. Am. Fish. distribution and population dynamics of 0-group Soc. Monogr. 4:191 203, plaice (Pleuronectes platessa L.) on nursery Saucerman, S.E. 1989. ( Abstr,). Distribution and grounds in the Firth of Forth. Est. Coast. Shelf pnxtuctivity of juvenile winter flounder (Pseudo. Sci. 21:845 857. pleuronectes americanus) in Waquoit Bay, MA. Reed, M., M.L. Spaulding, E. Lorda,11. Walker, and Tenth biennial International Estuarine Research S.B. Saila 1984. Oil spill fishery impact assess- Conference, Baltimore, M D, October 8 12,1989. ment modeling: the fisheries recruitment problem. Scott, W.B., and M.G. Scott. 1988. Atlantic fishes Est. Coast. Shelf Sci.19:59l 610. of Canada. Can. Bull. Fish. Aquat. Sci. 219. Ricker, W.E,1954. Stod and recruitment. J. Fish. 731 pp. Res. Board Can. I1:559 623. Simpson, D.G. 1989. Codend selection of winter Ricker, W.E., 1975. Computation and interpretation flounder Pseudopleuronectes americanus. NOAA of biological statistics of fish populations. Bull, Tech. Rep. NMFS 75.10 pp. Fish. Res. Board Can. 191. 382 pp. Sisaenwine, M.B. 1984. Why do fish populations Roff, D.A. 1973. On the accuracy of some mark- vary? Pages 59 94 in R.M. May, ed. Exploi-recapture estimators. Occologica (Berl.) 12:15 34. tation of marine communities. Springer Verlag, Roff, D.A.1981. Reproductive uncertainty and the New York. cvolution of iteroparity: why don't flatfish put all Sissenwine, M.B., and J.G. Shepherd. 1987. An their eggs in one basket? Can. J. Fish. Aquat. ahernative perspective on recruitment overfishing Sci. 38:968 977. and biological reference points. Can. J. Fish. Rothschild, B.J., and G.T. DiNardo. 1987. Aquat. Sci. 44:913 918. Comparison of recruitment variability and life Smigielski, A.S. 19 75. llormonal-induced ovula. history data among marine and anadromous fishes. Lion of the winter flounder, Pseudopleuronectes Pages 531546 in M.J. Dadswell, R.J. Klauda, americanus. Fish. Bull., U.S. 73:431 438. C.M. Moffitt, R.L. Saunders, R.A. Rulifson, and Smith, E.M., E.C. Mariani, A.P. Petrillo, L.A. 1.E. Cooper, eds. Common strategies of anadro- Gunn, and M.S. Alexander. 1989. Principal Winter Flounder 83

l fisheries of Long Island Sound, 1961 1985. changes in intensity upon total >icid, ar.d yield Connecticut Dept. Envir. Prot., Bu. Fish., h1ar. per unit gear. Rep. Int. Fish. Comm., No. 8. 49 Fish. Program. 47 pp. + app. pp. Smith, T.D. 1988. Stock assessment methods: the Tuljapurkar. 3.D., and S.it Ortack. 1980. Popu. Grst fifty years. Pages 133 ir. J.A. Gulland, ed. Idion dynamics in variable environments. 1. Fish population dynamics (second ed.L John Loag run growth rates and extinction. Theoret. Wiley and Sons, New York. Pop. Biol.18:314 342. Smith, W.G., J.D. Sibunka, and A. Wells. 1975. Vaughan, D.S. 198 L An age structure model of Seasonal distributions of larval flatfishes >cllow perch in western Lake Erie, Pages 189 (Pleuronectiformes) on the continental shelf 216 in D.G. Chapman and V.F. Gallucci, eds, between Cape Cod, hlauachusetts and Cape Quantitative population dynamics. International Lookout, North Carolina, 1965 1966. NOAA Co operative Publishing llouse, Fairland, htD. Tech. Rep. Nh1FS SSRF.691. Veer, ll.W. van der. 1985. Impact of coelenterate Snedecor, G.W., and W.C. Cochran. I967. predation on larval plaice Picuronectes platessa and Statistical methods. The Iowa Sta'e University llounder Platichthys fic.ws stock in the western Press, Ames, I A. 593 pp. Wadden Sea. h1ar. Ecol. Prog. Ser. 25:229 238. Sogard. S.M., and K.W. Able. 1990. ( Abstr.). Vcer, it.W. van der.1986. Immigration, settlement, Growth parameters of newly settled winter Oounder and density dependent mortality of a larval and (P3calopleuronectes anwricanus) in New Jersey early postlarval 0 group plaice (Pleuronectes estuarine waters, international Symposium on platessa) population in the westein Wadden Sea. flatlish ecology, flatfish symposium 1990. Mar. Ecol. Prog. Ser. 29:223 236. Netherlands institute for Sea Research, Texel, The Ware, D.M. 1980. Bioenergeties of stock and Netherlands, November 1990. recruitment. Can. J, Fish, Aquat. Sci. Southwood, T.R.E. 1978. Ecological methods. 37:1012 1024. Italstead Press, New York. 523 pp, Weidner, E.1973. Studies of microsporidian disease Spaulding, M.L,, S.B. Saila. E. Lorda,11. Walker, E. transmission m winter flounder and smelt. Bio. Anderson, and J.C. Swanson. 1983. Oil spill Bull.145:459. fishery impact assessment model: application to Whitehouse, S.T. 1989 Bottom dwelling shrimp selected Georges Bank fish species. Est. Coast. and their role m Narragansett Bay. Maritimes Shelf Sci. 16:511 541. (University of Rhode Island Graduate School of Steele, J., C. Clark, P. l arkin, R. Lasker, R. May, Oceanography) February 1989:15-16, B. Rothschild, E. Ursin, J. Walsh, and W. Wooster. 1980. Fisheries ecology: some con-straints that impede our understanding. Ocean Science Board, National Academy of Science, Washington, D.C. Steele, J., and R.R.C. Edwards. 1970. The ecology of 0 group plaice and common dabs in Loch Ewe. IV. Dynamics of the plaice and dab populations. J. Exp. Mar. Biol. 4:174 187. Stuart, A., and J.K. Ord.1987. Kendall's advanced theory of statistics, Vol.1. Distribution theory. Oxford University Press, New York. 6N pp. Stunkard, fl.W.1969. The sporozoa: with particular reference to infections in fishes. J. Fish. Res. BoaniCan.26:725 739. Stunkard, it.W., and F.E. Lux. 1965. A microsporidian infection of the digestive tract of the winter flounder, Pseudo;>lcuronectes ameri-canus. Biol. Bull. 129:371-387. Thompson, W.F., and F.lt Bell. 1934. Biological statistics of the Pacific halibut fishery. 2: effect of 84 Monitoring Studies,1990 l

Al'PI'.NDIX ! &hedule of enuammets and f ahmg itwrishties with aJsntmenti for tht6ard emntah% st impl(mtmird lin 01c Hmulatmn. See 'Iable I thnogh 5 for the bain and taumale of ihne data INneninges of par dm redactim Time $1mulation ut there levels of Im al entramment- Man mal I tasinmi l- f or : itcp year t su Mednen lhgh I' Age i A ge 2 Age 1 0 1960 00m O a x) O uxi 0 40 0 0360 02a00 04mo i 1961 0.(kI) O lE R) O (x x) 0.40 0 0160 02400 0 4(Nio 2 1962 0 000 O (k X) O tak) 0 40 0 0lN) 02 00 0 4000 3 1963 0(x0 O iX X) 0 (x u) 0 40 0 0160 0 2100 0 4000 4 1964 O(XI) 04xk) 00:10 0 40 0 0160 0 2 UW) O4000 5 1965 0.(x t) O(XX) O (XX) 0.40 0 0' M) 0.2400 0 4tX)O 6 1966 O lX X) O(XX) O(XX) 0 40 0 0160 0 2400 0 4W H) 7 1967 0u0 O(XX) O lxX) 0 40 0 0160 02400 04000 K 196X O (X R) O(xx) O D K) 0.40 0 01N) 02400 0 4000 9 1969 O(XX) O fxX) 0lxx) 0 40 0 0360 0 2400 0 4000 10 1970 O (x t) O(XX) O (X X) 0 40 0 0160 0 2400 0 4(K10 11 1971 3 375 4 500 5 625 0 40 0 0360 02400 0 4000 12 1972 3 375 4 $(x) 5.625 0 41 0 0169 02460 0 4100 11 1973 3 375 4 $(x) 5 625 0.42 0 0.178 02520 0 4200 14 1974 1 375 4 5fXI 5 625 0 41 0 0387 0.2$60 0 4300 15 1975 3 175 4 500 5 625 0 44 0 0346 02640 04100 16 1976 7.7MS 10/180 12 975 0 45 0 0405 0 2 7(K) 04500 17 1977 7.785 10 3%0 12 975 0.46 0 0414 0.2760 0.4600 18 1978 7.785 10 3hu 12 975 0 47 0 042) 0 2R20 0 4700 19 1979 7.745 10 3MO 12.975 0.48 0 0832 0 2 AKO O4h00 20 1980 7.755 10 380 12 915 0.49 0 0641 0.2940 0 4900 21 198) 7.785 10 3hu 12 975 0.50 0 0450 0 3(xx) 0 5(x10 22 19R2 7.785 10 380 12.975 0 51 0 0306 024M9 0.5100 23 1983 7 785 10380 12 975 0 53 0 0118 0 2268 0 5100 24 1984 7.765 10 3X0 12 973 0.55 0 0.130 0 2354 0.5500 25 1985 7=7 k5 10.no 12 975 0 57 0.0142 0.2012 0 5700 26 1986 15 0f C 20 000 25 0(N) 0.59 0 035l 02124 0 5900 27 19147 15 0 () 20 0lX) 2 5 0lk) 0.61 0 0166 0 2196 06100 28 19n8 15 000 20 (x x) 25.ux) 0 63 0 0378 02068 0 5355 29 1989 15 000 20 000 25 (XXI 0 65 0 0190 02340 0 5525 30 1990 15 Out) 20.(XX) 254*10 0.65 0 0390 02140 0 5525 31 1991 15 0lX) 20 0lX) 254xx) 0.64 0.0384 02304 0 5440 32 1992 15 (X U 20 000 25.(XX) 0 63 0 0378 02268 0,5155 31 1993 15 (XO 20.(XX) 2 5.(XX) 0.62 0 0172 0.2232 0.5270 34 1994 15(xx) 20 (XX) 25 0ix) 0 61 0.0166 01196 0 5185 35 1995 15 &X) 20.tx 0 254xx) 0.60 0 0160 0.2160 0.5100 36 1996 15Oto 20.0 X) 25 (xx) 0.60 0.0160 02160 0.5100 37 1997 15 0tx) 20RM) 25 0x) 0 60 0 0360 02160 0,5100 18 1998 15 (xX) 20 (x10 25 (XX) 0 60 0 0360 02160 0.5100 39 1999 15.(x x) 20 000 254XO 0 60 0 0360 02160 0.5100 40 2000 15 0f x) 20 000 25 (xx) 0.60 0 0160 0,2160 0 5100 41 2001 15 0tU 20 GX) 25 (x10 0.60 0 0160 0.2160 0.5100 42 2002 15txX) 20fxx) 25 (W10 0 60 0 0360 0.2160 0.5100 43 2001 151x0 20.ux) 25 txx) 0.60 0 0360 0.2160 0.5l00 44 2004 15 000 20 (X O 25 0X) 0.60 0 0160 0.2160 05100 45 2005 154XX) 20 000 25 (xx) 0 60 0 0)60 0.2160 0 5100 46 2006 15 fx0 20 (XX) 25 000 0.60 0 0360 0.2160 0.5100 47 2007 15 (X O 20 010 25 (XXI O 60 0 0160 0.2160 0.5100 43 200R 15 0X) 20 lX x) 25 0x) 0.60 0 0360 0.2160 0.5100 49 2009 15 0m 20 (X H 25 0H) 0 60 0 0160 02160 0 5100 50 2910 15 (x)0 20 0x) 25 NW) 0 60 0 0160 0.2160 05100

              $1          2011          11.625         11 500        19 375     0 60     0 0360          02160                 0.5100 52          2012          11 625         15.5f o       19'115     0.60     0 0160          02160                 0 5100 l

Winter Flounder 85

APPL.NDIX 1. kontinued). Percentages of > car <lus reducta True Simulation at three levels of larval entramment. Nominal I:ractional I; for : step year 15 % 20% 25% l' A ge .1 Age 2 Age.3 53 2013 11.626 15.500 19.375 0.60 0 360 0 216 0 $ 10 54 2014 11.626 15.500 10376 0 60 0 360 0.216 0.510 55 2015 11.626 15.500 19375 0 60 0 360 0 216 0510 56 2016 7.215 9 620 12 025 0.60 0.360 0.216 0 510 57 2017 7.215 9.620 12.025 0.60 0.360 0.216 0 510 Sn 2018 7.215 9.620 12.025 0.60 0360 0.216 0 510 59 2019 7.215 9.620 12.025 0.60 0.360 0.216 0.510 N) 2020 7.215 9 620 12 025 0 60 0.360 0,216 0510 61 2021 7.215 9 fa0 12.025 0.60 0.360 0 216 0.510 62 2022 7.215 9.620 12.025 0.60 0360 0.216 0 $10 63 2023 7.215 9 620 12.025 0.60 0 360 0.216 0 510 (4 2024 7.215 9 620 12.025 0 60 0.360 0 216 0 510 65 2025 7.215 9.620 12.025 0.60 0360 0.216 0 $ 10 66 2026 01XX) 0 000 01XX) 0.60 0 360 0.216 0.510 67 2027 01x0 0 (Xx) 0 000 0.60 0.360 0.216 0 510 68 2028 0.(x10 0J100 0 000 0.60 0360 0.216 0,510 en 2029 0 (x0 0.000 n(xX) 0.60 0360 0.216 0.510 70 2030 n0lb OJXO 0.000 0.60 0.360 0.216 0.510 71 2031 00l0 0 0(X) 0.000 0.60 0360 0.216 0.510 72 2032 n000 0 000 0.000 0.60 0.360 0.216 0 $10 73 2033 01x0 O (xx) 0 (x)0 0.60 0360 0.216 0.510 74 2034 n(x0 0 00() 0 (x0 0.60 0.360 0.216 0.510 75 2035 a(XX) OJXO 0.000 0.60 0360 0.216 0 510 76 J036 n000 0 lxx) 0 000 0.60 0.360 0.216 0,510 77 2037 nNx) 0.ux) 0 0tX) 0.60 0 360 0.216 0 510 78 2038 0(x10 n000 0100 0.60 0.360 0.216 0.510 79 2039 0 (XX) n000 O (XX) 0.60 0 360 0.216 0.510 80 2040 00(I) 0 000 n(xx) 0.60 0.360 0.216 0.510 81 2041 0 0ix) O (XU 0.ux) 0.60 0360 0.216 0.510 82 2042 0.0W 0.000 0 000 0.60 0.360 0.216 0 510 83 2043 0.000 01XX) 0.000 0.60 0.360 0.216 0.510 84 2044 n(x'1) OJXX) 0.000 0.60 0360 0.216 0,510 85 2045 n000 0.000 0.000 0.60 0.360 0.216 0.510 86 2046 n000 O (xx) 0.000 0.60 0 360 - 0.216 0.510 87 2M7 Q(XO 03xx) 0.000 0.60 0360 0.216 0.510 88 2048 0.(xx) O (xx) n000 0 60 0.360 0.216 0.510 89 2049 n000 010) 0.000 0.60 0 360 0.216 0.510 90 2050 n(xU 0 000 0 000 0.60 0.360 0 216 0.510 91 2051 n0(X) O (X XI n000 0.60 0360 0.216 0.510 92 2052 nurx) 0.0lx) OJXX) 0.60 0.360 0.216 0.510 93 2053 ntan 0.000 01xW) 0.60 0360 0.216 0.510 94 2054 n00) 0.txx) OIXK) 0.60 0.360 0.216 0.510 95 2055 n0(0 01X10 0.txx) 0.60 0.360 0 216 0.510

              %          2056      n000           0.000                            01x10      0.60    0 360                0.216         0.510 97         2057      nunt)          atxx)                            0 000      0.60    0.360                0.216         0.510 98         2058      0 (XX)         OJX X)                           OJXX)      0.60    0360                 0.216         0.510 99         2059      0000           0 000                            011)0       0.60   0360                 0.216         0.510 100         2060      a(xx)           0 (X10                          OJXX)       0.60    0.360               0.216         0.510 86 Monitoring Studies,1990

Contents Fish Ecology Studies . . . . . . . ... ......... ..... ............. . . 89 Introduction . . . . . . . . . . . . . . . . . . . . . . .. .. ............... 89 Materials and Methods . . . ........ ........ . .... ..... . . 89 lehthyoplankton program . . . . . ............... .... .. 90 Trawl program . . . . . ...... ..... ... .... ...... .. 91 Seine program .................. .. . ... . . . . . . . 91 Entrainment mortality study . . . ... ......... .. . . . . . . 91 Data analyses . . . . . . . . . . .. ...... ... .... ...... . . . 92 Results and Discussion . . . . . .. . .... . ... ... ...... .. 93 Ichthyoplankton monitoring . . . . ....... . . ... .... . . 93 Trawl monitoring . . . . . .... ...... .. ......... . . . . . 93

                                                                                                                                                   .....,.95 Seine monitoring . . . . . . . . . , . . . . .                     . ....                  .          . .

Entrainment estimates . . . . . . . . . ......... .......,... . 96 Entrainment mortality study . . . . . . . . . .. . . ......... . 98 Selected taxa . . . . . . . . . . . ... . . . . . . . . . . . . . . 99 American sand lance .. ......... .. . ......... 49 Anchovies . . .. .... . . .. .. .. ........, . 100 Silversides . ... ... . .... . . ...... ..... 102 Grubby . . . . . . ..... . .. . .. . ..... 105 Tautog . . ...... . .... .. .............. 107 Cunner . . . .... . . . ..... . 109 Conclusions .... .... ... .. ... ... . ,. ... . ... . 112 References Cited . . . ... ... . ... . . . . ... 113

                                                                                                                                                                 , 117 Appendix . . . .     ...        ... ...............                                       .                ..         ...                         ..

Fisti Ecology Studies Iniroduction temporal pauerns of fish abundance and establish the direction and extent of natural changes in these as-Fish assemblages are an important component of semblages, and evaluate the significance of observed the trophic structure of estuarine communities. They changes attributable to MNPS operation, with inhabet a variety of habitats in the vicinity of particular emphasis on the period since Unit 3 began Millstone Nuclear Power Station (MNPS) in eastern olvraung. Long Island Sound (LIS). The signdicance of fish Three monitoring programs were conducted which assemblages to estuarine ecology is widely provide data on the life history stages of fishes suscep-recognized. Shore zone and demersal fishes are tible to impact: demersal trawl; shoreanne seine; and important consumers (Richards 1963; Beck and ichthyoplankton, including entrainment sampling. Poston 1980; Woodin 1982; Bailey 1984; Witman The life history and population characteristics of 1985; LeMao 1986; llorn and Gibson 1988) and atm potentially impacted species are presented in this serve as prey as eggs and larvae and juvenile and report and are evahiated to determine if MNPS has had adults (Pearcy and Richards 1962; Hunter and any detrimental effects on them. Data from June Kimbrell 1980; Jamieson et al.1982; Leak and 1989 through May 1990 are summarized and Houde 1987). Additionally, fishing is an important compared to historical data from June 1976 through part of coastal economics (Clark 1967), in May 1990 for trawls, seines and entrained larvac, and Connecticut, million:; of dollars are produced annually from June 1979 through May 1990 for entrained by both commercial and sport fishing in LIS eggs, and larvae collected in Niantic Bay. Results of (Sampson 1981; Blake and Smith 1984), entrainment mortahty studies ccaducted in 1990 and The objective of the fish ecology monitoring recalculated entrainment estimates are also presented programs at MNPS is to determine whether the in this report. operation of the power plants has any effect on local fish assemblages. These effects have been defined as power plant related changes in the occurrence, distribution and abundance of fish species which Materials attd Metitods would affect the community structure. Fish assemblages in the area of MNPS could be adversely Data reviewed in this report are from the period, affected by impingement on the intake screens, January 1976 through May 1990, A reporting year entrainment through the cooling water system or by extends from June of one year through May of the changes in thermal regime or in physical habitats. following year; thus, the report year 1989-90 included impingement on the intake screens may remove data from June 1989 through May 1990. Because of juvenile and adult fish from populations; however, occasional overlap in the occurrence of a species fish mortality due to impingement has been mitigated during the May-June transitional period, with the addition of fish return sluiceways at species specific analyses are based on the actual Millstone Units I and 3. Eggs and larvae of various periods of occurrence instead of being constrained to fish species also suffer mortality when they are June I as the commor, starting point. When the entrained through the condenser cooling water system, season of occurrence of a species crossed a calendar The effects of increased mortality rates on the year, the year was reported as "1989 90", but when abundance of fish populations depends upon size, life the species occurred only within a calendar year, the span, age structure, and the effectiveness of any year was reported as "1990". MNPS trawl catches of compensatory mechanisms. Spatial distributions of cunner and tautog were summarized by calendar year local fish populations may change in response to the so that direct comparisons could be made to catches thermal effluent or changes to the physical habitat. reported by the Connecticut Department of Environ-To determine the impact of MNPS on local fish mental Protection (DEP) Marine Fisheries trawl assemblages, monitoring studies have been survey data. The material and methods presented established to describe the occurrence and abundance below for the 1989 90 reporting period are essentially of fish in the Millstone area, identify spatial and the same as those used in earlier years. I Fish Ecology 89 I

                      .in           _m                  -                              u   _m_a       -                        ,   _2 lehthyoplankton program                                           Larvae were also collected in mid.Niantic Bay at station NB (Fig.1). Two day and two night samples Entrained ichthyoplankton (fish eggs and larvae)                         were taken weekly from April through August, and samples were collected luth day and night three                             one day and one night sample taken biweekly from times per week from June through September, once                            September through March. Pc red 041 x 3.3 m per week from October through February, and four                            conical plankton nets, mounted on a bongo frame, times per week from March through May. Sampling                             were towed to collect siunples. Tows were taken in a alternated weekly between the discharges of Units I                         stepwise oblique pattern and sampling duration was 5 and 2 when plant operations permitted, and all                              minutes each at surface, mid depth, and near bottom       ,

samples were designated as having come from station depths. Sample volumes wcre measured using one l EN (Fig.1). A 1.0 x 34 m conical plankton net General Oceanics flowmeter in each net and ap-with 333.pm mesh was deployed with a gantry proximately 300 m 3 of seawater were filtered for each system into the discharge water. Four General sample. Nel mesh si/c was 333.pm, except for a Oecanic nowmeters (Model 2030) w ere positioned in period from mid. February through March, when the mouth of the net to account for hori/ontal and 202 pm mesh nets were used to reduce the extrusion vertical flow variations. Sample volume (about 400 of yolk sac winter llounder lanac. m3) was determined by averaging the four volume Plankton samples were sphi using a NOAA Bourne estimates from the flowmeters. splitter (Botelho and Donnelly 1978). Fish eggs and n 1KM / - - - TRAWLS () } - , 888 SEINES 1 MI + PLANKTON T NIANTIC

                                                                          ,' nivEn                f NR
                                                                                                 )>
                                                                                                \

l

                                                               '                               (

C' N! ANTIC JORDAN BAY J A .. enbc. { COVE

• WP

[4 e' ~ TN

                                                                                      %g^
                 , p (J,                                                       ....       % b

g pq TT ( 43 9 4g

                                                                       .Q R.

Fig.1. Location of trawl, seine and ichthyoplankton samphng stationt 90 Monitoring Studies,1990

1 1 larvac were removed under dissecting miemscopes. total length of up to 50 randomly selected indh,iduals Successive splits were completely sorted until at least of each species from each replicate were measured to 50 larvae (and 50 eggs for samples processed for eggs) the nearest millimeter. Catch was express-d as were found, or until one half of the sample was number of fish per haul. examined. Samples examined for larvac included all NB samples plus all EN samples collected froin January through May and July through Decemter; for Entrainment mortality study June, only two (one day plus one night) EN samples per week were cuunined. Three day and three night EN samples collected m April through September in 1990, NUSCO conducted a pilot study to deter-were examined for fish eggs. Fish eggs and larvae mine entrainment mortality of labrid (cunner and were identified to the lowest practical taxon. Cunner tautog) eggs. On three different days, July 10 (test and tautog eggs were differentiated from a weekly com- 1),16 (test 2) and 23 (test 3), ichthyoplankton posite sample of their eggs using the criterion of e.amples were collected simultaneously in front of the bimalality of egg diameters (Williams 1967). Ich- MNPS intakes in Niantic Bay (lN) and at EN. Thirty thyoplankton densities were reported as no/500 m3 minutes later (approximate transit time in the quarry), an ichthyoplankton sample was collected at the outfall of the Millstone quarry (QC). Eggs collected Trawl program at IN were used to determine natural hatching rates; those collected at QC were used to determine entrain-ment mortality. The eggs collected in the EN Triplicate bottom tows were made using a 9.1-m samples, which were actually part of the regular otter trawl with a 0.6 cm codend liner. Demersal monitoring program, were used to determine the ratio fishes were collected biweekly throughout the year at of cunner to tautog eggs, Paired 0.61 x 3.3 m,202-six stations: Niantic River (NR), Jordan Cove (JC), pm mesh plankton nets, were towed to collect Twotree Island Channel (TT), Bartlett Reef (BR), samples at IN and a 0.5 m,202-pm mesh plankton intake (IN) and Niantic Bay (NB)(Fig. l). A standant net was used at QC. Nets were deployed for 10 tow was 0.69 km and this distance was measured minutes and volumes measured with one Gerrral using onboard radar. When the trawl net became Oceanics flowmeter in each net; volumes aseraged loaded with macroalgae and detritus, tow distances 159 m3 at IN and 149 m3 at QC. were shortened and catches standardi/ed to 0.69 km. Samples collected at IN and QC were returned to Catch was expressed as the number of fish per tow the lab and placed in running seawater, Samples were and up to 50 randomly chosen individuals of certain viewed immediately with a dissecting microscope and selected species per station were measured (total cunner and tautog eggs were removed using an eye length) to the nearest millimeter, dropper. During tests 1 and 2, 200 eggs were removed from each sample; because fewer eggs were found in samples collected during test 3 only 100 Seine program eggs were removed from caeh of these samples. Ten eggs were placed into each of 20 hatching chambers (10 chambers for test 3). The hatching chambers Shore zone fishes were sampled using a 9.1 x were 25 mi beakers with three 1.5 cm diameter 1.2 m knolless nylon seine net of 0.6 cm mesh. openings covered with small mesh netting to allow

             ' Triplicate shore zone hauls were made parallel to the       seawater to flow through. During test I,202 pm shoreline at White Point (WP), Jordan Cove (JC), and        mesh netting covered the beaker openings, however, Giants Neck (GN), monthly from November through             some newly hatched larvac escaped through the net.

March and biweekly from April through October ting. To prevent this during tests 2 and 3,110 pm (Fig.1). A st:mdard haul was 30-m and this distance mesh netting was used. Chambers we u viewed once was measured using the pace method. Collections per day to detennine how many eggs had hatched; any were made during the period of 2 hours before and i eggs that had not hatched at the end of a 72 hour hour after high tide; generally all three stations were perial were.considen:d dead, sampled the same day. Fish in each haul were iden-lified to the lowest possible taxon, counted, and the l Fish Ecology 91

Data analyses the first derivative of the Gompertz function with respect to time and directly described the larval abun-dance over time. This density function has the form: The occurrence, distribution, and abundance of potentially impacted fish as well as their observed 4 = (uDK)/(exp(D.expl<t) +vtD [2] spatial distributions and temporal abundance ductua-tions were analyzed to assess possible plant related wlere 4 = density at time t impacto Indices of fish abundance were selected on and all the other parameters are as described in liqua-the basis of underlying distributional assumptions; tion I, except for n, which w as rescaled by a factor of failure of the data to conform to these assumption; 7 because the cumulative densities weie based on may reduce the precision of the estimates or, worse- weekly geometric means and, thus, accounted for a 7-provide biased results. nus the 6 mean was used t estimate abundance. The S mean was selected 1 dwrid Daily entrainment estimates were determined from describe both annual abundance and longterm abun' the daily densities, calculated in Equation 2, which dance trends because it is the best estimator of a were muhiplied by the daily volume of coohng water population mean that approximately follows the that passed through MNPS. Annual entrainment lognonnal distribution and contains many zeros estimates were detennined by summing all daily es-(liennemuth et al.1980; Pennington 1983, 1986). t mates during a defined period when the selected The calculation of this index and its variance estimate taxon occurred (see lehthyoplankton Entrainment was described in detail in NUSCO (1988a). The 5- Estimation Section). This represents a change from mean was used as an index of abundance for juveru,les previous years in the way entrainment was estimated. and adults collected in the trawl and seine programs, The presence of density dependent mortality during for larvae and eggs coltected at EN, and for larvae the early life history stages would lessen the effect of collected at NB. The S mean mdices for ichthyo- losses due to entrainment, becau.,c the natural sur-plankton were weighted by the largest number of v val would increase when density is lower. When samples ever collected in a week to standardim data abundance estimates of both eggs and larvae of a across weeks and years. For any species that occurred seasonally, the data for calculating the 6 mean were species were available, the presence of density-dependent mortality was investigated using restricted to its period of occurrence to ehmmate zero the following relationship (Ricker 1975): values in the distribution tails Running averages based on the 6 means were calculated from the begin-L = a(E)exp(b E) (3) ning of each time senes to investigate the presence of long term trends in the abundance data. The where L = index of larval abundance running 6 mean is a stable statistic, with smaller year-E = index of egg abundance to year fluctuations which facilitates the detection of a = scaling parameter long tenn trends. b = densi:y dependent pmuncter For dominant ichthyoplankton taxa, the number of individuals entrained was estimated using the if the parameter (b) is significantly different from Gompertz function which was fitted to weekly zero and positive, then the density dependent mor-geometric mean densities at station EN* tality is depensatory; if it is negative, then mortahty The form of the Gompertz function used was: is compensatory. These parameters were estimated using non linear regression techniques. Ci = a(exp[$cxplmt))) [Il Data on the annual abundance of fishes in LIS and adjacent areas were examined to detennine if changes where Ci = cumulative density (noJ500 m3) at time t observed in the Millstone area were localized or t = time in days from the date when the evident over a larger area. Trawl data were available larvac appear from the DEP random trawl survey in LIS from 1984 a = total or asymptotic cumulative density through 1990 (P. Ilowell, D. Simpson, CT DEP,

                    = location parameter                                            pers. cornm.). Sufficient data were available for x = shape parameter                                                 cunner and tautog catch comparisons from the DEP         l trawl data set.

A density function was constructed by determining 92 Monitoring Studies,1990

   . _ _                __               _ _ _ _ _ _              _ _ . _ . _ _ .           . _ . _ _ _       _m   .

I i 1 Results and Discussion mer spawners and their parallel abundance fluctuations suggests that similar factors may have influenced l Fishes that dominate the Millstone area are typical their survival. Because water temperature has been I of those found in New England waters (Oviatt and linked with recruitment success (Cushing 1973, 1 Nixon 1973; Saila and Pratt 1973; Jefferies et al. 1977; Sissenwine 1974,1984; Roff 1981) the annual  ! 1988) and in LIS (Grecicy 1938; Warfel and Mer- 6-mean larval densities of these three species were I riman 1944; Wheatland 1956; Richards 1959; Pearcy regressed against MNPS summer water temperatures; j and Richards 1962; McHugh 1972; Geomet Tech, no significant relationships were found. Other ex. 1983). One hundred and eighteen egg, larval, juvenile planations for simultaneously low larval abundance and adult Osh taxa have been collected in ichthyo- for these three taxa may be that they were heavily I plankton.1rawl, and seine samples from June 1976 preyed upon by other organisms, or that food ] through May 1990 (Appendix I). Winter flounder availability was low (lloude 1977,1978a,1978b; (Pseudopleuronectes americanm), anchovies (Anchoa Leak and floude 1987). milchilli and A. hepsetus), silversides (Menidia menidia and M. beryllina), grubby (Myo.rocephalus Trawl monitoring ) nenaeus), American sand lance (Ammodytes americanus), skates (Raja crinacca,3. ocellata, and R. One hundred and five taxa of juvenile und adult eglanteria), scup (Stenotomus chrysops), windowpane fishes have been collected by truwls at six stations in (Scophthalmus aquosm), tautog (Tautoga onitis ), and the Millstone area since 1976 (Appendices !! and Ill), cunner (Tautogolabrus adspersus) are the most com- Six taxa accounted for over 80% of the catch. Winter mon fish taxa collected. The occurrence, distribution flounder dominated the catches and accounted for over and abundance of fish in the MNPS arca follows. 40% of the catch from June 1976 through May 1990; I scup (14%), windowpane (8%), anchovies (7%), I lehthyoplankton monitoring skates (6%) and silversides (44) combined accounted for another 40%. These taxa were within the historic in MNPS sarapling programs,59 ichthyoplankton range in terms of numbers of Gsh caught in 1989-90, taxa have been collected since 1976 (Appendix !). Of winter flounder remained the nest abundant species those,7 egg and 20 larval taxa at EN and 19 larval (37% of the total catch). The winter flounder is taxa at NB were found in sufficient numbers to caught throughout the year and, because of its com-calculate 6 mean densities (Tables I,2 and 3), in mercial and recreational importance, is discussed in addition to providing entrainment estimates, ichthyo- detail in a separate section (see Winter Flounder plankton collected at EN were used to calculate Studies). Scup (12%) was the second most abundant seasonal density estin ates for comparison of species in 1989 90; most scup were juveniles taken abundance and species composition information. The primarily from June through October at NB. Win. most abundant egg taxa collected at EN were cunner dowpanes and skates are resident demersal fishes found and tautog and, except for the low abundance of primarily (over 60%) at TT and BR, The 1989 90 per-cunner eggs in 1986 87, their levels of abundance centage contribution of windowpanes (12%) and have remained relatively consistent from year to year. skates (10%) combined was over 20%. This propor, llowever, anchovy egg densities have fluctuated tion was higher them the average of the 14 year series, greatly, with the lowest densities occurring in the Young of the year anchovies accounted for 5% of the past 3 years. trawl catch in 1989 90. . Over 75% of the anchovies

          - Larval densities in 1989-90 fell within historic ran-  were caught at NB from August through October.

ges (Tables 2 and 3), except for larval Atlantic men- Because anchovies typically have a patchy haden(Brevoortin tyrannus ) whose densities at EN -distribution, their catches in trawls were highly were higher this year than in any previous year. The variable. Annual totals ranged from more than annual densities of the . dominant larval taxon, 10,000 in 1985 86 to less than 20 in 1979 80, anchovies, was higher in 1989 90 than in the Silversides, accounting for 2% of the trawl catch in preceding 2 years, but still low relative to historical 1989 90, were found primarily from October throu.gh densities, February. The 1989 90 trawl catches of tautog, sand Annual abundances of anchovy, cunner, and tautog lance and threespine stickleback (Gasterostens larvac have been low since 1984 85 at both EN and aculeatus) were the lowest recorded. Sea robins NB. Larvae of these three taxa are products of sum- (Prionots spp.) and fourspot flounder (Paralichthys Fish Ecology 93

TAlltI1. The &mcan' density (noJ500 m ) of3the most abundant fish eggs mllected at IW for each report year during June 1979 through May 1990, - 1mnm 70 80 80 81 Ri-t2 82'83 83 84 84 85 R S-86 86 87 87 88 8089 89 90 T, adsperius $870 8223 5171 5501 7068 5719 7484 2969 $002 5395 6904 T. onita 1364 2842 2647 2244 2114 2157 3237 2756 3011 2269 2887 Anchoa ' sip 1447 1245 1080 765 2257 4880 '145 910 89 38 54 S aquosar 50 63 65 34 19 7l 365 181 520 178 94 Prionnytur spp. 61 206 398 385 425 156 367 52 63 89 64

                                                               . _S chryrops                                                                 21           1    133       113          98      194          25          69      31        4        36
                                                               - II. c u&c .                                                                 22         11       31        34           8        10        14          55      58       65       05 i

• Data scaumally resincted to May 22 July 23 for Taurogolahrar aspersar , to May 23 August 25 for Taurogo unitis , to June 15 August 5.

for Anchoa spr., to May August for ScorAtAalmu aquosar, to July Auguss for Prwnotar spp., ia May July for Stenoivmur chrysors, and to April. August for EncAslyopar cimbriar. TAlllEE 'Ihe &mcana density (no./500 mh of the mmt ahtmdant fish tarvae collected at IW for each report year dunng June 1976 through May 1990. Jnon 76 77 77-78 78-79 79-M0 80 81 818L 82 83_ 8314 84-85 85 86_ 8687_ 87 882lLg9 $9 90 7 Anchoa spp- 1152 931 463 2168 2430 5768 816 1421 302 1102 1244 126 359 619

f. americanu 106 143 114 285 129 233 297 210 180 87 109 116 203 106 4 americane 94 318 119 1Ii 136 21 27 -18 9 3 13 41 31 24 Al.aenatur - 41 38 36 38 107 72 68 50 68 34 29 95 63 30 P. gunnellar . 13 13 16 13 58 27 13 14 14 22 4 26 9 6 B. tyrannus =5 4 4 0 3 i 11 23 2 41 3 2 6 72 T.altpersar ' 29 $8 1 13 58 78 31 49 4 12 4 5 9 12 T. onitis 37 36 1 11 46 83 44 33 3 15 3 7 17 12 Lipari,r gy.; 27 30 10 16 22 5 11 8 36 1 4 42 18  ;

U. subbefurcas.: 5 9 14- 14 '17 6 4 to - 7 -9 23 41 51 l 5.fascw ' 4 'l 4 9 8 13 7 9 9 5 4' 6 7 4 E cimbriar. 2 8 6 8. 6 1 -6 13 5 8 8 12 45 36 3 aqwum to il 1 5 $ 5 2 _. 13 3 1 4 '3 '$ 4 P. friacantAmr

                                                                                                           ~

14 3 1 2 11 17 9 9 1 2 3 0 9. 5

                                                             . Gobiidac -                                                                        6       3     1      0'         i     'O     O       I         4        3   3       2      4        8
                                                            - Priom>tm spp.                                                                      2     '2     0-      1          3    18      0       4          1       6   0       0      1       _1 AI extalecemennosu                                                             I       i  -1       i'         l      '3    4       4~         l     _0-   0       0      1        I S chrysop., '                                                                 5       8    0       4         6       8      1      0         0       -0   0    .0-       0        2 C. Aarengar                                                                    i       l    i      O         6        1    0-      1         0        2    1     14      1        1 C. regalu f                                                                    i    -3     0       6         0       7-    6       3         0        2    1      0      1      _1

• Dais seasonally restncted to July September for Anchoo spp.. to March June for Psamlopleuronect let tuarystay for Alyotocephalus annaras, to July December for 11revoortia tyrannas, to AprilJuly for Enchelyopas cimbrins, to klay.0ctober je

('. SwpA1Aa! mar aquosas, to Janshlay for Pholi. gunnellut, to June September for reprelat triacanthar, to klarch41ay for Liparis spp., to April-Septemher for Syngnafhat fccur, to June September for Trionorar spp., to Ap il June for Ulmraa,subbifurrafa. :., Juuarv41ay for Alyotocephalar ocialecervpine.uw, to June August for Paralichshys oblongut. to June August for Cynoscion regalu, io June August for . Stenotomu.r chryrops. ' oblongus) were more abundant in 1989-90 than in Seine monitoring ,. . any of the preceding 13 years. Ten times as many Atlantic menhaden were caught in trawls in 1989 90 Tw6 !axa among th.c 41 fish taxa caught in seines than for all of the preceding 13 years combined, from June 1976 through May 1990, accounted for Menhaden aro currently increasing in abundanec along over 90% of thn cauA (Appendices IV and ,V). the Atlantic coast because of reduced commercial Juvenile silversides dominated the seine catches )

                     ~ fishing pressure, precipitated in part, by the closure of                           - during the summer months (June through September)                                   !

, fish processing plants and a reduction of fish meal .throughout the 14. year monitoring period. " Juvenile ji exports (D. Vaughan, NMFS, Beaufort, N.C., pers, and adult silversides combined accounted for 82% of comm,). .

                                                                                                             -the total catch. la 1989 90, 80% of all fish caught -

Annual variations.in the abundance of the six by seine were silversides. Mummichog and striped

dominant 1rawl taxa were evaluated by examining - killifish (Fundulus .spp.) accounted for 13% of the .

J yearly S-mean catches for all stations combined The catch in 1989-90. Fish captured in the shore zone ai L annual S-mean catch of each taxon fluctuated widely, JC, a productive nursery area, accounted for over 70% which is common for trawl catch data (Geomet Techi of the -total catch at all stations. Silversides are-1983tPennington 1986; Jefferies et al.1988). The. . discussed in a later section as a potentiallyl impacted = 1989-90 S.mean catches for all six taxa were within taxon because of their dominance in the shore-zone of historical ranges (Table 4). ' Jordan Cove, an area periodically affected by the ' three unit cooling water discharge. l l (I Fish Ecology : 95 l t b S im _ _ . _ .u . ._ .._ u . . . _ _ _ ._. - - - - __ - _ ---- - - -- _ -

_ _ ~ . - . -. . ._ -. -____~___-._..m.m . _ _ _ . _ . . - . - - _ - . ~ . _ . . . _ . . . - 8

                          'I AHIF.4. he 8 tncan catch      (noJo 69 km) or the rnost abundant rish tollected by trawl for each report year during June 1976 through May 1990f Tat on                              76 72 77-78 78 79 79 80 80 81 817,R ,,12M ,QM4 8445 R346 tb 87 E7 kN A8 89 M9 90
                       ' P, amereagar.                        -16,6 13.5      15.7       26 8 32 6 24.1           41.8     27.7       29.5 22.0          19.8 19,3         2f 2 I k.?
                          $ chrytofu .                         10 6 Iv 8 13 3            19 5 17 0 20.4 27.5               26.6       22,3 13 6 30 6 2L7 Ih o 14.5 tai Aoa app-                        t1.1       3.3 39.3        0.1      0.1     40       0.2     04         0.7 113 k $7.3               16       31 15 9 3 ayaume                                 2.9     24   1.8        2.9 .- 35        29       67      5.0         4.4      4.7      3.5      4.0       5.1       5.7
                       .- Ray spp,                                1.4      12  08         0.8      *. .i   1.4      61      5.3         3I       ILS      4.5       46      63         5.3 Mankfia app.                         l 6.2      97   2.H        6.2      65      18       1,5     2.1        05        l9      17.8       21       34         1.9
                                                                -                                                                                                              -~

I'

                          ' thta scawnally restricted to Junedktohcr for Strassomat cAryrvet,in August (ktober ror AncAva spp-.,(kkhir iebruar) for Mceidu ipp , and renuming tais gear.round (June %)).

lIntrifiHHiellt eSilulateS Tant.fi 3- hwnomic winposioon or ichthyiplankinn collected at tin (as a percenuge of the total) dunne lune 1976 An increa'ic in mortahty precipitated by entrain. # ment losses at MNPS could affect local fish popula- rm lu- . m. u tions becmiw early. lite history mortality rates are AacAna spp. 58.6 81 among the most critical factors influencing adult fish ' P3'al"F l<arva<cm ame'wd*a' II 4 0.0 stock abundance (Cushing and Ilarris 1973; iTannister A*'%'" 'PP- *" "" et al.1974; Cushing 1974; May 1974; DeAngelis et alz 1977); While cunner, tautog and anchovies ac- f,',", ,1 "' "'","' " rAot p .,ttu

                                                                                                                                                                $                    "0 0.0 l

2.1 coun.ted for over 90% of all eggs entrained from June routorw aorm ainitu 16 $ 3.7

                        ' 1976 through May 1490, anchovies, winter flounder,                                   rawsa mira -                                      16                30.6
                       = samt lance, and' grubby accounted for over 80% of the                                 E*' A< '*"P"' *6' h' _                          '2'                 07 larvae entrained during the unne perial (Tahle 5).

Preyiously.(NUSCO 1990), entrainment estimates

                                                                                                               , , ' " p' "                                     d                    ["

sy,pa,Aufoco to o.0 were obtained by multiplying the median density at ScopA4Aalms aveu o.7 2.7

                       ~ EN during the season when 95% of a species' total .                                   P<prile irixonshae                               0.6                  0o                  ;

annual abundance occurred times the total volume of. *h'id" 04 00 water passed llyrough MNPS during the same perim!. Using this methmli both the start date of each species' h',j#"' $,

                                                                                                                      ,,p Suna ,ma, cA,yrops jj,,,,,p,,,,, .

0.2 N 0.8 "scason" (the period of Teurtence) and the duration Clup<a Am,4pv 0.2 . 00 changed from year to year. This year, we used a new M<astia spp. 0.2- 01

                        - method to calculate annual entrainment (see ich-                                   #7**i"* "rans                                      0.2               '0,1-thyoplankton Entrainnient Estimation), l'stng this methal, a species' " season" was redefined so that it

[$'j'$f aan ma rusrata - 0.1

                                                                                                                                                                                   $0.0                  ;

was the same from year to > car; it started on the day clupeidu 0.1 0.0 '

                         -that corresponded to the earliest recorded historical                                Scha'oiles nucauw                                Al                ' O.0-catch urid lasted until the day that corresponded to the                             Alma ipp.                                        or                   o.6                 ;
                                                                                                                     "##" 'PP' latest historical recorded catch. This approach makes the season longer The new estimates were calculated N                    $;2
                                                                                                                                                                                                          ~
                                                                                                             - Scamber ipp                                    - 0.0                 0.1 from the daily volume of cooling water that passed ~                                 Alma ps,*loAar<n ot                              0.0                . 0.1 through MNPS during this redefined season and thus c the cooling water volume used in the ca(culations was
                        . greater than That used ;previously. Also in this                                              .

determmed to be a better measure of abundance than -! method, the cumtalative abundance of the daily den. sities of dominant ichthyoplankton collected at EN me an. Ilecause f the change in the way entrainment was estimated, all estimates changed

                         ' calculated from the nParameter of the Gomperte func,
                        -tion was used instead of the median density / The n-                                  from those previously reported and they usually were parameter of the Gompertz function was chosen to                                     higher (see Ichthyoplankton Entrainment Estimation).
                        ' calculate the entrainment estimates because it was                                   These estimates for selected taxa, and the volume of 96 Monitoring Studies,1990 w        . n < p , - -n- s e       - e-m e  .,n -
                                                       ,-.                        m e --      .,me       a -..h+

c ooling water upon w hich the estimates are bawd are eggs increased along with cooling water volume. presented in Tables 6 and 7 - Except for 1986, anchovy egg entrainment was lower When Unit 3 became operational, the cooling water during three unit operation than previous years (Table volume ttsed at MNPS approxirnately doubled, as did 6), Although some larval entrainment estimates the volumes used in calculating entrainment es- inercased with increased cooling water volume, most,- timates. Entrainment estimates for cunner and tautog however, did not dauble (Table 7). 3 6

              'l AllLli 6L ILstimated annual number (410 ) of cunner, tautog, and anchtwy eggi entrained and the annual volume of coolmg water (t106 ml )

on which the entrairimerit estim4tes are based. Omner Ilaeg Anshey Year No. entrained .3 3 Volume (m / No entramed ' Volume (m / No. entrained Wilume (m )' 3 6 (X IO*) (X 106) (XIO*) (X 10') (X10 ) (X 10*) 1979 1,534 . 728 705 728 215 711 1980 2,302 806 1,273 806 91 795 1981 1,736 8lb 1,735 816 172 799 1982 2,726 853 1,486 853 234 843 1983 2,631 798 1,180 798 618 786 1984 2,031- 827 1,369 827 657 812 1985 2,802 831 1,784 831 20 825 1986 2,932- 1,870 3,907' I,870 517 1,846 1987 4,533 1,784 3,7 to 1,784 37 1,752 1988- 4,386 _1,953 2,813 1,953 16 1,920 1989 3,885., 1,643 3,094 1,643 5 1,611 8 Volume wat determined from the condenser uolmg water flow through the piwer unitt dunng the seawn of occuncnce for cach tata l TAllLE 7, Estimated annual number (x106) of anchovy, winter flounder, Amenean sand lance and grubby L vae entramed and the annual

          - volume of cmling water (m3 x10 )6 on which the entrainment estimates are twd.

nnthovy Winter Nunder Amenc.in und bnce Qmtiy 3 3 3 Year No. entrained Volume (m / Na entrained Volume (m /. No. entrained Volume (m / No. entrained Volume (m / 3 6 6 (X 10 ) - (X 10*) ~ (X10 ) (X 10*) (X106) (X 10*) (XIO*) (X10*) 1976 419 616 108 663 20 . 839 13 625 1977 424 570 31 586 84 983 32 65) L 1978 173 657 87 491 190 808 11 446 l 1979 887. 552 48 474 154 941 21 534 1980: 918 505 176 633 124 1,090 34 702 1981 1,784 633 48 455 90 713 43 414

          .1982'               464              550                 170            674                '32            1,065                      49           -629-
           -1983             '623              '482                 219=           648                  41            1,127                     57           -704<
          '1984                 169             602                   88           574                  20              981                     41          .643 l           -1985               712              601                   83           528                  10           1,031                      37            582 l             1986.          1,328             1.259                 131          1,353                    5          1,734                    - 56         1,286-1987               124           1,161                 172          1,324                  48           2,186                      55         1,370 1988              396-          '1,338                 193          1,382                126            2,036                    124          t ,273 -

l 1,201. 1989 :546 - 175 1,046 - 55 -1,927 -72 1,110 l 1990 . ,b - . 139 1,303 2,242 1,335 61 49 8 Volume was determmed from the condenser cmling water now through Ow power units dunng Ltw season of occurrence for each tata . b Not calcubted becauw larva: occur after end of report perial(May 1990). Fish Ecology 97

a , l Entrainment mortality study results (MRI 1990i. Labrid eggs were not identified by species before Fish eggs and larvac entrainec through the MNPS being placed in the hatching chambers to mmimize cooling-water system are exposed to elevated water handhng of the eggs that may have biased the results. temperatures, mechanical strestes and chlorination. After hatching resulting larvae were identified to To determhc the extent of losses caused by entrain- species. To determine if differential monahty esisted ment of cunner and tautog eggs, NUSCO conducted between the two tasa,a ratio of conner to tautog eggs entrainment mortality studies in 1990. The objective was determined from samples collected at EN at the of these studies was to compare the natural hatching same time that the entrainment mortahty samples rates of conner and tautog eggs collected near the in- were collected. This ratio was compare;i to the ratio takes in the Niantic Hay (lN) to entrained eggs col- of larvae that hatched during the study (Fig. 3). The lected in the Millstone quarry (QC). Eggs collected two ratios were similar, indicating that differential for this study were initially identified to the fatnity mortality by species probably did not exist. This Labridae because cunner and Lautog eggs entrained at comparison also validated the technique of deter. MNPS have only been differentiated using the mining the bimodality of egg diameters (Wilhams critenon of bimodality of egg diameters (Wilhams 1967) to identify cunner and tautog eggs. 1967). /s ratio of cunner to tautog eggs was subsc-quently generated by determining the bimodality of egg diameters of eggs collected at EN and identifying [qy'g hatched larvae from the IN and QC samples. g moq

                                                                                                                  "~
                                                                                                                                         ^

Previously, NUSCO (1990) calculated .tautog and 9 H

                                                                   $[
                                                                                 ~

cunner hatchability indices using the ratios of annual densities of larvae to eggs in entrainment samples. $ w; its ao m These ratios suggested low egg to larval survival. We h 50- - do not know of any researchers that reported tautog  : 40 - ~ egg to larval survival rates in LIS, but Wilhams et 2 "- " al. (1973) calculated hatchability indices based on egg survival for cunner in LIS. They collected cunner kf[ E I eggs during five different spawning seasons: 1962 through 1965 and 1968 and compiled a stage-suTvm Ttst o ( i J 'W' 2 N y' 3 t1 y' Avtu on frequency distribution to predict egg mortality rates. They reported that cunner egg su~rvival in LlS was h g. 2. Itaching rue of Lbna (tautog and cunner) eggs poor (59) and surmised that predation was the "U"kJ bd 'c OS and after (QC) pauing through MNPS primary cause of cunner egg mortality, d " '"' 8 ' h * " F* " ' """'"*"' """' ' " Y "" dY U"'Y IN Entrunment monahiy was calculeed as the diffnence between Results of our entrainment mortality study .in' haiching raies at the two uauont dicated that the natural hatching rates and entrainment survival are much higher than previously believed. Mortality due to entrainment was calculated as the dif- Q utrioo O ct:ssty. ference between the natural hatching rate and the im- m 'S 3 ,r hatching rate of entrained eggs. Mortality estimates > *~ $ fE 'I

h  ;-

ranged from 31 to 73% and averaged 57% (Fig. 2). hI y m-h h  ! [ Natural hatching rates for eggs collected at IN ranged  %,f hE ,A from 8198% and average survival was 914 (Fig. 2). 5 Sor '

                                                                                                                       "2 Survival at IN was highest for eggs hatched during

{ m test 2 and lowest for those collected during test 1. g 20 [~,;,, ' Ahhough for impact assessment purposes entrain. E ici ment mortality had always been assumed to be 100%, i i s' ri i i i i i i i these results indicated that almost half (43%) of the 8""" "WW "WW "WW TI.S l i 2 3 entrained conner and tautog eggs survived entrain-ment. Labrid egg entrainment mortality studies were hg. 3. Percent d tauing and cunner eggt a M and brvae M W also conducted at Pilgrim Nuclear Power Station and and QC in sa:npies coticceed dunng the July 1990 special rCsultS Were quite similar (45% survival) to our enumnmeni monabiy uuay i 98 Monitoring Studies,1990

Selected taxa TAna x The 6 nun' acnm> w, /5on in b ana 955 u,si-dence mtenah of Arnencan und lance larsar colleded at 1.N ] 6 Seven taxa were selected for adthtional examination, based on their prevalence in entrainment samples or and NH for euh repon gear dunng June 1976 through Me I"U their susceptibility to thennal impacts. Because the g winter flounder has been studied extensively, it is dis-3 -~- cussed in a separate section (see Winter Flounder 1976-77 m I? Studies). Larvae of anchovies, sand lance, and grubby 1977 78 31M i i17 were abundant in entrainment samples and anchovy, cunner, and tautog eggs were the dominant egg taxa 3939 g ig 3; { ,g entrained. Silversides w cre also selected because they p> x m 214 3:o];o y dominated the shore-tone in Jordan Cove, w hich may 19 k 2 4 ) 272 h 54 3 23 he thermally impacted by the MNPS cooling water 19 M 44 18 1 4 5^ 1 30 discharge (NUSCO 1988b). These six taxa have been I"5 912 "I 4 1985 86 T.t 3, i selected m past (NUSCO 1987,1488c,1989, i933 ,7 6,4 i 3 ,' 3 1990) and arc described in detail below. 1987 4 s .u i 13 uI 4: 198 K 49 31 i 13 35 i 15 American satullance Iwo 24 7 161 5 The American sand lance is a schooling fish com-mon in estuaries, along the coast, and in offshore

                                                                       '#"""      '"""""""        """~

waters from the Arctic to Cape llaucras (Bigelow and Schroeder 1953) . The sand lance feeds primarily on plankton, lises 5 to 9 years, and spawns between December and March (Richards 1%,1982; Leim and 3n Scott 1966. Westin et al.1979; Grosslein and Azaro- 13

                                                               ~ _""                             odd?l[os I on'd?llos sitz 1982). They are caught predominantly as larvae            e l

in the winter and spring around MNPS, and are sel- pU" i dom caught in trawl and seine nets, perhaps because Sm ' adults burrow into the sand (Leim and Scott 1966). h l Eggs are demersal and adhesive (Frit/ sche 1978), and g l are not found in greal numbers in plankton samples. M ""4 Sand lance larvac were typically collected near 3 su MNpS from December through May. Catches were vanable and annual entrainment estimates have ranged o, .. g1ErN nn nm mm nc nu nn en U bbn. from 5 to 190 million larvae (see Table 7). Their abund;mee has varied by over two orders of magnitude us over the past 14 years; S mean densities ranged from NR odj?i[os l odj2((os 318 (1977 78) to 3 (1985 86) at EN and from 238 i "" I (1980 81) to 3 (1985 86) at NB (Table 8). Mon- 3n" l teleone et al. (1987) also reported large abundance flue- $ :no I tuations of s;md lance larvae in LIS. They reported 6 h

                                                                 >. I M 4
                                                                                                            }

during a 17 year period larval densities varied by two t- , orders of magnitude. The running S mean of larval density was compared 5w"".j - l

                                                                                                                   -O to the annual S mean to determine abundance trends M i     r-- rT r 7 t1 1lW 6 rn7"r Ol    rn and annual variation (Fig. ,.). Because sand lance                    nn    n,       nn nu nu un eu                     o, larvae were so abundant from 1976 77 through 1950-                                             YEAR                           ;

81 report years, the long-term trend since 1981 82 hg 4 Dc ennual (J) and running (-) 6 mean denug was downward and, except for 1987-88 at NB, all the (no /$no mo of Amerhan una tanse tanac ai !3 ana Nn i annual S mean densities since 1981-82 were below l the running 6 mean. l Fish Ecology 99

   - .          . -               - . ~ - -                . - - -               .     .~ -          -          . - . = - .          -. . _ . - - , -

Some of the annual variation of sand lance larval Anchovies abundance was explained by the temperature of the water in March. Larval densities were regressed The bay anchovy ranges from Cape Cod to Mexico, against average MNpS rnonthly water temperatures but it can occur as far north as Maine (Ilildebrand from December through May to investigate whether 1943; Bigelow and Schroeder 1953). It is typically sand lance larval abundance was related to found inshore during warmer months and moves temperature, Results indicated that 68% of the annual offshore in winter (Grossicin and Azarovitz 1982). variation in density was explained by March water The t;ay anchovy is perhaps the most common fish temperatures (r2=0.68; p<0.001) (Fig. 5). Colder along the Atlantic coast and is typically the principal March water temperatures generally were associated ichthyoplankton species in estuaries within its range with higher larval densities, and the highest densities (McHugh 1977; Leak and lioude 1987). Both the and the lowest temperatures of the 14 year time series bay anchovy and the striped anchovy occur in the occurred in 1977 78, Because sand lance larvae can Millstone area, but the bay anchovy is more abun-survive prolonged periods without feeding,(up to 60 dant; more than 80% of all the anchovies caught in days at O'C; Monteleone et al,1987) colder water MNPS monitoring programs are bay anchovies aad temperatures may be advantageous to survival. the ensuing discussion will center on the bay

           -Several researches have reported diat both adult and            anchovy, larval catches of sand lance along the Northeast Atlan.               Anchovy eggs comprised the third most abundant tic coast have fluctuated dramatically during recent               entrained egg taxon (see Table 5). Annual entrainment decades. Meyer et al, (1979) reported that the average             estimates ranged from 5 to 652 million eggs (see trawl catch of adult sand lance in spring in an area               Table 6), More than 50% of the anchovy eggs col-north of Cape Cod during the 1967 75 period was                    lected annually were found during a 2 to ? "cek near 0, increased to 50 in 1976, and exceeded 10,000               period from late June to rnid, July. The 69 enn in 1977, Although few sand lance are caught in                     density of anchovy eggs nt EN in 1989 was the trawls at Millstone, their abundance fluctuated from               second lowest in the Iliycar series, with only the year to year (Appendix II), As described previously,                1983 densities being lower (Table 9),

the density of larval sand lance in the MNPS area and throughout LIS (Monteleone et al.1987) also :i exhihited. large annual fluctuations, Given the

       . dramatic changes in abundance of this species, effects            TAllt E 9. The 6-mean* density (noJ500 m)) and 95% conti, of MNPS operation on sand lance may be difficult to               dence intervals of anchovy eggs ath! larvae collected at EN and aSecriain.                                                        Nil for cach report year during June 1976 through May 1990, IIX1S                        tARVAE Year             I!N               El                 Nil 40n -                                                       l976                          1152 1419 1977                            931 1408 e                                                                1978 E 300-48312th 1979       1447    1 336      2168 1 908          3801 13981 h                                                               198n       1245 1 597         2430 11249 -        5716 1 7652 o . 200 -                                                       191st      1080 12M-          576n 1 3326         7873 1 9799
         ~U                                                                1982        765 1228            816 1240          2103 i 1358
                                                  ,.                       1983       22571 IW6           1421 1 530         286012 tl2
         -{ 100-m                                *=

1984= 48801368n: 302 1 165 - 3271254 U r b o tAs 1985 145 175 O 1102 1 453 1117 1575 P < 0.001 .

                                                     *             !    . 1986        910 1 547          1248 1893 -        1224 1 1071 0                ,.        ,
                                                         ,8-
                                                         ,v          ,l    1987           89 146           126 1o t            79 159 1              2         3'        4              5  1988          3713  3         '359 1216            303 1257 1989          54 147            619 1416           462 1333 MARCil WATIR TEMPERATURE (*C)

Fig. 5.1.incar relationship between the annual 8-mean density

       .(nol$no mi) or American sand imce at EN and March water g,            g temperatures ('C) et MNPS In>m 1976-77 through 1938 90.

100_ Monitoring Studies,1990

Larval anchovies dominated plankton collections at Juvenile anchovies, which resulted from the sum-EN and NB and peak larval abundance ranged from mer spawn, are typically captured in trawls from mid July through mid August. Estimated entrain- August through October, predominantly at NB ment of larval anchovies ranged from 124 to 1,784 (Appendix 111). Even though anchovies ranked fourth million larvac (see Table 7). The 1989 S-mean among fishes caught by trawl, their annual catches larval densities at both EN and NB were higher than were highly variable and more than 70% of them were those in the previous 2 years. The running S mean of caught in only 2 years (1985-86,1986-87) of the 14-larval densities at EN and NB peaked in 1981 (Fig. year series (Appendix II). I 6), and all the annual S mean densities since then Anchovies mature within a few months of hatching l have been below the running S mean. In 1989, the and live only I or 2 years (Stevenson 1958) and j- S mean density of anchovy larvac were low compared short lived species usually exhibit large oscillations to historical levels but were higher than the 1988 den. in abundance. Large annual fluctuations in abund;mce sities (Table 9). are evident in our anchovy egg data; the 1983 and 1984 6-mean egg densities were so high that they were the only 2 years when densities were above the

                                              ""*"         Egos                  wstr        i  wstr                 running S mean (Fig. 6). Large annual changes in f                 g gy                mumos i munos                        bay anchovy egg abundance w etc also observed in LIS juxn-                                              i                       from 1952 to 1955 (Richards 1959) and in Barnegat E                                                  '

Bay, NJ from 1976 to 1981 (Youglitois et al.1987).

                                         $ ims                                              i                        it is likely that these large annual fluctuations in g                                                  j                       abundance are the result of events that take place out-p                                                  i                       side the MNpS area during the winter migration of       '

8 .

                                                                        ,       h                                   bay anchovies. Factors controlling the migration of 0-     t   i . . i ii-rTT*ig-           i i ii i

anchovies are not well understood, and neither rates of survival during the winter nor whether anchovies 75 77 79 81 83 85 87 89 return to their natal estuary are known (Youglitois et al.1987),

                                              **"~

LARVAE 2 extr ' 3 UNrT A comparison of the annual abundance of eggs and n gs amnos l onunos larvae at EN (Table 9) indicated that the index of c cAU - I annual abundance for eggs was generally lower than h l for larvae, and there was no apparent relationship be-6aan- I tween these indices. Tbc low abundance of eggs y l relative to larvac may be related to the length of time

                                         $2mn.                                             l                       that each developmental stage was available for e                                                                         capture; the incubation period for eggs was only a
                                                          @ / " d, Tf S ng p        n                           few days and larvae weic available for captme over a i    iiiiT i i i i                             i i i 75 77         79      81    83 - 85        87      89 period of weeks. Another possible explanation for low egg abundance, compared to larval abundance, was that Niantic Bay was not a primary spawning
                                                         'ARVAE                QUpl,r l g rg                       area for anchovies and that hirvae were transported by A.B3                            i                        tidal currents to the bay,
                                         ; um -

l In any case, there should be some relationship be-E i tween the abundance of eggs (a measure of spawning b anon- / l stock size) and resulting larvac, unless there are an-

                                         $-                                                                        nual fluctuations in the survival rates from egg to y2an.                                            l                        larvae. In some years there appeared to be an inverse o                                                r                        relationship between egg and larval abundance, Vauglitois et al. (1987) reported a similar pattern for 73
                                                           '77' 7' [iQ]yggg.                                       Barnegat Bay, NJ, during a two year period. This would suggest that compensatory mortality occurred hg, 6. lhe annual (O) and running (~) 6 mean denmy                                                                       "

(na/5co my or anchovy eggs at EN and larvae at EN and Nlt a nWQn&nt Mon @ Ween imual gg . Fish Ecology 101

l numbers and surviving larvae at some later date was and Poston 1980). Because they were not always investigated using Ricker's model (Eq. 3). The data identified to species in MNPS programs, the two used for this purpose were the annual &mcan abun- species were analyzed as a single taxon to determine dances of anchovy eggs and the &mean abundances of long term trendt flowever, when identified, over anchovy larvac in August of the same year. A den- 90% were Atlantic silversides. sity dependent relationship was demonstrated by the The annual &mean catch of silversides in trawls 2 and seines varied by two orders of magnitude. This reasonable fit of Ricker's model to the data (r =0.61) and by the negative and highly significant (p<0.01) high variability is typical of short lived species density-dependent parameter (b= 9.22 x 10'4)in the (Stevenson 1958). Catches of silversides in trawls model. This relationship appeared to be strongly and seines in 1989 90 fell within the range of influence by 1984 data point (Fig. 7). This point, previous catches at all stations (Tables 10 and 11). nevertheless, was a real occurrence of a very high egg abumlance with subsequent poor larval survival, as , 9 would i e expected if mortality was compensatory, dena intenal of siberudes couetted by irewl ai selected sia-noni for each repon year durmg June 1976 through May 1990 g 25m- , b;rt Year IN JC NB M_ b .-9 22 X 10 4 6 77 15 16 13 1 20 61 k 77 12k1 g ,!RU - I977-78 v. p < 0'm 29 12 Y D1 Dl2 181 25 10 121 8,6 1978 79 f0 1 105 91 8 81 7 211 3" 1500 M 1979 80 42 1276 61 16.8 0.7 11.6 4 16 h g 6f 1980 81 8 1 17.4 41 46 191 41.5 3 138 y; 10t u -ss . 1981 42 6192 0.7 104 5164 618 E s2 1982 43 213,5 1124 0.51 12.5 12 1 47

     ~d 500- .o                                                                      1983 4 4               214.2        41 1.1        41 J.6       1163
     $             $                                              Sa 1984 45                 2163        51 113         11 1.4    0.5 10.9
     $      O.   ,-m,         r , . ,           , . , -     ,         ,

1985 46 7 1 8.2 61 7.6 211.4 315.9 0 1000 20m 30m 4000 50m 1986 87 5 1 3.1 81 6.9 412.9 110 1 222 i 1987 88 3 14.6 21 1.6 31 4.0 15 1 27 EGG DENSITY (NOJ500 m ) 1988 4 9 210.8 110.4 1104 25 1 14.2 lig. 7. Nonhnear relationship between the abundance indices (64nean denuty) of anchovy eggt and August larsal. a Data seamnally restncted to Novemberfebruary at IN, Nil and NR, and October . January at JC. Several researchers have concluded that com-pensatory mort:dity in the bay anchosy larval stage can result from several mechanisms which include TAHtl 11. The 6 means catch (nof30 m) and 95% confidence starvation and predation (lloude 1977,1978a,1978b; inten al r silversides c llected by seine for each repon year dunng June 1976 through May 1990. Leak and floude 1987). Causal mechanisms for the compensatory mortality of the early life history ypr JC GN WP stages of anchovies in the MNPS area are not known, 1976b but because compensation appears to be occurring at 1977 1251 1 2094 151 1 569 621 168 the same time as entrainment, this would help lj78 2j12 i $ mitigate the impact on the anchovy population. l- f5t 2 1980 497 i 930 104 1 96 551 70 1981 1141 107 81 1 72 31 1 40 Silversides 19s2 108 1 in: 441 112 192 1 567 1983 5801 989 42 1 59 112 1 158 The Atlantic silverside ranges from the Gulf of St. 1984 351 35 11 1 9 313 85 8 6 Lawrence to the Chesapeake Bay and the inland sil- j j9 f93 verside from Cape Cod to South Carolina (Johnson 1987 1141 92 for 48 641M 1975). Along the Connecticut coast, the Atlantic 1988 125 1 132 521 28 361 23 silverside and the inland silverside are among the 1989 86 1.79  % 134 38 1 28 most common shore-zone species. Both species are important forage fish, spawn as yearlings, and live

• D'ta inwnauy restncied to June. November at au stations.

b from I to 2 years (Bigelow and Schroeder 1953; lleck Not enough data available m 1976 to calculate 6-mean. 102 Monitoring Studies,1990

Although the annual catches of silversides in trawls

         '"~                                                    -

have fluctuated throughout the data series, the rutining Nn 2 t*Nrr 3 tsri t a m noN,OnnAroN S mean of silversides collected by trawls at JC, IN

                                                                '                                                   and NB has declined since the late 1970's and con.

l tinued during three unit operation (Fig. 8). Although k "" ' running S mean of silversides at NR also decreased g! is - l

  -                                                               i                                                 between 76 77 and 85-86, since the startup of Unit 3 0*                                                               '                                                 in 1986, the running 6-mean catch has beca b 23                                                             !                                g                increasing and the 1989 90 S mmn was higher than the running S mean catch. During the late 1980's, o . . r r II TM'r" r#T r

hT r-t4 !L dI ."L r l r,gm, i i nin8 Sm of hib h b wim M Y 73-n n 7i i, so si.s2 33 u as an :) in i remained relatis cly constant (Fig. 9). i 80 [N 2.UNrr i t'N rr y 001 R AllON IOPlH AllON g g ,

                                                                    '                                                              JC                                  3 t str ' s t str E                                                                                                                                                             OPi k %10N I On k AT10N

• 60 - 1 I

                                                                                                                      ^ 12(D -         I R                                                              I I                                                          '

i

                                                                                                                             %K) -                                               I 6 *
     -                               r l

l g I D / i I

                                                                                                                                 ~

l 20 -

                           /                                         I
                                                                                              ,n    n
                                                                                                                                 ~
                                                                                                                                                                         \

0- , , , j , , SA7 ( , i1 - r i 7%M 77?S 79 80 81-82 AI M Ai se IT s4 $4 90 76 78 $n 82 84 86 88 90 20 - N]) 2 t%rr ' i t'Nir opt RATION I OMS ArlON E

                                                                       '                                                     *g ,GN                                     timrt s t'str M 15 -                                                          1                                                                                             On R ATioN I nn k AllON 8

S i - i i B R r 3 8a- - l l150- l

   -f"         5-i 6 100 -

h - l 1 i b I 50- '" "

                                                                         ;                      Q                       d o-                         P              a      niO                             11 nn                                                                    ]             l 7{rn,}g!,,,,,
                         <     l   1     i i i i i i i                              E          i i i i            I                                                       l 73 '7e      77 78 79 8n 31 R2 81 M tit 6 B t ta                                       89-90 0yr              777 76      78       Bn            82        M               86       88    90 13 JC                                   2tmrr          ' 14mtr
        ,                    q On_ RATION I On R ATION                                                y,                                                         '
                                                                          '                                                          WP                                  mrr                    s usrr li 12 j                                                                 I                                                                                           Ott RAlinN I OltR ArlON I

c I - Q 9 I E 150~ l C I t U 1

                                                                                              )                           o                                                               I 5 '-                                                          .l" N                                               6 no-
                                                                            '                                             U                                                                '

d i s i i i i i i i nn ll 00(l i i i i i i I 7s 4 n is 19 no si s2 stu sin 6 si as s9.eo l 0-- Th T i i i i ^ i% T T *t--'t YEAR 76 78 80 82 84 86 88 90 iliAR l'ig. 8. The annual (D) and running (-) 5 -rnean catch (noJO,69 km)of silvenides taken by trawl at NR, IN, nil and JC. I;ig. 9. The annual (C.1) and running (-) 5-mean catch (no /b) of silvenides taken by seine at JC, GN and WP. Fish Ecology 103

i Juvenile silversides dominated the inshore seine O m m ona^ m collections in summer and early fall (July October), and adults were taken by trawls during the late fall and h* id _

                                                                                               ~

O Tuarmn on arixw winter (November March) This pattern suggested $ _ that adults in the MNPS area overwintered in deeper E 20 _. waters close to shore, To determine if a change in the  % j ., length frequency distribution occurred after Unit 3 be- $"'- 1, I, came operational, the length frequencies were t expressed as percentages for the periods before and M]-r 2m 4i e r m mo

                                                                                                                             ,1 n-no nuo u:o
                                                                                                                                          ,N, after three unit operation were examined. The length frequency distribution for silversides collected in bodi trawls and seines remained similar during two unit M-and three unit operation (Fig.10).                                       TRAWL                            O m en erum The relationship between summer water temp-             g m-eratures and the annual 6-mean catches of sihersides           d9                                          O ruant%n onum was ir.vestigated to understand the effects of temperature on the interannual variability of seine-b p "~

caught silversides. A significant positive relationship g 30-- __ gm

                                                                                                             ~

(p< 0.001) was found to exist between the catch of _ silversides at JC and July water temperatures (Fig. x 11), but no significant relationship was found for d* catches at either GN or WP, JC is a productive 0- r~'" i i i "r i 2* ** ' ' * "-"" "H 48 d ?" nursery area and most of the silverside catch at that site is comprised of young of the year. Warm water telnjVratures lead to quicker hatching and growth (tiil- 1:ig.10. The perceni icngth4requency distribution, in 20-mm debrand 1922), which may be advantageous because inien,i,, or suveruJn from se nes and mwi conections paru. larger fish would be less susceptible to predation. tioned into two unit (June 1976 May 19156) and three unit (June The potential for changes in seasonal distribution 1986May 1990) operatimal periaat of silversides inhabiting the shorceone at JC and WP exists because the thermal effluent from three-unit operation has been shown to encompass Jordan Cove (NUSCO 1988b). Sampling frequency during April l* r2- 0.620 through October at these two sites and at the control station, GN, was increased to biweekly in 1984 to e <00nl , improve the ability to detect changes. The frequency T of silverside abundance in each month from Junc hl* through October (as a percent) was examined from { 1984 through 1989 to determine if changes in seasonal distribution patterns have occurred during the g* q - three-unit operation period (Fig.12). The season of U occurrence for silversides (June through October) has . .., . remained the same during two unit and three-unit 0 '+ i i i i i i 20 22 24 26 28 30 32 operation, but the monthly distribution has varied from year to ycar. Distribution patterns are variable JUtJ W ATER TEMPER ATURE ('C) AT JC both among stations within a year and among years at a given StatioD. Ilowever, there was no obvious Iig 11. t.inear relationship between the annual 6-mean catch d 5d""id" I"*" ' cine couecues at JC (no.no m) and the change in the seasonal distribution at the two Jordan Cove stations, (JC and WP) compared to the control l"'[9*"

                                                                        ;9        """""" I'C)  "'iion JC f r m 1976 ibrough station (GN), after Unit 3 became operational.

1(M Monitoring Studies,1990

                                                         "-                                                                                                                                                                                        The grubby was the fourth most abundant larval or 70-                          _                                                                                                                                                     taxon entrained and accounted for 4.6% of alllarvae U    60                                                                                                                                                                                 collected at EN from June 1976 through May 1990 h so-     .           _

(see Table 5), Annual entrainment estimates of

                                                    @ .io .           _

grubby larvae ranged from 11 million in 1978 to 124 R w. _

                                                                                                                                                                                               -                                            million in 1988; an estima'.ed 49 million grubby lar.
                                                                                         ~

Q 20 , - - - vae were entrained in 1990 (see Table 7). Larvac l t g,; have been collected from February through May and gf 7 ~i _ uovrn 67 s 9 iole 7 9 iol67 : 9 iol6 7 s 9 iole 7 s 91o16 7 :9iol l l most were found from mid March to early April, Ex-ecpt for 1988, larval S mean densities have been fairly stable at Nil; but, at EN, large, annual fluctuations oe-curred especially during the early 1980's (Table 12).

                                                                      -                                                                            sc                                                                                       The 1990 6-mean densities at EN and NB were below                  i i~

g the running 5 mean, but were within the historic ran-6

• 6 ge. Although the 1990 $ mean densities were below 8 "- the running 6-mean, the overall trend, as indicated by I

                                                    $ *-                                                                                                           -                                                                         the running S-mean, has Iven increasing (Fig.13).

w. ___

The grubby was the eighth most abundant taxon in 20 trawl collections, accounting for more than 2% of the o io. catch at all stations during the past 14 years (Appen- j o.

                                                                           ~L                                                      Tb                                                 r             r       -

l dix 11), Individuals are caught primarily at the near. .i uovrti 6 7 8 9 tol67 9 tol67 : 9 :ol67 : 9 tol67 s 9 :ol67 s 9 tol shore trawl stations (NR, IN, JC); juveniles and J I adults found throughout the year at JC and NR and f

                                                        .30                                                                                                                                                                                  during their spawning season at IN. The 1989 90

'.l ,o.

                                                                                                                                                *"                                                                                           S mean index at JC was the lowest of the 14 year data d                                                                                                                                                                                       series (Table 13), At all three station (JC, IN and
                                                     $ on,                                                                 ~

_ NR) the 1989 90 S means were below the running & '

                                                                                                                                                                                                            ~

mean (Fig.14) The nonnalized length frequency dis-E" ~_ tributions (each period equals 100%) of trawl caught

                                                                                                                                                                                                                   ~

grubby were simihtr before and after three units began h 5 "20-

                                                                       ~

_ operating (Fig,15), indicating no change in sire _~~

                                                     'm-           -
                                                                                       '-                                          N                                                             -              -

distribution as a result of MNPS operation. g -u- _ r- r-MONrli 67 8 910167 8 91ol67 8 910167 8 910167 8 91ol67 8 9 lol . , YEAR- 84 . 15 46 87 ts 89 , , rep rt year during June 1976 through May 1990,

                                                 ' Fig.: 12. Percent frequency by month Qune September) of silversides taken by seine, 1984 1989.                                                                                                                                                                                       IW         N fl -

Year 1977 4119 1978 3H 29 OrWhh,y 1979 36A7 1980 38 17 31 212

                                                                                                                                                                                                                                                                                               )

The grubby is found along the Atlantic coast of [8j , 3$ [g[3 North America from the Gulf of St. Lawrence to New 19s3 6s99 .39 2a i Jersey, primarily in eclgrass habitats (Bigelow and 1984 501 15 24 a13. Schroeder 1953), It is a winter spawner (Lund and 1985 68 423 is 210 Marcy 1975) and larvac are found from February to 1986 34 210 .26 2 11 L-7 s April in shallower areas of LIS (Richards 1959). 2ja Grubby eggs are rarely collected, probably because 1989 632is u en ,. they are demersal and adhesive (Lund and Marcy 1990 30 2 s 25 2 8 1975),' but larvac are abundant in MNPS ichthyo-plankton collections. The grubby is a resident fish in

                                                                                                                                                                                                                                              ' D*'d "amuy reurkied io renury May.

the Millstone area.

                                                                                                                                                                                                                                                                                      ' Fish Ecology 105
        -- ~ * . -                                  e  acwe._           - - - _ .                           __4-__                                                         -_..._-o              ____-___.____.__.-__._______._________________.__..___.________________.._s.

                                                                                        "~

MO-EN 2 twrr ' s twrr - NR mn ' Ofi N ATON !Ol'ijt A10N n'N rr oftRATON i Ol'l RArON E r 120- i e u. I i S i 100 - i 4,. I o i 6 I h a-0 l, E 60 - l il n'

                                                ~              --

n 0 c , ,

                            #                                                     b ,,

{o ' I ' 40- ,, i 20- I '7 ~ f" T"T ~T TN i i i i i 7 I ts w n-w 7, iio si-sa s>u es se 7 sa is so l 0- i i i i i y , i i h T"T'T'T T 1 76 78 80 82 84 86 88 90 _ 3] JC 2 twn s tNrr E Ol1RATUN 'WiKATMN

                                                                                    "                                                                                                  I 140- Nil                                      I 2 UNrr             1 tmfr                   $                                                                                                  l

1. 120 - *"*"l"'"*'"" $ I E

100-i o 6 7] C , g - i o 80- l I 6 < V d I g M-I l q I 8-r 40 - f  %,, I 33 3 i i 77 7,i ), ,o i i

                                                                                                                         ,3
                                                                                                                               ,'s 3
                                                                                                                                                     ,i3p i ,h ,,i ,i7 ,,i i,,-              3                , n n

{ Q 20- I D- i i i i i i i i i kiiiin _ [3 2 tmn t imrt 76 78 80 82 84 86 88 90 E OliRAllON l Ol1 RA10N YEAR $ i Q; 2 - i o r i l'ig. 13. He annual (Q) and running (~) 8.mean density 6 f. L_ , (noJ500 mi) of grubby larvae at EN and Nil. 6 i- f

                                                                                                                        /                                                          ,l
                                                                                                                                                                                                                 ~
                                                                                     ~                ~, -                                                                                 ,

b l o , i , i i i i i i !i i , i , 75x M 7: 79 so si sa >u st:6 sisa S eo TABl.E 13. %e 8-mean* catch (noJ0.69 km) and 95% confi. YliAR dence intervals of gnabby collected by trawl at selected statioru h, g. The annual (Q) and running (-) 8-enean catch for ca.:h report year dunng June 1976 through May 1990. (noJn69 km)of grubby taken by trawl at NR, JC and (N. Rerort year NR JC IN _ 1976 77 0,91 0.3 0.61 0.2 0.61 0.1 1977 78 0,510.1 2.21 0.5 1.11 0.2 g] - 0 NRNim 1978 79 1.21 0.2 2.01 0.6 0.7 t 0.2 > ' 1979 80 3.3 1 0.9 0.71 0.1 0,910.2 O man UNrrmtRAr)ON 1980 81 3.81 1.1 1.11 0.2 2.110.6 a 20- " ' 1981-82 7.512.5 1.01 0.2 2.310.6 E7 , 1982 83 11.71 2.7 1.41 0.2 2.21 0.5 g -

                                                                                                                                                                     ~~

1983 84 4.11 0.8 1.71 0.3 1.7 10.3 t- - 1984 85 5.91 1.2 1.61 0.3 0.910.2 b M- - 1985 86 2.31 0.5 1.41 0.1 0.7 s 0.1 M 1986 87 7.21 2.3 1.11 0.2 0.91 0.2 IC 1987 88 3.7 i 1.2 1.21 02 1.110.2 g h 1988 89 10.512.3 1.01 0.1 1.410.3 g i g g ' ,, 'g i gg 1989 90 3.612.0 041 0.1 12 03 m Fig.15. The percent length. frequency distribution, by 10-mm intervals, of grubby taken by trawl partitioned into two-unit

• Data seasonally restricted to December. June at IN, and year-(June 1976-May 1986) and three. unit (June 1986.May 1990) round at Jrand NR (June-May).

                                                                                          ,,,;,g g ,

106 Monitoring Studies,1990

~ - - _ _ _ _ - _ _ _ - UN ImOS y'pb m'N b C Ni IW 'i Th:; tautog ranges from New Elrunswick to South j wnq i Carolina (Cooper 1965) and is most abundant from Cape Cod to Delaware (Bigelow and Schroeder 1953). 4

                                                            $no_                         y g

i

                                                                                                                                                              '  h i
                                                                                                                                                                                 .I it is an important recreational finfish resource in        g                          /                                                                           l coastal waters from Massachusetts to New Jctsey and        r                                                                                                       i in Connecticut commercial landings have increased significantly in the past decade (Simpson 1989).
                                                            $ **                                                                                                    l i

Tautog reside in rocky nearshore areas in the spring, 0- i r i i i i i i i i h 'r, i i summer, and fall (Bigelow and Schroeder 1953; 75 77 a 81 83 85 87 89 Wheatland 1956; Cooper 1965); juveniles also c'., ell in the areas among macroalgae (Tracy 1910; Briggs 100 - ggyg., mn i n3n and 0 Conner 1971). Adults move into deeper water in the winter and remain dormant, while juveniles c

                                                             $     75-ATIN                                                                                      l ""

i overwinter in a torpid state near shore (Cooper 1965; E l Olla et al.1974). d 50 - ' The lautog is the second most abundant egg taxon g n { entrained and accounted for more than 30% of the p a

                                                                   '5 ~

total eggs collected since 1976 (see Table 5). At f l MNPS, tautog eggs are found each year during mid to late June. Eggs are pelagic and hatch in 42 45 hours o- i i ergrTYrv r@[ a rE rTg, r at 22*C (Williams 1967; Fritzsche 1978). Along 75 77 79 81 83 85 87 89 with the increase in cooling water volume during the three unit operational period, tautog egg entrainment 150 - my i my t,ARyAt, estimates have increased (see Table 6). Entrainment ranged from 705 million in 1979 to 3,907 million in c 125 j AT NB ~ ! ~~ i 1986 and was estimated at 3,094 million in 1989. E 100 - ' Studies conducted in 1990 revealed that entrainment mortality of tautog eggs averaged 57% The 1989 [> 75-hI / S mean density of eggs at EN was above the running $ 50 -

                                                                                       .j                                                                         ,t 6-mean (Fig.16 andTable 14). The running S-mean for tautog eggs has been increasing since the begin-h3                                                                                               ) l!

ning of the 11 year data seri;s. 0 , r,-- r T T r ~ T T 2 r4 i n Although tautog eggs are the dominant among fish 75 77 79 81 83 85 87 89 eggs in the plankton samples, tautog larvae accounted YEAR for less than 2% of all fish larvae (see Table 5). The S-mean densities of larvae were always higher at NB Fig. Itk The annual (3) and runnmg (---) 6 mean density than at EN (Table 14). Since 1984, larval densities at (nwsoo nismuusogsi ai is and t.uw at is anna EN have been declining to levels comparable to those in the late 1970's. This decrease was similar to trends years) fmm January 1976 through December 1990, so observed for other summer spaw ned larvac, anchovies they could be compared to DEP trawl data. Although and cunner. the 1989 90 (June 1989 through May 1990) catch Historically, tautog catches in the MNPS trawl was the lowest recorded (Appendix II), the 1990 program were low. The 1989 90 total catch was the (January through December 1990) catches were the lowest recorded in the 14 year data series (Appendix . highest in five years because many juveniles were II). Because tautog catches were low and the data caught in trawls between June and December 1990, contained too many zeroes, the annual S-mean catches especially at NR (Table 15). could not be calculated. As an alternative, the annual The DEP began conducting a random trawl survey sums of all the catches at each station were used as of LIS in 1984. The DEP catch-per-tow (DEP CPUE) of tautog from 1984 through 1990 were compared to indices of annual abundance (Table 15). These data were summarized by calendar years (rather than report the total annual catch per station (hTEL CPUE) of Fish Ecology 107

  . - ~ . -                                     __-                   - - . - - - - - . _                                                         --             - - _ . -

I. 1 Aliut 14. m 8.e..can* oeniity (no /5m m )2and 95% conti. tautog at stations Nil,1T. and IIR, where habitat dcnce inten ali uf tautog eggs and larvac collected at LN and Nil types were similar to those ul Mations trawled by the for each returt por during June 1976 ihtuugh May 19w1 DEP (NUSCO 19'19). ~lhe comparison resulted 61 a gm guya significant linear relationship (r2 =0.59, Ix0.05) be. l Im,__, j,3 ,_ m. Nu tween NUEL CPUE asid DEP CPUE (Fig.17). The DEP catches decreased slightly in 1990 throughout 1976 37 t 16 LIS, although there was a large decrease in the catch l'77 3^ 117 in the castern pari of LIS (D. Simpson, pers. l 1979 136 1 231 11 i 5 49 2 22 comm.). Results indicate that the decline in the 1980 2n4216:3 4n i in $9 ,gs NUEL CPUE may be a part of a general overall , 1981 2r.471 414 - 81 1 1fi 91 2 'o decline seen throughout LIS. 1982 2244 3 4 14 44 1 21 110t$9

             ~ 19M . 2114 1472                  33 1 21            119   1 122                 16.g t le 0,39 1964.      21$71440                )12               On 120                                                                                           o 194'       3237 11073             15 112             44 1 14                    14         p < 0 05                                                    a p     j i a         "$6 1 794               1 12              1216                                                                             el                        '

N7 vsll_1823 1 13 13 47 W 12 *

               .s.        2269 1 600             17 210             29 2 11                h                                                                                   ,

f4kV IO* 2En7 11(no 12 2 $ 22 19 g , 8,' j N s. '.' . no

• D4ta ensmnally teattuted to May 23 - Aupit 2n fue cggi and 6- 4 June Auguit for larvac. d 4- --,-

                                                                                                                                ,      _ ,_,                         _.i 1                         2                   3                       4 Dl:P CPUli Feg.17. *lhe sclnuonship between the annual trawl caich per                          i
                                                                                             *         " E * "** ""I "' ' " ' "                      ""                    '

1 Alti.1-; 15. Abundance indnes (of tautog collected by trawl in ' h C.M) and the ikpartment of I;nvironmental Pniitwuon trawl DI.P* ran4wn irawl surve y and in the NL'SCO umulna nonng g g g pggg progism. Trawl caught tautog length frequency distributions ig, gwp, yo, nu 13 . Jc 2_25.hl. before and aftcr three unit operation were calculated. . .  ; 7e 11 76 73 In 46 27 2$1 Ages were assigned to length categories based on 77 27 10 113 37 is 30 292 recent age length work in LIS reported by Simpson y $"3 , 59 y [ y f6 (1989). Young of the year lautog accounted for a high prolcrtWn of the fish caught after three unit operation 80 10 46 20 23 25 14 138 si 23 28 24 23 126 7 233 began (Fig.18). 83- 12 ti: 35 21 ho 25 228 g3 29 40 19 2) 'll 17 159 60 -

                                                                                                            ~
            - t4 764/200 tows .(3            k2) 21 46 16 14 5 8- 110                                                               O TwouwrortsA7ios 23 720/240 tows (3.17)          14 47 27 12 23 11 136                            N" b

E6 791/il5 town (2.51) . l$ 25 58 3 100 _ $ 206 y ,, , g umiy,.tg ogg3noy 57 624/32b 'ow s (1,95) 20 13 _33 3 26 1 96 88 610/320 loci (1.97) 4 37 31 14 $n 10 146 pg 30 ,

              $1 791/320 town f 47)            0 25; ?) 14 .38              2 102                                  -
                                                                                                                              ~

M , 692/297 low s (2/32) I 17 34 12 87 5 156 20 .-

                                                                                                                                       ~
                                                                                                                                                          ~

10

              ' Connecticut ikpartment of finvervunental Pttucclum (11HP)                                                                                         ~

0 - ranJom trawl survey for sin arras e 1.ong island Sound. 1.F.M iril <j40 14n199 2m250 2513m) 301350 3514X) >i(0 (Indet annual sum of caiches and numhet of Lows (average AGE I 11 111 IV V VI > VI catch per tow)) (D. Simpwn, pers. comm ). ' b Northeast Utihties (NUSCO) momtonng dnta Ined trawl y,g , 13. The percent length frequency distnbution and age survey for six statimt m Ac Millstone area (Fig.1) (Indet (Sunpion 1989), of tautog taken n y trawl partaioned into two-annual sum of catches (0 69 km tows)). unit (June 1976 May 1986) and there unit (June 1986-May 1990) opersilonal periodi.

             - 108 Monitoring Studies,1990

Concurrent with this c hange in the length distnbu. dance should fall and the relatise abundance of older Lion was a shift in the percent of tautog caught at fish should rne. The perantage of jusende Inh each station. Ilefore Unit 3 operation 429 of the increud during the three urut operational penod, and, tautog were collected at NR and JC. Ilowever,in the therefore, changes in the clatne proportion of Unit 3 operational period,6N9 were caught at these juveniles and adults was prolubly unrelated to entrain-two nations, lloth stations are shallow water es- ment loses, Current salues of F (fishing mortality) tuarine areas typically inhabited by juvenile Lautop for tautog were estiinated to be about one thod of (Olla et al.1974). Okler tautog (> age 11) were lound Fmn (Simpss a P A91, and, at this rate, the equivalent at the deeper water stations (IN, Nil, IIR and TT). udult population lowes resulting from egg and larval During the two. unit operational period (19761986), entraimnent would han to amount to more @an 589 of the lautog were found at these deeper water twice the current annual commercial catc hes in order stat ons, but only 339 were caught at these stations to become critical. The most conservatne estimates during the three unit operational peruxL Removal of of the losses (using equivalem adult methode are

;he Unit 3 colfer d un proNbly accounted for the reduc-      much leu than the losses due to the lhhery, and addi-tion of tautog ut IN. This reef.hke structure created         honally these assessments auume 1(NYi egg entrain-un artificial embayment that probably attracted reef          ment mortality. Our studies mthcated that actual egg dwethng tautog while it was in place. The reason for          entrainment mortality ranged f rom 31 to 739 and the reduction in tautog at Nil,ilR and 'IT is not readi-      averaged $79, thus reducing the c!fect of entramment.

ly apparent but, as reported above, there was a similar decrease in the DEp catch of tautog in the eastern part Cwmcr U S. Conunercial and recreational fishing for tautog in The cunner mhabits rmly coastal habuals from LIS has inovased over the last decade, but a recent as- northern Newfoundland to the mouth of the sessment of u,. population indicated a healthy stock Chesapeake Bay (I cim and Scott 1966,liigelow and (Simpson 1989). Smith et al. (1989) reporteo a large Schroeder 1953; Serchul 1972; Olla et al,1975, increase in the commercial catch of tautog m LlS in 1979; Dew 1976; Pottle and Green 1979). In-recent years (1980 85). Simpson (1989) reported a dividuals maintain highly localized home ranges and large increase in the recreational catch of tautog f rom mature in i to 2 years (Dew 1976; Gleason and 196(Ts to the 1980's and a two fold increase in the RecksitL 1988). In cold weather,(water temperatures commercial catch in LlS from 1985 through 1987, below 8'C), they become torpid (Green and Farwell Simpson (1989) calculated yield and stock biomass 1971; Green 1975; Dew 1976; Olla et al.1979), per recruit to assess the condition of the tautog stock Cunner eggs are pelagic and hatch in 2 6 days, in LlS and its response to fishing, lie concluded that depending upon water temperature (Williams 1967; the current fishing rates were modest and well below Dew 1976: Fritische 1978), he critical biological reference points Fm,n (the loint in the MNPS area, cunner eggs and larvae were beyond which additional fishing effort wouhl actually found primarily Irom June through August, and reduce yield per recruit) and Fo 1 (the point cor- juveniles and adults were caught at all sis trawl responding to the fishing rate at w hich the increase in stations, mostly from spring through fall. Eggs are fishing effort results in a gain in yield only 10% of abundant at EN Som May through Jnly and larvae that expected from the same increase in effort on an occur from mid June to mid July, unfished population). lie also concluded that the The annual 6 mean densities of cunner eggs and stock biomass per recruit (currently at $$% of the un. larvae at EN and Nil all increased in 1989 (Table 16). fished stock) indicated a healthy sto;L condition. The 1989 egg density was within historic range and Ahhough tautog larvae and adults have declined in annual S mean density was abon the running 5-mean abund.mcc during the 1980's, egg abundance, probably (Fig.10). Laival densities were consistently higher our best measure of stock reproductive capacity for at Nil than at EN throughout the past 10 years. Den-this taxon, has increased. Egg entrainment has sities of larvae in 1989 were comparable to or higher increased along with the increase in egg abundance than densities in any other year since 1984, the year and the increase in cooling water volume during the in which the abundance of all summer spawned larvae three unit operational period. If egg losses due to began to decrease. The running S-means foi cunner entrainment affected recruitment, then juvenile abun. eggs and larvae collected at EN have remained relative-ly stable, but the running 5 mean of larvac collected Fish Ecology 109

 ,         . - - . . - _ . - . - ~                                 -     . - . - . -                  . .          . - .              - - - - - ,                            . _ -   . _

4 TAllt.E 16. The 4 inean' density (no/500 m 8) and 95% emfi. U"0-den 4* intervals of cunner eggs shJ lanae udiened at 1:N and Nil e togs AT CN gg; gg for each returt year dunn June 1976 thmugh May 1990 f MW- , 1RIS tARYAE k 20-( n I ' o h

                                                                                                                                 -               ~

year 1:N *N Nil 6 ' 1976 29214 { 4Wlo - l 1977 p t, 58 128 1978 120 f 2(m- I 1979 $870 t 1301 1335 92 140 1980 8223 i 1645 58219 143 1 83 ' 'T" T7" 1981 $171 1 882 78 136 96 170 73 77 " U U U 87 8' 1982 $501 11377 31 114 1311 72 1983 l 7068 1 2679 49 :26 198 1246 100 - 1984 I'AR \, AI. s ewrr e $.twrr

                        $719 11246       442              37 g27                                                                    mmw i mm 1985           74k4 1 2659      12A10             303 11                      Qa                    ATEN                                                                         ;

19so 2969 11082 521 813 75 j 1987 1988 5002 i 1t44

                       $395 i 1756 523 9t4 10 2 $

28 i12 [g 30-I 1989 6904 130n 12 210 39 2 to - , I O 5 l /

• Daia seauinany restricted io May 22 - July 23 for essi, and '

June Augun forImae. o - - 7 T T* T O i i i TOpN Y [] i 75 77 79 81 83 85 47 89 at NB had a downward trend that began in 1984 (Fig. 25U

• 19). De annual 6 mean egg densities were consis- LARVAt tently much larger than that of larvae. Williams et al, odEEw!MOEm j 20n-AT Nil i (1973) found that cunner survival from egg to larvae i g

in L!S was poor (5%) and surmisef that predation was o 150- - I the primary cause. 6 / Cunner is the dominale egg taxa entrained at l

                                                                                      $     100-                         /

MNPS (see Table 5). The 1989 estimate of cunner g j egg entrainment was 3,885 million and, historically, 25 50-the values ranged from 1,534 million in 1979 to ' 4,533 million in 1987 (see Table 6). The increase in 0 ' 0 [}i T entrainment in 1987 can te partially attributed to the 73 g' '79' 'g' 'n' 'O T s9 additional cooling water demands of Unit 3. "^" Entrainment mortality has always been assumed to b lis.19. The annual (D) and runnins (-) 5-mean densiiy 100% but results of our entrainment mortality study W500 iM)of cunner egs: at LN and larvae at EN and Nil. indicated that nearly half of the entrained labrid eggs survive entrainment. The trawl catch of cunner has been decreasing at all cunner catches were used as indices of relative abun. six stations and the 1989 90 catch was the second dance, and were compard ameg the six monitoring

     . lowest in the 14 year time series (Appendix 11). The stations and with the DEP data (Table 18), %c 1990 6-mean trawl catch was calculated for three (IN, JC, and NB) of the sh trawl stations (Fig. 20 and Table total catch of cunner at all the monitoring stations was tre same as 1987, which was the lowest of the 17). Since the early 1980's, the annual 5-mem catch 14 yen series. DEP and NUEL (stations NB, BR and of cunner has been below the running 6-mean wause of the large catches made during the 1970's.
                                                                                   .IT) c mner trawl catches were compared, no sig, nificant relationship was found between the two Total annual (calendar years, 1976 90) cunner catches were compared to cunner trawl catches of the indices from for 1984 through 1990 (r2=0.29, p>0.01). The 1990 NUEL CPUE was the lowest of DEP random trawl survey data. Because MNPS trawl the 7 year series (1984 90), while the DEP CPUE sampling ef n was similar among years, am.ual 110 ~ Monitoring Studies,1990

l l 30- :twrr ' s twn TABt.E 17. lhe & mean' catch (no]O 69 km) and 95% confi-

           '     IN (si stat ton l (su r1 KW                         dence intenals of cunner collected by trawl at selected staums
 }
         ~

i for eoch report year dunns June 1976 through May 199a S 20- 6 IN JC NH R I lear [~ 15 - l 1976 261 19 4120 1 1 0.7 Q10- i 1977 24t23 311.0 1.t 0.6 I 1978 61 3.7 31 1.4 0.7 1 0.3

  $     5-                                                I 1979           291 13                   915.0                              21 1.0 1980           231 16                   612.0                              31 1'.

Om, , , , , , li t%y' n ' ' 1981 121 10 S i 2.2 31 0.9 75 77 79 81 83 85 87 89 1982 52 3.0 412.0 22 09 1983 31 1.3 4i 10 11 06 10- 1984 21 1,0 211.0 0.41 0.2 ( Nr"xm I wNkw t 1985 1 > 0.6

                                                                                                                 .                  11 05                            04 1 0.7 j g-                                                     1                                1986          0.11 0.2              0.51 04                             0.11 0.1 g                                                        l                                1987          0.210.2               0.4 1 0.2                           0.01 00 R    6-                           ,                      I INI           E3 1 EI                  313^                             E21 UI o

• i 1959 0.91 0.4 0.81 04 0.21 0.2 6 I f'  % ,,,, ,/

                                                                                             ' D ' " ' ' ' " r " "  d ' " M ' r ^ " 5 "   N                       "'r-52-                                                       I                                  Sepember at JC, and April-Novemler at NH.

0 - y 773 , , , , , nn, ,0, i i , 75 77 79 81 83 85 87 89

                      "                     (dNT$1Nl(M1                   k)N 7                                                        i                               DEP' random trawl survey and in the NUSCob trawl monitormg g3-                                                      I program.

R I c) U

             '                         p     ""

i l ynr IEl* nB IN JC NB_,bli II_lgial NLEG9

                                   /                           ,

76 21 710 134 56 32 56 1,009 I i 77 54 822 79 38 3 36 1,032 b- i 78 17 214 88 23 4 13 359 gI,p " 79 61 992 228 63 15 221,381 0- , , , , , , , , , , , , ,U,", , ko 9 645 191 91 4 41 981 75 77 79 81 83 85 87 89 81 47 341 202 85 M 26 825 YEAR 82 23 174 196 7"> 70 25 561 83 60 107 131 40 62 12 412 84 144C00 tows (1.72) 49 64 73 13 30 17 246 Fig. 20. The annual (0) and running (-) 6-mean catch 85 Mn46 tows (a40) 36 39 30 13 13 12 143 (nolo.69 km) of cunnce taken by trawl at IN, JC and Nil. gfgg; g, , )) g 7 4 9f 88 72/320 town (0.22) 17 13 145 10 9 10 204 89 268/320 tows (0.84) iI 36 36 12 16 7 118 was the third highest since 1984 (Table 18), The oo 196/297 iows (0 66) 2 23 50 4 11 5 95 DEP survey is conducted throughout 1.lS and the increase in catch occurred in all regions, including eastern LIS (D, Simpson, Fr, comm.). There has

                                                                                               ' C "" ** *k"' D*P'"'"'"'       '  E""'""'"I                    I' * "" " ( D ")

random trawl survey for six arr.as in L.ong liland Sound. been an overall decline in abundance at all stations (Indeu annual sum of catches and number of tous (average around MNPS, but the largest decline occurred at !N, catch per to.)) (n. sirnpion, peri. comm4 This decline began in 1981 and coincided with the h Nonheast Utilities (NUSCO) monitoring data fixed trawl removal of a fish boom in front of Unit 1. A second survey for sit stations in the Millstone area (Fig.1) (Indec large decline occurred in 1983 after the removal of the annual sum of catches (a64km iowin Unit 3 cofferdam and was not unexpected. NUSCO Tish Ecology ill

(1976) reported that the colferdam for Unit 3 would . that of the tautop, cunner may tw more sensitive than - create an artificial embayment potentially attractive to tautog to increased mortality rates. Ilowever, the fish during the period it was in place. Unfortunately, entire compensatory reserve of the unfished cunner trawl monitoring was not done at IN prior to the stock should be available to compensate for losses installation of these structures and it could not be related to entrainment. i determined if these structures actually caused an increase in the cunner population around the hiNpS intate. Conclusions Cunner collected by trawl were assigned an age based on a age length key provided by Serchuk Six fish species (sand lance, anchovy, silverside, (1972), during toth two and three unit operation grubby, tautog, and cunner) were identified as periods. The normalized frequency distribution was potentially impacted based on their abundance in calculated for each period (each period equals 100'11) to entrainment samples or their susceptibility to thennat determine if a change had occurred since the start up impacts. Abundance indices of available life history l of Unit 3. These distributions differed between the stages of these six taxa were generated to evaluate j two perials and over 50% of the cunner caught during 1989 90 abundance levels compared to long term threc unit operation were young of the year (Fig.21), trends. The 1989 90 abundance indices of tuost of and most (>$0%) of these were trawled at JC, these six taxa continued in the direciion of the long-term abundance trends. Tautog egg abundance I continued upward, while anchovy and cunner egg O 1watwrrormrxw ' ' 50 lance, anchovy, tautog, and cunner larvac continued 50 - O TuarrtstrormuoN downward. The abundance indices of trawled siher, side and cunner also continued to decline. The d8 ' g numbers of silverside in seines in 1989 90 remained i p 30 - relatively stable, as they have throughout the

                                        ~

i - d 20 _ monitoring period. The trend of grubby abundance g g p changed direction this year; both trawl catches and larval densities, which had been increasing in the E" #*" igurnato ' 'n no ' in 140 ' 14po ' ni o ' y ' c,te fratue, ich has been linked with recruitment success, was investigated as an ex-lis. 21. The percent length. frequency distritiunion and age planatory variable foJ describing observed changes in (Sctchuth 1972), or cunner taken by trawl parutioned into two- the annual abundance of early life history stages of unit (June 1976 May 1986) and three unk (June 1986-May selected taxa. Although annual sand lance larval 1990) opernimnal periods. abundances fluctuated substantially, hiarch water temperatures explained some of the variation. Ad. ditionally, variations in the abundance of young of. Several changes in physical habitat near the h1NpS the year silverside in the shoreaono at JC were intakes may have contributed to the decline of cunner explained by July water temperatures, in the area. Concurrent with the decrease in trawl Ichthyoplankton entrainment in the 1989 90 repon catch was an increase in the percentage of Jt venile year was estimated using a new method. The same fish. If changes in trawl catch were related to method was also applied to data from previous report entrainment losses, then juvenile recruitment would years and new annual entrainment cslimates were likely decrease and the relative abundance of older age obtained As a result of this change, most historical fish would larcase. Results of our entrainment estimates were higher than previously reported. mortality study indicated that almost half of the For all ichthyoplankton except anchovy eggs, < cunner eggs survived, which would reduce the effect entrainment was higher dt45g three unit operation of entrainment. Because no fishery exists foi cunner, than during two-unit operation. During three uni; there is no published work assessing the present condi- operation, the cooling water volume used at hiNPS tion of the LIS population as there is for lautog- was approximately twice the volume used during two. Since the life-span of the cunner is much shorter than - unit operation, so the observed increase in entrain-112 hionitoring Studies.1990

                 -.             . - - -           --      -. -                     ,u                                                                   -- - - . ,                               _-     -

--- - - - - - _ _ _ - -- = _- =-- l ment was mt unexpected. The 1989 90 Ikferences Cited ichth)oplankton entrainment estimates were within , the ranges established during the three unit operation. Ilailey, K.M.1984. Comparison of laboratory rates l al perimi, escept for anchovy cus. Anchovy egg of predation on five species of marme fish larvae entrainment estimates during three unit operation by three planktonic invertebrates: effects of larval (except for 1986) were actually lower than previous si/c on vulnerabdity, h1ar. Iliol. 79:303 309 y ears. Bannister, R.C.A., D. liarding, and SJ Imckwod. The effects of ichthyoplankton entrainment on fish 1974. Larval mortality and subsequent > car class populations may be moderated by two factors, strength in the plaice (Pleuroncrics plate.tsat entrainment survival and compensatory mortality. Pages 2138 in J. hts. Illaster, ed. The early life Evidence of the first factor comes from the results of history of fish. Springer Verlag. New York, our mortality study. Neatly half of the labrid eggs fleck, A.D., and ll.A. Poston.1980. Effects of diet i entrained survived the process; thus total entrainment on survival and growth of the Atlantic siherude. i losses are less than those reported. Evidence of the Prog. Fish. Cult. 42:138 142. second factor comes from the results of our analysis liigelow, ll.B., and W.C St hroeder. 1953. Fishes of anchovy egg to larvue ratio. This revealed that of the Gulf of hiaine. U.S. Fish Wildl. Serv. , density dependent mortality occurred between egg Bull $3:1577. releae arid subsequent late larval stages. Blake, M.M., and E.M. Srnith. ink 4. A marine ! A shift in the length frequency distribution of resouces management plan for the State of Connec. , tautog and cunner before and after three unit opera- ticut. Connecticut Dept. Envir. Prot., Mar Fish. j uons was evident. Young-of k year recruits ac- 244 pp. I counted for a ingher proportion of t.atog and conner Bothelho, V.M., and G.T. Donnelly. 1978. A  ; caught during three unit operation. This aift could statistical analysis of the performance of the not be attributed to the increased entrainment, cecause Bourne plankton splitter, based on test obser-  ; l entrainment losses wouhl be e pected to shift 'he valions. NMFS unpub. mt distribt. tion toward the larger, okler fish. The shii: Briggs, P.T., and J.S, UConner. 1971. Comparison i toward young.of.the year tantog couhl be explained by of shore tone fishes over namral vegetated and the increase in cori.mercial and recreational fishing for sand filled bottoms in Great South llay. N.Y. i this species in LlS during the last decaJc. ilowever, a Fish Game J. 18:15 41. recent assessment of the tautog population in LIS Clark, J.1967. Fish and man. Littoral Soc. Spec. mdicated a healthy stock. Current values of fishing Pub. No. 5:1 78.

mortality for tautog would have to triple before addi. Cooper, R.A. 1965. Life history of the lautog, i

uonal fishing effort would actually reduce yield.per- Toulog onitis (Linnaeus). Ph.D. Thesis, Univ. of recruit. At this rate, the equivalent adult population Rhode Island. Narragansett, RI.153 pp. losses resulting from egg and larval entrainment Cushing, D.il 1973. Recruitment and parent stock would have to amount to more than twice the current in fishes. University of Washington, Div. of Mar. annual values in order to become entical. Because no Resources, Washington Orant Pubt WSG 73 l. fishery exists for cunner, there is no published work 197 pp, assessing the present condition of the LIS population, Cushing, D.il. 1974. The possible as there is for tautog. Since the life-span of the density dependence of larval mortahty and adult cunner is much shorter than that of the tautog, cunner mortality in fishes. Pages 10311I in J.fl.S. may be more sensitive than tautog to increased mor. Blaxter, ed. The early life history of fish, tality rates._ _ l_lowever, the entire compensatory Springer-Verlag, New York, reserve of the unfished cunnet stock should be _ Cushing, D.fl. 1977. The problems of stock and available to compensate for losses related to entrain- recruitment. Pages 116-133 in : J.A. Gulland, ed. ment. Fish population dynamics. John Wiley and Sons, New York. 1 Fish Ecology 113 l L

  -.- -                            - _ .. _ -.~~                  -

1 j l Cushing, D.ll., and J.G.K. liarra.1973. Stosk and llidlebrand, S F.1943. A review of the American i recruitment and the problem of density depen- anchovies (Family Engraulidae). Dull. Bingham dence. Rapp P. v. Cons, int. Esplot. Mer Oceanogr. Coll. 8:1 165. IM:Id2155. llorn M.H., and R.N. Gibson. 1988. Intertidal DeAngelis, D.L., S.W. Christensen, and A.G. Clark. fishes. Sci. Am. 256:M 70. 1977. Response of a fish population model to lloude, E.D.1977. Food concentration and stocking young of the year rnortality. Oak Ridge National density cifects on survival and growth of Laboratory Publ. No. h)65. laboratory reared larvae of bay anchovy Anchoa Dew, C.ll. 1976. A contribution of the life history mitchcIll, and lined sole Arhirut lincarut. Mar. of the cunner Tautogolahrus ad3 perm, in Fhhers liiol. (Berl.) 43:333 341. Island Sound, Connecticut. Chesapeake Sci. Iloude, E.D.1978a. Critical food concentrations for

14

101 113. larvae of three species of subtropical marine

Fritnche, R.A.1978. Developrnent of fishes of the fishes. 11ull. Mar. Sci. 28:395-411, Mid.Adantic liight. An atlas of egg, larval and floude, E.D. 1978b.J Simulated food patches and juvenile stages. Vol V. Chaetodontidae through survival of larval bay anchovy, Arn hoa min hcl /i, Ophidiidae. Power Plant Project, Off. Biol, and sea bream, Archosurgus rhomboidalii. Fish.

Serv., U.S. Fish Wildl. Serv., U.S. Dept. of the Bull., U.S. 76:483-487. j interior, IMS/OllS-78/12. 340 pp. Ilunter, J.R., and C.A. Kimbrell. 1980. Egg can. Geomet Technologies, Inc. 1983. Preoperational nibalism in the northern anchovy, /?ngraulis aquatic ecology study Shoreham Nuclear Power mordar.~ Fish. llull.,U.S. 78:811 816. Station, Unit 1.1982. Prepared for Long Island Jamieson, l.G., N.R. Seymour, and R.P. llancroft.

Lighting Company, Ilicksville, NY. 1982. Use of two habitats related to changes in Gleason, T., and C. Recksick. 1988. Synopsis of prey availability in a population of ospreys in nor-biological data for the cunner Tantogolabrus theastern Nova Scotia. Wilson llull. 94

5575M.

adsperau.i (Walbaum). Univ, of Rhode Island, Jefferies, ll.P., S. Itale, and A. Keller.1988. Contrib 2420 of the Rhode Island Experimental llistorical data assessment finnshes of the Narra-

Statios.. gansett Day area. Narragansett Day Project Final Greeley, J.R.1938. Fishes and habitat conditions of report. Grad School of Oceanography University the shore zone based upon July and _ August of Rhode Narraganset RI. 362 pp, seining investigations. Section 11. Pages 72 91 Johnson, M.S.1975. Biochemical systematies of c in A biological survey of the saltwaters of Long the otherinid genus Alenidia. Copeia Island, Pt. II. N.Y. Conserv. Dept. 1975

662 691.

Green, J.M. 1975. Restricted movew.'s and Leak, J.C., and E.D. Iloude.1987. Cohort growth homing of he cunner, Tautogolabro.:..persus and survival of bay anchovy, Anchon mlichelli, (Walbaum) (Pisces; Labridae). Can. J. 2001. larvac in lliscayne Day, Florida. Mar. Ecol. 53:1427 1431, 37:109 122. Green, J.M., and M. Farwell. 1971 Winter habits Leim, A.ll., and W.H. Scott. 1966. Fishes of the of the cunner, Tautogolabrus adspctsus (Wal- Adantic coast of Canada. Bull. Firh. Res. Iloard baum), in Newfoundland. Can. J. Zool. Can.155. 485 pp. 49:1497 1499. LeMao, P.1986. Feeding relationships between the Grossicin, M.D., and T.R, Ararovitz. 1982. Fish infauna and the dominant benthic fish of Rance distribution. MESA New York Hight Atlas Estuary (France). J Mar. Hiol. Assoc. UK. Monograph 15. New York Sea Grant Institute, 66:391 401, Albany, NY,182 pp. Lund, W.A., and H.C. Marcy, Jr. 1975. Early llennemuth, R.C., J.E. Palmer, and. D.E. Brown. development of the grubby, AIyoxocephalus 1980. A statistical description of recruitment in acnaeus (Mitchill). Biol. Bull.149:373 383, eighteen selected fish stocks. J. Northwest Atl. Marine Research, Inc. (MRI) 1990. Ichthyoplankton Fish.1:101 111. Entrainment Monitoring at ' Pilgrim Nuclear llildebrand, SF.1922. Notes on habits and develop- Power Station, January - December 1989 In ment of eggs and lar .ae of the silversides Atenidia Marine Ecology Studies related to Operation of menidia andittenidia ber>Ilina, Bull, of the U.S. Pilgram Station. Semi. annual report No. 25 Dureau of Fisheries Vol. XXXVill, January 1989 December 1989.

i14 Monitoring Studies,1990 J

1

_. _________.m _ _ _ _ . _ _ _ _ . _ . _ _ _ _ _ . . _ _ May, R.C.1974. Lars al mortality in marine fishes Olla, ll.L., A.J. llejda, and A.D. Martin. 1974. and the critical period concept. Pages 3-20 in Daily activity, movements, feeding, and seasonal J.lLS. Blaster, ed. The early hfe history of fish, occurrence in the tautog, Tautog onnis. Fish. Sprmger Verlag, New York. Bull., U.S. 72:27 35. McIlugh,J. L.1972. Marine fisheries of New York Olla, llL, A.J. Dejda, and A.D. Martin. 1975. State. Fish. Bull., U.S. 70:58$ 610. Activity, movements, and feedmg behavior of tic  ! McIlugh.J. L.1977. Fisheries and fishery resources cunner, Tautogolabrut adsrcrse, and comparison l of New York Bight. NOAA Tech. Rep. NMFS of food habits with young tautog, Tautog onitis, J Cire. 401. 51 pp. of Long Island. New York. Fish. Ilull., U.S. I Meyer, T.L., R.A Cooper, and R.W. Langton, 73:895 900.

                                                                                                                                               ]

1979. Relative abundance, behavior, and focxl Olla, B.L., A.J. Bejda, and A.D. Martin. 1970 i habits of the American sand lanu, Ammodytes Seasonal dispersal and habitat selection of cunner, americanus, from the Gulf of Maine. Fish. Bull., Tautogolahrus udsrcrsus, and young tautog. U.S. 77:243 253. Tautog onitis,, of Long Island. New York. Fish. Monteleone, D. M., W.T. Peterson, and G.C. Wil. Bull., U.S. 77:255 262. llams. 1987, interannual fluctuations in the Oviatt, C.A., and S.W. Nixon. 1973. The demersal densily of sand lance, Ammodycs americanus, fish of Narragansett llay: an analysis of com-larvae in Long Island Sound, 1951 1983. munity structure, distribution and abundance. Est. Estuaries 10, 246-254. Coast. Mar. Sci. 1:361 378. NUSCO (Northeast Utilities Service Company). Pearcy, W.G., and S.W. Richards. 1962. Distribu. 1976. Environmental assessment of the sondenser tion and ecology of fishes of the Mystic River cooling intake structures (316b Demonstration), estuary, Connecticut. Ecology 43:248 259 i- Volumes 1 and 2, submitted by Nortbest Utilities Pennington. M.1983. Elficient estimators of abun-

Service Company to the Connecticut Department dance for fish plankton surveys. Biometrics l of Envininmental Protection. 39:281 286.

NUSCO. 1987. Fish ecology. Pages 161206 in Pennington, M.1986. Some statistical techniques Monitoring the marinc environment of Long for estimating abundance indices from trawl Island Sound at Millstone Nuclear Power Station, surveys. Fish. Bull., U.S. 84:519 525. Waterford, Connecticut. Annual report,1986. Pottle, R.A., and J.M. Green.1979. Field observa. NUSCO.1988a. Deka distribution. Pages 311320 tions on the reproductive behavior of the cunner, in Monitoring the marine environmerit of Long Tautogolabrus ad3persus (Walbaum), in New. Island Sound at Millstone Nuclear Power Station, foundland. Can. J. Zool. 57:247 256. Waterford, Connecticut. Annual report,1987. Richards, S.W.1959. Pelagic fish eggs and larvae NUSCO. 1988b. Ilydrothermal Studies. Pages of Long Island Sound. Bull. Bingham Oceanogr. 323 355 in Monitoring the marine environment of Coll.17:95124 Long Island Sound at Millstone Nuclear Power Richards, S.W. 1963. The demersal fish population Station, Waterford, Connecticut. Annual report, of Long Island Sound. Bull. Bingham Oceanogr. 1987. Coll. 18(2):1 101. NUSCO 1988c. Fish ecology. Pages 255 310 in Richards, S W. 1982J Aspects of the biology of Monitoring the marine environment of Long Ammodytes americanus from the St Lawrence Island Sound at Millstone Nuclear Power Station, River to Chesapeake Bay, 1972 75, including a

                 . Waterford, Connecticut. Annual report,1987.                comparison of the Long Island Sound postlarvac NUSCO, 1989. Fish ecology. Pages 161206 in                      with Ammodytes dubius. J. Northw. Atl. Fish.-

Monitoring the marine environment of Long Sci. 3:93-101. Island Sound at Millstone Nuclear Power Station, Ricker, W.E.1975. Computation and interpretation Waterford,Cor.nceticut. Annual report,1988, of biological statistics of fish populations. Bull. NUSCO. 1990. Fish ecology. Pages 81118 in Fish. Res. Board Can. 191:1 382, Monitoring the marine environment of Long Roff, D.A.1981. Reproductive uncertainty and the Island Sound at Millstone Nuclear Power Station, evolution of iteroparity: why don't flatfish put all Waterford, Connecticut. Annual report,1989, their eggs in one basket? Can. J. Fish. Aquat. Sci. 38: 968 977. Fish Ecology 115

               -         - - -.-~. - . - - . _ - - - - . - -                             . . _          _ _ . _ _ - -                    -  __

l 1 3 s Salta, S.B., and S.D. Pratt. 1973. Mid Atlantic Williams, O.C.1967, Identification and seasonal liight fisheries Pages 6.1 6.125 in Coastal and sire changes of eggs of the labrid fishes, offshore ensironmental inventory. Univ. of Rhode TautogoW>rnt adspersus and Tau;og onitis, of Island Mar. Pub. Ser. Long Island Sound. Copeia 1 % 7:452 453. Sampson, R.1981. Connecticut marine recreational Williams, O.C., D.C. Williams, and R.J. Miller. fisheries survey 1979 1980. Conn. Dept. Envir. 1973. Mortality rates of planktonic eggs of the Prot., Mar. Fish. 49 pp. cunner, Tautogolabrus adspersus (Walbaum), in Serchuk, F.M. 1972. The ecology of the cunner, Long Island Sound. Parcs 181 195 in A. Pacheco, Tautogolabrus adspersus (Walbaum) (Pisces: ed. Proceeding of a workshop on egg, larval and

Labridae), in the Wewcantic River Estuary, Juvenile stages of fish in Atlantic Coast estuaries.

Warcham, Massachusetts. M.S. ' Thesis, Univ, of National Marine Fisheries Service, Middle Mauachusetts, Amherst, MA.111 pp. Atlantic Coastal Fisheries Center. Tech. Publ. Simpson, D.O. 1989. Population dynamics of the No,1. tautog, Tautoga onitis, in Long Island Sound, Witmari, J.D.1985. Refuges, biological disturbance M.S. Thesis, So. Conn. State Univ., New flaven, and rocky subtidal community structure in New . Ct,65 pp. England. Ecol. Monogr. 55:421445. Sissenwine, M.B.1974. Variab'lity in recruitment Woodin, S. A. 1982. Browsing: important in and equilibrum catch of the Southern New niarine sedimentary environments 7 Spionid England yellowtail flounder. J. Cons. int, polychaete examples J. Exp. Mar. Biol. Ecol. Explot. Mar. 36: 15 26. 6135-45. Sissenwine, M.II. 1984. Why do fish populations vary? Pages $9-94 in R.M. May, ed. Exploita-tion of marine communities. Springer Verlag, New York. Smith, E.M., E.C. Mariani, A.P. Petrillo, L.A. Gunn, and M.S. Alexander.1989. Principal fisheries of Long Island Sound, 1961 1985. Connecticut Dept. Envir. Prot. Mar. Fish. 47 pp. Stevenson, R A. 1958. The biology of the anchovics Anchoa mischelli and Anchoa hepsetus in Delaware Bay, M.S. Thesis. Univ. of Iklaware, Newark, DE. 56 pp. Tra:y,it.C. 1910. Annotated list of the fishes known to inhabit the waters of Rhode Island R.I. Ann, Rep. Comm. Inland Fish. 40:35 176. Vougillois, J.J., K.W. Able, R.J. Kurtz, and K.A. Tighe, 1987. Life history and population dynamics of the bay anchovy in New Jersey, Trans. Am Fish. Soc. 116:141 153. Warfel, ll.E., and D. Merriman. 1944, Studies on the marine resources of southern New England. I. An analysis of the fish population of the shore zone. Bull. Bingham Oceanogr. Coll. 9:153. Westin, D.T., KJ. Abernethy, L.E. Meller, and B.A. Rogers.1979. Some aspects of biology of the American sand lance, Ammodytes americanus. Trans. Am. Fish. Soc. 108:328 331. Wheatland, S.B. - 1956. Oceanography of Long island Sound.1952 1954, II. Pelagic fish eggs and larvac._ Bull. Bingham Oceanogr. Coll. 15:234 314. 116 Monitoring Studica,1990

Appendix Fish Ecology 117

i. 1 J Alt!'.NDIX l. ljat of fishes uillected in the hsh Ikology samphng programs. Suentific name Gunm<m name Trawl Seine Ishthyoplankton lI Acapesser crythyncAat Atlanic sturgeon

• Alusa mesanalis bluetmk herring *
• l Alma medmcns hickory shad
• Alata pseudehartegut slewife * *
• Alosa sapsditsima American shad *
• y Alpsa app. alusiJ * *
• Aluterut schiepji oratigt filefah *

, AmrwJytes amerscanut American sand lance * * * ?. Anchoa Aersesus striped anchovy

• Antowa milc Adli hay stuhovy Angsulla rostrata American eel * * *

                     . Apeltes gaadra<ur                              fourspmc slidichatk            *     *

• Itaird4r/la cArytours silver gwrth
• Ifrevoorfia tyrannat Atlantic enenhaden * *
• ltrosme brosme cusk
• Carant (tysm blue rimner *
• CaraarAip/os crevalle jad * *

                   ; Centroprhth striata                              black sea bass                 *

• CAaeson4fue prellate spotfin butterflyfuh *
• Chipcise herrings * *

' Clupeaha*ragut Atlantic herrtrig * *

• Conger oceanicas songeres; *

                   '. Cyclopserkt lunyiat                           - lutnpfish                      *

• Cynmeson regald stakfuh -
• e e Cyterenodos variegate . sheepshead rninnow * *

                   - Dactylopresat volaae                            flying gurnard

• llasyath centreura roughmi sting ray * '

Decapserut macarellut maderci scad

• 1achelyoput timbriar fourbeard rodling *
• 1tropat mictmsornat smallmouth fkiunder *
• I:wcianstornus lefreyl nuntled mojarra
• fitsularia salwarja _ hluesp<sted cometfah
• Tustulat d4aphaec . banded kilhfish
• Furlule keteraciaat mumminhog *
• TuSMat turiae - spotfin kiihfish
• Tundulat publit atnped Llilifish
• GaMie sodfishes *
• Galat mor Aus Atlantic cnd *
• Gelerosleut erulealur threcspine stickleback * *
• i Gastermlear wAratlasti blad spotted .stidleback * *
• p Gahidae - gobics * *

                   ' Gobiosoma gimburgi                              scaboard goby

• llemitripterat americanat aca raven *
• llippocamput erectut . hned senhorse *
• Lahridae - wresses
• IAcwphrys epp. 6efi h
• Leimiomat ransAurat . spot- *

                     .Liparis spp, .                                 seminail__                      *                      -*

LopAim americanat goosefnh * *

                                                                   . rainwater killifish             *

• r

                   - Larconia/wrw Atacrosmice.' urnericaaw                       ocean pout

• Afstanogrammat ooglelisar haddad .

                    - Aleaticirrhat sasatilit                        northem kingfish                *     *-

• Aleaidia beryllsaa inland silverside .*
• Afenidia me= idea Atlantic silverside * *
• Aferlucciut bilinearis *
• e silver hake . _

Aficrogadut somcod Atlantic tomuul *

• Afonacas#Aur Aspidat planchead filefah
• Afonocesths spp. filefith
• 118i Monitoring Studies,1990

_.___a_._ ._. a.  ;._ . . . _ _ . .. -.._ _ _ _ _ _ _._ _ a

- -- - --~ .- ___- . - - _ - - . - . ~ . - . . ~_ -- -- APPlWDIX l. mnunued.

• kienufg name , Gwnm(vi name irsal Seine lc hthyoplankton ,

Aforont amerkau white perch *

• Aforone sasards.t striped tote *
• Af ugil repAatus - sinped snullet * *
• Af usii t urtena white emellet
• Af ullat euratat ted goatfish
• Alaittla.t ranis smioth dogfish
• Afylwbatis fremnevillri battnose toy *  ;

Afpowerphalat arnarut grubby * *

• Afyosotephalut ociadact reuranco ut longhorn sculpio *
• t 4iyosoctpAalue app. neulpin
• OphidnJoe (unk wels
• Ophntma twgsnatum sinped $uik ect * * *

Ophidion urh M l created cud cel

• Op.tanut fan oyster Wdrish
• U.irnrrutmordt* tainluw smelt * *
• l'aralick Aye olentatue suenmer flounder
• e Paralk Athyt chinagut fouripol flounder *
• Perrilus truuantAnt huuerfish * *
• PAstu gunnel!=.e ta k gunnel * * *

[- /WlacAim varent pullo6 L *

• femalomat taltalris . hiuefish '
• Traacarithan artnatut bigeye
• thanshav crurruatut glaueg snapper *

                 - frklogeny.s alta                                          shutt higeye

• l'rionoint tarottnat northem sututun * *
• Prmnormi e wtans striped scatolun * *
• l'srulopleuronectan americannt m inter iksuuh.t * * *

funguim pungsflur tutienpmc stickleback * * '*

Raja tglanteria (learnme skate

• Raja trinacea - little sksic
• Raja n'allata . wintet skate
• Salmo trutta brown trovt _
• kinnidae drwns
• ScophtAdImae aguosas windowpanc * *
• i Sc.vaber scombrut - Atlanik snaderal *
• ScyliorAinas artifer ' them dogfish
• Setar trumenorthalmu hageye and * '

. Selene setapinnit Atlaniis mmmfish * ' Selene somer - hwkdown *

• Synatarfortent inshore hratJfish *
• l Sphyrarna In.,oraint northem sennes
• L 3photroides orksculatur * *
• nonhern pulIct Squalat ecoalAats spmy dogfish *  ;

Stenotomat chrysopst scup *

• l Strengylura marina Atlanta needlefish . *-

                 . 5ynpatAat fattat                                          nonhern pipsfith                       *                *                *-

l+ 7au!opolabrut edittr. tat cutinct ' * *

                 'Touloga onitit .                                           taviog                                 *                *                *
               - 77achinoist fakatat                                         permit.                                *                *
                 - TracAuruta Aami                                           toughscad

• TracAinocephats* myopt' snak tfish -
• Transcles maculatut hophoket *

                - Ulvaria subh(urcata                                        radiated shanny                        *                                 *-                                   l
                ' Upencktfurvat                                           _ de*at( guntfish. ~                    -*

UropAyeis tknss red hat *

• UropAycs, tenuis ' white hake , .

Urophyelt spp. . hake * * -*-

                                                                                                                                                    . Fish Ecology 110-u 4
      ,a.---                       emor..,w,,,..mrM-rw+w.-rw.i--.egrm-..w.,,.-,*,,w-.r,.*v~                          -
                                                                                                                         ,,wv--,.-_c    - ,  ---,-..,.....e-,--.,,,ww,,[.m      w . . , ,,

  ._-.._.. - - . -                                                                . - - - . _                                                     n-.-.~.----                                                                       -
                                                                                                                                                                                                                                                                         -         ..~ -

l d APPf:NDIX 11. Toul traml utch of hih tau and emnder of umples colicoed by reguri pernal . Tasm8 76 77 77 78 78 79 7940 F() Bl $1-82 82 81 63.$4 14r85 8$-86 $6 k7 67 48 An49 69 90

                           - Numhef of samples                                            468            468                    468 464              468 467                         474         460 466        468   4tl 465 468                                          468

f. agerkannt 7415 6045 7236 18442 13296 10749 19201 12560 13260 9k49 9321 8877 13440 8690

3. chrynps 1918 4040 23$6 4094 3644 3401 4896 $268 4206 2640 $20$ 3632 3294 2kb9 3 ayunear 14hD 1296 k7$ 1$08 2016 l$lk 3$17 2475 2199 24$3 165$ 1966 2399 2735 Ant Ana spp 979 . $no 2226 16 109 $78 3a 109 l$7 10004 kd35 292 496 1241 Raja argi. 661 $79 362_ 402 V34 696 2797 2493 1583 3501 2207 2183 2n64 2437 Afrauha spp 2132 1647 1463 1340 R32. a01 $16 $43 322 $19 3438 698 982 da$

Gaals 112 326 230 211 3206 1424 476 All $62 630 168 $43 ks M Af a<natut 266 636 297 342 632 870 996 672 477 348 727 434 9h9 615

                              '/. a.fisvisut                                               n1A n75                             400 1399              940 840                         611         362 24A        114    147               f.1                20$            109 l'rivam spp.                                                33R 322                               13k 313              40$ 661 1039 422 371                                       19$   436 159 356 1277                                                                 !

l' drasaint 2R6 14) 92 73 122 . 240 230 269 1917 28: 653 617 360 k0 l

                              /' anacantAue                                                 37               44                407         174          44              69           182         244      19    133    (12            til 131)                             179 Af, bdenceae .                                              425 -163                                 69      134       $$8 220                         3)2         147    100     173   191             Ils                         73       32J l/ rop 4yrit app                                              99               87                 103         f6       163 313                         61$         266 231       272    286 164                                174 ' 141 0 scultatur                                                     10              17                    47       77       206 103                            63 21b 1102             116   354 405                                     91          10 T. onus                                                     229 283                              263 270               146 228                         239         140 119        134   215                K7                  162             H l' guaertius '

65 106- 99. f5 2$1 273 302 143 ~ 127 l$1 186 203 407 189 3 /s cui 41 $4 49 kt 131 264 232 202 234 196 207 273 321 M

                             // am<ruamme                                                   34              4R .                   39      148       278 410                         $$7         377    125       41    44                11                           3       7 f) mer.An                                                    ill 266                                 90          $     123                63              k9        26 227       391    257 249                               152              26 11 murrutomai                                                  43                  7                     0        3        31              91              94        $6      85   21h    640 190 339 -                                          b2 A qieerut                                                        10                6                   24       2/       194 765                            76        il    112     130   107             -$2                        31          11 If tyrannu.e                                                       i            14                     11          i          i              1               0         1       0     31    10                 4                           1 13;0 l'. chlongus                                                   31                 7'                  21        11         $1              32           138          34      81      66    72               2A                 123            133
                        - C stesna                                                          33                 9                      3       4         10              63              23        3X      30      80  412                16                      43          to                       s AI edstemersaavus                                                il          -10                      V7        40         30 145                        172          51     20       13    12                 $                      u          18 A fuemioAarenga,                                                 11 272                                13        17           4             15                5       26        4     16  20h                   1                         4-       3 0 rav                                                           98              21                        7      Ill       31               33             25         23      24      32    $6               51                      48          30 A smarranur                                                         $           59 . 128                        36       117                14              19        il      19       6-   Il               29                            I       I A raitrala                                                      19               16                       8       $         10              37             29         24     22       34    2h               22                      20            $

C. lurvue 19 ll 24 $4 11 0 14 1 29 1 1 44 6 1 lJfurie n[gi, 9 27 10 10 16 33 l$ 16 il 3 IN 8 12 22 C regals 9 21 4 2 2 41 7' 0 1- $ 36 $ 14 9 A sapiArrima 33 6 l .$ 40 !2 - 0 29 0- 0 1 1 9 $

                            $ n xularme                                                     16               10                       1       0-         9              14-             16        l$        7      7     3                 1-                        9       14 Chquine                                                            2                1                    0        0          0               0               0         0       0   l l(>     0                 0                         0        0 C. Aattarur                                                         l              9                   13         0          0               1               0         2       9     61     10                 2                          1-       2

, AI. canis 2 5 45 _ 18 1 .5- 4 6 0 J 2 1 2 2 L/arrugwa 7 $ $ 2 .3 15 6 0 4 0 0 23 0 '3 A aartevolit - 3 11 8 12 4 1 'i 17 $ 2 4 2 -2 0 Af. Aurstur 3 6 8 4 0 0 8 1 8 9 2 2 2 11 Af. *nericana _H 17 3 .$ .8 2. 1 0 D. 0 0 0 $- Il 1/iyecampus f opp. 0 0 0 0 0 0 0 1. ' 4 7 29 12 6 4 Gohnd4e 3 0 0 0 4 0 0 3 0 7 2 5 '10 2

                        ' Af 4 americanut                                                      3               7                     9        2          2               2             '2          2       3       1     0                6                          2-       2 Alota slp                                                           0              0                      0        0          0               0               0         0       0       0_    ()               4                     Il          26 S setariasis                                                        0              0-                     0        0          0           _0                  0         0      .I       O     O                O                    30             0 I taturarea                                                            2-              3                   .0       -0           3               0            _l--       .0        8       i     2                0                          1        3 1,.saasAurne                                                        $-             6                     0         0          0               0                         0       0                              0                      '$

2 3 1 0 t). mtuans 3 0 0- 0: 0 e l 3 1 0 3 4 1 2

                       - A scAorr/i                                                           0-          '2                         2        I           I              O               O         I        i. 2     2                0.                        3         4

I. wmst i 2- 0 -0 0 0 0 0 0- 0- 1 I 11 1' Af ,sanatifie 0 1- O l- .0 3 1 0 -0 0 4 4 2 3 P. saliafris ' l. 1 -0 2 'l 2 3 3 () 0 0. 2 1 0 0 margiaafurs .0 0 0- 1 0-- 0 0 0 -1 2 .4 4 4 0' 8

hih ihntified in the loweit practical inu. 120 Mouitoring Studies,1990 t Tr e -%'t1*-X--'t T M-um- wte-t-'ri- em w - e et s --m -eas-e TM w e w h**w Bitr >- 1emm+4w e t mete t +-wm-=4~eu-4ww*W* -J.-e WeW9e-_re=ehmmed---rea*tatew-T-+wM__ ==-wi* ear't i==s ,,__--*e.-e+*+.--t+t- - eum+s---wa--6

 ~-~_---.-.-._-n-                                                            -

APPlWDN 11 codinued Taum' 76 77 77 78 78 79 79 $0 $D 81 AlA2 6243 63 84 84 83 b5 k6 66 $7 h7 68 $5 kV 69 90 l'5 pungitic 0 0 0 0 1 2 0 0 5 1 5 0 0 0 Gatietostridae 0 0 0 43 0 0 0 0 0 0 0 0 0 0 Tus/ulutspp D 0 0 0 0 $ 2 0 0 2 1 0 1 0 5 boreolu 0 0 0 0 0 0 0 1 1  ? O 1 6 0 U subbg/ccata 0 2 0 0 l 1 0 0 0 1 1 1 4 0

                     /* cruratarw                        0        0       0       0      0       1        0      2      3       1    1    1     1      0                  4 l                     6 ameruanae                         2        0       0       0       1      0         l     I      O       O    I    4    0       0                  )

l C. <reaskue 1 0 0 0 1 0 0 0 2 0 i 1  ! 3 5 /nettet 0 1 4 0 0 3 1 0 0 0 0 0 0 0 l Al. ouratae 0 0 1 0 0 0 2 0 0 0 1 0 4 0

f. latfurtsu - 0 0 0 4 0 0 0 0 0 0 0 0 4 0

7. suculatus 3 i () 0 0 0 0 0 0 1 2 1 0 0 I Gc wheallas:!i 0 0 0 0 0 1 1 1 0 1 2 0 1 0 M. susatila 0 0 2 1 0 1 1 0 'O 1 0 0 0 0 C nyscu O O O O 1 0 1 0 1 2 0 0 0 0- 1 A nha 0 0 0 0 0 1 0 0 2 1 1 0 0 0

C. oc ellatw 0. 0 0 0 1 0 0 1 0 0 t 1 i o

= l'. re malas 0 0 0 0 0 0 0 0 2 1 0 0 0 l Af cephalw 0 0 0 0 0 0 1 0 0 2 0 -0 0 2 ll. cumbric 0 0 0 0 0 1 0 0 0 0 1 I i 0 C. A ppos - 0 0 0 0 0 0 1 0 0 1 0 _0 0 2

l. lattophryt ipp. 0 0 0 0 0 0 0 0 3 0 0 0 0 _0

1. parva 0 0 0 0 0 0 0 0 0 0 0 3 0 0 5 nromhrat 0 1 O I O O O O O O O O O I A msdweris 1 0 0 0 1 0 0 0 0 0 0 0 0 ()

                    /) matarellar                        0        0       0       0      0       0        0     0       2       0   0    0     0      0 M. arstefmar                         0        0       0       0      0       0        0      1      0       0   0     1    0      0 i ncanthia,'                         O        O       O       O      O       O        I     O       I       O   O    0. 0      0               ';

C. margatar 0 0 0 0 0 0 0 0 0 0 0 1 0 1

4. oxyrhyarhae 0 0 0 1 0 0 0 0 0 0 () 0 () 0 A maculatue 1 0 0 0 0 0 0 0 0 0 0 0 0 0

                    #, t hrywura                         0        0 -. 0       0      0       0        0      1      0       0   0    0     0      0 C. ocellaine                         0        0       0       0      0       0        1     0       0       0   0    0     0      0 li brosms                            0        0       0       0      0       0        0     0       0       0   0     1    0      0

() centraura 0 0 0 0 0 0 -0 'O I O O O O O Afonacantantspp. 0 0 0 0 0 0 _0 0 0 0 1 0 0 0 Af freminvillri 0 0 0 0 0 0 1 0 0 0- 0 0 0 0 , Afyotocephalue spp. U- 0 0 0 0 0 0 0 0 0 1 0 0 0 OphiJudd 0 0 0 0 0 0 0 0 0 0 1 0 0 0 S fruna 0 0 0 0 i -0 0 0 0 0 0 0 0 0 S tet/tr 1 0 -0 0 0 0 0 0 0 0 0 0 0 0 X crumenorthalmae 0 0 0 0 0 0 0 0 0 1 0 0 0 0 3 marisa 0 0 0 0 0 0 0 0 0 0 -1 0 0 0 7 myopt _0 _ 0- 0 0 0 0 0 0 1 0 0 0 0 0 Tfalcatae 0 0 0 0- O' 'O O O I O O O O O f wrvae 0 0 0 0 0 0 0 0 0 1. 0 0 0 0 L-

                   -Total                           17941- 18147 17497 22469 29010 24773 37699 27860 28169 33546 35566 21674 29529 2347?

I 8 Iish identified to the lowen practical uta. Fish Ecology 121

   . . u ._2... _ a_ :. _.        2. - .-      , _-_ . _ _ _ . _ _ _ _ _ _ _ _ _ - . . _ _ . _ . - _ _ _ . _ _ _ _ _ _ . . _ _ _

__._m~._____.__-- - _ - -.

                                                                                                                             =_        _ ._             _        -

1 APPL.NDlX Ill haal trawl takh of fah tasa and twmtwr of samples collectnl by station (June 1976 May 1990). Taaori

• JC NR NI Tl itR IN *1UI A1.

Number of samp;es; 1U17 1015 1017 1017 1017 1013 6098 l' americanst - 13516 $1940 19425 23190 16969 2434 151381 S. thytes 3493 262 19975 8515 $426 14194 $1865 3 agmavat 1436 2493 2523 3739 13441 4468 18122 AncAte app, 191b 1162 Iku$4 303 19 340k 24862 kass spp. 1146 13 3346 6595 0492 022$ 24019 Aftni.6a spp. 4048 5127 1556 890 334 3$$5 13330- . Us& Jar 1698 7RS 2748 1023 263 1962 6681 Al. stnar ut 1201 3R24 447 469 764 15A9 h294 l

7. u.Lepe rius 1601 339 $13 270- 4k3 1930 71$6 l'ren w usspp 93 611 646 1200 3177 833 6632 i- /t d.atatue 779 1255 716 1700 232 721 $403 P fruvaarAar $$ 11 648 614 1277 1003 %DN Af bilsacato 146 6 4h4 471 1408 $k7 3082 l/rophych app 361 67 322 271 1533 449 3023 0 acultaine 2014 790 10 9 6 6 2837

                      / veitsi                              579             633                2n7        193          260         Mn          2600 I'= guentItas                        1383             3$4_               300        lii)          29         140         25k9 j --                  5 fuscui                               738            1187                133          k)          V9         179         24.'l
                      // americana,                         4 43              IL2            -402         298          496         402         212.3 0 mor.br                             1403             280                134          82          76         120         2093 Il micrcesomat                          116              17               121        l'i6         941         308         Ik19
                     .4 quira u,                             162           1389                   1           !           1             2      1$36 If tyruanes                           521             849                 24            2           0             3      1399 it ablongui                              0              11                70           9        733            27         850 C struta                                 70             152                47          38          47         449          843 Al octodetemspinseu.t                    3'               O               20          $2         $45            16        tih A perSlohartagai                          7              M                  19         12        255          242          $99 0 lau                                    9            488                   0          ()           0          12         $09 4 amerswoue                             19              95                  5         29         299              9       456 A ruestein '                            38-           2ll                   0         20            3             7       279 C, lumpas                               143                6                14          1            2          $2         224 inurie spp.                              26              10                35          35          79           27         212 C. trgalis                             ' 22 .              O.              26          11          70         - 31         160                i A sapidae ma                              k              17                52 -        10          33           22         142 S. marelasar                             12              63                 13           4          15          14         121 Clupcidae                                 U                l                 0           t           0        111           113 C hartagne                               65                4'               13          9           16             4       113 Al. reas                                 6                1               40            3         32              6          &R L ferrupera                               0                0                 0           8         65              0          73 A meslaalis                               1              20                 16           R          14          13            72
                   ' Af, hirpida,                             17                1                10          9           15           12           M Af amarsca44                             8              22                  4           l           $          20            60 -

llipporampat siy 21 20 '2 3 1 4 54 - Gobiidae 2 43 0 0 0- -0 45 Af.americaeme 0 0 0 1 42 -2 45

                    ~Alosa spp,                                1                4                 3          6          23              2'         41 S. setapinnis '                          16                0_                7           2-          0             6          31 fi tahataria                             17                3                 0          0            0             4          24 f . xantAurut                             4                0                 5          0            4             6=         22 It volstasr                              .I                8                 0          0            0          10            19
                   . A. schorpfi                               4                0                 2_          2-          l             $          19.

S. vomer . I 1 14 0 0 1 17 Al. sa natilis 0 6 3 4 1 3 11 It saltafria 3 4 3 0 5 1 16 i -O margiutam 3 3 1 2 5 1 '15 I l

                      ' fish identified to the km est practical tata.

122 Monitoring Studies,1990 :

  ~       a.                - -- . .                          --_.n.._-.-._.__--.--...-..                                                       . --     - . -.w

APPINDIX Ill usittnutd 'I s uvi ' r M NI Tl ing IN It)l Al P rangshat 10 3 0 0 0 1 14 Gaste roiteid4r 2 11 0 0 0 0 13 l'un.lulut ipp 1 10 0 0 0 (> I1 5 borrald 5 0 0 0 0 0 11 U ,vuMyfuS ala 3 0 0 1 6 I 11 P crw at.atus 2 0 1 3 0 4 10 L ameraranc 1 0 1 2 5 1 10 C uragi e 1 3 3 1 2 O 10

$ fortent                                 0           3        0       2         4                                    0                  9 Af au glut                                 1         0         0       0          1                                   6                  h T laltwau                                  4          0        1       0         0                                     1                 h I ruplalc                                 5          2        0       0         0                                     I                 h G = Ararian.l.                             6           1       0       0          0                                   0                  7 hf sanahlss                               0          6        0        0         0                                   0                  s C (9mt                                     0          0        2        0         1                                    2                  3 P aha                                      2          0        0         1        1                                     1                3 C orrllatut                                2           3       0        0         0                                    0                  $

l' aernatut i 1 0 0 1 2 3 AI rrrA>!at 0 2 1 0 2 0 3

 / rimbriu                                  1          ()      0        0         3                                     0                 4 C korpos                                  0           0       0        0         0                                     4                 4 loclorltyi i  $pp                          2           1       0       0         0                                     0                 3 l parto                                    0          0        0        (,        1                                    0                 3 5 scombrai                                0          0         1       0         1                                     1                3 4 me.fwcris                                1         0        0        0         1                                     0                2 D macarellut                               1         0         1       0         0                                     0                2 Al avgirlines                              1          0       0         1        0                                     0                 2 S acanthia.                               0           0        0       0         2                                     0                 2 C va'irgasut                              0           1        0        1        0                                     0                 2 A. oryrAymthus                            0           0        1       0         0                                     0                 1 4 #wulate                                   1         0        0        0        0                                     0                 I li chrymura                                0          0        0        0         1                                    0                  1 C. ocellaf at                              0           1       0        0         0                                    0                  1 11 bruimp                                  o          0        0         1        0                                    0                  g

() ra417oura 1 () () 0 0 0 1 Afonord9that spp. 1 0 0 0 0 0 j Af freminvallei 0 0 1 0 0 0 1 Af >otortr Aa!u: spp. 0 1 0 0 0 0 1 (yhtdiidae 0 0 0 0 1 0 g

   $. fr9tla                                  ()          1       O        ()       0                                     0                  g S f ebftr                                  ()          1       0        0         0                                    0                  g 0          0        0         t        0                                    0                  ;

S crumenortkalma 5 rwanJ 0 0 0 0 1 0 t

    'l myopt                                   1          0       0        0         0                                    0                  1 T.falcatut                                 0          0       0        0         0                                     1                  1 U parvat                                   1          0       0        0         0                                     0                  1 Total                              39640      74813     73643   50667     61116                               67458            299899

• fish idenafied to the lowest peutKal tua.

Fish Ec010gy 123

Y t

APPlWDIX IV. heat seine utch of fuh inte and immter d samples collixted by aquet par.

laum" 76 77 77 78 78 79 79 80 00 nl $182 E243 83 54 64 ns $5 k6 66-67 $74k kh 69 69 90 Mimlet uf samples 6h 72 72 72 72 72 9k 120 174 156 156 156 156 160 J Mensh,e app. 40619 15194 1335 1062 7996 3166 $413 9607 l$3R 1375 $441 h542 6015 547 l'un. lular err 1693 1199 $15 659 952 613 915 1081 146! 906 111 412 3140 631 A gudiare 464 60.1 255 266 49 94 $9 th27 167 106 297 98 142 302 q C. varsegasus 48 673 39 30 10 352 146 50 29 28 2 2 21 3 g- A a w aranar 6 $20 16 Si 10 318 k2 30 21 0  ? I 4 0 P. rungam, 5 1 28 2 5 2 80 321 8 11 & 4 30 24

                $ faveur                                          V                    3      9  108     6       6                            ?!                  12        35          30         33               19     74         11 U erstrans                                        9                 IS4    27      $     3       2                                 5              $3         6           6          19              IS    36            8 P sahalen                                         .I                    #     1    6     0       2                       13$                         4      19          )$          12              12      5           6 P a w rwanue                                      4                    6      4    1     6       3                                 2                 3      17          40          18              17     16         en M serAalui                                        0-                   4      3   23   di         1                                4                 4       1           0         38                4    4h            0 A. pSe nlahae ragur                               0                    0      0    0     0       0                                 0                 1      93           0           0               4      0           6 Omin!=                                            2                    0      9    2   20      16                              11                    6      11          il           N               O       I          2 U nheallar6/i                                     0                    0      0    0     0        R                                6                 6      19          12           9              22      h           h

h. Iyeanami 0 0 17 0 4 0 7 1 0 h 6 6 3 23 M rur.%s 0 0 0 0 0 0 0 1 9 0 0 0 43 3 1 C. Aarratur - 0- .0- -O

                                                                                           -      .0     0       0                                 2                 0       0           0         30                0      6           i L parva                                            l                   2      0-   0     0       0                                 0                 2       0            1          0              16     14           2-                                )

Aromau 10 $ l2 3 2 0 1 1 0 0 3 0 0 0 L /akaise 0 0 1 0 1 0 0 0 0 0 0 0 22 7 M armarui 3 2 1. 2 0 0 3 l 3 3 3 2 4 0 0 more 0 0 0 0 0 0 0 0 0 2 () 0 lk 0 Am Amt opp. 0 0 0 0 2 0 7 2 1 0 0 0 0 0 Gaurernsru, app. 0 0 0- 0 0 0 0 0 0 0 12 0 0 -0 4 ottinato 2 6 0 0 0 0 0 0 0 0 0 0 0 4 l , 3. su ulatur - 0 0 0 1 0 0 1 0 0 3 3 0 1 0 C. Aijyvs 0 0 1 0 0 l 0 0 0 1 0 0 4 1 , T- vaiso - O '- 0 0 0 0 0 4 0 0 0 0 0 2 0 .l T aihrersut 0 0 2 0 0 0 3 0 1 0 0 0 0 0 l A. saphlasiru 1 0 0 0 0 0 0 0 0 1 0 0 b 0 M. satahlo .1 0 1 0- 0 0 0 0 0 0 0 0 0 0 f #riacanthur .0 0 0 0 0 0 0 1 1 0 0 0 0 0 P t=994"Ila' . 0 9 0 0- 0 0 O_ 0 0 l 1 0 0 0 S. imriu 0- 0 0 0 0 1 1 0 0 0 0 0 0 0

              ' Clulwidae                                          1                   0      0    0     0       0                                 0                 0       0           0           0               0      0           0 C trgalu                                          O                    O      O    O     O       O                                 O                 0       1           0           0               0      0           0 friogotar app.                                    0                    0      0    0     0       0                                 0                 0       0            1          0               0-     0           0 S, ogamus                                         0                    0      0    0     0       0                                 0                 0       0           1           0               0      0           0 (Irophyrse spp.                                   0                    0      O_   0     0       0                                 0                 0       l           0           0               0      0           0 Tidal --                           42kR1 21372 2579 2221 9109 4609 6k69 13215 3444 2582 6061 9196 9667 6336                                                                                                                                             i t

• Ihh hientified to the loweit prutical tau. -

3= ):

124 ' Munitoring Studies,1990

c

 , .E - * - ,   en'e-  , - - --e.n    --w,e--w.e_n-.,w-v,-e-,-e..--.----mea.~,www.%                         .---,-..,..ww.w                                        ..---v-,    ,-e.+ee,*e,--et-,.--1,m--,--.ww-.+--n.---ke.ww,=.--e,.~.--  --ee. "w wwee4,--c-,

AN't.NDlX V. lotal seme catsh of fish Lasa and numkr of sample s solleted h Hatitui(June 1976 % ) 1990) r WP (N 'lul Al, lason' 462 $09 Alb 14h7 Numhr of sam lus Afr4*fea spp 65983 lb29 13321 il5$b7 / uslu,'un spp 1illB 212.1 1$71 14h12 4736 17 19 4772 A vmba ur  ;$ C varirgasu, 640 76% 1433 A awru..wi 3 198 hf4 IWi6 P. pung uiar 349 kB 21 459 73 $9 246 37b N futcut G aculcatui 275 29 46 350 P sahatea 146 17  ?$ 23h 2h $6 10.1 1h7 l' amerstanut 98 42 29 1fW Al rt/Ailue li 93 3 10:1 A p<rululwengus Gadids 65 29 7 1Oi 33 30 33 Vil U. u hrattan.h 10 35 77 B lytannus 32 Al curema $3 3 0 $6 C hartrgut 39 0 0 39 31 2 $ ') K i ,wva 2 4 37 A rostrata 31 30 1 2 33

 'l falcasui Af cenatur                                            7               11                                           9                  27

0. msd i is t il 0 2 20 Anchoa spp 11 1 0 12 O I 11 12 Gavirrattrue spp.

4 assiivata 3 6 3 12 0 l R 9

  $ truculaint 6                0                                           2                    k C. Agros T, castit                                              4                2                                          0                    6
                                                         $                 1                                         0                    6
  'l' slspersus A sajmlawns                                            0                0                                          2                    2 Af. ianatila                                           1                0                                           1                   2 0                 1                                          1                   2 r sawcanthus IL tunnellus                                          0                0                                          2                    2 S. marina                                             2                 0                                         0                    2 0                  1                                         0                    1 Claintne C trgalu                                               i                0                                          0                    i raionstui spp                                          0                 1                                         0                    1 5 aquotus                                              0                 0                                          1                    1 (teophycit spp                                        0                 1                                         0                    I "l otal                                     103763              19923                                     16435               140141 8

17ssh idenitfied to the lowcoi prattkal tua. Fish Ecology 125

. . . . . -- .. . . . ' - . . . . -...-..-.,----,............l ' Contents Lobster Studies . . . . . . ....................................... 129 I n t r od u c t io n . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 129 Materials and Methods .................................... 129 Ilesults and Discussion .................................... 131 Abundance and Catch per Unit Effort ..................... 131 Population Charactuistics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 134 Size Frequency ..............................134 S e x It a t ios . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 135 It e p rod uctio n . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 137 Molting and G rowt h . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 139 Culls ....................................... 140 Tagging Progra ni . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 141 Movernent ........................................ 143 Entrainment ....................................... 145 Conclusions ............................................ 146 Ilcierences Cited ........................................ 147

Lobster Studies l recruitment patterns; the thermal ellluent may l Introduction affect molting and growth of lobstco, in the i discharge area. Potential effects of plant i The American lobster, Hmnarut americ<mus, is operations on the local lobster popula00n were the most economleally important fishery resource assessed by comparing the results of the 1990 in long kland Sound (Lis) (Illake and Srnith study (catch per unit elfort si/e frequeng growth i l 19&t). The estimated annuallandings in Lls (1.2 rate, ses ratios, female slee at sesual maturity. l to 3.5 million poundQcar) hase ranged in value characteristics of egg bearing females, hibster ! - between 2 and 10 rnillion dollars per par since movernent and larval entrainment) to other 3-l 1978; 25 30'4 of the total landings were made in unit operational study 3 cars (19E19N9) and to . New London county, which includes our sampling data collected during the period of 2-umt area (Connecticut Depattment of linvironmental operations (19781985). Data i am the bunit Protection CTDEP, Marine Fbherv Statistics; period were abo compared to data frota the 3-Smith et al.1989). The lobster reso'urce in Ll5 unit period (198N1990). Additionally, the results b highly exploited and the_ magnitude-of legal of this study were compared when appropriate to catches depends on the availability of seasonally other studies conducted in LIS and throughout recruited lobsters from premolt iublegal stocks', the range of the American lobster, At Millstone Point, it has been estimated that over 4R of the legal sized lobsters are caught in Millerials and Methods the Iltst year alter molting to the legal size range. Lobster fishing effort in Connecticut waters of A detailed description of methods used 10

                               .LIS has increased from 1 million trap hauh in               conduct lobster population studies can be found 1979 to nearly 8 milhon trap hauls in 1985                in NUSCO (1987). From May through October (Smith et al.1989). In an eflort to stabili/c the           1990,20 vinyl coated wire pots (76 x 51 x 30 cm; lobster fishcry, a new regulation was implemented           2.5 cm mesh) were used to collect lobsters at l

in Connecticut to increase the minimum legal site three stations around Milhtone Point (Fig 1.). from 81.0 mm (3 % in) in 19S8 to &l.1 mm (3 The pots were arranged in pot trawls consisting of

                               % in) in 1993; the minimum legal site increases             five pots equally spaced along a 50-75 m line 0.79 mm (% 'in) each year from 1989 to 1993,                buoyed at both ends. The four pot trawls set in with no increase occurring in 1991. It is expected          Jordan Cove are near a rocky outcrop about 500 that by increasing the minimum legal size, larval           m east of the Millstone discharge. Pot trawls at production and subsequent recruitment should                the intake station are about 600 m away from the incres,e.

discharge along the western shore of Milktone Pm Allon characterhtics of local lobsters la Point near the power plant intake structures. At the m.ty of the Millstone Nuclear Poww the Twotree station, located south of Milhtone < j Stau (MNPS) have been studied extensively Point, pot trawh are about 2(XX) m offshore of since 1978. The objecthe of NUSCO's lobster the discharge near Twottee island. The pots were studies is to determine if operation of the MNPS- hauled on Monday, Wednesday, and Friday of has caused changes in the local lobster population each week, ucather permit 0ng; on hiday weeks beyond those expected from natural. variability the pots were checked on the first and last work and the high level of fishing pressure. _ The_ days of the week. All lobsters were removed potential impacts of power plant operations on: from the ' pots; individuals larger than 55 mm the local population of -lobsters - include: carapace length were banded to restrain chelipeds; entrainment of larval lobsters through the cooling . brought to the lab, and kept in a tank supplied water . systems, impingemcet of juveniles and with a continuous now of seawater., The pots adults on the intake traseling screens, and effects were rebaited whh flounder carcasses and reset in of the thermal discharge. Entrainment and the same area. On Fridays, lobsters caught that impingement may increase natural mortality of week were examinut and the following data were the local lobster population and thereby alter Lobster 129

i r t, ' 6 ;i

                                                                     \k                   '

bU

                                                                       \ 'y                                            ,            ,
                                                                                                                                            ' US p             i n " ' j 's
                                                                       \                                               <           a,                       sn m      ..          ,

1

                                                                                                                            -g
                                                                              \ n.                           <
                                                                                )

N ea t h ' i' If}e -

                                                                                                                                    )

7, __ / , J-~ ,h _} j "a - tu n, j g n,o . . , ,

j. r. . ~ s .

                                      ,     .3               ;                                                                                           ,

z,,ay \ o'

                           *.                      ., u n,m 1                                                              (

d \2 b ,; , . i < l ig 1 1 ocanon or uic hhlMone bicar Power Suhon (MNPSL e,nd the three loner tanth ng nunom to t Jr Jordan Cow. IN intake. Tt =Twoirce. recorded; sex, presence of eggs (berried), carapace the geometric mean which is better suited for length (CL; measured to the nearest 0,1 mm), constructing asymmetric confidence intenals for crusher claw position, missing claws, and molt log normal data (Snedecor and Cochran 1067). stage (Aiken 1973). The maximum outside width Annuai rometric mean CPUE's were calculated of the second abdominal segment of all females for the total catch of lobsters (all sizes of was measured (nearest 0.1 mm) and later used to lobster), Since 1984, the number of other estimate the size at which females become organisms (crubs, fish, etc.) caught in each pot sexually mature. Lobsters were tagged with a was counted to examine their potential influence serially numbered international orange sphyrion on lobster catch. The total CPUE values were tag (Searratt und Elson 1965; Scarratt 1970), and adjusted through covariance analpis for the effect released at the site of capture. Recaptured of competing species that significantly (p s 0.05) tagged lobsters, severely injured or newly molted affected lobster catches. (soft) lobsters, and those smaller than 55 mm CL The CPUE of legal size lobsters was expressed were released untagged after recording the abose as the 6 mean (Pennington 1983; NUSCO 1983) data, to compare the annual variation in legal CPUE. The annual abundance of lobsters in the The use of the 6 mean is a more appropriate MNPS area was described using catch per-unit- statistic for describing legal size lobster abundance effort (CPUE; i.e., the number of lobsters caught since a large number of zero observations are per pothaul). Because these CPUF values are present in the data (i.e., many pots often contain ratios, which are not additive and have an no legal sized lobsters), asymmetrie distribution (approximately log- Lobster larvae were sampled during the period normal) about the arithmetic mean, we computed of their occurrence in each year (May to August) 130 Monitoring Studies,1990

                              -                           -_      _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ - - _ _ _ = _ _ _ _ _ _ _ _                  _ _ - -            __- --

l l ulu i t coo h m.osoa 10: lAu n unht in we" P"a 00'" P O '" l'"" tout nunavr Nmiavr von ' lou ci ci . 957 tt t tral (Tl4

• 9' i C 1 tonstet uppta tuuled (pninictru rocan) (d "lun t 2 M o "'"'

f At o a kl s a 82 n _____ _ _- - - - - - - - - - - - ----- - ~~~~' 1978 IN28 IU2h I """ !N~I UI "I " ' pcy 3;s9 :ou i 404 I w I 511 013 " 101 " " ' ' " I"' " I b p,wi usu nn i no o w ' 1;;l " 109 0 0 '" " "" i i""2 - " 12" p,sg 23, ;is? o wl Ob W - 09'4 O!"' 0 0 (H '"" " "" ' " I I I g9si 9pn ahl 20% 193 20s9 o lni o l2n o loh 014 8 -- O l % p,sl o u,, 4:ss t ni 1250 tals oin oun o in t o id = o D^ p,q 73s7 auo i no? I540 1677 o 159 o 120 o lol " 14" " l '" pm3 gou 4 v.7 ty: 1P 1 4"" o I"5 " os" " "' d " ' "" ' " 1 2" p,sn 7;n a:43 1se i 501 tm o oso o ono o 0 49 " 07 4 - ("" 7 p,s , 7;w .en inu L562 t 707 0 079 ""'4 o 0 16 ""'"""'" 39 9; M7l 4%7 i 929 l Nih 2 0l5 " U79 " "5 "W U '" p,y, w,o aua i 7;9 1 645 1 817 o il: c ont o o31 tu"7 'ol2a pni ;mn a lso imi i ass . i um o ini o in o o76 o 141 -0 17"

      , Unn p;w               ao;nt              25o2:              1At              L "7     14"3    oiM " H '" " "' 5              " 12' ' " l'H IP:ui pm. "o            Elis               215m               16'7              1 64" ' L714    " ' "3     " " " " """         '""'~"I""

Titi%iTG,a sialiliniiMoJiiisisEWiiiii?IriThiXr~iss. and iisiiiiiiiiiQiisoner isEiliisiiGKiGi i ai emh suoon in.m ist,n nimwh oaoner vis m 1 ht nulumum Icpil site irom (978 to 14s'4 was si.o non ( 4 % no nunmum. Icpal suc was mirrased m 14x4 to Ni s nim ( ( # ,m) aba m P19o 10 N b nau (3 % in) at the discharges of Units 1 and 2. Samples were Results and Discussioil collected with a 1.0 x 6.0 :n conical plankton net of 1.0 nun mesh. The volume of cooling water Abu0da0ce a0d (L'atch per-U0it-Effort sampled was estimated from the average readings of four General Oceanic flowmeters located in in F%),7,Hki lobsters were caught. Wii was the mouth of the net; about dutio m of cooh,ng the lowest number of lobsters caught during 3-water were filtered in cuch sample by deploying unit operadon (7.21l-8,871; Table 1). This lower the nel for 45-60 minutes depending on Unit cmch was also reflected in the catch.per unit-110w. Day and night samples were collected four cUort (CPUE) for all si/cs of lobsters, 1.531 dys a week to exandne diet variability. Each during 1940, which was below the range of values sample was placed in a 1.0 mm mesh siese and tcported in other 3 unit studies (1.5S5 1.929). kept in tanh supplied with a continuous flow of The total number of lobslers caught and mean seaw a ter. Within 24 hr of collection, samples CPUE in FM)were, howeser, within the range of were sorted in a while enamel pan, larvae were values reponed during 2 unit studies (19S2 55) esamined for mosement and classihed a lise or when 20 wire pots were used at each station dead. tobster lanac were also classified into 4 (6,37tn9,109; 1,3312.006). The mean CPUE for stages according to the criteria established by Ell s /cs of lobsten caught during combined 3-lierrick (1911). The density of lobster larvae in unit studies (1.677) was higher than the combined entrainment samples was standardized as the abundance of larvae sampled per unitrolume' 2-unit value (1.364). The minimum legal size from 1978 to 1988 was Annual larval density estimates were based on the SLO mm (3 '/o, in); in 1969 the minimum le}'al mean of the assumed Delta distobution s /c was increased to St.S mm (3 % in), and in (Pennington 19S3; NUSCO 198S). To estimate the total number of larvae entrained, the 6-mean FM) to S2A nun (3 'h inh The 6dnean CPUE gy g,al sized lobsters (a S2.6 mm) was 0.076 in density was scaled by the total volume of water UM)I This CPUE was hieher than the 6 mean pumped through the plants during the sampling ' period. legal CPUE during 1989 (0 065) when the legal s /c was 81.8 mm, but lower than the range of { lubster 131

...mmum-valuck reported in other 3 unit and 2 unit studies ,,, _, when the legal si/c was 81.0 mm (0.079-026; ,w NW n, O W 8-0.173, respectively) (Table 1). The in mA regulation to increase the minimum legal site { **  ; , n, f appears to have been effecthe during the first two 1 ' -) 1 /}Y1 o w "t

    )carb of implementation as evidenced by the                                  {[                                        xf 'j-h                       cn inercase in legal CPUE values for lobsters a 81.0                            g,,                                                                    wg mm (the old legal si/c), from 0.079 in 1987 and                             b , ,,                             \<                          .!       e 's y
                                                                                                          *[i*l,I*l 19x8 to 0.112 in 19x9 and 0.161 in 19'K). The                              i ew                                                       l           toi trend of inercased legal catches in the past two                            Y ns          o                 .
                                                                                                                                              .          *[

3 ears was aho apparent in the legal CPUE values '* m, 7, ppggggr7qr;;# for lobsters a 81.8 and a 82.6 mm, 0.052 and 0.0-87 in 1988 compared to 0.065 and 0.053 l's 19x9 and 0.102 and 0.076 in IVA). Ilowever, values for mean legal CPUE (lobsters a 81.0, d ,,,,_ __m 81.8 and a 82.6 mm) during combined 3. unit **t

                                                                                        ,w                                                               m studies were lower (0.103, 0.066, 0.054) when                                    m                                                                 n,. s.

compared to 2 unit studies (0.134, 0.10ll,0.085). l 2* , ,s y The fact that legal CPUE increased from 1989 to 1 ' q ) -. ~ IVA) concomitant with the increase in minimum {'] g [ k, ew ( in legal st/c is unusual; typically, , shen minimum legal si/c limits are rahed, a lower number of j,, e . .. ,

                                                                                                                  ;j 1
                                                                                                                           \[]\I                   l      u i.

on 7 c 'c tegal4ited lobsters are available for capture. The 1 7*] V. g. ! +; -1

                                                                                   ,5 e w                      n j                                             ;

increase in legal CPUE from 1989 to IVA) was S o$ .'l* . ** '

• u probably due to recruitment of a large sublegal- - 7, ;g g ,, ,, ggggryggp si/c class observed in 1988. The increawd abundance of legalaited lobsters obsersed in the 1990 catch was also evident in the commercial landings, which increased from 2.7 million pounds ,,, ,

in 1989 to 3.5 million pounds in IVM). Similarly, ,w '" "4r n, a strong recruit class in 1982 was followed by 7. n n 5,

                                                                                                                                   /N i /                  .a j higher commercial landings in 1983 and 1984 (NUSCO 1987).

i am L "' , j\j .= y The trends observed in mean total CPUE and on n x'.

                                                                                                     '\

mean legal CPUE from 1978 to IVAl were aho evident al cach station. The geometric mean {E. "",, j ,

                                                                                                       ,\

s on R o is 7 total CPUE during 1990 was highest at Jordan S'ono w " b'If *{ ,.o 'c i Cove (1.781), followed by Twotree (1.627) and ** i Intake (1.234, Fig. 2). The 199i) total CPUE at * - ,, r, ,, ,, g, gg, ,, og , , ,, ,, a

• Jordan Cose was within the range of other 3. unit studies (1.4621.901); however, the mean values at Twottee and intake during IVA) were the lowest values reported in 3 unit study years (1.833-2.144 I41 Mcan toul WUli tscomcme mean 2 vn c.l.) and and 1.3601.771, respectively). The IVX) mean mean imi cm (ancan 2 vm c.1) for LAen, t 81 u total CPUE at each station was within the range of previous 2 unit studies (Jordan Cove 0.753-l"[i f,8M,"[, "[$"" [ " * **"""

1.821; Twotrec 0.988 2.430; Intake 0.839 l.869). at the nearshore Jordan Cove and intake stations. The 6-mean CPUE of legal sized (t 82.6 mm) The 6 mean legal CPUE (a 82.6 mm) at each lobsters was highest at Twotree during 19A) station was lower during 3 unit studies (Jordan (0.108) followed by Jordan Cove (0.077) and Cove 0.047, intake 0.041, Twotrec 0.075) when intake (0.044; Fig. 2). Since the study began, compared to 2-unit studies (Jordan Cove 0.063, legal CPUE was generally higher at Twottee than intake 0,059, Twotree 0.133). However, legal 132 Monitoring Studies,1990

1 Ani i 2. Momuy taub uanuu lor lonsim oupi n emb st.uion dunng om Nomber or lohil . umber Anthmcot AJ JuucJ 'I otal it pk Iopl Momb put hauled uppl.t inran CI'UI . mean CPUl " t a u g h t' ( Tl'l . Loyp sN con Mw 22n 44o 2m ie. ay 0 07 to i n JllN .'r d i $% 2 29 21(45) o ns in 17 ) Jul. 2 iu 502 2m 27 ( N o il (o u,i Allo 279 $47 1 94 21(%) 00%(U20) si P 219 313 1 42 4 ( 4. ; 0 n4 to 15) Oct 2w 299 i 2< 17 923 n o? in in IN] AKI MAY 220 132 1 $i 1.59 7 Go) ooL to mi JtlN 2no 40? I 37 1 64 11 GI) e on Hiny

.it !]                    240                       11%               1 19                       ] 67                            14 ( 10 )                          O 07 (O 16)

AUG 2%0 472 1 64 132 19 (ll) 011' (D 16 ) M.P 21$ 235 1 07 Uh4 4 (th) 002 0107) 0C1 240 l69 0 70 0 hs 4 (l 4) O 42 01 ON l Wf i l'l(l l-MAY 220 375 1 70 th 1 6 ( 41) 0 0% (o 14) Jt!N 2no 5%9 2 14 2 14 35 pio) o14(024 IUI. 243 514 2 14 2.12 49 (7#,) 0 20 to 32)

   %lJO                    2't0                      412               1 47                       1 43                            2k(hl)                             U 10 (U 2 4)
  $l:P                     22u                       3nl               1.37                       1J5                              12 (Th                            0 00 g o 15 )

OCl 219 300 lA lA 14(W 0 00 (o loi d CPill. valun at intake adjuurd (or the takh of spider crabs and at 'lwottre ror the cakha of whells, rmL and Jonah uabs limimum lept Mir for 1990 was 82 h mm. (3 /, m). put'nthetical solum f tpresent lepi t'akhn lor the old lept wt of Al O mm, (3 '/g in). CPUB values at each station have increased oser IVM), spider crab catches significantly innuenced the past two years due, in part, to increasing the lobster catch at Intake, where 9,462 of the i1,228 minimum legal .si/c and to recruitment of the crabs were caught. Similar results at this station 1988 sublegal size class. were observed in all other study ) cars but 1985 The monthly pattern of lobster abundance (Table 3). Rock crab, jonah crab, and whelk during '9'K) was similar to that obsened in catches during 10(X) had a significant innuence on previous studies. The CPUE during 19(X) was lobster catch at Twottee, similar to results in greatest in June at Jordan Cove and Twottee previous studies (19S5,1986,1987,1989). None (2.29 and 2.15, respectively), and in August at of the incidental species caught at Jordan Cove intake (1.69, Table 2). Legal CPUE peaked in during lWl) affected lobster catches at that July at all s'ations, following the spring molt. station. As a result, the monthly mean CPUE The seasonal variation of lobster catches is salues at intake and Twottee were adjusted for related to the seasonal increase in water the incidental catches that significantly affected temperature; as water temperatures rise above lobster CPUE using covariance analysis (Table 2). ItrC during June and July, lobster activity (e.g., Other rescatchers also found that the incidental feeding and movernent) increases causing catches catches of rock etabs and spider crabs had a to increase (McLeese and Wilder 1958; Dow significant effect on lobster catch in their studies 1966, 1%9, 1976; Flowers and Saila 1972; (Richards et al.1983; Richards and Cobb 1987). NUSCO 19'A)). Soaktime did not have a significant influence The total catches of incidental species from on lobster catch in IW() at any of the three 1984 to IVA) are presented in Table 3. During stations (Fig. 3). A two day soak yielded 1.5S Lobster 133

TAntt 3 Total numte of not.im and incatenini cauh ot omr yuus 6npa in naps in m ivs4 ini , iwa iu s i vst, i%7 t yw p,w in, i a ic, Tsu 70i4 72it 7250 w?: 7mo 7 pin

                                                                                                        ]Og                   79                      4A p                  g4 p Ibs b .lotudl (Inh         46%                )T7          l $ 61 3247'                         1344*              17349              72we                        t,9 N              l l 2;.,

• spidtt tra,b 1930 lleil.iH (tah 42% 4%8 43% 7;te  ?!) 3 <ai 4to 4- at og luurtrah 40 2i 28 71 U lhlrr nitUhdtt 4s 40' 19' 'd 2x k 13 sunamt nonnat e.o 24' 3e t 2s 4 n, sbM ls 17 U 4 lh '4 i 40 (lptor toattlah 7h 67 $4 14 34 pi In N bp 27 90 2M l e,9 47 8l ;e

( ~vtihet 141 207 Wor, i t,7 lN1 h? 7) l autog 39 230 19n 20% 48 kJ 30 sC,4 flh tti 20 l9 is 2 0 2 4 ww e,n ?c p .e im 27 ui 40

                                                                                                                               ~ ~ ~ ~ ~                       ~ ' ^ ~

t') ihne oat hes urniin ahu) atletird luiwtrt ( PUl. (p<005)

                                       -                                                                (Table 4). The percentage of legal 41/ed lobster 3

la 82.6 mm) of 4.5'i during IM)was higher than i the 1989 value of 3.59 when the legal site was a iW 81.8 mm and higher than the range of other 3-n i. un!t values (3.2-4 49) when the legal si/e was a iy , , 81.0 mm (Tabic 4). llowever, percentage of legal

                                . i.!                                                      -!        site catch during 1941 was lower than the 2 unit i\
                                      '-}                                                       )        values when the legal st/c was M 810 mm, which 4                                                        !       ranged between 5.9'4 and 9,l'4, The smaller st/c aj                                                           ,

of lobsters collected during 3. unit operation

                                       'd        ,
                                                                      .                                   relative to 2 unit studies was tc0ceted in the
                                                            . , . , $m,                                   percenture of legals (P 81.0, a 81.8, a 82.6) caught during the two operating conditions (4.7 ng 3 Mean tauh ot lotsitti tot a 2, 3, 4. 5, and e da)                    vs 7.5'4, 3J vs. 6.39, 3.1 vs 5.39 ).

Miaktmit dunng 1Y90. (, -) rtptnents a 9% Cl. Carapace length statistics for lobsters caught at lobsterUpot compared to 1.70 for 3 days of each station from 1978 to IVA) are presented in soaktime, tal for 4 days,1.68 for 5 etap and 135 Table 5. Lobsters at Twottee continue to be for 6 days. These results contradict our findings larger thah those at the nearshore Jordan Cove of previous study years (NUSCO l*A1) and the and intake stations. The mean CL was 71] mm results of Thomas (1973) who reported that at 'Twottee during 19%), which was the highest varying the amount of time between pothauls had value icported during 3 unit operation (70.0 71.0 a significant effect on lobster catch. mm) and within the range of values reported in 2 unit studies (713 733 mm). At Jordan Cove Popuhttion Characteristics the mean CL of lobsters during 1990 (69.4 Intn) was within the range of other 3. unit studies (69.2-O. nuu) but smal er than the runge of mean Size Fmfuciky CL's reported in 2 unit studies (69.8 71.1 mm). The mean CL of lobsters caught at intake during During luA), the mean CL of lobsters was 70.2 1990 @9A mm) was within the ranpc of both 3-mm and within the range of other 3 unit studies unit (64.0-70.2 mm) and 2 unit studies (69.2 71.8 (69.5 70.2 mm). The overall mean CL was nim). The average sites of lobsters collected at smaller during 3 unh opera' ion (70.0 mm) than 2- each station during 3 unit operation were smaller unit operation (71.3; range 70.8 71.8 mm) Oordan Cove 693, Intake 69.4, Twotree 70.6 mm) 134 Monitoring Studies, IVA)

I Anti a summary a mier cutanut troph aena for wuc no catchen imm h% through maer 1978 im Y cmnho icoph tmno ren ent Itangr htcan tusq cl legad t ht 0 r 5t h e A2 h pcx nas ST iii 714 10 n 73 59 4x 1979 2% l6 44 100 71/ 1 026 7h hh 5l lVs0 2% ll 40 w, 70.7 1 027 h4 $0 4l 19%l j9%) 4s 96 710 1 03% M.N ih hh 1982 7M i$ 4 L t01 70 H 1 0 t $ 47 $7 47 19s% $112 40 121 717 2 019 91 7.4 h3 1%4 6156 4% 107 71.N 2 0 lh ki 74 64 1983 3723 N'- 101 71.3 1 017 5.9 51 41 low, Swil 36 107 o i s U 17 44 3h 40 l9s7 $924 3ht rl 702 1 017 39 32 27 19e 7145 21 97 69.$ :t U lh 32 'h /3 19k9 671$ 34 lU7 699 1 017 4.4 Is 29 pro e,0 40  % 102 702 1 020 7M %9 45 2 tinn poss$ uOi4 w 121 71.3 2 007 u h3 3a 3 tinn 1996 90 3i7Hi 21 107 700 1 004 47 37 ll

• IMapturen nol Ou hided
• ~lhe nummum legal ute Itom 197M to 19% we HI O nmi 13 '/g in). minimum legal nier we inuraud in 1949 to 81.h mm (l '6 m), and m 1990 to 82 h mm (38 /, in) than averages during 2-unit studies (Jordan Cove of legah (2 81.0 mm Cl.) in 1983 (9.ld ) and 70 6, intake 70.7, Twottee 72.3 mm). The 198-8 (8.7%). This increase was also evident in percentages of legal.si/cd lobsters (2 82.6 mm) commercial catches; increased landings were caught at Jordan Cove (4.0'1 ) und Twottee reported for Lis in 1983 (2.4 million pounds) and (6.1%) during 1990 were higher than 19d9 values 1984 (2.8 million pounds) (CTDl!P Marine when the legal site was 81.8 mm (3.0 and 4.2';;, Fisher) Statistics). landings for 1989 (2.7 milhon respectively) and higher than other 3 unit studies pounds) and 1990 (3.5 inillion pounds) were the when the legal si/e was 81.0 mm (3.3 3.79 and highest reported for LIS, reflecting both the 3.5 5.3% respectively). At Intake, 3.1% of the strong iceruit class obsersed during 1988 and the catch was legal si/c (2 82.6 mm) during 1990, increased yield of lobsters due to raising the compared to 3.0'4 legal si/c (2 81.8 mm) in 1989 minimum legal stie, and between 2.9 and 4.79 legal si/c in other 3-unit studies when the legal si/c was 81.0 mm. Sex Ratios Although the proportion of legal si/cd lobsters (2 81.0, a 81.8, a 82.6 mm) was lower at each The sex ratio of lobsters during 1980 was 0.71 station for combined 3 unit data compared to female per male, which was the lowest value combined 2 unit data, percent legal st/c has reported in our studie3 since 1978 (range 0.79-increased during the past two years despite the 0.97) (Table 6). Twotree catches contained more increases in minimum legal site. The trend of females (0.90 female / male) when compared to lower percentage of legal-sized lobsters observed intake (0.65) and Jordan Cove (0.60). The beginning in 1986 appears to be reversing, despite pattern in sex ratios at the three stations was the increases in minimum legal si/e from 81.0 consistent from 1978 to 1989, when Twotree had mm in 1988, to 81.8 mm and 82.6 mm in 1989 more females than male lobsters and intake and and 1990. The increased proportion of legah in Jordan Cove had more males than females. This the 1989 and 1990 catches may instead be due to pattern has reversed at Twottee; the 1990 value a strong recruit class observed during 1988 of 0.90 represents the lowest female / male sex (NUSCO 1989), Similarly high catches observed ratio at this station since the study began (Keser in 1982 were followed by increased percentages Lobster 135

l' Alt! 1: 4 4, mmari el l<itv.trr targue lereth shilotwt for wirr 9 4 tot ( ta s (tom Mw Ibniur_h (iciober 19?m 14aii JOROAN N* Carapue kngtli immi Pertent COYl'. Range Mean 2 95'"e Cl lepl/ r x10 1 x1 k z x 2 t. 1974 449 34 ill 70 3 2 0 $4 39 3s 27 1979 lih 4o 'k' 707 2 039 67 $.7 42 1941 831 40 93 702 2 045 4x 33 23 19M1 $$6 43 93 70 h 2 0 64 72 67 59 19<2 2324 49 Ami 698 2 026 47 40 g2 19a'3 l'm3 40-](kl 71O 2 032 x2 4, 3 33 1944 IW) 52 107 70 7 2 029 37 44 40 1945 1722 44 96 711 1 OJ2 39 50 4l 1u%6 1744 .h 99 69 k 1031 1$ 2 s. 21 1947 1n90 44 95 70 2 t 0 32 37 30 24 1%M 2249 21 97 692 2 029 33 27 23 1989 2077 A98 r,9 A -. 030 40 30 2o IWO y h44 v,9 4 + o 11 0 49 1o 2 linit 197% M3 1102) 40 lil 706 2 O13 60 49 ai T-il ni i 19%#,3As 9%e 2 21 99 697 3 014 43 3g ;7

    ~~~

INI AKl-1978 645 55-110 718 2 050 92 o7 (7 1979 10M7 $0100 114 2 041 7n eo g4 19%U M53 40 95 ?on 10 4% so 43 3o 1941 6%6 419% 69.2 1 0$3 44 34 29 IH2 2 4162 51 10T 702 i O 27 $ _O 4I 32 1981 1434 52 110 712 2 037 63 $$ 49 19%4 1840 4310$ 70.5 2 032 6. l 49 42 1995 1215 44379 71.2 1 037 36 49 aj 19%6 I N% $0107 69 3 0 31 43 36 30 1987 Ito? 47.94 70.2 1 032 47 33 30 19%N 2253 39 95 692 1 027 29 2O 1.g 1989 2005 39 98 690 2 032 a0 30 ;4 l'N 1721 bl02 e,9 4 3 0 % 61 44 3y 2 Umt 1978 NS 10156 43 110 707 1 0.13 60 49 4.2 3 Unit 19%h AA0 9834 3o 107 ny 4 1 0.14 43 32 26 TWol14l F 1978 374 53-94 72.2 1 067 94 7s 39 1979 n21 44 94 7 g .g , 0.3 g 9.0 gj gg 19%0 k45 403)u 71.3

• O 49 M.M 7.1 60 1983 741 4M 96 730 2 0.54 14.2 12.2 10 4 1982 3110 45 102 72 0 t 0 25 94 8l 1,0 1983 2031 43-121 72.8 2 032 11,8 97 g. )

1984 2327 $0105 73.7 1 029 1,34 11j 10.3 1985 2786 M101 71.510.25 c.1 32 44 19 6 2325 36 97 710 1 0.27 3,3 44 3o 1987 2547 A 99 702 1 0.27 3.6 31 26 1958 2^33 A95 70.0 s 0.27 3.3 3.0 2.x 1989 2h33 M 107 706 2 0.28 34 4.2 34 l

• 80 2211 19-102 71 7 ? 0 11 10 0 79 g, i 2 Umt 1978 85 12835 38 ,21 72 31 O g2 gou g3 7,3 3llmt 19shA)0 12369 34 107 706 1 0.13 $.4 44 36
• l(ecaptures not includest.
• The mmimum ici;al sue from 1978 to 19s8 was 81.0 mm (33 '/ in) mimmum lept we was mercawd in 1989 to kl,8 mm (3 '/n in), and in 1990 to 82 h inm (3 '4 in) 136 Monitoring Studies, IW1

Tant.t! 6. l'cmale to male ses rathu" or loistern caught in /g7;Qpfjpg wire pits from May through October, 1978-19'80. The site at which females become sexually Jordan intalc 't wott ee All mature can be determined by compaling the owe station' atxtominal widtti to carapace length tatio oser the site range of lobsters caught (Templeman 1935). 1978 o.79 0 97 to2 0.92 Mean ratios of abdominal width to carapace 1979 om o 83 Lis 0 82 length were computed for each 5 mm CL Increment and plotted against the carapace length

    !N         $7          I71           i.

of female lobsters collected during 2. unit (It>81-19s2 0 62 o m> ler 0 79 19x3 0.72 0 67 125 0 87 85) and 3 unit (1986sA)) operation and during 19s4 0 60 0.71 122 0 82 1990 (Fig. 4). The site at which females begah to sexually mature was similar during 2. and 3 unit

        ,                   I7           1]                operation; females began to mature between 50 19s7        0.71        0 63         1.24      on 19 %        ou          o 72         Lis       o ss    and 55 mm and nearly all were mature at 95 mm.

1949 9 64 0 63 im o.79 1990 0 60 0.65 o.40 0.7)

                                                                                                                          , , i mn,          .an 2llmt*       0 67        0 72          1.21     0.86        f(>                                        4 i                              '

5" 3 Umt' o.65 0 68 1.12 o N2 J y ,,n..,w~,,, . , " Recaptures not included. a , ,

• 2-Und operation (1978 83).

' 3-Umt operaoon (14C8ot 6% m-

                                                               =
                                                                          . j*'f                                                                 ,

et al.1983), The female to male ses ratio for t.'l im j stations during combined 3 unit studies was 0.82 ( compared to 0.86 female / male in combined 2 unit " n- - ; - ;7-- , g-  ; , f studies. Similarly, the catches at each station c % w.m .. contained fewer females during 3. unit opration (Jordan Cove 0.65, intake 0.68, Twottee 1.12) l'is. 4. Morphomeine rtiaiionsh.g tviween ihe ahiommai compared to 2 unit operation (Jordan Cove 0.67, width to ca.upace length ratio an,d the carapace length ror intake 0.72, Twotree 1.21). Other researchers un 1 working in different areas of LIS have reported sex ratios of lobsters caught in the commercial De smallest berried females (females carrying fishery ranging between 1.06 and 1.81 female / male eggs externally) collected during 2 unit and 3 unit (Smith 1977). Females greatly outnumbered studies were 62 mm; these individuals were males in castern LIS commercial trap catches; between 50 and 55 mm when oviposition occurred 2.61 to 6.29 female / male (Blake 1988). The assuming 14% growth per molt and thus confirm predominance of females in the commercial the morphometric ietationship between atxiominal fishery could be attributed to variation in female width and carapace length. Briggs and Mushacke lobster behavior related to molting and (1979) reported similar results in western LIS reproduction, fishery regulations designed to where females became sexually mature at a small protect egg bearing females, and the fact that size (60-65) and most are mature at between 80 mature females molt less frequently than males and 95 mm CL; similar results in western LIS (Ennis 1980), Other researchers have reported were recently obtained by Oraulich (1990). In sex ratios close to 1:1 for most of the nearshore contrast to the LIS population, females in the lobster populations (llerrick 1911: Templeman Gulf of Maine begin to mature at larger sites 1936; Ennis 1971,1974; Stewart 1972; Krouse (about 80 mm CL; Krouse 1973). In the Bay of 1973; Thomas 1973; Cooper et al.1975). Fundy and in offshore waters (Georges Bank), female size at sexual maturity is largest; half of the females are mature between 110 and 120 mm CL and the smallest berried females are about 90 Lobster 137 ,

TAHl.li 7. Percentage of bertied females caught at each stanen and annual carapace length statisucs from 1978 90.

                                                                                                                                                                                                                                   ~
                                                                          - Penent berned femme All         Jordan      intake                                  Twotree  N*               Carapace t.cngth (mm)                                 Perecnt stanona          Cme                                                                     RanFe           Mean 195% C.I.                            subiegal'
                                                                                                                                                                                                    < 810 ( kl .8 < 82.6 1978           34            1.4         2.6                                      5.1   58         7J - 88                         80.1 1 I A4             73    78           78 1979           31            ! .9        2.7                                      1.2   70         64 93                           80.511.28               59    64           70 1980           3.3           3.5         18                                       5.6   71         66 93                           79.l i 1.27             70    73           79 1981           42            1.6         27                                       7.1   82         69 4 97                         81.011.35              55     59           62 1982         - 3.1           UA          09                                      6,1   los         64 99                           N0 0 t 1.08            u)     tai          70 1981           4.7           0, t -      3.2                                     8.5   123        bi,     103                     80.5 t 1 At             63     65           67 19s4           6.2           36          3.5                                     10.6  173         62 95                           79.! 1 087            69      75           76 1985          6?             3.5 -       4.5                                     8.5   171         63 94                           77.0 1 081            82      85           br, 19 %           4.8           30          0.3                                     80    135         65 94                           789 2 095              '17    80           83 1987           5.7           3.2         1.9 -                                   9.6   158         62 90                           76.5

• 0 67 92 92 93 1948 38 24.

t9 64 124 63 W 76.9 2 082 89 90 90 1989- 6.4 2.8 3.3 8.2 161 65 98 77.3 t 0.78 82 85 8a 1990 66 2 40 11.2 165 65 102 78.1 2 082 75 81 87 2 thut 78-85 43 2,0 2.2 7.1 854 62 103 794 1 0,39 6N 72 74 3 timt 86-W ' 5.2 2.7 26 82 743 62 - 102 77.420,36 83 86 ci8

                                               " Rrcaptures not 'ncluded,
                                               * 'the mmimum 1 gal site from 1978 to 19s8 was 8I.0 mm (a '/g in), nunimum legal sue was increr.ed in 19S9 to kl.8 mm (3I /u
                                              .in), and in 1990 to 82.4 mm (3# /, in).

mm CL VadMion in the female size at sexual studies (1.9 3.3%), but within the range of 2 unit l maturity over the geographic range of lobsters has study results (0.945%). The percentage of been attributed to water temperature; the higher herried females at Jordan Cove during 1990 summer water temperatures of LIS, relative to the (2.7%) was within the range of 3. unit (2.4 3.2%)

                                          . Oulf of Maine and the thiy of Fundy, favors early                                                     and 2. unit studies (0.8-3.6%). Derried females niaturity of female lobsten. (Smith 197,; Aiken                                                    were more -abundant during 3 unit operation arvi Waddy 1980). The sexual maturity of males                                                     (5.2%) than 2 unit studies (4.3%); similarly, the has been well ' documented and therefore r.ot .                                                    proportions at each station were higher during 3 invesdgated in our studies. Male lobsters us
                                                                                                                                                 - unit studies. The mean si'.c of berried females

small as 40 45 mm CL were found 10 be mature during 1990- was 78.1 mm whkh was slightly (i.e., produce mature spermatozoa) in; coastal larger than the ran;.' of val,ues in other years of l waters of LIS:(Briggs and Mushacke 1979)'and 3-unit operation (76.5J&G mm), but within the Maine - .(Krouse! - 1973), although Templeman range of values reported during.2 unit operation-

                                            .-(1935) questioned whether these small males are                                                     (77.0 81.2 mm). The percentage of sublegal sized capable - ' of successfully mating with and                                                        berried females (< 82.6 mm) was 87% during inseminating mature females.                                                   .                  '1990 compared to 85% in .1989 when the legal The percentage of berried femalea caught                                                       size was 8'.8 mm and to 77 92% in other 3. unit during 1990 (6.6 % ) was greater t!'an values                                                       study years when the legal size was 81.0 mm.
                                           . previously reported (2 unit range 3.16.2W; 3 unit                                                    The proportion of sublegal sized (< 81.0, < 81.8, range 3.8-6.4%; Table 7).                     Twotrec . catches                                    < 82.6 mm) berried females eaught during 3 unit continued to contain u higher proportior of .                                                      studMs was higher (83,86,88%) when compared berried fer.iales compared to intake and Jordan                                                    to 2 unit studies' (65, 72J 74%). The higher Cove, a trend consistent since the study began,                                                     proportion of sublegal. sized berried females The percentage of berried females collects d at                                                     collected during 3 unit studies is a reflection of Twotree during 1990 (11.2 % ) was the hyhest                                                        the high levels of fishing pressure in recent years;                                                            .

value reported since the study began (rany S.3 most females are removed by fishing shortly after 10.6%); at intake, the 1990 percentage (4.0%) reaching legal size. C<mtinued maintenance of was greater than valum reported in other 3 unit the lobster resource is highly dependent on the

                                               .138        Mrmitoring Studies, IWO

percentage of berried females; the increased bottom water temperatures were the warmest percentages obse ved in our catches during the (10.2 C) and conversely, the latest molting peaks past .two years is important and is most likely (29 June 1981 and 1982,30 June 1984) occurred related to the increases in legal size m 1989 and when May bottom water temperatures were the 19(XL The fishery objective of increasing the legal coldest (9.0, 8.7, 8.9 "C, respectively). No size was to allow a larger proportion of females significant differences were found in the timing of to spawn before reaching legal size, thereby molts for pooled 2 unit and 3 unit operation increasing larval production and subsequent bsed on the examination of the shape (s) ind recruitment, kication ( ) parameters of the Gompert/ growth curves in Figure 6. Aiken (1980) fo'md that in Mohing and Gmwth

                                                                                                                                                                      ,y                 _                                           _

Lobsters in near-molt condition were observed .*# throughout the 1990 study period (May October) $" oM% ,- I I and comprised 3.3% of the total catch, compared $" M5 i s" to the 2.13.2% observed in other tunit studies e and 2.5 6.4% in 2 unit studies. The mlationship i ** 4A between water temperature and inolling was y* ,

• C5 examined to compare the timing of annual molts 5 " ..

                                                                                        - during 2 unit and 3 unit operations.                             The      [*            c                                                    hi
                                                                                                                                                                                                                                       "^         !

Gompertz growth . function was fitted to d* f l cumulative percent molt data and the inflection O g 77m y , point of the growth curve (in p/x) was used as an we estimate of the date of peak molting. The annual l Fig, 6. Gomperta growth runction fitted to cumulathe

l. mean bottom water temperature during May was percentage data for molting lobsters caught during Lunit significantly (p < 0.05) correlated with the dates uudies (.--) lunu uudies (. > ano dunng two (o) of pak molting (Fig. 5). In years when May water temperatures were warmer than average, addition to temperature, molting and growth were molting peaks occurred earlier; molting peaks affected by a combination of several other factors occurred later in the season when May water including light, nutrition, social behavior, habitat,

                                                                                        - temperatures were colder.than average. ' Bottom                        season of year, injury and regeneration, weler temperatures during May 1990 averaged                         . reproductive development and genetic potential.

l 9.9"C and the peak catch of lobsters in near molt Of all these factors, temperature and nutrition

                                                                                      - condition occurred on 21 June; the earliest                              had the most influence on molting and growth.

molting peak (l$ June 1986) occurred when May Our results indicate that molting was delayed one to two weeks for each I"C of lower water

                                                                                                         .m,                          _ . . - - -

temperature; similar findings were reported in the l N '* Canadian Maritimes by Templeman (1936). ]

                                                                                                          ~

m. NM .w Growth per molt was determined for lobsters N

Ci?" a that molted between the ' time of tagging and j** 'N, "* recapture. Para, deters for lobster growth were -

                                                                                             ; ,,                                     ,                         estimated using simple linear regressions of 3
                                                                                                                                            ,   ,_            carapace lengths at. tagging (pre mott size) and i=                               *
                                                                                                                                         .                       recapture (post moh size). This method was 9

s useful for describing growth per molt for the size f"" '~

                                                                                                                                                     ' w.,      range of lobsters recaptured in our studies (55 -
                                                                                                                                                       'N 85 mm CL) and has been used by other
                                                                                                           ~6             e         o             e'        s   researchers to determine crustacean growth (Wilder i153; Kurata 1%2; Mauchline ' 1976).
                                                                                       ' Fig. 5.1,incar relationship between the date or peak moltig            Growth rer molt was calculated separately for On #< estimaied from Gompene gnmih runctionp H annust mean tonom water temperature during May.

males a'id females caught during 2. unit (1979 85),3+ nit (1986 89) and 1990 studies (Fig. 7). Lobster 139.

                         .                     --              . - . ~ ~ . .                , ~ ~ - - +                           -.               .           . . - - - -                ~ . .         - --

e . 100 100, MALCS r[MALCS #

i. /

                                                                  ,/

90 ' v 904

               .                              0,0 0 0 h                                                                                    ,

g

                                                     /
                                                    ,8                                                  fy       ~

pg

                                                                                                                                $8
                              /'o o            ,

70- 70 y /' . l ,l' 40 40 6 M'. . . . . . M'. . . . . . 60 40 70 to to 100 40 to 70 80 to 600 CARAPACC L[NGTH AT 1AGGING (MM) CARAPACC ([NGTH At TAGG!HG (MM) MIM ii M alm J N GrowIh t N Grmth r2

                               . _ _ ~ . -                                        . - - -                                                                                        ._

2-tInH 379 y = 22.lt M & O H03(x) 0 70 2 tJnit 580 y = 12.c 7M + 0.942(x ) 0.79 3 tindt 107 y a ltE.HM O H90(x) 0.7M 3 l}nd $27 yu l4 $43-t 0.914(x) 0,74 1990 102 y a l4.8974 0 8M(s) 0.73 .1990 - 98 y a l3 6124 0 937(x) 0 09 y msue at .ccitpture, A ast/c at lagging (mm).

     . Fig. 7. Im <ar seiermions and rurameter naimates for cara[wce lengths at lagging und recapture timo for male and reinale kiNten caught during 2 und studies (197t45, --). 3-unu studies (198o 89,                                   .), and during 1990 (O).

Ilesults indicate that lobster growth per molt was growth per molt for males and 12.5% for females, comparable 'during 2 unit and 3 unit operation. Growth. per molt of the LIS population is incremental growth for all lobsters averaged 9.4 considerably slower when compared to the mm (14.4%) during 1990, which was within the offshore lobster population (males 18.74; females range of other 3. unit- studies (8.4 9.4 mm) but 16.7%)- (Cooper and Uzmann 1980). The slower

     = slightly higher than growth during 2 unit studies                                                  growth per moll of the LIS population has been .

(8.3 9.3 mm; Table 8). On the average, female 3 attributed to lobster inactivity during months grew more per moll (9.6 mm) than males (9.3 when LIS water temperatures are below 8*C, The mm) during 1990; females aho grew faster than in faster growing offshore lobiter population

      . previous study years (2 unit range =7.9 9.4 mm; 3-                                                migrates seasonally to maintain a more optimal unit range =8.5 9.3 mm). Growth increments for temperature regime of between 8 and 14"C all . lobsters .were. slightly larger during 3 unit                                                (Cooper and U/mann 1971; Uzmann et al.1977),

studies (9.0 mm) than ir 2 unit studies (8.8 mm).  ; The growth per moll of 1obsters in our area was Cu/h similar to lobster geowth in other castern LIS studies, where male growth averaged from 13.4 to The percentage of culls,' lobsters missing one 15.8% and female growth from 13.8 to 15.4% or both claws, was 11.9% during 1990, which was

      '(Stewart 1972; Illake 1988).. In western LIS.                                                     within the range of both 3.unk (10.312.29) und Ilriggs and Mushacke (1984) reported 14.5%                                                        2 unit studies (10.615.5%; Tuble 9). Claw loss 140          Monitoring Studies, -:')90
                                                                                                                                                                                                             -s
                                                                                                                 ,,i-.                                                          , . . , - .     . . , .

l TAllt.!! E Summary of lotster growth (in mm and as a percentgae) for wire ptu catches from May through October 1979 to 1"90 All I ch.lers Females M Mes G n ath Growth Gr mth N (mm) Percent N (mm) Percent N (mm) Percent 1979 76 8.8 12.8 49 9.3 13.7 27 7.8 11.2 1980 92 9.2 13.4 61 9,1 13.3 31 93 - 13.5 1981 93 9.2 13.7 48 94 14 0 45 9.0 13.3 1982 199 8.7 12.9 127 K7 12.8 72 M.M 13 0 1983 134 93 14.1 78 9. t 136 56 9.7 14 9 1984 208 R7 13.1 117 h.7 13.1 91 87 13 2 1985 lb5 8.3 12.4 107 7.9 11.9 5M 90 13 4 1986 169 8.5 12.9 123 8.5 13 0 46 8.4 12 4 1987 179 84 12.7 98 KM 13,3 81 80 11.5 198H 255 9.2 14.1 163 90 13.9 92 9.5 14.5 1989 233 9.4 143 144 93 14 3 89 9.5 14 2 1990 202 9. 4 14.4 99 9.6 l $ .0 103 93 14 o 1979 85 967 R8 13.1 587 8,8 13 0 MO K9 13 3 19s6 90 103H 9.0 13 3 627 9.0 13.9 411 90 115 was highest during the summer months following The proportion of culls obser ed during combined the spring molt when catches and fishing levels 3 unit studies was lower (11.29;) than that were at a maximum, and lobsters more susceptible observed during 2 unit studies (12.091) and m.sy to damage (Smith and Howell 1987). The be related in part, to the escape vent regulation percentage of culls at the Twotree station during .,iplemented in 1984. The escape vent regulation 1990 was lower (8.1%) than values from the requires that pots have an opening (13 / x 6 in, 4 nearshore Jordan Cove and intake stations or two 2 '/ in. circular) to allow escape of 4 (12.3% and 16.291, respectively), a consistent sublegal-si/ed lobsters. The fishery objective of pattern since this study began (NUSCO 1987), the escape vent regulation was to reduce injuries and subsequent mortality associated with Tant.li 9. Claw kws for lotsten caught in wire pots from overcrowded pots, injuries resulting in elaw loss 1 * 'l'"" have been somewhat lower since 19M (11.1%) E51I n[ ny than from 1978-83 (12.6 % ) indicating that the one claw iwo ciaws regulation appears to be an effective technique to miniml/c trap related damage to sublegal sized

              ,973      g,                  gg                             q,                lobsters. Landers and Blake (1985) reported on 1979      153                 N .i                            1.2              the effectiveness of installing escape vents during 1980       13 6                12.2                            . .$             the first year the regulation was implemented in 1981       12.0                11.1                            1.0 eastern LIS. Following implementation of escape
                        !N                  1                              o vent regulations in their states, researchers from 1984      lo s                98                             0.7                Maine to Rhode Island have also noted similar 1985      ll.i                10.4                           o.7               benefits of incorporating escape vents in lobster 1986      10.6                9.8                            0.8                traps (Krouse and Thomas 1975; Fair and Estrella -

5 l[ iy3 g ff7 ] 1976; Krouse 1978; Pecci et al.1978; Fogarty and 1989 12.2 11 ? 1.0 OUIdCU I980)- 1990 11.9 11.0 0.8 Tagging Program

       ? Init 1978-85    12.0               11.1                            0.8

3. Unit 19s6w 11.2 10 4 0.9 The total number of . lobsters tagged during 1990 was 5,741 and within the range of 3 unit l

Lobster 141 l l l

   - . ~ . - . - .             . . -            .. - - - . ~ . _ -                           _ . - - _ _                    . - . _ .                                         - . - . . - . . . . -

(5,680-6,837) and 2 unit studies (1982 85), when lobsters recaptured in our traps which do not 20 wire pots were used at each station (5,160- contain escape vents increased from 17.2 9 (1978-7,575; Table 10). The percentage of lobsters 83) to 21.99- (1984 90).

recaptured during 1990 (18.69 ) was lower than The mean carapace length of lobsters the range of values reported in 3 unit studies recaptured in our traps (73.3 mm) and in (19.2 25.2%), but within the range of 2 unit commercial traps (79.2 mm) during 1990 was studies (14.4 23.9%). Commercial lobstermen larger than any of the mean values reported in caught a smaller percentage of tagged lobsters other years of 3-unit operation (72.0 72.9 mm; during 1990 (16.8';L) than in other years of 3- 78.0 78.9 mm, respectively) (Table 10). The 19W unit- (18.4 20.4%) and 2-unit operation (21,l. mean CL values for recaptured lobsters (73,3, 47.6%). A higher percentage of lobsters were NUSCO and 79.2, commercial) were within the recaptured in our traps during 3-unit studies range of values reported in 2 unit studies (73.0-

              - (21.6%)- compared to the percent recaptured                              75.7 mm; 75.5 81.1 mm respectively). The larger

during 2 unit studies (18.9%). In contrast, mean CL of recaptured lobsters during 199)

              . commercial lobstermen caught a smaller                                    reflects a recent change in the size composition of proportion (19.3%) of tagged lobsters during 3-                           the lobster population which was also evident in unit operation, than during 2 unit operation                             the percentage of legal sire (a 82.6 mm) lobsters (33.0% ).         The change in the percentage of                         recaptured during 1990. Our traps )(cided more recaptured lobsters in out traps and in                                  legal site (2 82.6 mm) recaptures (5.5%) during commercial traps during 2 end 3 unit operation-                           1990 than during- 1989 (4.4 % ), when the legal is due_ to the escape vent regulation implemented                        limit was 81,8 mm, and during most other 3. unit in 1984 and not to plant operation. Before the                           studies when the legal si/c was 81.0 (4.3 5.5%).

escapc-vent regulation was implemented (1978- Commercial lobstermen caught more legal slied 83), commercial lobstermen recaptured 38,0% of (2 82.6 mm) recaptures during 1990 (26.69 ) than

               -all tagged lobsters; with the regulation in force,                       during 1989 (20.7%); the 1990 value, however, the percentage recaptured in commercial traps                            was within the range of other 3. unit values (25.3 declined to 19.8% By contrast, the percentage of                          27.59). The increase in the percentage of legal-TAtll,li 10. totwier tag and recapture statisucs for NUSCO (May Oct.) and commercial (Jan Dec.) pon from 1978 to 19%                                                                ;

t NUSCO Commercial _ . Nutaber 'Numter Percent Percentage Mean Numtwr Percem Percentage Mean tagged recaptured . recaptured legar Cl,(mm) recaptured recaptured legal" Cl4mm) 1978- 27nM . 198 18 0 16.7 75.5 M4 31.9 436 81.1 19791 3732 722~ 19.4 11.5 75.I t778 47.6 27.2 77.6 19M0 3434- $22 14 4 . I8.8 75.7 I363 37.5 27.5 76 4 1981 4246 707 in.7 12.0 74A ' [484 ' 35.0 25.9 - 76 3 1982 -7575 1282- 16.9 10A 73.2 251r 33.2 23.0 .75.5 1983: '5160L 932 18.1 113 73.6 -22n6 43.9 27.6 76 9 1984- -5992 143t 23 9 84 73.0 -1290 21.5 34.3 78 8

               -1985       15609           1216             21.7           7.7      712               1185      21.1          29 3                            783 1984         5740:       :1144              20 8           4.7      72.3              1173      20A           27.5                            78.2 1987         5080          1356              219           5.5      72 8              1161      20.4          25 3                            78.9 19M          6837          1725             25.2 '         4J       72.0              IE4       20.2          26.7                            78.0 1989'        6438l       -l233               I92        44 (93)     72.9              1184      l 8.4     20.7 (24 8)'                        78.2 19W ' '5741               1066-             18 6      5.5 (12.7)   73 3               905      16A       266 (323)                           79.2
               = 1978 85 38716             7310              18.9          11.0     73.9             12769      33 0          27.5                            77.1 1986a0 30436              6514              21 6        43(6.9)     72.0             5867       19 3     253 (27.t)                           78.5 d 'the mmemum legal aire trom 1978 to 19MM was 81.0 mm (3 % m). mimmum legal arze was increased in 1989 to 81.8 mm (3 '/,e in), and 1990 82.6 mm (3 % in)J Parenthetical values for percentage legal in 1989.1990 and 3. unit studres (1986 90) represent lotsters a 81.0 mm carapace length.

142. . Monitoring Studies,.1990 i 4 __.i9c_ _____ _ _ _ _ _ _ _ _ _ _ - _ _ _ _ _ _ _ - = . - - - - . .

sized lobsters recaptured in ours and commercial from our sampling ciforts and those of traps during 1990 was more obsious when lobvers commercial lobstermen. Lobster movement a 81.0 mm (the original legal size) were included between the three stations during 19W was in the percentage of legals (12.7% in NUSCO minimal; 969 of the lobsters recaptured in our and 32.3% in commercial traps). These values trap 3 were caugot at the station where they were are larger than other 3 unit values and strongly released. These data are comparable to previous suggest that the new regulation to increase the 3. unit and 2 umt studies when E and 45G of m:nimum legal size is effective, lloweve., the the lobsters were caught at the release sites. The inercase may also be attributed to the large catch similar behasior of the local lobster population of sublegal sized lobsters in 1988, these lobsters was also evident in the proportion of tags subsequently molted to legal size in 1990. returned by lobstermen lishing in the sicinity of Changes in the size composition of the lobster MNPS; during 19W, 48G of all the recaptures catch from commercial traps were also noted in were made within 5 km of Millstone Point, the results of out tag and recapture studies similar high percentages were reported in 2 unit following the implementation of the escape vent and 3. unit studies (919S4; 94 98% , respectively) regulation in 1984. The mean CL of lobsters (Table 1!). Lobsters traseled, on aserage, 2.04 recaptured in commercial traps before escape km during 1990, before they were recaptured in vents were required (1978 83) was smaller (76.7 commercial traps; this type 01 rr u : m was mm) than the mean CL of lobsters recaptured in similar to that found in other 3 umt it W-3.16 commercial traps equipped with escape vents km) and 2 unit studies (1.70 3.01 km). The (78.5 mm). The effects of the escape vent homing behavior of the nearshore castern Lia regulation on the eastern LlS lobster fishery were lobster population was demonstrated in studies reported after the first year of implementation conducted by Stewart (1972). Mosement studies (Landers and Blake 1985); the results of our tag in coastal New Hampshire waters (Spurr 1974) and recapture studies continue to support the and in the western inshore region of Cape Cod effectiveness of escape vents. Day (Lawton et al.1984) also documented that most lobsters were recaptured near the release Movelnent sites. Results of our tagging studies indicate a limited home range of the local lobster Movement patterns of the local lobster population agreeing with tagging studies population were assessed using recapture data conducted in coastal waters of eastern North

    'l Allt.E II. The average distance (km) lobsters nuwed from hhnstone Pomt ror all commercial pots, ihme ut vathm 5 km, and those wt more than 5 km rrom the uie An recaptures                         M Hhin 5 km or %1NPS               Stare tha a 5 km trom stNPS Number or             Awrag '       Number (9 ) ot                Aserage      Number (9 ) or                    Average tags returned       distance (k.a)     tags returned            thstance(km)     tags returned                 distance (km) 1978              798                 3 01            725 (91)                    1.71            73 (9)                         15.92 1979              1733                1.70            lui5 (9n)                   t.3 t          68 (4)                          I t.28 1980              1303                2 09            1257 (90)                   1.25            46 (4)                         25.17 1981              1478                1.M9            1451 (98)                   1.49            27 (2)                         23 49 1982              2509                2.M             2343 (93)                   1.58           166(7)                          13 04 1983              2258                2AS             2111 (93)                   1.70           147 (7)                         19 7s 1984              1288                2.33            1230 (95)                   1 78 58 (5)                         1193 1985              1183                2 84            1077 (91)                   1.81           104 (9)                         13.40 1986              1172                2.t>l           1112(95)                     1.76           60 (5)                          l 8.8.'

1987 1157 2.87 1124 (97) 1.77 33 (3) 40 09 1988 1371 3 16 1286 (94) 1.81 85 (6) 23 72 1989 1165 1.97 1147 (93) 1l79 18 (2) 12.86 1990 902 2D4 938 (98) 1.80 25 (3) 11.00 1978 85 12550 2.36 11K59 (94) 1.57 691 (n) 15.95 t986 90 5827 2 57 5(47 (94) 1.79 2l8(4) 22.57 I i' Lobster 143

 . - -.                                      _          . --.                     --         . = _ . _        - - - _ -     -   . . _ . . -.

Atlantic (Templeman 1940; Wilder und Murray Twenty four lobsters moved to the east and were 1958; Wilder 1%3; Cooper 1970; Stewart 1972; recaptured in coastal waters of Rhode Island Cooper et al.1975; Fogarty et al.1980; Krouse (Point Judith) and Massachusetts (Dumuds Bay, 1980, 1981; Campbell 1982; Ennis 1954). Marthas Vinyard, Nantucket Island, Chatham). Despite the nonmigratory behavior of the local One lobster tagged in 1988 was reported to be lobster population, 893 of the 69,152 lobsters caught in Massachusetts Day (Gulf of Maine) in tagged in our studies migrated long distances (Fig. January 1990, representing the northernmost 8). Since 1978, the predominant direction for point of recapture for a lobster tagged in our lobsters moving out of our study area was to the study. The results above were not unexpected southeast based on the number of recaptures because tagging studies at various inshore and made at The Race (n=759), a deep water channel offshoN locations throughout the range of 10.5 km from MNPS and in Block Island Sound nN,ters have demonstrated some mixture of local (n= 18), about 40- km from MNPS. Only 27 inshore populations with onshore migrants from lobsters were recaptured west of the Connecticut the offshore populations (Saila and Flowers 196S; River. Some lobsters (n=22) migrated 250 km Cooper end Urmann 1971; Lund et al. 1971; offshore where they were caught in deep water Morrissey 1971; Stewart 1972; Lund and Rathbun j canyons on the edge of the continental shelf (the 1973; Uzmann et al.1977; Cooper and U/mann Block, iludson, Atlanti.s, Veatch canyons). 1980; Campbell and Stasko 1985, 1986). l? l

                                                                                                            )                                !

_ tT fH f- A [ I'd ,

                                                       }Q ,

L!b #1  ! [Q 4 1 V

                                   //trW                      ~
                               /                                                                                                             l l

3 4 )

5. Y.

L. y 'i~ - ' Y~o 4 C,

• Q, l

l Fig. 8. treation and numtwr or tap returned ty commercial loNtcrmen for loNen caught more than 5 km from Maktone Point. 144 Monitoring Studies,1990

_ __ _ m __ -- ._ _ _ . _ _ . _ - . _ . ___ _ _ _ - _ - l 1 I I Entrainment 1990, Stage I larvae were the most abundant stage of lobster larvac collected in both 2-unit and 3- . A total of 281 lobster larvac was collected in unit studies. Stage I and IV larvae were also l samples of the MNPS cooling water from 14 May more prevalent than Slage _11 and lli larvae in i to 6 August 1990. His number was within the samples collected in nearshore waters of New range of 3 unit studies (185 571), but higher than Hampshire around the Seabrook Nuclear Power the number collected during 2 unit operation (102 Station (NAl 1989; Strube 1989). Lobster larvae and 143; Table 12). Stage IV larvac densities during 1990. were significantly (p < predominated in the 1990 collections (147), 0.05) higher in night samples (1.167/1000 m') ' followed by Stage I (127), Stage 11 (6), and Stage than in samples collected during the day ill (1) larvac, With the exception of 1986 and (0.341/1000 m'); similar results were noted for the 1986 and 1989 studies (Table 13). The annual TARIL 12. Summary of loNier larvae entrainment data from 1984 to 197t TAllLli 13 Delta mean density (number per spoo m' t 954 C.I.) or lohler larvac cohected in day and night entramment samples trom 19M4 to 1970 Stage i Stage 11 Stage til stage IV Total Year Time Deha mean 95"i C,l. L9H 21 stay.IOJuly of day densilf Day 15 0 0 4 19 Night 73 I I 8 83 1984 Day 0.158 O uil .0.256 Total 88 1 1 12 102 Night 0.737 o l 38 1..m J.9ES l$ stay-29 July 1985 Day 0.3W 0 041 0 820 Night 0.c20 0b0 0 951 l Day 56 0 3 2 61 Night 69 1 2 10 82 1986 Day 0.324 0 0G0.585

          'lotal       125        1            5        12   143                                     Night         1.3P/         0.556 2.242 l

j,986 14 stay.14 July 1987 Day 0.791 0.040 1.542 Night 0 667 0,205 1.129 Day: 33 1 -4 8 46 Night $4 to il 111 186 1988 Day 0.727 -0.199 1.653 Total 87 11 15 119 232 Night 0 688 0.271 1.106 l 1917 18sf ay.7 July 1949 Day 0.158 0.0M7 0.229 6 i Night 1.403 0.537 2.269 Day 104 4 5 3 lin N:ght 56 6 3 4 69 1990 Day 0.341 0.101 0.581 Total 160 10 8 7 185 Night 1.1676 - 0.569 1.765 198M

          -                         16 stay.l August

• NumM gu IM mA 6

                                             ~

Signiricant difference lecen day and night densities Day 179 107 l57 - 15 453 2. sample t. tests (p<0 05). Night $2 3 11 47 113 Total . 231 110 168 62- 571 variation in the number of larvae collected in g each stage and the differences noted between day L82 22stap2sJu'1 and night samples were similar to_ rmas of Day 24- 0 1 5 30 studica conducted by other researchers tirghout Night : 189 0 'O 16 207 - New England (Fogarty 1983). Early laboratory

        ' Total       213        0          .3        21    237                  studies have indicated that Stage I and IV larvae L990-                     t a stay.6 August                            initially exhibit positive phomFJ.!s, but later. Irl the stage they become photonegative _ (Hadley l          Day         43         0           0        32     75                  1908; Huntsman 1924). The field surveys by l          Night       84         6           I Tota' 115   200                  Harding et al. (1987) in waters offshore Nova 127        6           1        147   281 Scotia demonstrated significant vertical migrations of Stage I larvae, which were more frequently Lobster          145 L

w

TABLE 14. Annual mean density (number per 1000 m )3 or lobster lanae in entrainment samples during their season of occurence and annual entrainment estimaten with 95% C.I. ror MNPS from 1944 to 1990. Year Time pered Number Mean Cooling Vol. 6 included tarvae density' 95% C,1 (m' x 10 ) Istimate 95% C.I. 0.409 O lM.0 635 189.4 77,458 34.M7 120.239 1"" 2tMay-1dul 102 0.238a749 255.1 128.550 65.806 191,040 1985 15MayWut 142 0.504 0.857 0.418 1.297 6o6.2 566,619 278,457 ht,017 19%* 14May. lout 232 0.943 0.274 1.613 423.8 399f M 116,111 -r>83,529 1987 18May 30Jun ItW 1988 16May 1 Aug 571 0.717 0.296 1.137 837.6 600.573 247.935 952.372 0.701 0.358 1.044 562.8 394.518 201,480 587.556 1989 22May.2!Uul 237 0.748 0.4 36-1.Or,0 779.1 582,738 339,67 b825.805 1990 14May.30Jul 280

• Mean densities are calculated as the delta.mean (NUSCO 19Mb and Penmngton 19tG) 6 Unit 3 began commercial operation.

collected at depths between 15 and 30 m during 1970). In addition, relatively little is known the day but rarely collected below 10 m at night. about post larval behavior and survival (Phillips No significant relationship between depth and and Sastry 1980; Caddy and Campbell 1986, Cobb time of day was demonstrated for Stage il and ill 1986). Fogarty and Idoine (1986) recently larvae; fourth stage larvac were more restricted to described a relationship between Stage IV larval near surf.cc waters (Templeman 1939; Bibb et al. density and stock size 5-7 years later and 1983; Collings et al.1983; Harding et al.1987). Indicated a possible density dependent relationship The annual 6 mean density of lobster larvac between larval settlement and subsequent collected from 14 May to 30 July,1990 was 0.748 recruitment to the fishery. Post larval behaviot per 1000 m' of coo.nig water, which was within and ecology is an important aspect of stock the range of 3. unit studies (0.7010.943) but recruitment models for the American lobster and higher than values reported in 2 unit studies was recently referred to as "the bottleneck

• in (0.409 and 0.504) (Table 14). The total number understanding factors affecting lobster recruitr'ent of lobs er larvac entrained through the MNPS (Cobb and Fogarty, pers. comm.), The effect of cooling water systems was estimated by entrainment on the local lobster population, if multiplying the annual 6 mean density by the any, will not be apparent until lobsters grow to a combined 3 unit cooling _ water demand from 14 size vulnerable to capture in commercial traps.

May to 30 July 1990. During 1990, an estimated 58'2,738 lobster larvae were entrained, compared Conclusions to between 394,518 and 600,573 in other years of 3 unit operation and between 77,458 and 128,55 The total number of lobsters caught and total during 2 unit operation (Table 14). The higher CPUE in 1990 were the lowest since Unit 3 entrainment rates during 3 unit operation, relative began operation but were within the range of to 2 unit operation are the result of greater values reported for 2-unit operation. The changes coollng water demand of Unit 3. The annual in population parameters during 3-unit u. 2-unit differences in entralnment rates during 3-unit operation (size structure, sex ratio, proportion of operation were attributed to variation in power berried females, growth, and percent recaptured) plant operation during the larval season. For have been strongly related to the implementation example, refueling outages at one or more units of an escape vent regulation in 19M and the in 1987 and 1989 resulted in lower cooling water increase in minimum legal size from 81.0 mm in demands and lower entrainment estimates. 1988 to 81.8 mm in 1989 and 82.6 mm in 1990. Converting lobster larvae losses due to The increase in minimum legal size is expected entrainment into equivalent adult lobster losses is to result in increased proportions of betried difficult; estimates of survival between Stage I and females which will improve the recruitment of IV are highly variable, ranging from < 19e in the lobsters. The regulation to increase the minimum Canadian Maritimes (Scarrat 1964, 1973; Harding legal site appears to have been effective during et al.1982) to > 50% in LIS (Lund and Stewart 146 Monitoring Studies,1990 . l

the first two years of implementation; the Sound. NOAA Tech. Rep. NMFS percentage of berried Ic. ales increased and the SSRF 775:15 22. catch of legal. sized lobsters increased. How ever, Blake, M.M. 19sS. Final Report Connecticut the higher legal catches observed in the past two lobster investigations January 1,1983 December years may instead be due to .ccruitment of 31, 1987. NOAA.NMFS Project No. 3 374.R. sublegal sized lobsters from 19SS, when the 103 pp. number of lobsters just below the legal site was Blake, M.M., and E.M. Smith. 1984. A marine unusually high. A similar strong recruit class 'vas resources plan for the state of Connecticut. obsersed in 1982 and was followed by increased Connecticut Dept. of Environ. Protection, Star. legal catches in 1983 and 1984. Fish. 244 pp. increased number of larvae Briggs, P.T., and F.M. Mushacke. 1979 The The effect of entrained during . operation on the local American lobster in western Long Island lobster populatio o difficult to evaluate at Sound. NY Fish Game J. 26:59.Sh present, because of the uncertainty regarding post. Briggs, P.T., and F.M. Mushacke. 1984. The larval ecology and survival. The effects, if any, of American lobster in western Long Island lobster larvae entrainment on future adult stock Sound: Movement, growth and mortality. NY si/cs will not be apparent until lobsters grow to Fish Game J. 31:21-37. a site vulnerable to capture in commercial traps. Caddy, J.F., and A. Campbell. 1986. Summary ot The impacts associated with impingement of session 9: summary of research lob 3ters have been mitigated at Units I and 3 by recommendations. Can. J. Fish. Aquat. Sci. installing fish return systems in the intakes,which 43:2394 2396. return impinged lobsters to LIS. Lobster growth Campbell, A. 1982. Movements of tagged was slightly higher during 3. unit operation; this lobsters released off Port Maitland. Nova could be a direct influence of the thermal Scotia, 1944 80. Can. Tech. Rep. Fish. Aqual. dncharge, although hydrothermal studies indicated Sci. No.1136. 41 pp. Campbell, A., and A.B. Stasko. 1985, that the theimal plume does not reach the bottom at any of the lobster sampling stations. Movements of tagged American lobsters, Alternatively, the thermal discharge could have Homan4s amcricamis, off southwestern Nova indirectly influenced lobster growth by enhancing Scotia. Can. J. Fish. Aquat. Sci. 42:229 238. the abundance of prey species available to Campbell, A., and A.D. Stasko. 198n. lobsters. Continued monitoring of lobsters will Movements of lobsters (Homarus amcricamts) demonstrate the effects, if any, of MNPS tagged in the Bay of Fundy, Canada. Mar. operations on the local lobster population. Biol. 92:393 4N. Cobb, J.S. 19S6. Summary of session 6: ecology References Cited of population structures. Can. J. Fish. Aquat. Sci. 43 2389 2390. Aiken, D.E.1973. Proecdysis, setal development, Collings, W.S., C. Cooper Sheehan, S. Hughes, and J.L. Buckley. 1983 The spatio. temporal and molt prediction in the American lobster, distribution of American lobster (Homanis (Homarus amcricamss). J. Fish. Res. Board Cw. 30:1337-1344, americanus) in the Cape Cod Canal and Aiken D.E. 1980. Molting and growth. Pages approaches. NOAA Tech. Rep. NMFS SSRF-91-163 in J.S. Cobb, and B.F. Phillips, eds. The 775:35 40. biology and management of lobsters, Vol.1, Cooper, R.A. 1970. Retention of marks and Academic l'ress, Inc., New York. their effects on growth, behavior and migrations Aiken, D.E., and S.L. Waddy. 1980, of th; American lobster, Homarus americanus. Reproductise biology. Pages 215 276 in J.S. Trans. Amer. Fish. Soc. 99:409 417. Cobb, and B.F. Phillips, eds. The biology and Cooper, R.A., R.A. Clifford, and C.D. Newell. magement of lobsters, Vol.1, Academic 1975. Seasonal abundance of the American

              . ress, Inc., New York.                                                   lobster, Human <s americanus, in the Boothbay Bibb, B.G., R.L Hersey, and R.A. Marcello, Jr.                               Region of Maine. Trans. Amer. Fish. Soc.

1983. Distribution and abundar,ec of lobster 104:669 674. Cooper, R.A., and J.R. Uzmann. 1971 larvac (Homarus americanus) in Block Island Lobster 147

r Migrations and. growth of deep. sea lobsters, 1980. Movements of tagged American lobster, Homanis amcricanus. Science 171:288 290 Homarus amcricanus, off Rhode Island. Fish. Cooper, R.A., and J.R. Urmann. 1980. Ecology Bull., U.S. 78:771 780. of_- Juvenile and adultHomanes amcricanus. Fogarty, M.J., and J.S. -Idoine. 1986. Pages 97142 in J.S. Cobb, and B.F. Phlilips, Recruitment dynamics in an American lobster eds. The biology and management of lobsters, (Homums americanus) population. Can. J. Fhh. Vol 11, Academic Press, Inc., New York. Aquat. Sci. 43:2368 2376. Dow, R.L 1966. The ' use of biological, Graulich, K.A. 1990. . Annual report American environmental and economie data to predict lobster investigations in New York waters. supply and to manage a selected marine NOAA NMFS Project. No. 3.lJ il, 51 pp. resource. The Amer. Biol. Teacher 28:26 30. Hadley, PA 1908. The behavior of the larval Dow, R.L 1%9. Cycile and geographic trends in .and adolescent stages of the Americ a lobster seawater temperature and abundance of (Homarus amcricanus). J. Comp. Neurol. l American lobster. Science 164:l(21063, Psychol. 18:199 301. l Dowi R.L 1976. Yield trends of the American Harding, 0,C., W.P. Vass, and K.F. Drinkwater, lobster resource with increased fhhing effort. 1982. Aspects of larval American lobster Mar, Technol. Soc.10:17,25. (Homants americanus) ecology in St. Georges Ennis, O.P.1971, l.obster (Homunes americanur) Bay, Nova Scotia. Can. J. Fish. Aqual. Sci. fishery and biology in Bonavhta Bay, 39:1117 1129 Newfoundland. 1966-70. Fish. Mar. Serv. Tech. Harding. O.C., J.D. Pringle, W,P, Vass, SJ Pearre Rep. 289. 46 pp. Jr.,- und SJ. Smith.1987. Vertical distribution Ennis, O,P, - 1974. Obsenations on the lobster and daily movement of larval lobsters Homarus fhhery in Newfoundland. Fish. Mar,- Serv. amcricanus over Browns Bank Nova Scotia. Tech. Rep. 479. 21 ppi Mar. Ecol. Prog Ser. 41:29 41. Enr P. O.Ps 1980 Size-maturity relationships tierrick, F.H. 1911, Natural history of the and related observations in Newfoundland American lobster. Bull. U.S. Bureau Fish, populations of the lobster - (Homanis 29:149 408. americanus), Can. J, Fish. Aquat. Sci. Huntsman, A.0, 1924, Limiting factors ' (cr 37;945 9561 marine animals. 2, Resistance of larval lobsters Ennis, G.P. 1984. Smalt. scale seasonal to extreme temperature. Contrib. Can. Biol. . movements of the American lobster, Homarus Fish. 2:9193. americanus. Trans. Am. Fish. Soc, Keser, M., D.F. Umders, Jr., and J.D. Morris.

         'l13:336-338.                                                      1983.         Population - characteristics of the Fair, J.J., and B. Estrella~ 1976. A study on the                 - American lobs!cr, Homarus amcricanus, in effects of sublegal escape vents on the catch of                 eastern Long Island Sound, Connecticut.

lobster traps in five coastal areas . of NOAA Tech. Rep. NMFS SS.RF.770. 7 pp.-

        - Massachusetts. Unpublished manuscript, Mass,                Krouse, J.S,            1973. Maturity, sex ratio, and site Div.1 Mar. Fish. 9pp.                                            composition = of the natural- population of Flowers, J.M., and S.Bc Saita. 1972. An analysis                     American lobster Homarus americanus, along of temperature effects on the inshore lobster                    the Maine coast. Fish. Bull., U.S. 71:165 173,
        - fishery. J. Fish. Res. Board Can. 29:1221 1225.          - Krouse, J.S. -1978. Effectiveness of escape vent Fogarty, MJi 1983. Distribution and relative                         shape in traps for catching legal-sized lobster, abundance of American lobster, Homams                            Homarus americanus, and harvestable sized
        - americanus larvae: New England investigations-                   crabs, Cancer borealis and Cancer vrorams.

during 1974 79, NOAA Tech. Rep. NMFS Fish. Bull., U.S. 76:425 432. SSRF 775. 64 pp. .. Krouse, J.S.1980. Summary of lobster, Homarus Fogarty, M.J., and D.V.D. Borden; 1980. Effects amcricanus, tagging studies in American waters of trap. venting. on gear selectivity in the (189841978). Can. Tech. Rep. Fish. Aquai Sci. inshore Rhode island American lobster, - 932:135 140. Homarus americanus, fishery. Fish. Bulli, U.S. Krouse, J.S, 1981. Movement, growth,' und 77 S25-933. . . mortality of American lobsters, Homarus , Fogarty, M.J., D.V.D. Borden, and H.J. Russell. americanus, tagged along the coast of Maine. L 148 - Monitoring Studies,1990 - l f

                                                                         -    .n   - - . . .              .-     . . - .    . - - - - -                . , , ,

l l NOAA Tech. Rep. NhiFS SSRF 747.12 pp. characterization of baseline conditions in the Krouse, J.S., and J.C. Thomas. 1975. Effects of Hampton Seabrook area, 1975 1988. A trap selectivity and some population preoperational study for Seabrook Station. parameters on the size composition of the Technical report XX II. American lobster, Homants americarms, catch NUSCO (Northeast Utilities Service Company). along the Maine coast. Fish. Bull., U.S. 1987. Lobster population dynamics. Pages 73:,m2 871. 142 in Monitoring the marine environment of Kurata,11.1%2. Studies on the age and growth Long Island Sound at Millstone Nuclear Power of Crustacea. Bull. Hokkaido Reg. Fish. Res. Station, Waterford, Connecticut. Summary of lab. 24:1 115. studies prior to Unit 3 operation loS7. Landers, D.F., Jr., and M.M. I'lake. 1985. The NUSCO. 1988. The usage and estimation el effect of escape vent regulation on the DELTA means. Pages 311320 in Monitoring American lobster, Homanes americarms, catch the marine environment of Lorg Island Sound in eastern Long Island Sound, Connecticut. at Millstone Nuclear Power Station, Waterford. Trans. 41st Annual Northeast Fish Wild. Conf. Connecticut. Three-unit operational studies 9 pp. 1986 1987. Lawton, R.P., P. Brady, C. Sheehan, W. Sides, E. NUSCO. 1959 Lobster population dynamics. Kouloheras, M. Borgatti, and V. Malkoski. Pages 11 35 in Monitoring the marine 1984. Growth and movement of tagged environment of Long Island Sound at Millstone lobsters released in western Cape Cod Bay, Nuclear Power Station, Waterford, Connecticut. 1970 1977. Pages 119 129 in J.D. Davis, and Annual report 1988. D. Merriman, eds. Lecture notes on coastal NUSCO. 1990. Lonster population dynamics. und estuarine studies, Vol. I1: Observations on Pages 121 144 in Monitoring the marine the ecology and biology of western Cape Cod environment of Long Island Sound at Millstone Bay, Massachusetts, Spinger-Verlag, Inc., New Nuclear Power Station Waterford, Connecticut. Yor k. Annual report 1989 Lund, W. A., Jr., and LL. Stewart. 1970. Pecci, K.J., R.A. Cooper, C.D. Newell, R.A. Abundance and distribution of larval lobsters, Clifford, and R.J. Smolowiu 1978. Ghost Homan4s americanus, off southern New fishing of vented and unvented lobster. England. Proc. Natl. Shellfish. Assoc. 60:40- Homanis americanus, traps. Mar. Fish. Rev.

49. 40:9 43.

Lund, W.A., Jr., LL Stewart, and H.M. Weiss. Pennington, M. 1983. Efficient estimators of 1971, investigation on the lobster, Homarus abundance, for fish plankton suncys, americanus. Comm. Fish Res, Dev. Act., Final Biometrics 39:281-286. Rep., Proj. No. 3 44 R. 104 pp. Phillips, B.F., and A.N. Sastry. 1980. Larval Lund, W. A., J r., a nd C.J. Rathbun. 1973. ecology. Pages 11-57 in J.S. Cobb, and B.F. Investigation on the lobster, Homan liberated fisheries of bmg Island Sound, 1 % 1-1985. in Egmont Bay, Prince Edward Island. J. Fish. Connecticut Dept. Environ. Prot.. Div. of Res. Board Can. 20:305 318 Conservation and Preservation, Bureau of Wilder, D.G., and R.C. Murray. 1958. Do Fisheries, Mar. Fish. Pro. lobsters move offshore and onshore in the fall Snedecor, - G.W., and W.C. Cochran. 1967. and spring? Fish. Res. Board Can. Atl. Prog. Statistical method . The towa State University Rep. 69:12 15. Press, Ames, IA. 593 pp. Spurr, E.W, 1974. Completion report, lobster research program 1971 1974. NOAA NMFS, Comraer. Fish. Ret. Dev act. 34 pp. Stewart, LL 1972. The seasonal movements, population dynamics and ecology of the lobster, Hamanes americanus (Milne-Edwards),

          'off Rani Island, Connecticut. Ph.D. Thesis.

University of Connecticut, Storrs, CT.112 pp. Strube, J.N. -1989 Seasonal abundance and length frequency of American lobster, Homarus amcicanus, larvae off the New Hampshire coast 1978198& Page 34 in Life history of the American : lobster, Proceedings of a workshop Nov. 29-30, 1989. Orono, Maine. Templeman,- W. 1935. b) cal differences in the body proportions of the lobster, .Homarus americanus. J. Biol. Board Can. 1:213-226.

       -150       Monitoring Studies,1990

Contents Roc ky Inte rtidal St udies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 153 I n t rod u c t io n . . . . , . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 153 Materials and Methods ..................... ................. 153 Q ualitative Sa mpling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 153 Abundance Measurement ................................ 154 Recolonization Studies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 154 Ascophylhtm nodosum Studies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 155 D a t a An a lys is . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 156 Results and Discussion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 156 Q ualitative Studies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 156 Abundance Measurement ................................ 163 B a r n a cl e s . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 164 Fuctu .......................................... 166 C h o nd r u s . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 169 Similarity De nd rograms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 171 Recolonization St udies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 173 Ascophyllum nodowm Studies ............................. 177 Growth......................................... 177 M ortality , . . . . . . . . . . . ........................... 179 Co n cl u s i o n s . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 181 R e fe re nc es Cite d . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 182 i

l l 1 l Rocky Intertidal Studies Introcluction of species occurrence and abundance, and to identify the physical and biological factors that Studies of the plants and anin als that live on induce variability in 'ocal rocky intertidal i rocky shores in the vicinity of Millstone Nuclear communities. These studes include qualitative l Power Station continue to be a part of an algal sampling, abundanct (percentage cover) 1-extensive environmental monitoring program, measurements of it.t e r t idal organisms, whose printary goal is to assess the impacts recoloni/ation studies, and studies oI Awophyllum associated with construction and operation of that nalomm, whose growth responds to ens itonmental facility. Ilocky intertidal conununities are changes rad whose grow th strategy pennits particularly amenahic to such studies, because they quantitative monitoring esessment. are com]med of species assemblages whose This report presents results ol studies performed distribution patterns reflect _ their exposure to during the IW) sampling year (October l989-quantifiable biotic and abiotic factors. September 1990). These results are compared to Interactions among these factors, and among the average 3-unit operational studies (March 19S6 snecies themselves, produce almost universal September 1990),and to 2 unit operational studies patterns of zonation and communky organization (March 1979 February 1%). (Stephenson and Stephenson 1949, Lewis 1964; Chapman _1973). Many factors responsible for such S!nterinis nn<l hietilods zonation (e.g., immersion time, degree of exposure 1 to wuves, grazing and predation pressure) occur in @talitative knyling ' gradients, some experimentally manipulable (Connell 1 % 1, 1975; Dayton 1971; Lubchenco Qualitative algal collections were made monthly 1980; Vadas 1985). Many researchers use rocky at nine rocky intertidal stations (Fig.1). The,e intertidal microcosms to develop and test general stations are, in order of most to least exposed to ecological concepts such as succession (Odum 1969, Sousa 1979; Farrell 1991), life histor) prevailing winds (FE), Fox Island Exposed and storm forces: Millstone llay Point (BP)l Point (MP) strategies (Littler and Littler 1980; Lubchenco and

                             ,                               Twutree Island (1T), White Point (WP), Seaside.

Cubit 1980), equilibrium (Katz 1985; DeAngelis Exposed (SE), Seaside Sheltered (SS), Giants Neck and Waterhouse 1987), competinon (Connell and (ON), and Fox Island Sheltered (FS). Tbc MP and Statyer 1977; Menge and Sutherland 19S7), and 1T stmlons were added in September 19Sl; all recruitment (Underwood and Denley 1984; Gaines others have. been sampled since March 1979 and 1(oughgarden 1985). Studies of rocky shore Collections made prior to March 1986 represented

commumtles have also been used to assess impacts 2 unit operatingconditions; 3 unit collections were associated with many forms of pollution, e.};., made after that time, thermal (Vadas et al 1976, Wilce et al.1978)'

The FE station is anproximately 1(X) m cast of sewage (Murray and Littler 1978), and oil spills the MNPS discharges,'and directly exposed to the (Southward and Southward 1978); thermal plume (during part of the tidal cycIc); FS, The primary objectives of the NUSCO Rocky WP,1T, and MP are between 300 and 1700 m Intertidal Studies are to determine whether from the discharges, and potentially impacted by

   , differences exist among communities at several          the plume. Stations at GN, SE, and 'SS are                             5 sites m the Millstonc region, whether these            considered to be unaffected ny MNPS uperation.

differences can be attributed to construction and Qualitative collections characterized the flora at p operation of MNPS,and whether the mat;nitude of each site, during each sampling period. Al

   . these differences have changed since Unit 3 bep'       samples were identified fresh or after rm short te' cal y     operation. To achieve these objectives, studies freezing. Voucher specimens were preserved usiny t

were conducted to identify the attached plant and various methods: in saturated Nacl brine, as dried animal species found on nearby rocky shores, to herbarium mounts, or on microscope slides.

 ,   identify and quantify temporal and spatial patterns 1

I Rocky Intertidal 153 l l

E {l i sl f)I j) 1 i, ;j. .-.\ *lp 'j ' tj

                                                        ]bi               \                ,/Y v              \

r. Nbrth a l n ,e

[/ ', g,_ -.

                            !Lm j                               jO l
                                                      --    T. .
                                   }9         (                        ,
                                                                                   'N ?(

Mc M, ,f BP\ $ '

                                '(
                              .' '?

i i

                                                                           'i M>'TE eae
                            ,[=$         k                                                   h~       wr' g)      ?y           i                                                      SE'ss DN            w\                                               \
                             - m , mra q                                              53
                                             }

hg.1. In:ation td the MNPS rocky intertidal sampling siter GN = Giants Neck. llP atlay Point, MP= Mdistone Point, IT.= tiu bland-lapsed. I'5=lin Island-Sheltered. Tf =Two ree Nand, WP = White Point. St!-Scaudehput SS = Seaside-Shchered. Atiuitdance Measurernent substratum coverage. Each quadrat was assigned to a zone based on its tidal height: Zone 1 (high The abunaance of rocky intertidal organisms was intertidal), Zone 2 (mid intertidal), and Zone 3 expressed as percentage of substratum cover. At (low intertidal). each qualitative collection station - except TT (because of insufficient exposed bedrock), five Recolonization Studies permanent strip transects were established perpeadicular to the water-line, one half meter RecolonizaQn transect experiments were wide and extending from Mean High Water to designed to determine rates and patterns 'of Mean Low Water levels. Each transect was recolonization following substratum denudation at 5 bdisided into 0.5 m x 0.5 m quadrats and was four of the qualitative stations: FE, FS, WP, and non-destructively sampled six times per year, in GN. Sample design included two pairs of stations odd numbered months (or a total of 28 times in with similar degrees of wave exposure: exposed at the Unit 3 operational period to date). As there FE and WP, and sheltered at GN and FS.' The were no experimental manipulations, these are Fox island stations, because of their proximity to considered ' undisturbed' transects. The total the MNPS discharge, were considered to be number of quadrats in each transect depended on potentially impacted sites, while 'WP and GN were the slope of the transect. The percentage of classified as reference stations (hydrographie substratum cover of all organisms and remaining tp"deling indicates that the 3. unit thermal plame free space in each quadrat was subjectively extends past White Point (NUSCO 1938a), but to determined and recorded. Understory organisms, date, no thermal incursion has been recorded in or species that were partially or totally obscured by the area of the WP recolonization studies). Three the canopy layer, were assigned a percentage that transects were established at each station, one-half approximately correspcmded to their actual meter wide and extending from Mean High Water 154 Monitoring Studies,1990

t js N ..r t e, 3 N

                              ],                                                                  tw o ,             '

v. ., ~ -

                                 \                                                     '               te,t         Y
                              \                      \                                   \
                               \       \                                        i g
                                                                                           \

2 4[k (

                                                                                  $( t          '
                                                                                                     , .h - rp
                                                                                                     ,       t E Hiuem ~                                      '                      -'

m u m, . l

                                                 )                                       (                  ID'        Qu
                                     ;         /          \                               ' Y wt                 rb
                                         ,(/                                      't
                                                                                         \ )
                                                                                        ? orge
                                                                                      .-i m
                                         )    .]

j kuP t Fig 2. Detail nup of the MNPs vicinity FO noriginal expenmental Asayeyllum ute (197940, FN = new expenmental Amy4/imn ute (19MS-prnenO. monitored at an earlier site (FO, ca. 75 m east of to Mean Low Water levels. Each transect was the original Millstone quarry cut) from 1979-1984; scraped free of attached algae and invertebrates however, Ascophyllum was climinated from FO in and burned with a liquid petroleum gas torch. All summer 1984 by exposure to elevated water recolonization transects were sampled monthly in temperatures from the thermal plume discharged the same manner as described for undisturbed through two quarry cuts (NUSCO 1935). transee:s. During the 2 unit operational period, Ascophyllum plants were measured monthly denuding occurred in April 1979, and again in from April to the following April, after onset of September 1981 at the same transects, to new vesicle formation. At each station, fifty plants determine the effect of seasonal denuding on were marked at their bases with a numbered plastic recolonization. Auumn denadings (September tag, and five apices on each plant were markcd 1986) were re established during the Unit 3 with colored cable ties. Linear growth was operational period, to assess possible 3 unit effects determined by measuring from the top of the most on recolonization. recently formed vesicle to the apex of the developing axis, or apices, if branching had Ascophyllum nodosum Studies occurred hionthly measurement of tagged plants began in June; in April and hlay, vesicles were not Growth and mortality of tagged individuals of large enough to be tagged, and five tips were the perennial brown alga, Ascophyllum mdosum, measured on each of 50 randomly chosen plants. were studied at two reference stations (GN and Lost tags were not replaced, and the pattern of WP, Fig.1) and an experimental station (FN, ca, loss was used as a measure of mortality. Loss of 150 m from the quarry discharges, northeast of the the entire plant was assumed when both the base FE sampHng site, Fig. 2). Ascophyllum populations tag and tip tags were missing. Tip survival was at GN and WP have been monitored since 1979, based on the number of remaining tip tags, and those at FN since 1985. A3cophyllum was Rocky Intertidal 155 l

Data Analysis were plotted again',t the means of 2 unit (1979 1986) and 3 unit (19S41990) operational data Because the FN station was established in 1985,2- % For qualitative algal collections, a percent. unit operational data from this site included only frequency of occurrence was calculated, based on the percentage of collections in which each species the 1985 86 growing season. Data from the was found, in all possible colicctions (e.g., at a original Fox island Ascophylhan station (FO), station, in a month, during 2 unit or 3 unit illustrating the effects on an A scophylium operation). A frequency of occurrence index was population an.ociated with the opening of the determined, based on the number of times that second quarry cut, are summati/cd in NU$CO cach species was found at each station in each (lWOL year. These indices were used to calculate similarities among annuut notas, es5g the Bray. Results and Discussion Curtis formula (Clifford and Stephenson 1975): Qualitative Studies a 2 min (X ,X,) A- ,The local benthic marine Hora, as represented by sgti(X +X u g

                                      )                   cumulative qualitative collections at sites near MNPS includes 158 algal taxa. Before we proceed with notistic analyses, we mu,, prmide some where X3 is the frequency of occurrence index for       definition of this' nota. On ..ing tasonomic species (i) at station (j), X, is the index at station studies result in frequent revisionIol nomenclature (k), and (n) is the number of species in common.        (e.g., Schneider et al.1979, South and Tittley 19S6; A Ocxible-sorting (a= 0.25), clustering algorithm V llalard Dohnsack et al.1988). We have made a was applied to the resulting similarity matrix          particular efIort to update the NUEL species lists (lance and Williams 1967)'                              w th current name changes. A summary of recent Quantitative analyses included determination of     changes that affect these taxa is include'd in Table abunda nee of intertidal organisms, as percentage of     1. Synonymization of Antilhanmion americanum substratum covered by each taxon. Unoccupied substrata were classed as free space. Cover values      TAW.t! 1. Recent nomencluum! redwns incoriwated into were plotted against time for selected species.          NUUt. qualuative algal analyses, pnnunty unvr South & Tiule)

Similarities of communities among stations and (1% between operational periods were calculated using the Bray Curtis coefficient formula cited above' ou name new name substituting untransformed percentages for frequency of occurrence indices. The same aantorrichwn auidii sntonerna ahiah Clustering algorithm was used to form 1;r#rotrichia cihard Fruhrosnelwpchh ciliath statton/ period grouplngs. GChd""" "i"al' Grhd""" P"3ilh"" A Gompertz growth curve was fitted to "O""i"d *#d'd ^'d'

• dT""#"""

Ascophyllum lengtb _ data using non linear f,"[,"" [ """} ScdFhd I7'dhd<i regression methods (Draper and Smith 1981). The f;uacyncimurse cladmichon wucrac Gompertz function has three parameters; as they 5phacclaria fi,rcigra sphaularia rigidula apply to Ascophyllum growth, a represents the I:ntaclaJia virida Acrochacte viridh

                                                            *d"d "9'P'""d                ^'"'"'""""""9'l*""""'

asymptote, or total increase for the growing (namnorpha swnlandwa cofwpui gnenlandemn season, and # and x determine the scaling and shape of the curve. Together, these last two parameters specify the location of the inflection and A. pylaisaci with Scagelia pvlaisaci is the only point of the growth curve, the point at which change that alters the number of taxa reported,i.e., length is increasing most rapidly. Growth curve it reduces the total by one. Table 2 is a list of parameters were compared among years and currently used names, and the occurrence of the stations using 2 sample t tests P=0.05). Growth entities to which they refer. Note that some names and mortality data for the 1989 90 growing season have been retained, despite knowledpc that they do - 156 Monitoring Studies,1990

        ~1abic 2 Ottahtatwe algal cor !cctum (Mar.1979 Sep 1*rM) ty mon!h statwe, a+wi sma! 6,r stixty. Imt threr m3cmm rqwrwnt 2 emit ( t' 9 2.%) and 3 urn G%

9"M) sut tntah, and sti etthret quarrv cu!1cc6ms OD9-9fMt Wiun eqwtxct comt-cr of timo 6mnd, as a prcent y n! pmbic trmo hmd (.= abse*:t; O = proent. < !#I) A dah bchwe a specio name indicato th.et n was Imnd m l'rm Chlorophyta Jan Feb Mar Apr May Jun Jul Aug Sep Oct tiov Dec Ctt EP HP TT FE FC WP SE 55 tot 20 SU C 9 7 3

• 18 30 IS 35 30 27 25 28 42 31 25 31 32 31 8

  -Ulothrix flacca                           50 62 73 68 37                      .
                                                                                                                         *1 31 29 40 30 21 33 33 33                   8
  -Urospora penicillif ornis                 59 67 67 59 28           9    6    6    5 12 28 45 38 ". 2 36                .

7 6 11 12 7 4 6 3 3 6 2 5 9 5 6 2 12 6 10 4 2 6 4 9 1

  -Ur-spcra wornskjcidii                                                                             2     4     6   3      2   4    1   2     1    4    3   4   1    1
    'Urospora collabens*                       5 12      6   1   5    1    2     .    .   .      .

1 1 I 1 1 1 2 3 I 1 . . 1 1 1.

    *crochaeta viridis                         1    1     . I  1         1     .    .

2

  -Menestrana grev211ei                      16 53 55 63 48           8     1   1    1     . 4     5 24 24 19 23 14 27 22 219 24                     22 23 21 26 26 29 22         3
  -Monostrona pulchrun                       11 36 80 84 77 10             2     .    . 2      1    1 29 27 25 31 17 23 29                                  0   0    2 2   1                              .     .     . 1    .      .   .   .    .     . 2     0
  -Monostrona oxyspernun                       1    .     .            .    .    .    .   .

6 16 17 14 3 5 17 31 41 50 27 6 . 2 3 26 22 30 23 14 6 17 6

  -Spongonarpha arcta                                                            .    .

10 9 15 2 4 4 8 4 1 6 6 7 1

  -Spongonorpha aeruginosa                     3   1     5 17 23 16        4    2    2    .     .

0 0 . 1 . . . 1 . . . . . . . .

    *Codiolun gregariun'                       .    .    .    .  .     .        .     .

1 1 4 1 1 2 . 2 Capsosiphon fulvescens 1 . 3 2 2 1 . 2 . . . 1 . . . . 2 2 8 9 7 5 1 1 I 7 4 13 4 4 2 3 4 2 4 4 6

  -Copsosiphon groenlandicen                   3   9                                      .
  -312dingza minina                          55 54 43 58 69 67 53 70. 63 50                   52 54 61 56 77 72 742 201 662 481 681 601 542 671 61 5    2             2    1    3             2     1     1     2     2    . I Blidingia narginata                                   .    .                  .   .

5 3 25

• 9 2 22 32 31 3 15 17 18 16 47

  -Enteronorpha clathrata                     4    3     3 10 13 13 32 43 41 24
  -Enteronorpha flexuosa                     38 37 34 32 39 40 39 37 52 56 55 40 47 42 44 31 71 37 56 15 IS 43 IS 49 78
  -Enteronorphs intestinalis                 21 24 31 40 40 39 42 47 36 26 18 16 50 40 39 17 26 22 52 la Il 33 34 31 20 48 36 40 63 67 66 63 58 63 68 55 i9 55 77 81 44 76 42 69 45 37 58 55 62 40
  -Enteronorpha linea
  -Enteronorpha prolifera                    35 32 22       24. 29 3

30 7 19 5 26 4 18 1 39 3 34 1 42 35 4 29 1 27 1 23 1 29 1 27 4 42 5 17 35

                                                                                                                                               . 1 30 2 373 la1 42 4
  -Enteronorpha toria                         1     .    .   .

3

• 4 1 3 2 3

  -Enteronorpha ralf sii                           1     1       1   9     8    6    4   2     1      . 4     1   1     2                        .                 .

2 2 1 1 5 4 1 2 2 1 3 Percursaria percursa 1 . I 3 2 5 2 1 2 . . . . .

                                                                                                                                                            *2  93 64
  -Ulva lactuca                              92 87 74 81 SS 95 93 95 95                 *6    93 91 97 93 94 93 94 ?1 96 88 86 92
  -Prasiola stipitata                        25 24 20 23 24 26 30 '24 25 24 le 29 51                             1   2 89       1   1    1 73 17 25 24 27             .

7

  -Chaetenorpha linun                        71 50     32 3D 50 82 90 90 89 87 78 64 60                    1 76 75 79 47 62 72 78 81 700 750 62
                                                                                                                 .   .      .   .    .   .     .    .            . 1 Chaetonorpha melagoniun                         1             .     .    .   .     .  .      .     .

12 2 2 443 5 705 425 50

• 41 164 32 429 6 3'1

  -Chaetonorpha aerea                        30 25 25 23 29 28 41 34 37              8 31    33 2

34 303 9

  -Cladophora albida                           .    . 1   3   6   6     9    6        2           1                      .

2

  -

• Clacephora flexuosa* 11 1 3 7 18 38 55 31 30 30 13 9 12 30 30 3 17 19 21 23 19 18 211 161 291 2 3 2
• Clad:phora glaucescens* . . . 1 2 2 1 3 1 . . . . . . - .

4 1 1 0 2 3 2 1 1 . I 1 1 . Cladophora laetevirens 1 I . . . . . . 5 6 5 3 1 5 23 2C 16 16 23 11 14 5 26 16 6 14

• 15 13 7 12 18 -

    *Cladophora refracta'                                                                                                   3 34 37 36         8 19 22 24 21 37
  -Cladophora sericea                        12    4 10 22 41 30 31 34 19 21 14 18 29                      2 18 12            2   2    3     1         I   1   1    2
    *Clacophora crystallina'                   .   .     .   .   . 5     5    3    2   .     .     .           .   .      .

9 6 7 5 3 8 10 9 10 9 9 6 2 6 1 9 3 8 7 9 2 .

  -Cladephora hutchinsise                     1    3     3                                                                          3    4     1   4     2   2   2    2
  -Cladtphora rupestris                            1     1   1   6    7    6    4    1   1     1     . 2     3   2     3    1 2     3    5    3         2                 4              3   4    2     .    . 2   e   3 19
  -Cladophora ruchingeri                           .     .   . 2                       1           .     .         .      .

20 9 7 18 21 15 4

7. 17 19 11 14 21 28 29 22 21 8 13 31 16 6 6 14 41

  -Rhizocloniun ripariun                                                                             1     4     1                  I    1     1    1    1   1   1    1

• Rhizocloniun kerneri* 1 . 3 . 1 3 2 1 . . . . .

1 0 1 3 1 1 . . . 1 . . . . .

   *Rhizocloniu,tortuo:un'                     .   .     .   .   .         .    .    .   .           .

7 5 4 7 20 4 4 4 4 6 A 5 8 i 7 2 2 1 14 11 10 8 5 .

  -Eryopsis plunosa                                      .   .

6 4 6 3 3 4 8 4 5 4 5 5 3 7 5 l 72-Eryopsis hypnoides 5 7 14 7 5 7 1 27 j 1 3 3 3 7 8 4 1 3 IS 4 1 . 2 4 6 5 85 80 67 70 73 61 84 87 88 83 86 84 83 81 85. 94 100 91 86 64 72 84 83 84 54 4 4 2 1 . j Derbesia narina j y- -Codiun fragile 5 2 h Q

                                                   'CD                                                      Tshk l ; (amt).                                                                                                                                                                                                                                                                         t cc                                                                                                                                                                                                                                                                                                                                     .p L

7 R!-odophyta Jan Feb Har Apr May Jun Jul Aug rep Oct Now Dec CN BP MP TT FE FS WP SE SS tot 2U ' 3U Q 7 5 fStylonena alsidii 3 3 2: 2 . 3 6 9 15 2% 5 4 13 8 3 1 12 7 8 1 4 6 8 4. 28

-Erythrotrichepeltis ciliaris 30 17 11- 13 13? '9 9 17 30 48 30 23 35 18 11 17 34 ' 18 27 9 17 21 22 19 12 'l O -Erythrotrichia carnea 2 5 1 2 3 2 1 1 8 8 2 3 6 1 5 3' 5 4 3 . 2 3 3 4 4 r

                                                    ' L -Erythrocladia subintegra                                                                                                                                           .      .  ~1      1-    .   .1      -   3   1      4       4         3   1         2            3     1              5           . 1         1   2    2     1-  5 f$ -Erythropeltis discisera i

5 3 4 1 3 . 2 1 6 8- 7 6 2 8 5 2 8 1 2 3 4 4 3- 4 6 on -Bangia atropurpurea 59 76 82 78 28 12 4 7 28 26 32. 47 47 47 52 41 37 29. SS 39 .26 41 40 41 9 -;

                                                                              -Porphyra leucosticta                                                                                                                      55 71 69 73 55 27 11                       7   7 28 23 30 44 32 61 45 42 33 39 35 27 39 34 4e 16
                                                         .E,-Perphyra                                                                                                 unbilicalis                                        46 52 76 .79 85 63 50 38 24 22 29 37 57 43 63 51 61 45 50 67 32 52 50                                                                                         54- 20
                                                            -.-Porphyra linearls                                                                                                                                            . 1    2      .     .     .      .   .   .      .       .       4    .           .          2    2                 .   . 1    1          . 1   0     1    .
                                                       "3                            Porphyropsis coccinea                                                                                                                 1      l'     . 2      .     ..    .    .   .      .       .        .   .           .          1     .               . 2      .    .         . 0   0     0   1
                                                                    - Audouinella purpurea                                                                                                                                 2      2          2     2     1      1   2   1              3        1~ 1                        1                   9           1              I   1    2    0    I 31 41 31.         324 30 30 21 16 14

[

                                                                                                                                                                                                                                                                                                                 . 332 173 192 182 223 26 22 26 31 le 28- 14 13 32 43                                                                                                  7 "h"h                       Audouinella   -Audouinella                                                                      daviesii                  secundata    5       . 3          2      2     5    1   1      2       5         . 4          2                                                3         2    3    3    1    9
                                                         ' -Audouinella saviana                                                                                                                                          11:     5 10 12           9'    9    .5    4 16 18 10               '7    16 12                    9    9 15 12 10                      1        6 10 11        9 -20
                                                                             -Audouinella sp.                                                                                                                              .       .    . 2     .      . 3    .   .       .      .         . I          1            .    .              1      .    .    .         . 0    0    0   1
                                                                             -Audouinella dasyae                                                                                                                                                         1          3-                                          1                                     I     1                  0    0    0   1

12. 10 9 10 le 10 12 . 12 14

                                                                             -Celidiun pusillun                                                                                                                                                                              16' 18 -18            27           .           .   -2             2 78        4    1          . 13 - 9 . 19 - 2       .

l -Nena11on heinintholdes 1 2 2 0 1

                                                                                                                                                                                                                               .8. 13 16 28 48 34 l                                                                             -Bonnenaisenia hanifera                                                                                                                      6                                         9   1      1       3        5   1 14                    3.. 36               . 1 20 26 36 15 15 15 ~ 2 l                                                                                      'Trailliella intricata'                                                                                                              .      . 1.     .    . 1      .   .   .       . . .           .    .          .           .    .               .    .     .    .        1    0    0    0    -
                                                                            -Agarchiella subulata                                                                                                                         7      8     6     5    7 10 11 Ic 15 10 12 12                            3         4             5    1 45                 6 11      2         9 10 10 10 98
                                                                            -Polyides~ rotundus                                                                                                                          'S      8     1     5    8      6     9 11 13        8 12              9   2          5            7    9              6     5 13      1 21           6 10      5    .
                                                                            -Cystocloniun purpureun                                                                                                                      76 67 -61'         61 68      70' 37 16 '12 33 49                  58 57 38 58 69 37 45 62 48 59 52 60 41                                                           3

, -Gracilaria tikvahias 2 . 1 . . . 3 4' 1 2 2 1 9 1 1 0 3

                                                                                                                                                                                                                                   . 36 33 30         319 309 249 275 35           37 43 147 265 44                            69 446 146 45                   22 38 34 46 188

' -Ahnfeltia plicata 36 40 .

                                                                            -Phjllophora pseudoceranoides.                                                                                                               18 14 10 .10            19                        16 13 16                                       11 22                          33     6 11 12 15                   .

l -Phy11ophora truncata 9 14 8 6 7 '9 8 7 6 6 11 13 8 6 7 12 7 7 17 4 10 9 12 4 .

                                                                            -Chondrus crispus                                                                                                                           '94    94 94 94 94 94 95 95 94 93 94 94 100 100 100 100 75 100 100 100 100 97 97 97                                                                                   .

l -Mastocarpus stellatus 68 60 53 56 59 64 59 60 62 59 71 66 27 57 91 100 10 33 79 95 96 64 61 68 . Petrocalis niddendorfii . . . . . . . . . . . 1 . . . . . . . 1 0 0 . . Rhodophysena scorgii . 1 5 1 6 2. I 2 2 . . . . 1 . 1. . 2 2 1 7 2 2 1 . t I -Corollina officinalis 63 64 54 56 54 56 57- 62 57 63 58 67 2 99 ** 35 54 82 86 34 23 61 60 63 .

                                                                           -Dunantia contorta                                                                                                                            41 57 73 78 75 37                     6    e   1      .       I       o 38 17 35 50 16 94 31 28 42 33 35 30                                                         1 Gloisinhonia capillaris                                                                                                                 1       -    1     .           .      .   .   .      .       .        .   .           .           1    .             1      .     .   .         . 0    0    .   .
                                                                            -Choreocolax polysiphoniae                                                                                                                    8      9     9     9   -.7     3-    5    4   3     3        2        7 10 22                     6    3             1      . 3    .         6    6    6   5    .      .

l -Hildenbrandia rebra 3. I 1 1 2' 2- 3 4 1- 2 1 . 13 I 1 I 2 2 2 l 29 35 36 33 30 . 344 31 25 19 12 22 26 28 28 12 69

                                                                            -Palnaria painata.                                                                                                                                                                                                                                                 6      6 38 23 54 29 33 22                    .

t -Chanpia parvula 28 16 10 4 2 3?. 64' 73 67 55 45 33 23 19 34 35 35 53 27 45 35 37 31 2 ! -Lo.,entaria baileyana 2 . . . I 6 24 36 21 6 1 17 4 1 4 16 14 13 1 2 8 10 6 6  ; , -Lonentaria clave 11osa 8 8 .. 62.10 6 .1, 1 3 42 23 4 31 3 3 3 8 1 3 7 5 10 5 7 2 1 ' i tonentaria orcadensis 2 2- . . . . . 1 . . 5 . . 3 . I 1 1 1 1 l .-Antithannion cruciatun 41 23 9 '16. 11 17 44 . 57 53 61 61 50 35 46 36 39 31 35 53 27 40 35 43 31 24

                                                                           -Antithannion sp.                                                                                                                             22   21 14          8 10      l'J   17 24 30 18 23 24                      7 21 39 28 22 17 18 12 14 19                                                    . 46     5      ,

Callithannion corynbosun . . . . . 1 . 4 5 4  ; . . 4 1 1 1 1 3 1 1 1 2 . 7 $ l -Callitnannien roseun 4- 1 3 1 2 I 7 16 27 13 12 6 6 4 6 6 22 9 8 2 6 8 9 6 20 l -Callithannion tetragonun 41 33 21 25 15 8 '15 18 30 36 48 35 23 32 39 42 31 18 34 14 21 27 30 11 1  ! l Callithannion byssoides 3 2 1 1 3 1 0 11

                                                                                                                                                                                                                          . 13 7 5                                                                                                                                             I

' *Callithannion baileyi* 15 2 3 10 9 9 14 21 13 9 20 23 16 . 5 12 4 8 10 1 23 8 l -Ceraniun desiongchanpii 4 2 1 1 2 3 2 3 5  ? 2 3 2 1 1 2 3 1 4 '.2. ' .. '1 i -Cor_nium diaphanun '

                                                                                                                                                                                                                                       .          .      . 24 58 49         41- 11              7 12 27                     2 29              6 10 25 19 21 17 18 15 30
                                                                           -Ceranium rtbrun                                                                                                                              85 85        71. 75 81 87 '90           84 90' 87 88 85 85 ?6 80 93                                           80 81 95 83 84 86 88 84 33 Ceraniun fastigiatun                                                                                                                   .       .                                     1                                                   1                                                  0    0
                                                                                                                                                                                                                                                   . 30.. 28 37 31 61 61 61 45 53 28 33 19 24 66 33 45 39 43 34 21- 19
                                                                            -Spernothannion repens                                                                                                                       51 31 23                                                                                                                                                            6
                                                                           -Spyridia filanentosa                                                                                                                           .      . 1     .     . I     1    3   9     4       '2        3 12           1            . 1              . 2    1    .          . 2    2   2    8
                                                                            -Scagelia pylaisasi                                                                                                                           2       1    4     4    3      . 1    . I     2        1        2   1          1            3    2'            1      1    3    2        2     2. 2   2    2
                                                                           -Crinnellia americanum                                                                                                                         4       .    . I    1      1     5    8   8     8 11             7    1         1             1    4             9      1. 10    2 12           5   4    5 18
                                                                           -Phycodrys rubens                                                                                                                              1. 3      4     8    7      9     4    4   4     5'       S        3                           1 11                1     1 15      4 10           5   5    4
                                                                                                                                                                                                                                                                                                    . 12
                                                                           -Dasya baillouviana                                                                                                                            7      1     .. 1     .     .   .7    30 24 22 19 15                   9                       4    7 22 16 14                     2 10          11- 12    9 52 t

TaNe l (amt). Rhodophyta Jan Feb Har Apr May Jun Jul Aug Sep Oct Nov Dec CN BP MP 77 FE F5 WP SE 55 tot OU 30 Q 5 4 1 1 1 I 1 1 1 .

                                                          .   . 2        4     .    .               -            .          .   .

3 3 2

   -Chondeza sedifolia             .    .   .     .  .

1 1 3 14 8 1 3 6 3 8 3 . 4 2 . 1 .

   -chondria baileyana             1    . 1     .       .

1 3 1 1 1 . 1 . 3 3 3 . . . 4 . . . .

   -Chondria tenuissina            .    .   .        .

1 . . 0 0 . . 1 . . . . . . . . .

   .ChenJria dasyphylla            ,    .   .     .  .    .   .    .

2 5 4 4 5 1 3 4 1 4 1 1 2 3 2 55

   -Polysiphonia denudata         1     1   1     . 2   1    4    1                         .
   -Pol:<siphonia harveyi        50 27 16 17 12 40 65 70 69 49 55 46 42 45 44 38 58 42 46 37 45 44 58 24 49
   -Polysiphonia lannsa          7e    68 67 60 70 68 64         602 651 675 673 735 796 91      12 1002 45   2 28  2 37  4 1687 606 958 60     7 68 7 70  6   2
   -Polysiphonia nigra            4     8   9 10 16 14        1 4    10   14    14 53       9 l' 19 21 15               5
   -Polysiphonia nigrescens      15 18 11 23 13 25 19 164 174 202 19219 7193621                  18 22 17 14              3 32     6

• 17 23 14 8

   -Polysiphonia urceolata       17 17 24 40 46 27 10                                 4                       4                3       1        1    1     0    .
   -Polysiphonia elongata          .    .   .     .  . 3    . 2    .   . 1           .     .   .            .      .       .

1 2 2 1 6 1 1 3 . 10 3 1 1 5 3 . I 1 .

   -Polysiphonia fibrillosa                 .     .  .    .        .    .

1 2 1 1 1 2 1 1 0 2 1

   -Polysiphonia flexicaulas      6     1   .     .  .    .   . 1    . 2     . I                                    .           .
   -Polysiphonia novao-engliae   76 68     43 30 33 7 18 13      7 55 2

74 81 82 1 89 1 88 1 86 1 669 68 6 761 677 813 631 754 584 658 695 637 762 451

   -Rhodonela confervoides        5                           .

Phaeophyta Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec GN EP MP TT FE FS WP SE SS tot ZU IU Q

    -Ectocarpus fasciculatus       4 11 13 23- 29 33 23 15 24 26 21 11 19 24 25 38 18                                      8 22 19 14 20 22 18                   1 8
    -Ectocarpus siliculosis      18 34 40 46 48 51 43 31 22 201 213 14                 3 49 33 21 42 34 29 42 32 226 344 39 261 3    4    9     6      1     2        2                 5 Ectocarpus sp.                3     7  6     5   . 4   5    3    4                                                       1 3

3 2 2 4 6 7 2 4 1 4 3 4 2 5 6 6 2 3 1 2 3 3 6

    -Giffordia granulosa                                             .

6 12 41 14 24 4 4 17 15 19 17

    -Ciffordia nitchelliae         6    7   4     5 14 15 15 30 39 35 16                7 22 19 9 20 10 16 56              6   4 23         6 56 19        6   6 21 22 18               2
    -Pilayella littoralis        17 15 23 32 44 31 10 11                               3 14 17 11 14 12                    6 12 14     9 12 13 11
    -Spongonena tonentosun       11 22 43 2S 15           2   2    4     . 8      1                                                                             .

1 1 0 0 . Entonena accidioides . . . 2 1 . . . . . . . . . . . . . 0 1 . 10 2 1 1 . . . 1 . . . 1 . 1 . Acinetospora sp. . . . . . . . 0 0 I 1 . . 1 . . 1 . . . . . . Feld=0nnia sp. . . .. . . . . . 48 55 39 46 39 40 56 67 68 59 56 50 73 65 50 38 40 62 71 362 42 55 53 5264 56

    -Ralfsia verrucosa
    -Elachisia fucicola          40 47 62 71 756 832 752 76 70I 47139 32 71 165 65                 3 62 1

58 2 46 65 .

                                                                                                                                    . I 62 61 1    1      1
    -Halothrsw lumbricalis              I   1      .                .              .    -                            .

1 . 12 25 31 29 9 . . . . 17 5 26 6 12 4 14 1 2 9 8 12 .

    -Leathesia diffornis                                                    4          2 11 26 17 12                4      1 to    7   5 11 14             7
    -chordaria flagelliformis       .    . 1     4 17 34 29 23 13                1 2   2   1        1    2      0 Sphaerotrichia divaricata      .    . I     1  3    6   1     .    .   .     .    .     . I   1      3      .     .                                     .

1 . 0 0 . . Cladosiphon zosterae . . 1 . . . . . . . . . . . . . . 2 2 Asperococcus fistulosus . 103

                                    .       5 M

2 7 3 4 3

                                                               .    . 1 2
                                                                                   . 2
                                                                                        . 2 6

1 5 2 4 2 1 2 1 1 4 3 1 1 2 2 3 1 2

    -Desnotrichun undulatun        .                           .    .   .

1 1 I 1 I 1 0 . Phacosaccion collinsii 2 3 . . . . . 1 . . . I . . . 5 8 1 3 4 6 4 5 2 8 4 8 5 5 3 5 5 4 2

   -Punctaria latifolia            3    8 11      8                 .    .

7 4 3 3 2

   -Punciaria plantaginea          1    4   2     1  4    5   5    3    3   1     3    1     6     3   2      .                     . 1                        .
   -Petalonia fascia             6S 84 73 88 84 78 63              9    3 11 39 63 55 71 65 60 52. 55 68 53 35 57 57 57                                         8 5
    -scytosiphon Ionentaria      40 74 88 93 90 89 73 14                3   6 14 30 5? 69 56 43 45 61 58 47 36 530 560 50 1        .   .                   .    .

Delanarea attenuata 1 . . . 1 . . . . . . . . . . . 8 13 11 10 10 6 5 9 11 4 9 1 22 3 6 19 9 11 9 8 11 .

   -Desnarestia aculeata           9    7                                                                                                                       2
    -Dosnarestia viridis           1    3 28 42 49 33         1    1     .   . 1     . 12      l'  14 27         6 11 17 11 19 14 14 14 7 21 15                                 2     1   1 13         1      1 10    4   6        4    4     5     .

PC -Chorda filun . . . 2 2 . . . . 5 7 5 3 10 19 26 2 5 . . . 1 4 3 25 1 3 5 6 6 . O -Chorda tcaentosa . . . 4 . 10 6 2 2 1 Eh -Laninaria digitata 2 2 1 3 4 . . 2 1 1 . . . . . . . . 'c -Laninaria longieruris 9 12 10 14 12 10 14 16 16 17 11 12 9 2 8 53 1 1 23 17 16 14 12 16 . 7

-- -Laninaria saccharina         47 35 51 62 81 83 76 71 57 56 50 50 67 69 618 913 52                             57 36 492165 634 494 62  23 22  6325  62     2 3 -Sphacelaria cirrosa           31 17 12 13 18 15 21 20 25 32                  331 38 501 19          1                  I    1   1            1    0     1     .
$ -5phacelaria rigidula                 1   .     . 1    .   . I    2   1          .           -          .     .                   .

92. 92 93 93 93 93 93 93 924 924 92192 31004 100 100 100 61 100 41004 1007 100 957 97 8 93

=. -Ascophyllun nocosun                                                                            4 14 17          7                  1                   5 C. -Fucus distichus s cdentatus   8     9 13 17      9   3    1                              5                                                                  .

5 4 6 1 4 6 1 7 12 5 21 4 4 6 6 9 8 10 5 . E -Fucus distichus s evanescens 10 9 17 15 13 5 2 1 2 7 7 6

   -Fucus spiralis                4     1   2     8  7 10     8    7 13     8    5    3      6 31 12                      I                                     .
   -Fucus vesiculosus            95 95 96 So 96 97297 297 95           95  95   95   100   100 100         100 89   . 100 100 100 100 9e 98 100                 .

2 2 4 3 2 2 2 1 19 . . 2 0 5 .

,_ -Sargassun filipendula         2     2         2                                          .         .                  .    .

u, C

                                                                                                                                                   -                u

not represent distinct species (cf. NUSCO 1985), of the pitnt is extremely characteristie, but does For example, the red filament '7'railliella intricata' not conform to that of any reported North has long been known to be the tetraspotic life. American or European species (C, Schneider, pers. history stage of Bonnemaisonia hamifera, but is so comm.). The description closely matches that of dissimilar in habit from the gametophyte that, for Antithamnion nipponicum, native to the southwest our convenience, we consider it ' separately. Pacine, und the similarily is strengthened by a SimHarly, small green cells identified as 'Codiohem report of the recent introduction of A. nipponicum gregarium' are a stage in the life histories of to the >1editerranean (Verlaque and Riouall l4S9). distinct genera Urospora, Spor rpha, and 1.!cwever, pending confirmation, we will retain the Acrosiphonia. The .chrysoph tacosaccion name Antithamnion sp. co//insii has been included in Phaeophyta, again, The MNPS area Hora has remained generally solely for our convenience. Other taxa may be stable since sampling began in 1979, despite the: conspecific, or subspecific forms, and continue as addition of Antilhanm/on sp The components of a source of controversy. Keeping in mind the this Hora exhibit consistent patterns of spatial above c3planation, the local benthic marine algal (station tu station) and temporal (seasonal) flora includes 158 taxa. distributw tmong years, and between 2-unit and During the paf.t year,128 taxa were collected _

3. unit oyrMional periods (Tables 2 und 3; (Table 2); this the largest annual total species NUSCO 1990). Also present in 1990 was a number in the 3. unit operational period to date distinctly different community at FE that (previous range 118122) and increases the overall developed after the opening of the >econd cut in 3 unit species total to 144 taxa (Table 3). During 1983 (e.g4 NUSCO 1985,1987,1990). This FE 2-unit operation, annual totals ranged from 101 species assemblage remains distinct from those at 131 taxa, and the overall 2 unit total was 156. the other stations, due, in part, to characteristle Only 14 taxa (5 reds,5 browns,4 greens) that were species not found elsewhere at NUSCO sites. For found during 2 unit operation have not been found example, Sargassum filipendala maintained a ',

in the 3. unit operational period. None of these perennating population at FE during 1990, but was species were common during 2 unit operation; not found at any other station. On the other hand, each was found on average fev cr than four times some species, commonly found elsewhere, were in almost 700 collections. rare or absent at FE; e.g., Alonostroma grcril/ciwas Only two additional algal species have been never collected at FE, but was found in two to four collected since Unit 3 began operation. One, - collections at all other stations. Other species Nemalion Ac/minthoides, a gelatinous red alga, was characteristic of cold water collections have a found three times at Bay Point (once in 1988, shortened season of occurrence at FE, relatise to twice in 1989); this plant is not considered to be a. that seen at other stations. For example, during dominant component of the local Hora. The 1990 Bangia atropur/ntrca occurred at FE only in second species however, has 'become almost March, while at the other eight stations, it ubiquitous. A filamentous red alga, Antithamn/on occurred 46 times (3 7 times per station), in every sp.,was first collected in August 1986, at Millstone month but July. Similarly, Scytosiphon lomentaria

                         . Point. It has since been found at every station,-                                                                    was found from February May at FE, from and in each month. Antilhamnion sp. occurred in                                                                       December July at other stations. Still other 45% of the 3.tnit operational period collections to                                                                   species are characteristic of warm water collections, date (Table 2), including 79% of the collections in                                                                   a9 are more common at FE than at other the past year. This alga has become the. most                                                                         stations.- For example, in 1990 Gracilaria likrahiae common epiphyte on seseral . macroalgae, e.g.,                                                                        was present four times at FE, once at FS, and not Chondnis, Corallina, Ulva,                                                                                            at ather stations. Similarly, Agardhiella sulmfata Despite ' the abundance of Antithamnion sp.,                                                                      was found ten tim, at FE, once each at FS, MP, assignation of a specific epithet to this plant is                                                                    SS, and WP, never at BP, GN, SE, or 1T.

problematic, and confounded by the absence of' The distinctiveness of FE, and the consistencies sexual reproductive structures. The alga of species occurrence patterns at all other stations propagates entirely by. fragmentation and are Illustrated in Figure 3 a dendrogram that reattachment of distal branch portions. The habit represents-multiple pair-wise similarities among

                         '160       Manitoring Studies,1990

ph

      .y Q 'A
                                                                                             /g eA   +        a%o o.
                   'W                  IMAGE EVALUATION
 \O     t(9,#' %) 6*
                                                                                      b f]/J.%

\ \//// TEST TARGET (MT-3)

                                                                                               ' ^ 'l0 f;g
                                                                                ////

q fp . ,#, 4Q

            $9                                                                        %g46 l.0        5 3 "12

n. m m22 L ag4:

                                                             ,, n E'          M! 2.0 l,l        ..'*

Wing 3=: l.25 I.4  ! L_1.6 4 150mm > 4 6" > t

   $       ?'%.                                                                     / 4,
 .a m' n                                                                              p(),,        a s ,//ss 4,'

YEbr ' ,

                                                                                            ,36, o;,         i r
                                                                                               $p 5'**~..                                       __

                                    "'       4 %             .

f,

       ?      .~
    '; O'   7         IMAGE EV Al.U ATION                            /j//// j x
                                                                                      /J      w

//g// X'" 9)g/ TEST TARGET (MT-3) [p 4;6 7 4 g// 9?$# k / lg !L .- 2 8 .L 2 $

l. v L ,3'T i_ t 4 322 L. O r-J a

                                            ; y.

1,l U !!. !!]!3S~= I.8 lindius li I.23 1.4 [ 1

                          .__          s=s       i   m.6 4                        150mm                                          >

• 6" - >

A *% ,; w y

            , s' // c
                                                                    /+!b   4,     2///A
                                                                              ,p g o                     ,

Oy qts 4

                                                                                  <$6 L                                            . s          ..     . ..      __

                                                                                       ~

A rib & s-  % IMAGE EV ALU ATION j!I(/J/ \\\\ M^ O

   !1           v'         TEST TARGET (MT-3)
                                                                      \\     j;:>        b
                                                             //,9 it!N#
    ,fy g)                                                              Atg'%g l.O     ,_

P_

21_

h. j .

[- b t /~ q

                                                  !w!20tra l.I    ..

v., j"t25-- u la

                                         ===
                                                  ,    ,3 t        .

4 150mm > 4 6" > h' g'h\

     *V' &y,b p
                   "                                            4('O 4 k,y;/ >,,r           ,                                               ,+ ,g,,,o g*

l or e{(b g

 ~
                        .u                               ...
                                                                -f d'                 _.

                                                                                                /

_, h-e A iv e a, .

                                                                                             //(o               4 ev V                   IMAGE EV Al.U ATION                                                             ,t h
         %. 0" cv                                                                            </
 \/,O// ' i .'# ihI#         TEST TARGET (MT-3)                                                       [y(fg

[ 4'(

   \+/                                                                                             tc w,,

u m on wm "n gi2.0 1,l

                                                            ~
                                                                          =

M1 1.25 l.4 l 1.6 _ _ l 4 150mm > 6" > 4%4f

   . o at: y, y ,y,$ ,
                                                                                   ++3A's                         s ff8 s p ,p mg                                                                                       <              g e.
                                                                                                 ,p, .y y,/

o , .

                                                                                                        .p h-     .
                                                                                 .. F.           .         . .       . . . -
                                                                                                                             ~
                                                                                                                               =

      ,Q 14 q~pp v#*p,.

• g't<ev l.0 N

                                - ",, "21      ~

I+ IeI l. 2.2

                                              -+xt

[ 33 l' t 11 2 jjjjjam.0 c l.l [ E- = I.25 u.a _ 7, _,,_ 1 150mm > 4 6" >

                                                                 '                ss ad,, ogA,                                               , [#'e,,,,

y, y,,,, , - e 3

                                                                  .o.@{4 gcp-
                                                                                 ,s o,    ;

t Y

a. S 1

           ; ~.                                        ~ b cl,)                     .._

a

    #1 .t   Qz                                                                O v vn,.

v4 o

              .,y                                                                , O:,, %

IMAGE EVALUATION S W'L / [ft " d4 \//o//'( 4!$h#' TEST TARGET (MT-3) Y

 %           %>                                                        dQ I.0
                                  ,          F:

J m"" b i_ ,1, me U^ j,j g "" qqi m 2.0 El I.25

                                             =I.4 II'l   l.6 l

l ll 4 150mm > 6" > 4 4 +<$

    ?
               %g4              -                                 +.,, m gx      s/r A>

yy; - y , g>/ c ,o3 u., e .

                                                                          'fb     t' kh' t

3N is i 15(4to brim n l<G2) 15(21) 21(29) In(20) in(20) 2A27) 15(24) 32(26) ItG7) 12(21) 1923) IN 2s i bGI) 21<21; green U(32) 25(36) 2T(32) 5(31) 24(M)) ly2x) 2K35) M(31) 21(35) 2K40) 20t31) 22 A u 2 e s) \fi ni tit. 60 73 57 9s tout 72 70 73 80 79 82 124 Ss ni UN red 2343) 34(45) M(44) 3945) 37(45) 3x43) 34(44) Sn(45) 27(41) 3k42) 3941) 32(42) h t \) th4h l'rown 17(25) is(24) 23(37) 20(24) 17(21) 20(24) Ig25) 3GI) 17(2a) is(25) 1427) 21(28) 24 # , 3 Gs > green 22(32) U(31) 25(29) 27(32) 19 31) 1933) 24(31) 3g 31) 22(33) 3(32) 13 33) Ik30) 24(29) 32( % fod 68 75 86 85 82 84 77 125 66 71 bo in 84 107 htP red - 30(40) 1K43) 3)(40) 31(44) an(43) 2333; 2n(4n) 24(39) 35(47) 1K 47) 4 t( 44 l>rown 2q27) 22(29) 2K30) 15(24) 2g27) ItG4) 12(21) Ig tl) 21(2s) 17(24) :s2s) green 25(33) 22(29) 1K30) 24(32) 32(30) 22(33) IN32) Ig31) Ig25) 2iG9 2n(2n) total 75 77 77 73 107 67 56 62 75 70 99 5 11 red 27(46) 25(45) 34(49) 1\45) 32(46) 2341) 2944) 4g4 4) 24(41) 25(4n) 27(41) 2342) 2.g 41) 41(40) brown 15(13) 17(30) 1927) 20t27) 15(22) 2q29) 15(25) 2327) 15(25) IX;4) 14 6 , . Ig28) ItG5) 21(D) 'rcen 17(29) 14;25) 18(25) 20(27) 22(32) 21(30) 20(31) 32(29) 21434) Itgit) Ig31) ' (kly 21(32) 2g31) 41 " 56 71 73 69 70 63 109 59 54 c.2 o n5 90  % red 30(44) 33(49) 40(47) 40(45) *N47) 4k5t) 3(44) 56(40) 2345) 15(5 2) 3n(51) 1K 46) 3449) 4g44) brown 16(24) 13(1 % 23(27) 21(24) 3(27) Ig22) 17(25) 31(25) 17(26) th19) 12(17) 1925) 17(24) 2%(24) green 22(32) 22(32) 2'(26) 27(31) 22(26) Ik:7) 21(31) >>(29) 19(29) 1928) 22(31) 2t(2A) Ig 7) 2g2s) total 68 68 85 8* 85 85 M 123 65 67 70 71 71 104 'IT red 3345) 37(46) 37(49 40(51) 53(49) 3A44) 3g45) 31(43) 37(47) Y(4%) 30(45) brow n - - 2n(30) 1\;9) 22(29) 2fG6) 28(26) 22(30) 2n(30) 1K32) 1K 29) 25(32) 32(29) peen 22(25) 2tK25) IN23) is(23) 27(25) Ig20) 21(24) 1925) Ig24) 17(22) 28(25) total 67 80 77 7s los 73 56 72 7u 77 110 WP red 33(45) 39(47) 45(46) 42(44) 3g43) 4448) 41(47) 5s(46) 3n(4 4) Al(45) 3g45) 35(4 6) 3g4 4) 50(44) brown 1925) 20(24) 25(26) 24(25) 23(2n) 22(24) Ik26) 3K26) 20(25) leCl) 21(24) 22(2x) 2)(24) 2n(U) green 22(30) 24(29) 27(2x) 2331) ;g31) 25(28) 1h26) 3n(2x) 25(31) 2 % 33) 27(31) 22(23) 13 32) 3s(3\) total 73 83 97 95 90 90 87 127 31 75 87 79 8x 114 Total red 45(45) 4% 46) 59(47) 57(44) 57(46) 5%45) 52(46) 71(46) 54(45) 5g4s) 58(4s) 54(4n) n2(as) ns(ts) brtmn 26(25) 26(25) 35(27) 35(27) 32(25) 34(26) 29(25) 44G5) 31(26) 3G5) 30(25) 32(27) 31(2 1) 35(25) green 3)(30) 3G9) 34(26) 3% 29) 37(29) M(29) 34(29) 45(29) 35(2 9) 33(27) 34(28) 32(27) 35(27) 41(27) total 101 104 128 130 1:n 131 115 156 120 121 122 118 12s lit Rocky Intertidal 161 LV * -R . e' r. s. 7 s e e e s , , i. . .- . , , , , , . ,_ A-rC .+A _ La._.._ e4 e .,, 4 . ,_ ---{~*.+w._p = ,._, a: .. _ o 4 -E ,t.-.._ +4 a.$ ,- . d . *- . . . . ?.<9 +) 4 '-]r-- L_%u, , -. s M 3 v u_~ n .._ J. 4

• r _.--, W h4 L .-

w. .

e 2u r n - l.i> 1 _1._t_ ._w - .,, .f. p. .c .\ = 5 -._-.[L. 0:~L.eJ7 = ,n n_ _'e--<L- _ v, . _ j:.y . +, , d ,['I_' . u '7. A. 3 "g - '---- c ,:y g m - - - . ~k n.--lNe ._._..,+.c - 1 ~ r E [- - - _ F Z M. C -+,_-.s,ej. e- .

1. U s t _ csA,' u e

e C-4 -F _. .cA m L_... M eq. #u, A 3 a<. -l- - , G.* A# . 4 kt .E' J+ o.h, d C cy .tr C ~ pj _~ 7 'E i ~8%*4 ~ 5 8 a% g s. Mc s%fi ~ . 1 -g i. E c %e . g u 9 -L L M' 2 C e4__. iu . [C a,.e , u . t.x n #.* .a. , s. W ". e*) s e g - i.! C .?S  % (A

v. LI; 1:

, i- ,- , . , , .. . . . . . . t a- -n 'e' > s n- .n. 2 S 2 e s s Ap;cwg tvaneo . 162- Monitoring Studies,1990 - - . , . , oi. ,--s., , , - . - - - - , - - - - . - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - ~ ~ l j wt leppJaiut rpon Jno in uopisodinoa saiaads jo tuatussasse alcJnaac aJotu .woitn pun (nonnaja yaled) aaucq)nis!p su unJi m[n y m>aAaJ ayi icio!q ay: Aj! pour l l anscyaon alcas ((ctus jo pqou, alcupuya on a3Jeg pun aauanuu! sassaaoJd puuamuo2 ua leals44d [ . Apuap!.uns (sinJpenb jo Jaqwnu puu a/!s Ta) WGaoJd 3Do!qc puu apo!q Xuctu jo uotituigtuoa l l azis aldtuus appoJd or paufisap ajaw staasunji e on ainsodra tuoJJ ilnsaj smsiuc310 asayi jo I-acy.L 'siaasunji paq)nispun uI sa!pnisXyunmtuoa suJaned aaucpunge tepuds pun IcJodtua.L JSdNit pun sapads tuoJJ tiep aaucpunqejo s!d cun l Xq sitp Jo A11upp ay1 ut sajoys ApoJ yqtyut qcturun yqi diuoaan aAV aauepunqu jo sujaned ap!w-ain puu stueld jo a3ciqmame lucpunqu pun yap y l alqnts aiotu fjpuap! o) si y 'JaylcJ '(podal sly) jo unpaas sa!pnis uope/!uotoaatj ayi u! paqqasap - luatuajiwua[y aaurpunqy - l sc) jpnap ut aaucpunqu .sapads un aauanuu! l Jiayi J pun _ l lsd ysuopepi iujuodtuoa xaidtuna .. JuopeJado lucid Jawod 01 j asays uletdva 01 idmann un tou q aApaafgo ano palepj lou '(cale SdNIN ayl oi ds uo/mumpuute TLS61 [puuo3 !!N61 upri pun ouind) alquia!pajd Jo uopanpojiut ay: "al) a3ucya anspop pun luenuoa - ApAlicpi tyetuas aaucpunge n XJ puaps on sn pawope meJ3oJd Supoquom jo suJaned (optw uo!3aj Jo ans) o[cas 33Jel inq ojsnN atu jo taanj s!yt 'XItcuig . suopcis - 'Al pidea saducya pun sdoprap uoppodtuoa sapads palacdtuiun 1a1 sn le tuatudoprop 39014 aJnini j (yaind "a 1) alnas pctus aJayw '(LW61 asnoyjainAg ajudiuoa on yaiyw isuin3e pJepuelt u pun 'pasodx3 ~

ptic stp3uvac) tunpginnba - apunuAp jo sons pucpl xod 01 uolsjnaut tetujatp pa/!udoaa; I

e ut aq on paqtaasap unaq asny sap!untutuna ajoys n noddns 01 aauappa arpaa[qo aAny aw 'saniupje . -(tS61 esnod Jeas on max 'uopen 0: uopens Jainw ploa pue Jaicw tujnw *ipApaadcJ 'auty 93 moJJ v3uctp aaunjeadde aqw alusoni utdtuna in suopanpaa pun suopuaixa tpns parjasgo arcy n alcaja smquc3Jo leppJaius un sawaaoJd acy: aw yalyw Joj sataads ay asnnaaq 'ajotufayund I jo un jo asunuodtut aulep> pun AcidJatui ay1 ays pasandmt un te vapads jo aauajanaan jo { ' -(1861 uoscas ul uopanpaJ Jo uopuatu ayt Ta 'saducya upx] pun aupy) yaicd agi jo (atupaj!!) uopeJnp apqns ajota on aspisuas ostu aJe Xay1 *ina l Uniaso pun tuatudop3ap Jo adels leuopsaaans AJicnb puoaas ay1 jo Ju!uado ayi yyw paletaown ato 103 siunoaan najn pajeap e jo 03n pun sa3unya Ayuntutuoa Jo[etu =iuatunaop sa%cun a/is scaje poi sicap anoas aat Jo cAnw paanpu! acyl mej$oJd Jugoyuotu teppJalut Avoi ay: tuson moil asuntpn n!p teapf4d oso3oid jo osauodtuoa (cappa u uletuas usit eun anspou apseyaois ni painqune pun uoncuoi jo sulaned Ud in Oh! OJSON T861 'In avin uo pasodtupadns 9 ainianus fyuntutuoa la AJngpnag amn) u!ctuop leluatuuoipua wau u jo atn jo luauodmm spied y smquc310 p!ppfatu! iuamdop up atp Joj aauappa Jayunj q 'suopaanoa - incm to caia 'anuel 'clo;?h 'sajods se tpns spun 6Nhl puu SW61 uaawiaq fipentun jo aat;iap aspanptudal) ein3rdojd jo Xyl Net!cAn ancin;iaJ y3ty e dutuoys '((l dnojo jo uoispipqns ay1 ina-pue Joneyaq Ja/c3;f pue Jompaid aauanUu! AJJenh punaas agi jo Ju!uado ayi on iuanbasyns nye (icuoscas @a) siuau Mpopad tuJai Jum) gj moJJ suopaalloa Aq Xpannpu pamasaJdai nonnqpNp pun Jopryaq ja/nni pun Joicpa2d q pun 'sdnoni Jayto ay) on Jelpungp f i$uojis iaajje una pue 'iy3y Jo Aylenb pulsads pun si til dnojo '(q))) ss pun as moJJ suonaanoa . l Xysuaiui uopeaatop jo siuairnJ3 dacys u! synca pun (c][) it tuoJJ suopaajpu oiu! ipnap uop3e icpp su tpns iuara aspopad mjai uoys e opptpqns ll dnoio cip pawdu aJom jo Inaldst - 'aldmeu 103 suJaned uonnuo/ Jo uopcupujalap nJoy c uoddns (t86101 Jopd) Bd pun 'dW *da ato u! tunnedtu! aic inyi stua!pni3 pnuatuuoipua 'dA\ staDyw 'paJalPys APAprPJ 3Jn (41) SJ pun alcan siuau a!popad smara (tuopunj No tainsodo jo aanfap uo speg ayi un papp!pqns io) 3piripon ni utqciaipaid so) a!popad IpqnjaJ ain suonets I dntuo cacpns puuo/poy tuoy v3uts icip tunnaads e u! Jnro saApuuayt ucyl teapJas (pcau atom tp!w 'siapinoq a:fjel assaaond agi osoys (poi uo pauasgo sujaned moJJ i lgntupd palaanoa aJn rol d tues ic3p! 'cip pun ainlanJn iguntumoa 3utupujalap ut ionnodiu! acy) ly adpal pupaq pasodu app l arry (ss u vsu3ojd avyt ;iuotun uopacjatui 'n yieauaq *gs'11)utopenIl dntuo "xl 'ninJngns Rupait!p dung stuqucJio no aJnsc1d ungnxpap pun poys jo anspalanintp aJe ieto siucid Jo sa3ctqtuasse asnw saanpa1 idouca pt3p: un vaunnu! 103 '(); tot luasaidu Xay asneaag it yntupd painicdas ain uruideyj) clu! Jai p'ap(yd layn una stuquc3Jo [t pun t sdnoJo w!inis tpna le suopaaltoa tenuun- m_ _ m ___ _ _ _ _ _ _ _ . _ __ . _ _ _ _ _ _ _ _ . _ _ _ sampling sites. Power plant impact causes Variability among populations of barnacles at all disturbance over areas.that are large relative to stations was considerable, although year to year sample size, altering established site wide patterns patterns were consistent within stations, important of species abiindance. The occurrence of dominant mechanisms ' possibly. responsible for barnacle specler responsible _ for observed patterns are abundance patterns can be determined by discussed below, comparing site specific trends in abundance to some biotic and abiotic environmental factors or Barnac/cs mechanisms, which vary from site to site. For example, in Zone I recruitment is lowest at GN The_ northern rock barnacle, Semibalanus and FS, our most sheltered sites. Limited wave balanoides, is the most common sessile animal on action and spray allow little ' soak. time' for cyprid intertidal rocky shores in the vicinity of MNPS. larvae to settle on high intertidal surfaces, This species occurs throughout the intertidal cone, compared to wave washed exposed sites- (cf. but is most abundant in the mid intertidal (Zime Underwood and Denley 1984). Chance of survival

2) where barnacles dominate primary space, of the few successfully settled barnacles is further -

Barnacles in our arca exhibit fluctuations in reduced at sheltered sites by starvation and abundance within a predictable annual cycle of desiccation brought on by longer emersion time occurrence similar .to that described by other (Grant 1977; Wethey 1983). Gaines and tescarchers (Connell 1%I; Menge 1976). Cycles Roughgarden (19S5) theorized that these areas of and patterns of abundance of : local barnacle low settlement are recruitment limited and that populations since 1979 are illustrated in Figure 4. Iluctuation patterns are low, as we base observed Maximum barnacle cover in Zone 1 during 1989 in Zone 1 at all of our sampling sites. 90 ranged from 2% (FS) to 40% (FE). Minimum Zone 2 is an area of high settlement that coverage ranged from 0% at FS to 15% at BP and becomes space limited (Connell 1%I; Gaines and FE In Zone 2 maximum barnacle coverage was Roughgarden 1985; NUSCO 19W). Barnacles lowest at FC (35%) and highest at MP (75%); settle densely in the tocal mid.lntertidat zone due, minimum coverage was also lowest at FE (39;), in part, to low predator density in early spring and

and highest at GN (30%). Maximum cover in limited interspecifie competition for available

- Zone 3 ranged from 1% at FE to 80% ut FS. space. S. baianoides recruits successfully under a During 1989 90 in_- Zone 3, minimum' barnacle canopy of the mid intertidal dominant, l'ucus cover was_0% at four sites (BP, FE, MP and SE), resiculosus, wh;ch further reduces mortality by with the highest minimum (20%) at GN. protecting barnacles from desiccation. Habitat Local barnacle-populations exhibit an annual conditions in Z(me 2 allow barnacles to grow . cycle of occurrence,:in part characterized by a rapidly until crowding or intraspecifle competition heavy set of cyprids on rock surfaces in late winter for space becomes important. - When crowded, L -- (FebAlat Substratum coverage of barnacles barnacle morphology and growth strategy change-i; ' increased dt.@ spring and summer as successfully Horizontal 1:asal expansion becomes impossible

recruited individuals metamorphosed and when primary space i used. up, so barnacles l

developed. Peak barnacle coverage in our area ~ growth becomes ' vertical and _ their morphology occurs in Junc or July. Coverage progressively gradually changes from cone. shaped (widest at the . decreases through the remainder of the year as base) to columnar (same diameter throughout). In ! - barnacles are continually removed by a variety of cases of extreme crowding the diameter of the li biotic and abiotie mechanisms, opening substratum upper most portion of individual organisms areas that permit the start of another cycle >he becomes greater than the basal diameter. - This following winter. For all sites except FE, the - phenomenon causes groups of barnacles to form annual cycle observed during 1989.90 was similar distinct knolls or hummocks (Grant 1977; Hughes : to that observed- throughout 2. unit and 3. unit and Griffiths 1988; Bertness 1989),which are more operation (Fig. 4 and NUSCO - 1987, 1990). susceptible to removal by physical -disturbance. Alterations to_ annual patterns observed at FE, Overcrowding is largely responsible for high associated with.the opening of the second quarry fluctuation in annual abundance of high settlement cut, will be discussed later in this section, areas (i.e., high seasonal variability; Gaines and IM Monitoring Studies,1990 --->n . + - . - - - .  % & e A 3a_---- -w.... a. ,- e- aM _._a_ w.4a - =a a .,a... . , . . e, y NS'Nbd.5 O PP.4418*. Uhl! ) ${grt up

• gge,qcfgg 3 p.ggary Uss,l j g tg { ,,,p w so

$3 . w M  % e +3 t~ u .; . . y e. , u ., \[ ft 5 h } jy}\ .$ \"l\. l f\ 1 \4l \,"/l k) '~ [ , . .I 4 . ,3 i f - - \; i j . f)r4,.6} j/ i' ;;t \ ~jY:\ld\  ; ,i ll\ .b A'* l .h [_ _. /_\ u%_m_A_ .i k _ . - . h.Y,_. ; .,_.s_a !l l \a

: : : ::::::::::::: : : : !: _:  ::::::::::::::::::*  :::;J i,4 ;4w.'.4 n -;.4sle., .;f -- a IM w.) .W A4.' kJ..ur. r Ad .;J '3 8 idw.;J n ;A - wle. . :A !.A /J., >i..,t .v o J /.n,Ad...

l . .... . ..... = ** M . , r, w uma 3 .uo ~o ..., a r.w . u.a a ino .c be. tid . seed F e, w N k S4 I a u ' \ .

• gw -

f . a ge u )'  ;'

• i l

y,a *' ,9, 6 -[ ,5 #x n y p i i ; rs q $ h.av \'. s /t \ i i . ., .r._N,z,,\ A(' f,./. ' . n h~. S M, \ ,I , I , ,l'\NN.E.I.hku $[124,4d.$.d.d, , $, ,gN .

::::::::  :::  : ::::::::::::::::::o

 ;,t. ;4w .;J s .- .;.4 w ;M. in:-,4  !. /Ww.s4.t-.e /.J.uW a. iid ist, id w n.',4- w , 14 ;e. ;M i.4 TW u,1 4.t Ja..ou., -. w ad as I Vr%t ) st.) t -up

• p Newuss 4 p.444.r1 e,wa.s a p.. < , ' U,vt 3 itet s,p es

.e .3 M - W h a e W 1 r $ \ I Il h - e-s I i, ,f ti ,* ,p, 1 e - 'E 3. fl I ,I t O I I 1 f f I {l ) h se f-f '. 1 '$ l '  !! b f 4 I k v{h" Ep w \l' l t

M'L ]fl.,\.H, N i d

!hO' a - l l  !.lS#db ,s. .a w i.u - w;a u.;a,:- U%..A.hiw ia i,.:3 i. h ],.L ;4 a 6u- a. . . v.u.W' v J ,.e.: L w a w .ia ca. .-w 3ad .ca. r .ou.. u ,.t,

n. t aa. :.d.. u . \

l 'u M4P%5dd O PF.ed.4.'1 V8'ht! ) Sid'$

• U@

e I4P% 4 4 4 F.fi.ter. k)EMI ) &I'3fI *Op 30 4 e "' f " a

e. x ,

, .- = "g'

• 4 r\IN \.l v \,!"v f'y? ;IllI, 4.^\

i A ( p \.- h l\p Q f\ \ l.\, f f !  : L. J. O v m',  :!V.,I\, W t #d1! UlT!%j Lh lLL

T . r. _ l N

_ _. ' ._h,, :s_;bftQ.. .. _. ' deiw 4i -.Vw id ;e.': i - i -M. .a d iad M.w.4,. 4 M ' 4 ',4 .. *.4-.._.,,.43 ;e ;d, T: int twt 4J ..,.a. W ad & Fif ; .l AhlJiht.ince til klitl/NiliJillir in c;ich tone, and O( l1ted.itor) sittih in /tillt'1 Of uthinibilival it.tthecib itsnii M.trt h l'M*l kjiten)ltf 18)'80. Rocky Intertidal 165 Roughgarden 1985). We have observed such Annual abundance maxima in Zone 2 at FE show patterns at all study sites in Zone 2. a decreaung trend through 1989 (NUSCO 19AI). Low intertidal regions (Zone 3) are exposed to The annual maximum during two wat .imdar to planktonic e)prids for a greater portion of the tidal that observed in 1989, which may indicate a lesel cycle,3ct settlement and successful recruitment are of successional adjustment of this community to 3-typically lower than in Zone 2. Space limitation unit operating conJilions. Continued monitoring occurs here as well, although because of different is necessary to document new lesels of adjustment, mechanisms interspecific competition and pre- if they occur. emption of space are the dominant controlling mechanisms in Zone 3, as opposed to intraspecific Furus competition in 'one 2. At most of our sampling sites, Zone 3 i dominated by perennial algae While Furut relers to all spetics of thn genus m (usually Chondrt, crisjnn, ewept at FE), which our study area Furus tesmulosut is, by lar, the present barnacles from setthng through pre- dominant fucoid at our study sites Other less empilon of primary space (cf Underwood and common Furus species include F. dimchus ssp Denley 1984). Where Chondnu is less abundant rumruens and F. Jorit hus ssp. rdenhuus, w hich are (e.g., at FS), recruitment of and coverage by found mostly subtidally and occasionally in the low barnacles is much higher. In the case of barnacles interti<lal zone, and F. spirahs, present in sescral that successfully recruit, interspecific competition high intertidal quadrats. Patterns of occunence for for spate (e.g., with mussch, NUSCO 19M) and these species in the AINPS area are similar to predation (by l/rosalpint cinera and Nurella those reported in New England and elsewhere lapilha, hienge 1976; Katz 1985) aho cause (Schonbeck and Norton 197S,1980; Lubchenco reductions in barnacle cover, a phenomenon 19S0,19M, Topinka et al.1981; Keser and Larson observed at all sites in Zone 3 through the summer 1984). and autumn. Local form abundance patterns from 1979 to the Pre.cmptive competition aho appears to be a present report year (19S93M) are represented in major controlling mechanism of barnacle Figure 5. During 19893M, maenum Furnt abundance in Zone 3 at FE, as the dominant abundance in Zone I ranged from less than l'1 at perennial green alga Codium frap/c has occupied BP to 654 at FE. Alaximum coser in Zone 2 most of the primary rock surface space in this /one ranged from 1% (BP) to 759 (FE and FS). In since 1988. Codium is aho responsible for Zone 3 maximum coser was less than 1% at both sediment accumulation on rock surfaces making BP and MP during 10S93M, compared to the high such surfaces unsuitable for barnacle seulement. maximum of 109 at GN. Excluding FE, and Aho, interspecific competition with mussels may perhaps MP (both sites to be discussed in detail reduce coverage initially at this site, flowever, all later in this section), abundance estimates for barnacles are climinated by late summer in Zone 1989AM were consistent with those reported during 3 owing to high . water temperatures. l .ow 2-unit and 3 unit operational studies (NUSCO intertidal barnacles are exposed to power plant- 1987, 1990). elevated water temperatures for 9.'O hours each Factors affecting the vertical distribution of tidal cycle during 3 unit operation. We have Fucus are smilar to those discussed for barnacles obsersed 1(U% mortality of S. balanoides in Zone in the previous ,ection. In the Milhtone area. 3 in late summer since Unit 3 began operation Fucus populations appear to be at the extremes of (1986). when water temperatures exceed the their ensironmental range in the upper and low thermal tolerance of this species. Thermal intertidal /ones, where stresses from phpical and tolerance of S. balanoules was also exceeded in biological interactions, respectisely, are greatest. Zones I and 2 at FE during 2 unit operation atter Fucus recruitment is hmited in Zone 1 by the opening of the second quarry cut. Ilowever, proportionally less exposure time for settlemem of with 3 units operating, populations in the upper planktonic 7)gotes (Underwood and Denley 19SI). and mid intertidal zones persisted throughout the Esist lished young plants (germlings) in Zone 1 year, because these zones are exposed to air at the my aho be climinated by occasional severe time of maximum water temperature incursion. desiccation in this zone (Schonheck and Norton 166 Mon!toring Studies,19'o ,i.cu a cum u ts.u t.op n u s cum un.t a .i-ut- w 30 M 80 M .a .* E" X"  ?* t* 5" 5" Vw ar r r t  % . . . . . . T. ~ii .**' ', ' .?',' i 1 . .' . , . g. .i ..... . ...T M M M r;%7 71  ;*;*: ::::*;;?* .. mse. . -w.,..- . um 5 n . . . - . _, t.. .a .! * ! : : .ss.._ wm . ..a . : * ;..;. :. : :..* ?.. -: .? . w. . - w. 2 :e.*1; ..., t : : -.. cu., _ , . . . , _ . . . . . ~,...... /' *e pe  ? y* i y* ?w 4;f~,N \ it i., b, \ ly  ! 5m ,o. . .mms4 3 .m jh tAMAM& , . n::: l:$: y .n:%, wyJ. W .I.; n n:n :::n ::::::: ., s..@. n' . f,n'.4n-'.4. i ;s_n ,i  : : : : n :tu1 i.s..a'A_is.  : :i.nt ;d.. .iid iid "i r. 'i4.*.4. - . ie ;e. 8'M lut. to1 /.u..f.iol .ud .;d ~>.t.. - ...... _s.,_. 8 80 , M M M )Y%,v gf ,/ 1: r- nm x ~ ,f y qu. s An ,, ~

e. s ,, y s ,,

jfqD'VN,h6 ..%q%R/W,,,em.yfN8 j

• t, n :: n n n :: n::::n n: n : n n:n n: n o:::n o

,. l ',4.',.4. , ;4_ i.d {u:_ut_l.uj h..e.t a_d .AJ 4J ',st, ' J_'.J. , ;J_ ;A. w { 1 ed._inj l.u..r ,4_J .ud ad M Nu

• ru . Ua.t 3 styt.vo ru., , cum int 3 start.up M

= m 9 3 er 88 W m gw ga- .x m O. , a w pl s . \ f/ fT ' h kqb,Mk. B- [Y'?WNhh?@ n n ::n:n n n:n:n rs . n: nn:n:onnonn:n (u.wg / f*4 r,a..,s .gg dd i, ' f, ',4. w",4. e ;4 l4 "w:_ wd .am id 4,,5 .ur,Ad amm ,' / ,;g

• r, ',4. w'.g

.s _ ;g un te (2g -. a ~ Fig. 5. ' Abundance of liscu in cach mne, aed of granng snaih in Zone 3, of undhiurbed tranvech. from March 1979 Septemtier Uni. l' l Rocky Intertidal Ifi7 t l-I ,, ___ . _ _ . _ _ - - + _ _ _ . - _ - - - - - - - - - - - . - . - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - . _ _ . . . m._ _ _ _..__._ _ _ _ _ _ _ __ _ _._. _ .- __ _ __ 1978). Moreover, lack of refuges (e.g., interstices sampling sites. between barnacles, protected niches) and relatively The major cause of mortality to adult fucoids in slow growth may cause plants to be more Zone 2 is senescence. Old_ individuals are more susceptible to grazing by snails (Keser and Larson susceptible to epiphy tism and overgrowth by other 1984). These factors account for the generally low algae, and the large surface area represented by abundance of hFucunbserved in Zone 1 at our adult plants and associated epiphytes creates sampling sites. Exceptionally high Fucus cover in - increased drag und abrasion. These processes Zone I at ' FE is probaNy due to moderate increase the probaNiity of partial or entire plant exposure and gently sloping substratum at that site loss from the community, and result in decreased (Fig. 5). Steeply s: iping rock surfaces and physical percent cover (Menge 1975). When a Furus stress due to high exposure account for low Fucus population is composed of a variety of year classes, abundances observed in all zones at BP. annual geles of abundance are consistent from Fucus abundance in Zone 3, the lower shore year to year (e.g., at SE, SS and WP), with plant limit for this alga, is determined by biological removal balanced by plant recruitment. As noted mechanisms rather than by physical stress. Zone in previous reports, larger spatial scale processes 3 is exposed to planktonic typotes for a longer- occur occasionally (e.g., ice scour) which remove time, and Fucus germlings grow faster there, large numbers of plants of all ages, and cause an compared to the mid and upper intertidal zones unusually large decrease in percent cover. liigh (Lubchenco 19 % 1 983). _llowever, overall densities of the new > car claw of recruits recruitment and subsequent emerage is lower due recolonite recently opened substratum and ma) ' to pre-emptive competition for space by Chondms dominate these patches for several years. As these

crispus (Lubchenco_1980; Underwood and Donley plants age and approach the end of the ecological 19M), and an earlier onset of grazers (Schonbeck life span for. this species (3 5 years l'or F.

and Norton ' 1980)? The dominant intertidal resiculosu s), many simultaneously become herbivore in the Millstone area is Littorina Iiuorca; susceptible to causes of moriality cited abose. other snails (Litmeina obtusata, L saraillis, Lacuna Such -loudued ma.u ~ mortality represents yet rincia, Acmara testudinalis), amphipods, isopods, another unusual decrease in cover. Such a long polychaetes, fish and crabs also contribute to Fucus term year cycle has been noted at FS, the only site grazing pressure to an unquantified extent. In our where we have observed large scale removal of areaJinteractions with Chondrus appear to be the Fucus by ice formation and abrasion-major controlling mechanism of Fucus abundance Large seale removal of Fucus also occurred at in Zone 3. For example, at FS, due to low our experimental site (FE) after the opening of the Chondrus coverage, Zone 3 Fucus emerage is second quarry cut (Fig. 5). Elevated water

relatively high. _ Dy contrast, Chondrin coverage is - temperatures resulted_in 100% mortality of Fucus high at MP, and corresponding Zame 3 Fucus cover _ in all zones in the two summers following that is relatively low, event. As discussed in the. barnacle section, Fucus appears best adapted to the mid intertidal . temperature regimes there were moderated by Unit zone (Zone 2) of moderately exposed sites. Fucus 3 start up (particularly in Zones I and 2), allowing germlings are first present in early summer, prior Fucus plants to survive through the summer and to

= to grazing snail migration; high availability of initiate a long term cycle of Fucus abundance. A refuges provided by barnacles and a more rapid larger than normal -fluctuation -in cover -was growth rate in Zone 2, in contrast to Zone 1 observed from summer of i989 to summer of l990,

conditions, result in high sur ival of these . _as the 31/2 year old plants senesced, and were germlings to a threshold size of 3 5 cm. Above 3 5 replaced with new germlings. During 3 unit em, Fucus plants are much less susceptible to operation Fucus abundance maxima in Zone 2 grazers, because the development of tough cortical were similar to those seen during 1 cut operation;

- layers (Lubchenco 1933) and higher concentrations however, in Z(me 1, abundance levels appeared to of - phenolle . compounds (chemical -defenses; be consistently higher during 3. unit operation. 'We - Geisciman and McConnell 1981) deter grazing. attribute these higher levels to the climination of For_ these reasons, adult Fucus canopies are grazers that has continued since the opening of the generally most extensive in Zeme 2 at all NUSCO second cut. Fucus continues to be climinated in 168 Monitoring Studies,1990 e.-'~ ,. . . , , - Zone 3 annually at FE (in late summer), due to plants at FS by coscring plant surfaces and hmiting elevated water temperatures from the 3 unit 2 cut light. discharge. ChonJno coserage at FE increased to 154 by We do not have a satisfactory explanation for July 19% (Fig. 6). Ilowever, most of these plants the patterns of Fucur abundance obsened at htP. were climinated by the end of the summer anJ Fucus cover levels were highest there in September abundance sevels returned to less than l'i, typical 1952 (439 ), and continually dropped over the next of percent coser obsened in the past sescral years three years to a low of less than 1% in hlarch at thh site. These low lesels of Chondno coser are 1986. Abundance subsequently increased to 17G likely due to unsuitable enuronmental conditions in 1989 and the annual maximum remained near for this species, primarily thermai strew At all that level in 190 (15'i) If these trends are the sites, Chondnu is primard) restricted to 7nne 3; result of a protracted long term cycle, the cycle is but at FE, the low intertidal region is esposed to not yet complete, since lesch are well below the elevated water temperatures for o.10 hours each recorded maximum (1982) observed at h1P. tidal cycle. It appears that these thermal regimes Additional data are needed to determine the cause are beyond the tolerances for this speciet Most of of this unusual pattern of abundance, especially the Chondna population at FE occun in upper owing to the proximity of this site to the hiNPS Zone 3 quadrats, where it expenentes elesated dhcharge. water temperatures lor a shorter time penod than plants in the lowest pot tions of Zone 3. Chondrus Chondna was the dominant species in Zone 3 at i E belote 19S4, but was eliminated owing to a temperature The perennial red alga Chondnu cnspus forms increase after the opening of the second quarry extensive populations on low intertidal and shallow cut. Chondon was replaced by a dense population sublidal rocky shores in the hiilktone area. These of Codnon fragi/c and sescral ephemeral algae, nearly monospecific turh are common throughout including Uh a lacruca, Enteromorpha spp., and the North Atlantic (Niathieson and Prince 1973h Po@iphonia spp. These species remain dominant with its North American distribution from New in Zone 3 at FE. Jersey to southern Labrador (Taylor 1957) A significant canopy of epiphy tic algae occurs on Upright portions (thalli) of Chondrus aho sene as Chondnu periodicall). Two epiphytes substrata for several species of epiphytic algae, (Polysiphonia spp. and Afonostroma spp h laund including the ephemerals Polysiphonia spp. and commonly in the hiilhtone area, are sensithe to Afonostroma spp., discussed below. thermal impacts (NUSCO 19W,1937). These two Chondnu abundance patterns during l9S9 90 are genera include species that exhibit dilferent represented in Figure 6. Excluding FS and FE, patterns in abundance and seasonal occurrence. abundance averages ranged from 35G (SS) to 809 Afonostroma spp. are ephemeral green algae (htP). Ahhough some fluctuation in abundance commonly found in spring collections (Table 2h has been observed in the past at sites other than Af pulchnun is usually found unached to Chondnu, FE and FS, overall abundance patterns have AI. tlrecillei on rock, and AI. myspermum h ty pically remained consistent throughout the 2 unit and 3- found attached to Zmtcro marina. Staximum unit periods (e.g., NUSCO 1987, 1990). Chondna Afonosuoma cover salues (Fig. 6) during 1989 90 cover at FS, which decreased to less than 1% ranged from 4% to 15% at all sites except FE. during 1990, has been consistently low during our These levels were within the range of 2. unit and 3-2-unit and 3 unit studies, aseraging SG. We unit values at the respective sites. Afonostroma attribute these low values to the unsuitable abundance has been consistently low at FS, substrata and general habitat conditions at FS. FS probably owing to low Chondna abundance at that h the most sheltered NUSCO study site; low wase site and the lack of another macroalga host energy there allows fine sediment and silt to species. At FE, Afonmtroma has been virtually accumulate on low intertidal rock surfaces, absent since the opening of the second quarry cut covering the firm attachment sites required for (1983), but before that esent, maximum salues Chondrus spore settlement. Silt may aho restrict were relatnely high (20 40% ). Cold spring water growth and vegetative spread of the few estabihhed temperatures required for Afonmtroma rarely occur Rody intertidal 169 1 l i ....., i " (wus e appnyus Veut 3 start-up '" the%he a ewysee t)rwt 3 elsv <t up = . 8g ng }* * *- *ib f" sn : *- ' 6. A a a i

• d *'

w -M .p _ ' 3 .g, f_ y (i w ) * . f g(ly . i + , 7 u,A,[4 g,j v , /1 5o 'o. n L,

• f, a ygi\'!,- s't ,k a # y .se . I

\  ! \ l,  ! _ tit : ift: ! j: ::!; j ::::  : !: :

:J :N:5: 6: $il: d,"I,,:id.t '"y .): Y3I.$ d "!

t '"W Wdd b;".*U:!. '"I.?k'a%jl"I d - '" ' l"$I ' r = -4 . .,%i.. un.t 3 .i+ t so cw . .m.... u~ i .o. i- # e u a .N a > . w .. . o, ,;. i $H* .qL,i.V' V ' ]p{ \- = h a 't .$ % )t,( oe t h , 'Yg ,. )* a ;f .m s 1. , ' i= I. B, h J 'f , lf sv l yl\ ' s > , /1 *,,s\ s *< i v l  !\  ! \l Y  !.> !)lh j\ () ' \ , ,< 1 l ,*< '*i U;JUM,  : < 'B uJilli m uom i r  ::y::::j;; : :'  :  : : ;'; :'::::;:;:; ;' " k ;'*' W;.J$ l'$ dt..A*,l! ';"I.h .k:" ' "':'*'! ; I  ::;hd'J*L*h'd'j."1i'*I.?!ld!*[,i"; '4'* .4.... ._ 'a cw.w. , ,r, . ... W 3 .to i ~,  ; cw w . m.... u,.i 4 e o. * = 89 8 M M -u$. =. 9 =. :r: S. i n h 1= 5m Ea ilI y!! c; .'\ e . , 6l , A > a* - x. - _d- 1 ,-/ -. / y h. - 5 r c.4 . n .

h. - - t i.

- 4 I  % A!\ , , ig , ,~.  !!!]!:t 1;  ! 1v l t 'is O i..:.1.L r

j j ,,.! i.A

.,A,_ m,r,: int .- tut. l '.6.1./ .i i.)' ' e.4 .ij .l fut i.A. _r.', i. .sIit: ., tal' .,,i ', iul. tlL * ' j ' .4 ' , .,)

• ca +. e .,w . un,i 3.im v. = cu w. a .+,... u.,i3sim ,o, e u M a ',. ,

a -1 .:. E j% , -l, h . f by l'y! I lh YY I'\!! '9 m. rlNly:(k.!i %n n . s. Pn E= * . j ,j . n , )i fI pp .[ 'g r i. ( A t-f Ij [n : /  !,b I/ln UIf A %ML 3 (h Ol' \ L'!/1 \ ._j  !......'."W.9.,.....,.,L; '- W WdpMI .k 'dR.L' - e W M M Mid!&'d.'.se/>L/ e rig. <>J M>undance or ch<wdnu and nujor epiphpn in zone 3 of unanturtus iratucca, tro,n Mmh l'M9 Srptentber (W l 170 Monitoring Studies, IW) l l-l l . al FE, due to thermal incursion from the the Millstone area, and mcorporates abundantes of powerplant discharge. all species obsened in undnturbed Hansects A Polniphonia (pp. (primaril) P, imcar unghar and resulting clustenng dend topra m illust rates muluple P. hargi) eshbit an annual maximum cowr at the pair wise comparisons. The techmque n used to NUSCO study sites in late summer and typically compare communitie.s at all sites mer 2-unit and disappear during the winter (Fig 6). These species 3.umt periods, anJ to cunune annual cominunal pum epiphytically on sewrul species of algae thanges at our expenmental site, i E including Chondnn criiput Codmm pagi/c, Focut Similarities of species wmposinon among spp. and Aicoph,Ilum inalmum, and ma) also stauons in Zones ? and 3 during cath operanonal attach to rock surfaces. During 1900, masimum penod are illustrated m hpure 7.t As tcported coset at all sites ranged from 4'4 (F5) to 35'i (FE previously. 3. unit wlicetions at cat h station eucpt and llP). Excluding FE, levels obsened m 1959mo FE watinue to be mou similar to 2-unii were within the range of both 2 unit and 3.umt collections at the samt sianon un SW . leu l or periods ( N USC01487.1900). At FE, Poh uph<mia greater. NUSw im lour poupmps are exhibits a response to ensironmental conditions apparent at the Ni'. sunilarity leu l. Group I that is nearly opposite that oNen ed for consists of both operanonal penod collniions ai Afonouroma. The entire annual ewie of SS, SE and ON, and the 2 umt wileshon at FF abundame has been pushed upwards since the These cominunitics af e th nacitived by mo& taic opening of the second cut, with maximum coser amounb of fo us and rhomirut colk chans 1 om W1 to 55'7 and the PoMiphonia population at WP, MP and IIP trepardlew of operanon.d penodi FE persisting through the wintet Ikfore the comprise Group ll Chon hov is more abundant at opening of the second quarry eut Polpiphonia at these sites and fuens abundance is low . 1 he FE showed an annua! ewie of abundance similar to oppmite is true for Group 111; both operanonal that found at other sites Cowrage by these wllcetions trom l'S h;ne ws) low Chondru s species quickly increased to nearly 554 in abundance and relatiwly high Imus abundance response to suNequent Lunit 2 cut conditions Group lY consists of the 3umt opciational (demonstrating the opportunistic nature of these wilection at FE, which is prtally thwimilar from species), then iluctuated irregularly for the next collections at all other stationt As docuwed sem-1 years. Since 19S7, Poluiphoma spp. hase presiously.Chondnn has been sittually ahent from exhibited an altered but wnsistent annual cycle 01 FE during this period, and has been replxed by abundar.ce in response to 3 unit 2. cut temperature Cahum and sewral epheme. alt regimes. Figure 7a suggests diflerences betw een Owrall, annual and seasonal patterns of operational penod commumties at FE; however, abundante of Clumdrus and its inajor epiphytes the esent largely responsible for wmmunin have been conshtent throughout our studies at all changes at FE was not linit 3 stari up (los6), but sites except FE. Responsc3 of these species at FE rather the opening of the sewnd quarry cut in serve as a model that can be used to evaluate 1981 Comparisons of annual collecuans at FE similar responses at other sites near the power were done t hg. 7b) to help illustrate the extensise plant. changes that h.ne occuned at that site. Annual collec tions are dnided into three distinct groups at Similarity Dendrogrann the Su"I simdarn) le el. Group I consists of all ) cms prior to the openine of the sewnd cut. Occurrence and abundance of user 125 law hase Collections in Subgroup la (1979.X1) are been recorded in undisturbed transects since 1979; characterved by relatively high abundance of separate analyses of these data are used to furun declining values were observed in the two illustrate communal differences between sites. years of Subgroup lb (14S2 and 19S31 Group 11 Allered patterns of occurrence of less frequently consists of a single transitional year (19X4). when found organisms inay actually be a more sensitive significant coser of Chondon und Tucos was indicator of environmental stress than are climinated halfway through the ) car and was dominant species (NUSC01990). The Bray Curtis quickly replaced by high abundances of Similarity index is used to evaluate communities in Polniphonia, Entriomorpha and Uh a Subsequent Rocky interudal 171 0- -o to. - to 20 - - 20 M= -M g 40- - 40 8 - 50 jj 50 - L

i II Ill IV

- 60 g so . I 70 - - 70 ao - - so 90 l - 90 I I 4J 45 +J +5 4J 45 t5  % J 5 J 5 J 5 $J 45 tJ ngure 7e C1untering dendrogram of umiLinly, ty station and operating penod (2 unit and .hinit). -to - - -io o- -o to - - -o N- = to M- -M ( 40 - - 40 a E *'"- I il 111 i

j. --

. to la Ib Illa  !!!b io - - 70 00 - - so I 90 - 'S 'e '94, 'e 'ag , 'Sg 'S 'S4 '94 , 'S 'Sg 4 Ngure 7b, Clustering dendrogram of simitirity, by year, at Fox hiand-l;mmed. 1 l 172 Monitoring Studies, IWO years (1985 89)comprisc Group ill, Subgroup illa duc, in large part, to the large area sampled, consists of years of adjustment to 2 unit 2-cut relatise to patch size formed when biota are lost conditions (1985 86), characterized by the through most natural processes (cf. Sousa 1984; establishment of an extensive Codum population Connell 1987). That is, processes that ' create' a in Zone 3 and annual late summer climination of patch (grazing, predation, death) are balanced newly recruited barnacles and Fucus in all 'lenes (when averaged over all quadrats sampled) by (cf. Figs 4, 5 and 6). Subgroup lilb (1987-89) processes that 'close' a patch (settlement, represents development of an intertidal community recruitment, growth). In response to 3-unit 2 cut conditions. The Recolonization experiments at NUSCO study appearance, persistence and expansion of sites were designed to distinguish among the populations of the perennial 3 Sargossumfilipendula processes that structure local rocky shore and Gracilaria rikvahiac,and the reestablishment of communities. Removing biota from the a small population of Chondrus occurred during recolonization transects reduces the variability these years. Although this community is different associated with differing age structure, and from those at other sites, the high level of annual simplifies monitoring of settling and of juvenile similarity observed in recent years at FE indicates stages of recolonizing species, which are more the successional development of a community in sensitive to environmental conditions than are establishtd adults. Additionally, recent research response to present operating conditions. Future monitoring of this site will determine if this (e.g., Underwood and Denley 1984, Roughgarden community persists, continues to develop, or et al 1988) indicates that processes affecting changes, propagules and larvae in the water column, as well as their transport to the shore, may be more Recolonization Studies important in structuring communities than are adult adult interactions. Results from recolonization studies presented Patterns and rates of community development here cover two sets of denuding experiments, the on rocky intertidal surfaces are among the most intensively studied processes in the marine first from September 19M1 (during 2 unit environment (e.g., Fahey 1953; Sousa 1979, Paine operation) through March 1986, the second begun and Levin 1981; Menge and Sutherland 1987). In September 1986 (during 3-unit operation) and Communities on rocky intertidal substrata are continuing to the present. Data from the first 36 months following the 3. unit autumn denuding, and casily man;ptated (e.g., artificiJ. denudings, grazer / predator eclusion!cnclosure), and gradients comparisons to those from the 2 unit autumn denuding, were presented in NUSCO (19%) and of many environmental parameters (e.g., wave are summarized here. These data vill be exposure, tidal height, slope) are steep enough that different sets of conditions exist in close proximity. synthesized to support generai models of lite history and survival strategies for local recoloniting Studies of recolonization and species progression on rocky shores have been used to support (or organisms. Community structure and organization are refute) general models of succession (e.g., Connel: assessed in terms of percent cover of recoloniting and Statyer 1977; Dayton 1984; Underwood and species (NUSCO 1987, 19%). Recoscry is Denley 1984). Recolonization studies have been part of the complete when the recolonization community is NUSCO rocky intertidal monitoring program since indistinguishable from that on nearby undisturbed 1979. These studies complement the abundance surfaces under similar environmental conditions. measurements on undisturbed transects (previous By this criterion, recovery of high intertidal icauded areas is almost imn.ediate. In autumn, section) in several wap. For example, the previously discussed abundance measurements are few plants or animals remain in high intertidal primarily descriptive, i.e., spatial and temporal quadrats; scr7 ing and burning of Zure I surfaces does not appreciably change their appearance. patterns of species abundance are described in Following autumn denudings during both 2. unit terms of degrees of exposure, intertidal height, seasonal availability of propagules, etc. Observed and 3-unit operation, high intertidal recolonization ' was complete within 6 months; no differences in community persistence and pattern c4msistency are rates or patterns were seen among sta. ions or Rocky Intertidal 173 l between periods. , ,,, ,,,,,, = Recovery of denuded mid intertidal surfaces ,. ,,,,,o .,,,on,,  ? involves reestablishment- of both Semibolanus .. !l8,L , j!'k,, balanoides and Fucus populations (cf. previous ~ *- section). Abundance patterns of barnacles in Zone g** ,' --2 of the recolonization stations, following autumn 7 {  ! denudings, are illustrated in Figure 8. Maximum f ,", I [, - ( barnacle coverage in spring 1982 and spring 1987, f. t b [

following autumn denuding, ranged from 50 to = '

.70% and from 70 to 95%, respectively. The a g g g 3 . ),' coverage difference between 2-unit and 3 unit L. , m, i., ,,,,o, ,,,,m, , , , , . , levels was not attributed to power plant operation. ~ ~ ~ ~ ~ * ~ Rather, these differences appeared region wide, ,%,, ,,,,,, and were associated with year to year variability in . w,,o . wo . the abundance of larvae, and the ability of post- =  !!*,Lo, j!{L, a settlement larvae to recruit to the population. f\, Despite potential year to year variability, barnacles g "* 1 ~3' remain the dominant occupier of primary space in f.g < i i h, .j .U Zone 2 in early summer. - Patterns of barnacle - pi p! E ' '. k_ abundance are consistent among stations, between . I \. operating periods, and between recolonization and = \,/ . - undisturbed . transects. Barnacle -. populations = j . f reestablished 'themselves after the first settlement period following denuding in all our experiments. . - -- -=*-**a - Recovery in recolonization transects of the mid ,, , , , , , , , intertidal Fucus canopy. was somewhat more . . . , , , protracted (Fig. 9) than that observed for barnacle = j'*ko,  !!!Li, populations. In the recolonization transects, the " A time needed for Fucus cover to equal or exceed g"" , i l' . N that in undisturbed transects ranged from 17 to 37 I  ! ('y/\ '/ \ } i months following the autumn 1981 denuding, and from 12 to 27 months following the autumn 1986 f" . y Y ' denuding. Cover. percentages at 'the time of ' = -recovery for the autumn 1981 and autumn 1986 -= { denuding were similar at three of four sampling * [ - sites,with respective cover values of 42 and 45% at - ww - ~~asaa i ON,64.and. 65% at FS, and;15 and 19% at WP. ,m, _ , , , , , , ,

Recovery at' FE ' to' percentages observed - in on - ..

undisturbed transects was complete at 'a much a  !!!Lo,  !!*k,, ' lower level after the 1981 denuding than after the - a "" f ~ il986 denuding (10 and 58%, respectively). We . f, attribute the low 2 unit value to a combination of *" .I q. \.i a site wide . decline in cover as illustrated by . ~ f . ,, - undisturbed transects and an interruption in the - .) W i  ; (. recovery process in recolonization transects. Both = N' h " i phenomena were caused by altered temperature ' regimes following the opening of the second quarry . L, , m, [A , , , l' cut. As with barnacles, annual variability in -*=-**a=*a-successful Fucus recruitment was responsible for a more rapid recovery observed at all ' sites in-the Fig. 8. ' Abundance of Semibalanas m Zone 2 of recoloniution latter experiment, _ and undisturbed transects, from september 1981 september 1990. Vertical knes represent time or denudmg. 174' Monitoring Studies,1990 l l .m The rapidity with which denuded mid ititettidal f,,, ,,,,,, surfaces arc recolonized by dominant species (less . .wmo . w,,,, than 1 yr for barnacles,13 yr for Fucus) is related =  !!!h.,, !lIhi,, both to the ' survival strategy' of these species, and to the hydrodynamic characteristics of the Millstone area. For instance, Semibalanus j p balanoides matures in a single growing season, and W. a dense population (10'.10' m'2; Connell 1%1) . ,s k produces enormous numbers of larvae (10^-10' m ; 2 = a \/\ Rangeley and Thomas 1988). In our area, such fecundity results in barnacle larvae (nauplii and h , ,i;;; . . L j. . . , , , , . , cyprids) accounting for approximately half of the ~~w -~~ meroplankton density in March and April, i.e., fm,, ,,,,,, over 200 m 4 (NUSCO 1982). 1.ncal .. .wmo o m,,,, hydrodynamics (strong tidal currents) ensure that =  !!!Lo,  !!!Liy these larvae are widely dispersed, and that clear *, rock surfaces in the mid intertidal zone are g** , exposed to an over abundance of larvac cach g O ., spring (cf. Connell 1961). Therefore, annual I ,, m 1, '. T ..., t reestablishment of mid intertidal barnacle . populations is consistent and predictable, even on = denuded substrata.

• Re' colonization of Fucus is less predictable than L ;r; ,,,,- ,,,, ,,,, w ;;;;- , ,, ,,,, ,,

that observed for barnacles. We have no local data ~~w ---- on Fucus rygote densities in the water column, or rm , , , , , , , , on post settlement mortality, although workers in . .amn . s,. Maine found newly-settled Fucus germlings in =  !!!l,.S , !llk..,, a densities of over 43,000 m'2 in April, reduced to less than 4,000 m.2 by November (Keser and g *l ( Larson 1984). Inference from region-wide patterns 3 , j . " j, of Fucus abundance suggests that Fucus R' , .. recruitment varies from year to year. For example, . j\ j y recruitment success was low in 1982, resulting in = - v delayed Fucus recovery on strips denuded in

• I autumn 1981 (Fig. 9), whereas Fucus recruitment 6,.....,..

was more successful in 1987 and resulted in rapid ~~*-*=~ recovery on strips denuded in autumn 1986. fm,, ,,,, As discussed previously, Fucus is a perennial = .wmn . s. n alga, with individuals persisting and remaining * $lAky 5lIkia, capable of reproduction for 3 to 5 years in our area. Variability in reproduction is dampened, and g* has little effect on the population as long as at ,, least one successful recruitment event occurs E, during the normallifespan of Fucus. On the other = = 4 \ ,. j hand, very few Semibalanus live beyond two years .b ~ d and therefore two successive years of recruitment failure could lead to local extinction. Semibalanus k,..,...... population strategies include early maturity and ~~~ -~~~ vast over production of larvac which permit Fig 9 Abundance of f ucw in 7ene 2 or recolonuation and persistence of barnacle populations. Fucus exhibits unauuM uann ham septemNr twepwmNr im more variable recruitment, and develops Vertical hnes represent ume or denuding Rocky Intertidal 175 more slowly; this alga relles on physical toughnen em ,,,,,, and a perennial occurrence to - maintain a .oi.n . m., populatlon. *  !!!kn,  !!!ko, Persistence of tough, long-lived individuals is a

• particularly effective sunival strategy in an g*'4

environment where the frequency of severe, space. g A /\ ; d clearing disturbances is low, in our area, such an '" [ ,,  ! environment is exempilfied by low intertidal ledges, . j and the strategy is exemplified by Chondnu crispus =  ! (cf. previous section), Chondn45 is a tough, +  ! A perennL ilga, consisting of multiple unright b , . , m, m. . D.,, fronds, growing from a basal'erust. Ir..nvidual ** --a* fronds may live 4 to 5 years (Mathieno and Prince cu. ,,,,,, 1973), and the crust much leger, producing new .. . a.. uprights to replace those lost to senescence, =  !!!Ln,  !!!Lo, storms, ice. scour, etc. As the crust slowly expands. " and new fronds are continually produced, Chondn45 g** essentially monopollies suitable low intertidal and y shallow subtidal surfaces. P, , Chondna vegetative propagation is an ideal . strategy Ior maintaining its populations in a = l relatively stable environnicnt. The basal crust of a y A Chondna is not grazed and is not subject to L 7%c .vm,-- .. m. .m . physical . disturbance in our area, and uptight w'~ w -~~~~ fronds regenerate readily. Use of scraping and em , , , , , , , l burning in our recolonization experiments removes .a n .s . all blota, ensuring that Chondrus could reestablish *  !!!hn,  !!Ih , itself only through settlement of spores. This a method of recolontration is a slow process. Even under most favorable conditions, a minimum of 3 j y

• 4 A

/ .3"yg f On ,I;Q pY[ / V to 5 years is reported necessary for recovery of l - l,, Chondna on denuded surfaces (Ring 1970; . Y {y ( 1/ ' Lubchenco 1980; NUSCO 1987), Total Chondnes = l reccwry was obsened at only one site (FS) five j ( years after .the autumn 1981 denuding, where L. m, m, ....m. .. . , . . undisturbed Chondnes values are historically: low ' ~ " * - - * * (less than 20%; Fig.10), Partial recovery was co . , , , , , observed at .O N and WP (20 30 % below . A.,n . , , . undisturbed- abundance levels), and site, wide a  !!!hn,  !!!ho, climination of Chondnu occurred at FE following , g. . 3 the opening of the second quarry eut. Four years j " A i \ tA - / qj/* T/b. ( l ' , , after the autumn 1986 denuding,Chondnu cover at White Point and Giants Neck, with an increasing y E[, \l$ i trend, is still far below (by 40-50%) the levels seen . in nearby undisturbed transects. ' Chondnu is not = l - common in the low intertidal community at the other recolonization stations. It-is essentially L. m., . . - . . ( f

m. .. m.

l, . excluded from FS by heavy siliation of Zone 3 - **--a* l1 quadrats, ' and from- FE by elevated water -temperatures and preemptive competition with ng.91 Abundme or ouvidms m he 3 d ra<*nu.non Codiunt (cf. previous section).. ud undniurwd muwun, rnan septeniNr W1 septensa. lWL Venical knes reprewnt ume or denudmg. 176 Monitoring Studies,1990 _.__.____.e _ . - . . . . - . - .- . - - - - -- -=- -.- - - - - - - - - - - Recolonization studies at NUEL illustrate the et al.1981; Chock and Mathieson 1983; Carlson community development on cleared surfaces, and and Carlson 1984; Cousens 1984,19S6). This alga - the life history strategies of the recoloniting is also known to support abundant and diserse species. Since the identity of the earliest coloniter epiphytic and epifaunal assemblages (Johnson and p is dependent on. the availability of propagules . Schelbling 1987). The phenology and ecology of (spores, larvac, etc.) in the water column, when Ascophyllum are well documented in the literature substrata are totally cleared _ frequently and (David 1943; Printi 1959; Baardseth - 1970b; randomly, probability favors those species with Sundene 1973; Mathieson et al.1976; Vadas et al. p high reproductive output and long reproductive 1976, 1978, 1900; Keser et al.1981; Keser and - l seasons. ' These reproductive characteristics are Foerich 1982; Aberg 1990). Much research has L typical of r4clective, opportunistic, ' weed' species shown that Ascophyllum is sensitise to both natural L (Sousa 1979), and are exemplified in our studies by (David 1943; Baardseth 1970b; Vadas 1973, Enlemmorpha, Ulva, Po&siphonia, and many other Stromgren 1977; Chock and Mathieson 1979, ephemeral aseasonal annuals (NUSCO 1987). Cousens 1982) and anthropogenic (Rueness 1973; - When disturbance is moderate and less frequent, Bokn and Lein 1978; Vadas et al. 1976, 1978) ' but regularly periodic (e.g., winter storms that environmental changes, and that its responses can remove biota every year, or seasonal be quantitatively assessed. Ascophyllum growth grarer/ predator pressure), organisms have a short and overall persistence are particularly sensitive to reproductive season, with predictable space changes in water temperature. Moderate available for their settlement. This is the strategy temperature increases accelerate apical growth and exemplified by Semibalanus (and by many annual lengthen the growing season (Vadas et al.1976, algac). Another strategy for surviving storm forces 1978; Stromgren 1977, 1981; Wilee et al,1978; , and grazing pressure is to develop physical NUSCO 1990). As plants are exposed to greater toughness and defenses against herbivory, and to temperature increases, growth slon or stops, ~persist for _several years, the strategy utilized by apices become deformed, and mortality results Fucus.: Finally, where disturbances that totally _(Kanw! sher 1966; Vadas et al. _1978; NUSCO - remove biota are rare, relative to the lifespan of 1987)c For the above reasons, and because the organisms (e.g., in the low intertidal, or mid substantial Ascophyllum populations exist in close i intertidal at - sheltered sites), effective survival proximity to the MNPS discharge, this species has strategies include those considered typical of K. become a valuable biomonitoring tool as part of

- selective, ' climax' (sensu Clements 1936) species, the NUSCO monitoring program. Ascophylhem

-i.e., longevity, physical toughness, resistance to _ populations in the Millstone area havc been - grazing and at'rasion,'and reliance on vegetative studied since 1979 to assess impacts associated . propagation to maintain extensive populations. with the construction and operation of MNPS. These strategies are exemplified by Chom/ms, and _ Orowth and mortality results from the most recent are . also utilized by Ascophyllum nodosum, sampling year (1989 90) are presented below and _ discussed below. compared with the results from 2. unit and 3 unit periods. . Ascophyllum nodosum Studies Grow th . The importance of the perennial brown alga Ascophy//um nodorum to the coastal ecology of the A5 COPh ylham growth or annual tip clongation Millstone area and to _ the NUSCO monitoring during 1989M), as expressed by the a parameter in effort is_ multifaceted. As a dominant plant =on the Comperti growth model fitted to the data (Fig. Intertidal shores around Millstone and throughout lla), was significantly higher (P<0.05) at FN lts range, i.e, New-Jersey to -Baffin Bay .in the - (114.6 mm) than at GN and WP (93.3 and 94.3 western . Atlan_ tic (Taylor 1957), . Ascophyllum mm, respectively). Growth differences between r contributes significant amounts of dissolved and GN and WP were not significant.. The inflection particulate organic material to the coastal food point (time of maximum growth rate) during web (Baardseth 1970a; Josselyn ;and Mathieson 1989M) at FN was July 14. Inflection points at 1980; Filion-Myklebust and Norton 1981; Topinka reference sites occurred later, July 21 at GN and Rocky Intertidal 177 -- _ .-~ . - , _ _ _ _ _ _ . - ._, - . - _. _ _ _ . _ _ .._ _ ..._ _ _ _ _ . _ .) July 30 at WP, Within station tumparis ms  ?" r= *a w- between growth estimates for the 1989-W) scaxm "'~ and the overall growth estimates during 2. unit and * $." E 'I.** e i,. m ria wa 3-unit operation are presented in Figures lib d. ]"= - S*"'pr., Growth at FN was significantly greater during h," d.; ;(,.s - 1989 90 than mean growth durin3 3-unit operation g* q'4 (105.1 mm) and the 1985 86 2. unit year (90.5 mm). ]* j The difference between 2 unit and 3. unit estimates ', j ' .  % . io . i.,o = .. was also significant. Growth at each reference site (ON and WP) during 1989M) was not significantly _....c. oats n.o ... wei.tUwat- ro, won, different from that during 3. unit (8&8 and 85.4 'a g) mm, respectively) or 2. unit (90.0 and 90.2 mm, '[ =*~* s~* m -w respectively) operational periods. The inucction  ! i *. ", U 'l," points for within station operational comparisons -{; 4 vm _ um sia #, g' W occurred in distinct pernis, ranging from 4 days -= (FN and WP) to 6 days (ON). InDeetion points f".a ,,, # representing different operational periods at each station tended to occur near the same time of year, , and were earliest at FN (July 1417) followed by * ~ ON (July-2127) and WP (July 30-August 2). oi..t. u.cu = .a w . Patterns and relationships of .. Ascophyllum . . ,ia ... O ,i ises.9o growth in 1989 90,in general, wre consistent with 'a .) . those reported in the pat (e.g. NUSCO 1988b. [ *~*s~*--* 1990). _ Tips at FN typically gruw significantly . * "[.' U * ,7 s longer than tips at reference sites, where annual -y. p.- P 'g i m euus - == p growth estimates are similar. Clearly, Ascophyllum {* growth at FN during 1989-90 (Fig. lla) cont.inued -J. ; .. to be enhanced by exposure to power plant Ja efnuent, which elevates water temperature 3 4*C ]. for 3-4 hours each tidal cycle while all 3 units are " operating at full power, The time, duration, and w ww. Peang - .  % =. = .. . overlap of unit shutdowns complicate temperature , . . . 2 wt ... E vna _ ises.so regimes, and growth responses by the FN H j 7)- m-a Arcophyllum populationi Annual = differences in ***8~* _ growth between experimental and reference l  ?" ..*aY".M7 /,r C.. ' populations reDect Ihe degree ofincursion (i.e., the . + on jeu . m 4' ', . -

• level of. additional heat load produced by the-L- (}g * ,,

power plant), particularly during the peak growing .I. y a , d'/, ,/ j '1 period (MaytNovember). . For instance, year to year wriability in overall growth is evident at all: , . ',/ study sites f (Figs." lib-d) - and = is. attributed to a ' ' r , t t. 4 - varying annual emironmental condillons. Annual! m. e . w =. m- .. . variability is least at reference sites, which indicates ....' -wt!.- An 1989 00 a more stable Lenvironment from year -to' year, Variability is highest at FN, where the amplitude of environmental variation is , increased by: the Ms. Ik AscophyIAun growtni a) during 1989 90. tw) presen' addition of a fluctuating heat load resulting from _ year, 3< snit and 2-unit operational perxxis at cach station,' ~ Curves are the Gompertz growth model titled to up length data, . Inconsistent power plant opetaling status. During including innectica pmnts (i.p.). Error bars represent monthly years - when perk >ds of ? simultaneous :3-unit mean lengths 2 2 SE. operation were longer or more frequent (i.e.,1988 89 and to some extent, the most recent sampling 178 . Monitoring Studies,1990 l, l , -~. - + , ed _ , - - - - . , - - . . . - - , - . - - - - , , ~ , 1 I year,1989 90) tips grew significantly longer than , during years when thi operational event was less f requent (1986-87,1987 88),or never occurred (the . l_ , i ksl x 1985 86 2 unit year). Ascophy/Innt growth responses reported here are f* ( yx '~ , similar to those observed by other researchers [" y7_n'l M{ i\ studying temperature effects on natural Ascophyllum imputations (Vadas et al. 1976, 1978; l * , g Wilee et al. 1978). The sensitivity and I, predictability of these responses has abo been o "" M ,a

• T~7 documented in laborator) experiments (Kanwisher 7"[W '"-m-w 1966; Strompren 1977,1981). The i seation of the " 7 ,+t "-

FN Ascojihyllum population appears ideal for , assedg 3 unit operational thermal impacts. We , htxe documented that plants at FN eshibit a wide . N tange of temperature related responses (from no = \ tx prowth enhancement during the 1985 86 2 unit year to the near optimal growing conditions of l= k Q% ' ly 1988-89). Continued monitoring of Aecophyllum growth at FN and reference sites will be an l* *" 'Tht] extremely useful and important part NUSCO'3 1 ", ellorts to assess biological responses to annual dilferences in power plant operational regimes. ~ ._ W*""" D"at_ _" _ _ _ _ _*-' This monitoring is particularly important if - - N~i - 3 +' i** operational and temperature regimes observed in ,,_ the past at this site are exceeded, such as those ,, 'g documented previously at FO (our original . 3 experimental station) after the opening of the = x ' second quarry eut (NUSCO 1987).

f. .*. p, x  %

1 Mortality ,j* i e x, (n .,,., Breakage and loss of portions of, or entire, 8[ l Ascophylhim plants is a response to more severe , d Fa

• d environmental stress. Loss of Irond base tags (or ~ * *" * '* _*

plant loss including all associated tip tags) and loss - * - ~ wt - *W of individual tip tags (tip loss) are used to quantify plant breakage or Ascophyllum mortality. During Fig 12 A'#n#u"i nutoainw as ntnnM of nnuuning twd 1989M), plant loss at GN (fin.12a) was 729, *"""""""'"n- Wuc> dunns *

• iut rioned ag.unu means and ranges or Tunn and luiut operahotut higher than average 3 unit and 2 unit values pena.

(52.500 and 52.09, respectively). Plant loss at WP during 19894) (60.09 ) was also highei than (77.290) was ahn higher than during both during 3 unit (56.59i) and 2-unit (54.3%) periods operational periods (70.800during 3 unit operation (Fig.12b). The 1989M1 plant loss value at FN was and 75.190 during 2 unit operation). Tip loss at 629, and was lower than both the overall 3 unit FN during 1989M) was the same as the overall 3-and the 1985 86 2 unit values of 67.0Ci and 80.0G , unit value (82.09 ); during 2 unit operation (1985 respectively (Fig 12c). 86), tip loss was 90AG. Ascophylhun tip loss h summarited in Figure Temporal and spatial variabihiy in patterns of 13a e, Tip loss at GN during 1989M1 was 87.200 Arcophyllum mortality are due to unique and higher than 3 unit and 2 unit values (71.3 and dynamic combinations of site specific parameters 75.19, respectively). Tip loss at WP in 1989a) which cause environmental stress. Natural stress Rocky Intertidal 179 . - - - _ . _ -- - - - ~ _ , _ - - . . - _ - - ~- ,,, y previous reports (e g,, NUSCO 1990) reveal no m N t consistent area wide trends. Trends indicative of

= 'N \ temperature related injury or mortalliy were not m

y' s present at our current experimental site (FN). J* - ( Mortality values (plant and tip loss) during 1989- '* 90 at both reference sites were higher than those N .Jy_ ,~ # ' during 2 unit and 3. unit periods; however, k" 5Q N mortality at FN was lower than in these two 8[ *)cu e "* operational periods. It is noleworthy that in , previous years, mortality was generally higher at * *

• FN than at GN and WP (although this was not the

... r ea . 3- va - m o so case in 198941), yet annual fluctuations in ,,,, mortality at FN could not be attributed to power m I% k N plant operational regimes or degree of thermal = incursion such as that described in the Growth a section. For example, mortality during 1983 86 )* s g l was nearly the highest recorded since sampling was [N '* ,\ l I initiated at that site. flowever, the incursion of k, " N "  ?.7, , , the 2 unit effluent was minimal (0 2"C higher than  % 2- reference site temperatures) to the point that no 8" L i significant crowth enhancement occurred that year u mie Nat (NunU 19Mb,1991). Mortality estimates during - * * * 'a ~ ,,,, 1988 89 were similar to those in the 1985 86 2. unit ... 2 +a .- ha -issoso year (NUSCO 19>0), even though during 1988-89 ,,, , plants experienced an extended period of 3. unit . operation w hich resulted in the highest = temperature regime observed to date at this alle. m For these reasons, we attribute patterns of 3* . Ascophy//um mortality observed at all sites to -E natural environmental stress, in particular, the {* \ degree of exposure to storms and associated wave i Q%%:g.Q w action. FN is our most exposed site, GN and WP more sheltered. This conclusion is further 4 Fa W ad supported by seasonal trends in mortality. ~ * * * *

• Mortality rates are highest at a!! sites throughout

.. ru mwes ww - isson our studies during August thiough November, when strong storms are frequent. - ng.13. Amewwn nmnaloy, as number of renwning hP.at Ascophyllum mortahty is typically high each station. Values dunng 19KW are plourd agamst means throughout its range and he relationship between .and rangen or Luna and kunn operauenal periods. degree of site exposure t nd mortality is well results from storms and wave exposure (Cousens documerited (llaardseth 1955,1970a; Jones and' 1982), lec scour (Mathieson et al.1982), grazing Demetropoulos 1968; Va las et al. 1976, 1978; (Sundene 1973) and epiphyttration (Boney 1965). Wilee et al.1978; Cousens 1982, 1986; Vadas and Human impacts resulting in At;ophyllum mortality Wright 1986). Thatius Ireakage and annual are well documented and include harvesting (Seip dehiscence of receptacles are the two mechanisms 1980; Keser et al.1981; Vadas and_ Wright 1986), which account for the mnsiderable contributions pollution (Rueness 1973; Bokn and Lein 1978; by Ascophy//um to the detrital pool (Josselyn and Stromgren 1979, 1980) and thermal injury Mathieson 1978,1980). The high percentage of tip (Stromgren 1977; Vadas et al. 1976,1978; Wilee et and frond loss of_Ascophyllum plants is balanced by al.1978; NUSCO 1987). vegetative clongation and lateral proliferation of Ascophy//um mortality data reported here and in i ng lived individuals. Vadas and Wright (1986) 180 Monitoring Studies,1990  % w und Cousens (19S6) described unbranched identification and documentation of these trends suppressed fronds ('j us eniles') under well provide objecthe esidence of the elfects of developed densely branched canopy fronds as elevated water temperature on attashed alpac, ' meristem banks'. Such juseniles branch and hence the changes that would be espected at other develop when competition for light is decreased stations, should the 3 una plume estend to them. upon removal of canopy frondt Removal of the Qualitative algal analyses aho document the entire plant seems to be a rare occurrence, in this increasing frequency of occur .nce of Antirhamnion respect, Asaphylhim exhibits a survival strategy sp., recently introduced to the hlillstone area, but similar to that of Chom/nn, discussed in the unrelated to MNPS operation. previous secuon,i.e.. vegetative axis propagation by Analyses of abundance (percent cover) of plants long lhed individuals. And despite exceptionally and animah in undisturbed and denuded transetts low teeruitment success (Pnnt/ 1% Rueness permits determination ol natural sariabihty in 1973), A scophyllum maintains dominance on patterns of spatial and temporal dninbution at sheltered to moderately exposed regions unimpacted sites and the additional sariability throughout its range, including our study sites. imposed by thermal incursion to an impacted Therefore, established plants persist for long station. Thermal plume behasior deterrmnes that periods, perhaps decades (David 1943, Keser et al, the low intertidal /one at FE h esposed to 1981; Keser and Larson 1984). elevated water temperatute lor 0-10 hours each Successful recruitment on exposed to moderately tidal gcle, and thereb) b responuble lot the exposed shores involves a rare combination of deselopment of a community distintily +wimilar mechanisms or stochastic esents (Vadas et al. to low intertidal communities at oil a sues 1900). Removal of the Ascop/nllum population at flowever, the mid and upper mtertiJa!iones at FE our original moderately exposed site (FO) by are exposed to elesated temperatures lor a shortes elevated temperature 3 caused by 2 unit 2 cut time, and the community in these zones more conditions, followed by lessened temperature closely resembles those at other sites. Our studies extremes (at FO) of the subsequent 3 unit 2 cut demonstrate the procewes by which local species discharge (NUSCO 1987, 190d) allows us to persht and recoloni/e, and the ellect that ele,ated monitor recruitment and recolonization at an water temperature has on these processes. impa.ted site. Although several small (and Measurements of Ascophylhim document a clear apparently stressed) adult Ascophylhua plants are response to MNPS operation, i.e.. enhanced present in the sicinity of FO, no significant growth in a population ca. 150 m from the population recovery has occurred to date in this discharget The degree of enhancement appears to area. Present environmental conditions at FO, be directly related to the heat load proJuecd by although thermally less stressful than during 2-unit the power plant, and is greatest when all units

2. cut operation, still appear unfavorable for the operate simultaneously during the Awophyllum successful recruitment and population growing season, reestablishment of Ascophs//um. In summary, the rocky intt rtidal studies described above have ef fectively documented Conclusions population and community lesel differences in assemblages of organisms inhabiting local rocky During 19S9 90, rocky intertidai studies shorcs. Some dif ferences are attributed to natural continued to characterite rocky shore communities variability ot envu onmental conditions; predictable in the vicinity of MNPS; each facet of the seasonal cycles tesult in stable (although noi statit) monitoring program contributed to our assessment communities at most sites. Differences observed at of impacts associated with 3-unit operation. Fox lsland Exposed centinue to be attnbuted to Qualitati e algal analyses allowed us to determine alteration of water temperalmes in close proximity Doristic changes that occurred, and continue to to the MNPS discharges. Knowledge of the effect occur, at a thermally impacted station, e.g., that elevated water temperatures base on patterns presence or extended growing season of algae with and processes of rocky intertidal community warm water affinity, and absence or abbeviated structure is sital to our understanding of impacts season for species with cold water affinity. associated with operation of MNPS, and Rocky intertidal 181

determination of whether these impacts remain Introduction to Numerical- Classification. restricted to their present extent. Academic Press, New York. 229 pp. Connell, J ll. lo61. Effects of competition, Meierences Cited predation, by Thais lapillut and other factors on natural populations of the barnacle, Solanu3 Aberg, P. 1990.- Measuring size and choosing />alanoides. Ecol. Monogr. 31:61lN. category size for a transition matrix study of the Connell.J.ll.1975. Some mechanisms ploducing seaweed Ascophyllum mWosum. Mar. Ecol. structure in natural communities: a model and Prog.Ser, 63:281 28*, evidence from field experiments. Pages afnavd Baardseth, E. 1955. Regrowth of A.tcophyllum in M.L Cody and J.M. Diamond (eds) Ecology mdosum After Harvesting. Inst. Ind. Res. and Evolution of Communities. Belknap Press, Stand., Dublin. 63 pp. Cambridge, Maw. Daardseth, E. 1970a. Synopsis of biological data Connell, J.ll. 1987. Change and persisience in on knobbed wrack Arcophy//nm mdosum (L) some marine communities pp. 33o.352 in AJ. I 1.c Jolis. FOA Fisheries, Synopsis #38. 44 pp. Gray, MJ. Crawley and PJ. Edwards, edt i Haardseth, E. 1970b, Seasonal variation in Colonization, Succenion and Stability, l Ascophyllum muosum (L) Le Jol. In the Blackwell Scientific Publications, Oxford UK. Trondheimsfjord with respect to the absolute 472 Pp. live and dry weight and the telative con'ents of Conntil, JJ L and R.O. Statyer. 1977. dry matter, ash and fruit bodies. Bot. Mar. Mechanisms of succession in natural 13:13 22. communities and their role in community Bertness, M.D. 1989. _ Intraspecific competition stability and organization. Am. Nat. 111:1119-and facilitation in a northern acorn turnacle 1344. population. Ecology 70:257 2rA Cousens, R.1982. The effect of exposure to wme  ; Bokn, T., and T.E. lxin. 1978. Longterm action on the morphology and pigmentation of I changes in the fucoid association of the inner Arcophy//um mxlosum (L) lx Jolis in south. Oslofjord, Norway. Norw. J. Bot. 25.914. eastern Canada. Dot. Mar, 25:191 195. Boney, A.D,- 1%5. Aspects of the biology of the Cousens, R.. 1984. Estimation of annual seaweeds of ectmomic importance. Adv. Mar. production by the intertidal brown alga Biol. 3:105 253. Ascophyllum mdmum (L) lx Jolis. Dot, Mar, Bradbury, R.H,, LS. Hammond, and R.E. Reichelt. 27:217-227. 1984. Prediction versus explanation in Cousens, R.1986. Quantitative reproduction and environmental' impact assessment. Search reproductive effort by stands of the brown alga 14:323 325. Ascophylhem mdosum (L) Le Jolis in south. Carlson, DJ., and - M.L Carlson. 1984, castern Canada. Est. Coast. Shelf Sci. 22:495 Reassessment of exudation by fucoid $07. macroalgaeJ Limnol. Oceanogr. 29:10771087. David, H.M.1943. Studies in the autecology of Chapman, A.R 0,1973. A critique of prevailing Ascophy//um n<whuum lx Jol. J, Ecol. 31:178, attitudes towards the -control of seaweed 199 zonation on the sea shore. Bot. Mar,16:8n.82. Dayton PK 1971. Competition, disturbance,and - Chock, ' J.S., and A.C. Mathieson. 1979 community organization: the provision and Physiological ecology of A5cophyllum mWasum subsequent utilltation of space in a rocky -(L) LcJolis and its detached ecad scorpioidc3 intertidal community. Ecol. Monogr. 41:351 -(Hornemann) Hauck (Fucales, Phaeophyta). 389. Bot. Mar. 22:21 26. Dayton, P.K. 1984. Processes structuring some Chock, , J.S., and _ A.C. _ Mathleson, 1983. marine communities: are they general? pp.181 Variations in New England seaweed biomass. 197 in D.R. Strong, Jr., D Simberloff, LO. Bot. Mar. 26:87 97. _ Abele and A.D. Thistle, eds. Ecological Clements, F.E,1936. Nature and structure of the Communities: Conceptual Issues and the climax. J. Ecol. 24:252 284. Evidence. Princeton University Press, Princeton Clifford, H.T., and W. Stephenson. 1975. An NJ.,611 pp. 182 Monitoring Studies,1990 ym - - y---.- - - ~ ~ - , - . - ~ - - . - - . - - - - . - -- .---- DeAngelis, D.L, and J.C. Waterhouse. 1987, H. Barnes (ed.) Sorne Contemporary Studies in. Equilibrium and nonequilibrium concepts in Marine Science. George Allen Unwin Ltd., ect .ogical models. Ecol. Monogr. 57:121. London. = Draper, N., and H. Smith. - 1981. Applied Katz, C.ll. 1981 A nonequilibrium marine Regression Analysis. John Wiley and Sons, New predator. prey interaction. Ecology 66:1126 -York. 709 pp. 1438. Farrell, T.M. 1991. Models and mechanisms of Keser M., and J. Foerich.1982. Colonliation and succession; an example from a rocky intertidal growth of Ascophylh4m malosum in New community. Ecol. Monogr. 61:95si l3. England. Presented at the First International Fabey, E.Mi 1953. The repopulation ofinter.idal Phycol. Congr., St. Joh n's, Newfoundland. transectA Rhodora $5:102108. August 9,1982. Filion Myklebust, C., and T.A; Norton. 1981. Keser M., and B.R.1. arson. 1984. Colonization Epidermis shedding in the brown seaweed and growth dynamics of three species of Fucus. Arcophy//um nodosum- (L) Le Jolis, and its Mar. Ecol. Prog. Ser. 15:125 134. ecological significance. Mar. Diol. Lett. 2:45 51. Keser, M., R. L Vadas, and B.R. Larson. 1981. Gaines S., and J, Roughgarden. 1985 larval Regrowth of Ascophy//um mulosum and Fucus settlement rate: a leading determinant of resiculosus under various harvesting regimes in structure in an ecomgical communhy of the Maine, U.S.A Bot. Mar. 24:29J8. marine intertidal zone. Proc. Nati. Acad Sci. Lance, O.N., and W.R. Williams.1o67. A general USA 82:3707 3711, theory of classificatory sorting strategies,- 1. Geisciman, J.A., and OJ. McConnell. 1981. Hierarchical systems. Comput. J. 9373 380. Polyphenols in brown algae Fucus vesiculosur Lewis, J.R. 1964. The Ecology of Rocky Shores, and Ascophyllum mwlosum: chemical defenses English Univ. Press, London. 323 pp. against the marine herbivorous snail, Linorina Littler, M.M., and D.S. Littler. 198a The - linorca. J. Chem. Ecol. 7:!!15 1133. evolution of thallus form and survival strategies Grant, W.W. 1977. High intertidal community -in benthic marine macroalgae: field - and development on a rocky headland in Maine, laboratory tests of a functional form model. Am. U.S. A. Mar. Biol. 44:15 4.5i Nat.116:25 44. Hughes, R.N., and C.L Griffiths 1988. Self. Lubchenco,J. 198R Algal vonation in the New - thinning in barnacles and mussels: The England rocky intertidal community an geometry of packing. Am. Nat. 132:484 491. experimental analysis Ecology 61:333 244. Johnson, S.C., and - R.E. Scheibling. 1987. Lubchenco, J. 1983. Linorina and Fucus: effects - Structure and dynamics of epifaunal of herhivores, substratum heterogeneityi and assemblages on . the intertidal macroalgae . plant escapes during succession. Ecology. Ascophyllum mxfosum and Fucus resiculosus in 64il116 1123 Nova Scotia, Canada. Mar. Ecol. Prog. Ser. Lubchenco,J., und ). Cubit. '198R Heteromorphic 37:209 227. life -- histories of certuin marine algae' as Jones, J.E., and. A. Demetropoulos. 1968. adaptations to variations in herbivory. Ecology ~ Exposure to wave action: Measurements of an -61:676 687, important ecological parameter on rockyshores - Mann, K.H. 1973. Seaweeds: their productivity on Anglesey, Ji Exp. Mar. Biol, Ecol. 2:46 63. and strategy for growth. Science 182:975 983. Josselyn, -M.N., and A.C. Mathieson. 1978. Mathleson, A.C., C.A. Penniman, P.K.' Busse, and ' Contribution of_ receptacles from the fucold E. Tveter.Gallagherc 1982. Effects of ice on v L Ascophyllum mulmum to the detrital pool of a_ Ascophylhun mulosum within - the ^Orcat Bay north temperate estuary. Estuaries 1:258 261. estuary spiem of New Hampshire Maine, 'J. Josselyn,; M.N., and A.C, Mathieson. 1980. ~ Phycol. 18:331 336. Seasonal influx and decomposition 'of. Mathieson, A.C., and J.S. Prince 1973. Ecology autochthonous macrophyte litter in a porth of Chondrur crispus Stackhouse. Pages 53 79 in < temperate estuary. .Hydrobiologia 711197 208. M.J. Harvey and J. McLachlan (eds.) Chondrus Kanwisher, G.WJ _1966. . Photosynthesis and crispus. Nova Scotian Inst. Sci., Halifax. respiration in some seaweeds. Pages 407 420in Mathieson, A.C., J.W. Shipman, J.R. O'Shea, and i Rocky Intertidal 183 p m__. _. _ .-.._ _ _ _ _ _ _ _ _ _ _ _ - . _ ._._ _ _ _ _ _. _ _ _ . _ - R.C, liaseviat. 1976. Seasonal growth .and development. Science IM:262 270. reproduction of estuarine fucold nipae in New Paine, R,T., and S. A. Levin. 19X I. Intertidal England. J. Exp. Mar Biol, Ecol. 25;533 545. landscapes: disturbance and the dynamics of Menge, B.A. 19M Organization of the New pattern. Ecol. Monogr. 51:14$4178. England rocky intertidal community: role of Printz,it.1956. Recuperation and recolonitation predation, competition and environmental in Ascophy//am. Pages 194-197 in T. liravud heterogeneity. Ecol, Monogr. 46:355 393. and N.A. Sorenson (eds) Second Int. Seaweed hienge, B.A. and J.P. Suthetland. 1987. Symp. Pergamon Press, London. Commu nity regulation: variation in dist ur bance, Printe, H. 1959. Insestigations of the failure of competition and predation in relation to recuperation and repopulation in cropped environmental stress and recruitment. Am. Nat. Arcophy//um nm/osurn. Norske %densk, Akad. 130;730-757. K. hlat. Nat. Kl. 3:1 15. Menge, J. 1975. Effects of herbivores on Rangeley, R.W,, and AlLH. Thomas 14XS community structure on the New England rocky Littoral stratification in growth form and intertidal region: distribution, abundance, and fecundity of the rock barnacle, Senuhalanu3 diversity of algae. Ph.D. thesis, Harvard Unis. balanoides. J. Mar. Biol. Ass. U.K. fd591599 IM pp. Ring, P.D. 1970. Developmental and Murray, S.N., and M.M. Littler 1978. Patterns of ecophysiological studies of Chondnis cmpus (L) algal succession in a perturbated marine Stockh. M.S. thesis, Univ. Maine. 73 pp. Intertidal community, J. Phycol. 14:506-512. Roughgarden, J., S, Gaines, and 11. Possingham. NUSCO (Northeast Utilities Service Company). 1988. Recruitment dynamics in complex life 1982. Plankton. Pages 124 in Monitoring the cycles. Science 241:14(n1466. manne environment of Long Island Sound at Rueness, J. 1973. Pollution effects on liitoral Millstone Nuclear Power Station, Waierford algal communities in the inner Oslofjord, with Connecticut. Annual Report,1981, special reference to Ascophy//am nalosum. NUSCO. 1985. Rocky Shore, Pages 141 in Helgolander wiss. Meeresunters 24:446-454. Monitoring the marine environment of Long Schneider, C.W., M.M. Suyemoto, and C. Yorish. Island Sound et Millstone Nuclear Power 1979. An Annotated Checklist of Connecticut Station, Waterford Connecticut. Annual Seaweeds. State Ocol. and Nat. Illst. Sury. CT Report,1984. Dept of Environ. Prot.,11ull.1078. 20 pp, NUSCO.1987. Rocky intertidal Studies. Pages Schonbeck, M.W., and T. A. Norton. 1978. 166in Monitoring the marine environment of - Factors controlling the upper limits of fucold Long Island Sound at Millstone Nuclear Power algae on the shore. J. Exp. Mar. Biol. Ecui. Station, Waterford Connecticut. Summary of 31:303 313 studies prjor to Unit _3 operation. Schonheck, M.W., at,d T.A. Norton. 19S0-NUSCO. 198h Ilydrothermal Studies. Pages Factors controlling the lower limits of fucoid 323454 in Monitoring t_he marine environment algae on the shore. J. Exp. Mar. Biol. Ecol. of Long Island Sound at Millstone: Nuclear 43:131 150. Power Station, Waterford Connecticut. Annual Scip, K.L 19S0. A computational model for Report,1987. growth and harvesting of the marine alga NUSCO 1988b. Rocky Intertidal Studies. Pages Ascophy//um nodosum. Ecol, Model. 8:189199. Il 56in Monitoring the marine environment of -Sousa, W.P.1979, Experimental investigations of Long Island Sound at Millstone Nuclear Power , disturbance and ecolagical succession in a rocky Station, Waterford Connecticut. Annual intertidal algal _ community. Ecol. Monogr. Report,1987. _ 49:227 254. -'N USCO. 1990. Rocky Intertidal Studies. Pages - Sousa, W.P.1984. Intertidal mosaics: Patch sire, 185-218 in Monitoring the marine environment propagule availability, and spatially sariable of Long Island Sound at Millstone Nuclear patterns of succession. Ecology 65:19181935. Power Station, Waterford Connecticut. Annual South, O.R., and 1. Tittley.1986. A checklist and Report,1989. distributional index of the benthic marine algae - Odum, E.P. 1969. The strategy of ecosystem of the North AtlanticOcean. Huntsman Marine 184 Monitoring Studies,1990 - . m _._ _ _ _ _. _ _ _. I l l l l 1 -l Laboratory and British Museum (Nat llist,), St. Press, Cambridge UK. 617 pp. ] Vadas, R.L M. Keser, and P.C. Rusanowskt 'Andrews and LondonJ 76 pp. l-Southward, A.J. and E. C. Southward. 1978. 1976. Innuence of thermal loading on the ' Recolonization of rocky shores in Cornwall ' ecology of intertidal algae. Pages 202 25 in  ? l aher _use of toxic dispersants to clean up the G.W. Esch and R.W. MacFarlane (edu ' - ^ Tomy Canyon spill. J. Fish. Res. Board Can. Thermal Ecology 11. ERDA Symposium Series ' 25:6N2 706. Augusta. G A. Stephenson, T.A., and A. Stephenson.1949. The Vadas, R.L. M. Keser, and P.C. Rusanowskt un'iversal features of ionation between 1978. Effect of reduced temperature on  ! tidemarks on rocky coasts. J. Ecol. 38:289 305. previously stresse I populations of an intertidal  ; Stromgren. T. 1977, Shorbierm effects of ' alga. Pages 434 451 in J.ll. Thorp and G.W. I temperature upon the growth of intertidal Gibbons (eds ) DOE Symposium Series, fucates.- J. Exp. Mar. Biol. Ecol. 29:181 + 195. Springfield, VA. (CONF 771114. NTIS) Stromgren, T, 1979. The effect of copper on Vadas, R.L. and W.A. Wright. ly8n- , length increase in Ascophy//um nalasum (L) Le Recruitment, growlh and management of j Joli$. J. Exp. Mar Biol. Ecol. 37:153 159. Ascophy//um nodosum. Actas 11 Conyt Algas Strompren, T,1980. The effect of lead, cadmium, Mar. Chilenas! 101 113. and mercury on the increase in length of Ove Vadas, R.L and W.A. Wright, and S.L Miller. inteitidal- Fucales. J. Exp. Mar. Biol. Ecol. 19'n Recruitment of Ascophy//um nalosmn: , 43;107 119 wave action as a source of mortality. Mar. Ecol. , - Strompren, T.1981. Indisidual variation in apical Prog. Ser. 61:263 272. I growth rate in Ascophyllum nalosum (L) Le Verlaque, M., and R. Riouali.19S9. Innoduciion I Jolls. Aquat. Bot.10:377 382. de Po&siphonia nityevcent et d'Amithammon Sundene,O. 1973. Growth and reproduction in nipponicum (Rhodophyta, Ceramiales) sur le i Ascophy//um nalorum (Phaeophyceae). Norw. littoral Mediterranden franqais. Cry ptogamie, l ' J. Bot. 20:249 255, , Algol.10:313 323  ! Taylor, W.R. 1957. Marine- Algae of the Villalard Bohnsack, M.. P. Peckol, and M.M. i . Northeast Coast of North America. Univ. Harlin. 198;i Marine macroalgae of Mich. Pressi Ann Arbor. 870 pp. Narragansett Bay and adjacent sounds. Pages Topinka,J., L Tucker, and W. Korjeff.1981, The 101-118 in R.G. Sheath and M.M, liarlin, eds, , distribution of fucoid macroalgal biomass _along Freshwater and Marine Plants of Rhode Island. central coastal Maine. Bot. Mar. 24: 311 319. Kendall/ Hunt Publishing Company, Dubuque. , Underwood, AJ., and E.J. Denley. 1984. 149 pp. _ _ Paradigms, explanations and generalizations in Wethey, D.S.1983. Geographical limits and local models - for the structure of intertidal zonation: 'the barnacles Scmilialanus and

communities. of rocky shores. pp. - 151 180 in . Chthamalus in New Englandi Biol Bull. I D.RaStrong, Jr., D Simberloff, LG. Abele and- 165:330-341.

- A.B. Thistle, eds., ~ Ecological Communities: Wilce, R.T., J. Foerich, W. Grocki, J. Kilar, i1. l Conceptual issues and the Evidence. Princeton Levine, and J. Wilee. 1978. Flora: Marine i University Press, Princeton _ N.J. 61l'pp. Algal Studies. Pages 307 656in Benthic Studies ? Vadas, R.L .1973. Attached Algae, = Pages 195, in -- the Vicinity of Pilgrim Nuclear Power .; 261 in Survey of the _ hydrography, sediments - Station, 1 % 9 1977, Summary Rpt., Boston plankton, benthos and commercially _important Edison Co. . plants and _ animals lncluding finfish, in the .l Montsweag: Bay Dack River . awa: Prcoperational Summary. Maine Yankee Atomic. Power Company. Vadas, R.L 1985, licrbivory. Pages $31572 in M.M. Littler and D.S. Littler, eds.,1-landbook of Phycological Methods, Ecological Field l Methods: Macroalgae. Cambridge University p Rocky intertidal 185 - - .,ww-.y pr-,- ~ ,- ..,_r ....m.-m_w.%_.cor. .v.. . . _ , , s . . - . - . . _._ _ . _ _ _ _ -_ _ _ _ _ - _ ~ _ _ _ _ _ _ _ _ - - _ - - _ - _ _ _ Contents Eelgrass........................................................ 189 I n t r od u c t io n . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 189 Materials and Methods ....................................... 189 Results ................................................... 191 Sediments............................................ 191 S h oo t D e n s i ty . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 191 S h oo t Le n gt h . . . . . . . . < . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 192 S t a n ding S t oc k . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 192 R e prod uc t ive S h oo t s . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19t D is c u ss io n . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 194 Co n c l us io ns . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 196 References Cited . . . . . . . . . . . . . . ............................. 196 Eelgniss Introduellon studies found no relationship betw een the operation of MNPS and the phenology of Z(utcra Eelgrass (Zostcra marina L) is a marine populations. In addition, hydrographic and l Dowering plant, it has colonired temperate and hydrothermal studies indicated that the thermal sub arctic coasts of the Northern llemisphere plume of Alillstone Unit I did not reach the l (Setchell 1935), because local varieties of this celgrass populations in Jordan Cove (VAST 1972; I ~ species have successfully adapted to the local NUSCO 1979). ranges of temperature and salinity (Osterhout The present study was inhiated m 1985 followine 1917; Selchell 1929; Uphof 1941; Burkholder and the prediction that the 3 unit thermal plume would Doheny 1968; Dillon 1971; Thayer et al.1984), extend into Jordan Cos e (ENDECO 1977) The importance of eclgrass to marine ecosystems Throughout the range of Zoucra, researchers hase > - w as first recognized by Danish researchers demonstrated that temperature can affect (Peterson 1891, 1918; Ostenfeld 1905). Little populations by in0uencing growth rate, restslance additional research was done until the ' Wasting to disease, seed production and germkation Disease" destroyed ' most of the eclgrass (Burkholder and Doheny 196S; Phillips 1974,19S0; populations in eastern North America and western Orth and hloore 1983). The objective of ibis study Europe (Tutin 1942); scientists still disagree on the was to 3ce if operation of AINPS caused changes in exact cause for the disease (Renn 1934; hlitne and the Zortera population in Jordan Cose beyond Milne 1951; Rasmussen 1973, 1977; McRoy and those expected from natural variability. Bridges 1974; den liartog 1977; Short et al.1987, 19SS). Followmg the destruction of Zosiera Materials and Methods populations, increased wave scour and changes in current patterns caused shoreline erosion and Three celgrass sites in the vicinity of MNPS declines in abundance of many animal species, were sampled duritig 1990 (White Point WP, including commercially important fishes and Jordan Cove-JC, Niantic River NR) (Fig.1). The lobsier (Staurier 1937; Dexter 1947; Milne and WP and JC stations are located 1.6 km and 0.5 km Milne 1951; Orth 1973,1977; Rasmussen 1973, cast of the power plants discharge, respectively, 1977; Thayer et al.1975; Zieman 1982). and are within the area potentially influenced by Recovery of eastern North Atlantie celgrass the 3-u nit thermal plume (ENDECO 1977; , popuhtlons began in the 19Ws, and by 1970 NUSCO 1988). The NR site,!ncated about 3 km Zostcra populations in the Niantic River were so from Millstoac Point, is a control station in an dense that dynamite was used to clear areas area unaffected by power plant operation (Fig.1), through celgrass beds to maintain water circulation Water depths (mean low water) were 2.5 m at WP, (Klotz and Knight 1973). Eelgrass populations 1.5 m at NR and 1.l m at JC. were also' dense in the vicinity of Millstone The WP and JC sites have been sampled Nuclear Power Station (MNPS), and large amounts continuously since 1985 and the present NR site of eciprass washed ashore at local beaches due to only since 1987. An earlier NR study site, kicated the natural senescence of Zoatern plants in late midway between Camp Weicker and the navigation summer and early fall. Local residents attributed channel (Fig.1), was sampled throughout 1985 and the dic off of celgrass ~ to the operation of in June 1986. The eclgrass population at this site Millstone Unit 1. Northeast Utilities initiated wn; severely reduced, so the site was relocated (50 studies in 1973 to address these conecrns; the m) nearer the navigation enannel, and sampled for , studies included mapping of eclgrass beds in the remainder of the 1986 season. By September Jordan Cove and measurement of environmental 1986, the eclgrass population at this site also (e.g., water temperahre and sediment disappeared. In June 1987, the NR study site was characteristics) ad celprass population parameters finally moved to its present location in the lower (e.g., shoot lengths aral reproductive status) (Klotz river (designated 'new' in this report; Fig.1). and Knight 1973; Knight and lawton 1974). These Ecigrass has since recolonized several areas in the Ecigrass 189 l 0991,seidutS gnirotinoM 091 stnalp eht fo esuaceb dezylana yllacitsitats ton saw enies PW dna CJ eht ta deyolped erew sredrocer htgnel toohs ssargleE .kcots gnidnats dna ytisned erutarepmet suounitnoc ,noitidda nI .8891 yluJ 1 - l loohs ssarglec fo seires emit eht ni sdnert enimaxe ot enuJ 42 morf snoitats ssarglec PW dna CJ eht  ; ot desu erew sdohtem noisserger raeniL .)2m/g( ta sredrocer erutarepmet suounitnoc gnigrembus l; 3 m/thgiew yrd smarg su troper siht ni detneserp yb detagitsevni erew noitarepo - tinu 3 morf dna _ Qhsnoitaler thgiew yrd/thgiew tew eht detcepxe evoC nadroJ ni sesaercni erutarepmeT [ morf detamitse erew 0991 a' 8891 morf sthgiew yrd .noitats hcae ta seltsiretcarahc yratnemides enimaxe ,)99,0 49 0=2r ( sthgiew tew htiw det.kerroc ylesolc ot selpmas ssarglec htiw rehtegot nekat saw - sthgiew-yrd esuaceB .thgiew tnatsnoc a ot C eroc peed mc 5 x retemaid mc 5 3 a ,noitats hcae riS ta nevo na ni deird neht ,dehgiew erew stoohs tA .gnissecorp rof yrotarobal eht ot thguorb dna l ,7891 ot 5891 morF .tardauq hcae morf nekat . , gab hsem mm 333 0 a ni decalp ,detswrah erew  ; stoohs lla gnihgiew yb detamitse saw kcots gnidnats _ tardauq hcae nihtiw stnalp morf stoohs thgirpu ssargicE .dedrocer ton erew setyhpipe fo sthgiew ehT .rekram noitats eht fo suidar m 01 a nihtiw eht ,yduts eht tuohguorht laminim saw stoohs )2m 52600,mc 52x52( tardauq a gnissot ylmodnar - ssarglce no setyhpipe fo ecneserp _eht esuaceB srevid ABUCS yb detcelloc erew selpmas 61 ' .devomer erew setyhpipe lla , emit emas eht ta dna ,noitats hcae tA .ytisned tnalp dna kcots gnidnats setarbetrevni evomer ot retawhserf ni desnir erew mumixam - fo doirep_ eht ,rebmetpeS hguorht stoohs ehT .noitalupop eht ni stoohs evitcudorper enuJ morf ylhtnom detcelloc erew selpmaS -fo egatnecrep eht etamitse ot dedrocer ,5891 saw elpmas hcae ni stoohs evitcudorper fo rebmun ni etis emas eht ta detcelloc atad ot atad 0991 ehT .me tseraen eht ot derusaem saw )elpmas rep gnirapmoc yb noitats siht ta yrevocer fo tnetxe eht stnalp 02 ot pu( toohs hcae fo edalb tsegnol eht etaulave ot )rebmetpeS-yluJ()X(91 ni )m 5 0 htped _ l dna detauoc erew stoohs lla ,yrotarobal eht tA - retaw( etis RN dlo' ' eht ta nekat erew ssarglec 8891 yluJ 12 ot yluJ 41 morf )troper fo selpmaS .)troper siht ni 'dlo' detanylsed( siht fo noitces ygolocE hsiF ni I .gF ees( snoitats etis yduts 5891 lanigiro eht .gnidulcni ,revir .tmoP etihW=PW )%91 reitmetpesn91 yluJ detpmw=2 %91 enuJ 5891 detpmw=l( tcntt citmaN=RN cmc nadroJ=CJ ,)u( snoitats gnhpmas mplyc fo noitawk eht gniwohs aera tmoP enoMldM eht ro paM L gh. w n.a.o j 1 1 ltw i nh jec k v g ( m ,v y \ x_ p.,g - f) ,m.n N.,s,PW \ 9 {* % /  ! {/ j) w 2 # %W cw - ( A r fQ Y a- 2T _ , 6n 1 1 mvi b p htroN [' _3.-. i 3 vg \, AQ 1uV b T mode of growth and the fact that the leaf turnover ___ .% m rate is highest during the summet (Roman and m I l l l Able 1988) Mean sediment grain slie and silt / clay i I i l content were determined using the dry sieving } m. . i l 1 method (Fod 1974). Sedimeni samples were .- p  !. l . I 6 heated to 5(Kr C for 24 h to determine organle m ,,::: % .* . q . . sy: - ;b .. : . g .,,[ l cc.ntent, c>t: mated as the .urterence between dry- . ..) { l' , I weight and ash weight. Both silt / clay and organic o  ! ) r l vonient were recorded as a percentage of the total lm  ; --..- - . ~ ~.1 sediment sample weight. g"L.,. p - , " L -. ~L l .  ; .: -- Restills Iiiiifiliiiiiiiiitiii:ii ...+..,. E4 ' .- f* -% Sedimerits ,- u ..,  ! j o s . . , , e ' .i' 1 1 4 Mean grain si/c. organic umtent and silt / clay h '" ' .;. * " ,,, . ' S'+j 1 content f om June 1985 to September 19'K) are v '" ... + .. . ~, *J+'* !. -i presented ir, Figure 2. During 1990 (June. Sept.), l [*, c l' sediments were finest at WP (OW41.12 mm) and ,, j , coarsest at JC (0.23 0.25 mm). Values at NR were 1 , O.10 0.17 mm. Percsnt sill! clay and organ'c I ,, m .. .. . col.'ent were highest at NR (13.9 25.6%; M . Io 15.5'li), and lowest at JC (1.3 5.6%; 1.01.8%; ,, C

• j L _ *, " ' ' " * + - +- l lljjj(llt,Iis ,llljjj3jj l value. at WP were intermediate (11.123.1% 2.! . , , , , , , , ,  ;

3.2% ). All of the above values were within tr e *T 7 y1 i range of previous observations (19851989). ," in addition to the 'new' NR sampling station  ; "l ' ,j , i reported above, we sampled the 'old' NR site f >r i* ,. . the llrst time since 1985. Mean grain slic at ti.is t '" " "* ' * *~' ** station in 1990 ranged between 007 and 0.11 mm * "~'~' ' *~..a . i l"" '"I (July Sept.) compared to 0.09 and 0,16 in 1985  !' (June Sept.). Percent silt / clay and organic content 1 2 ,, l in 19% were 23.9 24.3% and 2.917.2% campared  ; in 21.6 34.4% and 4.6 7,4% in 1985. I "o L." _ .. ~. _ ~. L., . - "~ ,_.4._._,_.L.,. ,- 1..- _- Shoot Density ng 2 htcan grun we, orpnic mnieni and swa9 unient ni The pattern of shool density at the three scannenis ei Miliuonc ccyraia uanons unipico conng June, stations during 1990 (June Sept.) was similar to Scriemtc from im iloough t<m sedonent (Imratensio results from 1985 to 1989. Average shoot density I " " *'# N'""d' "" ""d"" " "I" I"d"d'd I"' J"4 durIng 1900 was highest at JC (338 shoots /m'), """ 8h "U"" "d" ' " "" " " "' " " """"' 'd I""" lowest at WP (185 shootsim') and intermediate at analysis of shoot densities at NR indicated a NR (225 shoots!m'; Table 1). The five year time significant decreasing trend from 1987 to IVXI series (1986 90) of shoot density data at JC showed (slope =.0 086; p<0.UI). No significani trendo a significant decreasing trend (slope =.0.245; werc !dentified in the shoot densities at WP, When p<0.01). The 1990 annual value of 338 shoots /m' the two slopes were compared (JC and NR), was the lowest reported since the study began in declines at JC were significantly greater than at 1985 (range 403 712 shoots /m'). The 1990 NR (paired t. test, p<0.05). densities at NR and WP were within the range of The shoot densities were highest in July at NR previous years (ranges 224 307 and 162 320 8 (266 shoots /m') and WP (212 shoots /m'), and in shoots /m . respectively). However, regression Septernber at JC (424 shoots!!f; Fig. 3). The l l Eelgrass 191 t l . . - . . . . _ . . . . _ _ _ _ . . - _ . . . _ _ _ . _ . . . . ~ , - - , - - . 1 AnlE 1. Annual and nainthh a$rrycs or stniol dcasuy, koph and dn wripa stanang stM for trigtav unipkJ not MNPs dunny the June to scpternber 1%i perimi and tach 3rar unce 19ss n33 w wnl 19%$ 19 % 1947 IV%s PM l'70 Jun Jul :sy Nt pt syynm in, M Joraan eme 37 712 sai 4o9 4e m n7 u m 424 Nunac iber Ali 70 294 307 224 22N ;no;* 22; 2wn;wo t vg 2% 2t% :; n White Ptunt 2M 21h 227 162 320 1"3 IW 212 tw Ill hil enrih tend Jordan o m 57 57 77 75 74 h 32 44 w at Nunut Rher 'o V Al M 94 74(40) h6 kl(**)  ??i H1 $2t22) Whnr Point 10s lin 12<. ho 110 10' 127 110 108 71 hi1_n& n t Als6 (ftt[] Jo,a.in cme 24i 27s 23s Zw 200 ms o i2s so 122 Nunin 16er l?$ 12 IN4 lk4 tho 14 h 54) 176 191(97) 112( 4 $ ) M4 203 Whne Point 244 2hu 200 90 21$ 1h0 JW lh 149 45 " Annual and ruonthly ascrge shoot denuty, length and stanang sh L durnig 19'80 of the o)J Nunbc 16tr Shinon shoot density in June 19M) at JC (167 shoots /m!) em). The 190 aserage sSoot length at WP was was the lowest obsersed at this station since 19S5, within the range of presious years (S4126 cm), but 6ensities for other months in 19M were at or Shoot lengths at the JC and NR stations during near the values observed in the same months from 1900 (3S and 74 cm), were the shortest reported 198749 (Fig. 3), The 190 monthly densities at since 19SS (ranges of 57 77 and S t .94 cm, NR and WP were cornparable to those from other respectively). Monthly shool lengths at WP and yeart NR declined from June (127 and 80 cm, The average shoot density at the 'old' NR respectively) through September (73 and 52 cm, station during 1990 was lower (2l10 shoots /m') Ihan respectively; Fig. 4). The 1990 monthly shool the density reported at this station in 1955 (413 lengths at JC were the shortest to date, and did 2 shoots /m ). Similarlyi the average annual shoot not vary greatly from June through September, density at the 'old' NR station during 19A) was The average length "I t. hoots at the 'old' NR lower than the value ut the 'new' NR station station during 19xl was 40 cm compared to 50 cm sampled since 1957 (Tab'ic !). During 190, shoot during 19SS (Table 1). Comparisons between the densities at the two NR stations were identical average shoot lengths at the two NR stations 2 during July (2Whools/m ), similar during August during 190 indicated that shoots were shorter at (189 vs. 209 shoots /m :new vt old), but dillerent in the 'old' station (22-55 cm) compared to the 'new' Septeraber (218 vs.124 shoots /m':new vs. old). station (5240 cm). Shoot Length Standing Stock The monthly (June Sept.)andyearly(19S$.lvo) Ecigrass standing stock during luo was greatest 2 average shoot lengths are presented in Table 1, at WP (180 g/m') followed by NR (143 g'm ) and During 1990, shoots were longest at WP (107 cm), JC (105 g'm ; Table 1). Annual mean standing 2 shortest at JC (38 cm) and intermediate at NR (74 stock at WP during 1990 was within the range of 192 Monitoring Studies, IVA) i i .m.. g.: - 4 3;W% ~ m . m 9 ,, - ,g. ,,, yy j ,,n + l 7l M,, l i I . Im i i l j i 4 ~y ., .( l  ! lIjl [ ] e u- l1 , ke j i 1 ~ li l l j j l ij,i i {I , i .\ !4 t . , , , i m i 3" - i l I g . ' 'i + .j- ), . - t j i i ,' l *  ; i ,;;. ;w;;,. }car. ;:xxw n;;z; win:4- * , r.w;a .x '..: .r.dr.ra! i.. . . h. .:,, - ., , . i. e !-  %- - pg ~ c4- -- . ' g,q -ut gy e  % ,, u g;g -} %, ;y i 3 g _- . ., l  ;  ! m. l t  ;" } .,. I ' f - ,  ;  : i, , . j o , i l i  !,  ! l' ' ;i , 2" I' ,,1 I .i '.! ' lli I l l (({ lIl{ l i lI; , , i f i * 'd t m ~ . .l.l. l_ ... . ._L_ .... .,,_. .. . ......._. a . _. _i g,g f( $4 4.g4 4i.8( 64*1 ,cpgm,-- ) ,,g g~ w- y ,, 3., , . y., ,,. H "' I > i .t ,.  !  : i ., ' i, i' h , i - . w ' i i . { '* * ,, , 16 ' ,q i Qu } f* i,  ! 4 '* -

• llIIl ,I l lI ll iggi li lli, i

I *a.7;;;,7;;.;.;;saat:5a:;~;w;;,tes. tut:w~ %e;www;;;; w, ;-;;;;  ;;.:::1: 1ig 1 Mean numter or ecist.m ahmts irr m?

• 959 C1. at ng 4 Mean $t.ooi icngih um)
• 95% cly Mmuone Mdluone rtigrm stations umpled durmg junc-5cptemtwt hum reigr.m 6tanons umpled dining June Septemtvr hom I'm3 1983 through 1990 (1 = Niantic IOwr eation umpled 1985 June through l'#A1(I = Nuntic 16er 6tation umpicd 19M June 19%.

19A 2=umpled July 19% Septamte 19%)  ;= umpled July 198ti Septemtwr 19%) previous years (90 2M g/m2 ), while at NR and JC, was significantly different than that for NR and 'the 1990 standing stocks were the lowest reported WP (i.e., declines at JC were greater). sinec 1985 (ranges ei 184186 and 200 275 g/m\ Standing stocks were highest in June at WP and respectively). Regression analysis indicated that in July at NR and JC (Tuble 1). The monthly the standing stocks had significan.ly declined since mean standing stocks (1990) at NR and WP were 1986 at ' JC- (slope =.0.109, p<0.01) und ' WP within the range of those reported from 1985 to (slopea.O.NO p<0.01) and since 1987, first year 1989 (Fig. 5) liowever._the IVX) nonthly meam of sampling, at NR (slope =.0.042, p<0.01). No at JC were all below the range of those reported in significant differences were found between. the previous years (Fig. 5). The annual standing stock slopes for NR and WP; however, the slope for JC value ut the 'old' NR station was considerably g lielgraw 193 l- !i .a.--.. .u.__... _ . , . . _...,... _ _.,.-__ , _ _.;-_ _.,._.,- _ . ~ _ .,- _ -- i Reproductive Shoots m .;,c ,.w s ._wy -  ; The percentage of reproducthe N/cra shoots ~ was highest in June at WP (23.6% ) ar d in July at l l d '; - j NR (12.09) and JC (1.99 ) (Table 2). The { ll I percentage of reproductive shoots declined in

3. , .l f August to 2.7'i and 1.I'; at WP and NR,

{ l,ll ' [ , respecthcly, and to none at JC. l'or the sceond ilIl.jl conwouthe 3 ear, no reproducthe shoots wete collected al any station in heptember. The percentages of repnxluctive slaiots in Pnt were .a a A .s .e. .;;. .: a, a. . ;t. .;. .c.: sirnilar to those in previous 3 cats at WP and NR but lower at JC. ,,.m ~ . ...- p... - ,,- ,a w; m,. I)bcu Won i l ,  !' Densuy, length and stantling sto(L of 2o00s l i. hoots were examined dunng 19A1 as pati of the  ! long-term sampling program to awee whether any .~ . l  ! changes in eclgraw populations hase resuhed hom 4 [  ; 3. unit operation at Mhl tone Nuclear Power -.. ll i l;' l Station. The -standing stock of eclgraw signif!;antly declined hom 1% to IW at JC and g=. ., . - + , . - , --{ . _ _ _j l WP, by 62'; and 319, respeethclys and front 1987 observed in eclgrau shoot density at JC (down ,-..wm ,y . ..c w , ~ ,w v $3'li) and NR (down 244) ovet the same > cars, g , ~ shoot densky at WP. Comparisons of the slopes htted to celgrass shoot density and standing stock i (* l data indicated that the declines at JC were s" significandy greater than those at WP and NR, y *- whereas no significant different'e was found i ~ ' t  ! j! l I between the slopes at WP and NR. When annual ,, l ' jl mean values of shool density and standing sto(L ,, [ [l l were contpared among ) ears, signi0 cant declines at JC occurred in each year from 19X6 to 194) Mrs ac;sucI:,m x;mT/n;;;.c.: (paired I. tests, pc0.05).' This consi tency was not ' evident at WP or NR, li ro example, ai WP, only lig.1 M'can dry weight (pann per ni ) 1 9n c.t at  ? the 1988 means phoot denshy and standing stock) AhlNonmipautahons un,pini dwing < tune Scg4cmbet tnun WCIO hIgDIIICdIIIIf I""CI Ib30 lbf MOUUA IlOM UlI 1985 nitough l9'M (i = Nianhc Rher stanon umpled l9MJune other study scars; at NR, standing stock did nol 19so. ;'-umpico ,tor y 19wsepmnher taso) change much from 19S7 to 1989 (184186 g'm'); only the 1941 value of 143 g/m was significantly 2 lower in' 1990 (54 g/m') than in 1985 (155 g'm ). 2 t cent down) than in. predous yeam - Data The monthly estimates of standing stock for 19'M) - coHecteti at NR during 1985 and 1986 were not l "d I"' """""I '"* E"' h""' h#'""* U",' "U"I"" at the 'old' NR station were also lower (20 97 ** i g/m ) than those at the 'new' NR station (89191 I" M U##""

• celgrass sufficiently recolonited the 'old, NR site by 1089, it was resampled during 1900 anti resubv compared to those obtained in 1985, in all cases, 194 Monitoring Studies,19Al I -

---.s..- -...,,..-.-~.-%- -,_-,.-,.---_,,...-..-..,.s. ,.--. ... ~ . _ . - _ _ . . _ . _ - . . , k w y (s e! e i nni 112 Numter of repnducuve plann, totat numtwr of plann and penchhipc of it puiJudisc plann ai reigiau samphng stanons inim June 1945 through \cptemtwr IV80 June Juh August Srphmk r #* 'l ot al" '~6 # 'l ot al 6 $ 'l ot al 'l # 'l utal 'i 6 . lain C.6 t 19%$ 10 $6L 17 23 391 39 11 314 21 0 622 ti o 19 4<. 24  ?$ei 3; ;l %s 3 r. 15 10 % i4 i4 aut 2A 19s7 Ik $st 31 24 30 43 19 49o 1A ll "3 20 paw 20 4e,9 .o i4 3o2 2h 2 415 .- o i  ;* ac $i l9%9 lh $M 30 12 $2h 23 2 Thh Ob o /2N tlo ]+o 2 167 l2 7 N.s 19 o yet 90 o 4;4 oo N nnhc. lh er 1983 31 414 kH lx %N 60 1 3's4 (01 0 $12 00 1956 1 3 33 3 14 170 N.2 0 9% 00 0 14 00 19%7 4 4hl jD 10 242 4I 6 239 2,t 4 294 1.4 19M 1h 3ns .19 17 in f3 8 gin 2x 8 273 29 1989  % 333 10 8 21 287 7.3 11 187 59 0 Itt 90 1990 19 228 83 32 206 12 0 2 189 ti o 21k op wtute poini 19N3 N 394 20 17 281 ho 2 222 (01 0 2M 00 1984 $1 29 1 17 4 14 thN k3 6 2 44 23 9 182 au 1987 19 305 6? 12 22% 33 13 1kc 72 8 1st 4.3 19M 3 186 1h 13 lol 80 $ 131 3x 9 it : 33 1959 31 461 67 3; 4W 67 0 194 00 0 2nl 00 two 47 tw 23 <> 23 2ai 12.a s iss 27 o 148 00 _~ "lotal numtier of reproductne plann in th samples

• Total numtwr or plants in th unples eclgraw abundance and growth in 19)0 were lower 1985. Ilowever, the percentage of reproductive lhan those recorded during 1985, shoots at JC in IVM was the lowest reported to The percentage of reproductive shoots at tbc date, and for the first time, no reproductise shoots three stations was esamined as part of the eclgraw were found in the August samples.

monitoring study. The tvAl percentages at NR The disappearance of celgrass from most of and WP were coinparable to those reported since Niantic River in 19s6 was sudden and attributed to Eelgrau 105 e i i 4 the presence of Labyin/N/a and a decline in water (1974) and Thayer et al. (1984) postulated that quality (Short 1988); however, Short's report did heated ef0uents frem p.mer plants muld climinate not include water quality data. Recovery of the eclgrass from areas near the plants. Studies of eclgran population in Niantic River began in 1989 another scapraw Thalaoin, in Florida (Roessler and continued through 19%L 1he recovery of the and Zieman 100 9, WooJ et al.1% Zieman 1970 'old' NR site during l9%) to about half thc otiginal Roessler 1971) and of Spartma uhcrmpora in population size reported in 1985 was attributed to hiaine (Keser et al.1078), showed a signincant recruitment of new plants through permination of decline in the abundance of these plants in the seeds tninsported from healthy beds at the mouth vicinity of power plantt The elesated water of the river Although eclgrau meadows persist temperatures increased respiration beyond levels mainly by vegetative growth (Tomlinson 1974), that could be supported by plant photosynthesh seed production and dispersal are important Recognl/ing that celgrau meadows are among the mechanisms for maintenance of a healthy most productive marine systems (hiann 1973, population. It is unclear whether celgraw beds in McRoy and Mehiillan 1977; Zieman and Wet /cl Niantle River will continue to recover to the levels 1980) and act to stabilize sediments (Wood et al. observed in 1985, or if eciprass abundance will 1969; Ziernan 1972; Orth 1977), a decline in continue to fluctuate widely from ) car lo year, celgrau abundance at Jordan Cove may also effect $1milar wide fluctuations were reported following the movement ol sediments and spedes abundance , substantial mortalities of celgran in Chesapeake of awociated infaunal communities. The changes ' Day (Orth 1976; Orth and Moore 1981, 1983, observed in the sedimentary characieristics and 1986). Infaunal community during 1989M1 al the Jordan Density, growth and stand!ng Mock of celgrau Coce intertidal sand station (see Benthic Inlauna shoots in Jordan Cove were highest during the first section of this report) may be related to' the ) ear of 3-unit operation (1986), followed by a decline of eclgrau abundance in Jordan Cove. , significant decline from 1987 to 199t Jordan l Cove is shallow, and large sand flats are exposed to Conclusions heating in summer, and freezing in winter. As a result, natural Ductuations in water temperature The decline of eclgrau beds in the Niantic River are greater at JC than they are at NR or WP, This in 1985 and 1986 was attributed to a disease area is also more affected by wind driven water (Labyrinthula) and decline of water quality (Short circulation patterns than are stations in deeper 1988L The reasons for the recovery which began water, in addition,since Unit 3 began operating in in 1989 and continued in 1900 are not clear at April 1986, the thermal plume has increased in present, si/c, and extends into Jordan Cose; this results in While the abundance of eciprao declined at all water temperatures slightly (0.8 22'C; predicted our t.tations throughout the stude, as shown by and verified by hydrothermal studies, NUSCO regression analysis, the decline at [ordan Cove was 1988) above ambient, and may have contributed to mon pronounced, resulting in a $3% decicase in the inillal growth increases seen at , in 1986, the density of plants this year (relative to 1986 increased prowth of Spartina alirrmpora observed values), and a 62% decrease in standing stock, in Maine following the initial release of a thermal The cause for the decline at JC is undetermined. plume, was attributed to Increased water although temperature increases of 13*C, resulting temperature; subsequently, over the next rew ycars plant abundance declined significantly (Keser et al.' from the 3 unil thermal plume along with the natural temperature variability, may play some role I978)- in the process. The importance of temperature in regulating celgrass growth and development was first stressed gy,.cnet's CM by Scichell(1929). It was later shown that celgrass is sensitive to small temperature variations (1 hayer et al,1984), Ecigrass plants do not produce seeds Burkholder, P R., and T.E. Doheny. 19M The at temperatures above 15 20 *C (Burkholder and biWogy of eclgrau. Contribution No. 3. Dept. Doheny 1968; Orth and Moore 1983). Phillips f Conservation and Waterways, Town of Hempstead, Long Island, Contribution No, 196 Monitoring Studies,1990 . -- -- - .- - - __ -_ ~ _ . - - - - -. I l 1 I 122712mont Ocologleal observa tory, Palisades. NUSCO (Northeast Utilities Service Company). New York.120 pp. 1979. Millstone Point Units I and 2 den Hartog, C 1977 Structure, function and hydrothermal survey report, July 25 August 2, classification in seagrass communities. Pages 1977. Submitted to Nuclear Regulatory 89122 in CP. McRoy and C Helfferich, eds. Commiuion, January 197R Scaprass Ecosystems: A Scientific Perspective. NUSCO. 19ss. Hydrothermal Studies. Pages Marcel Dekker Inc., New York. 323 355 m Monitormg the marine environment Dexter, R.W.1947. The marine communities of of Long Island Sound at Milhtor,e Nuclear a tidal inlet at Cape Ann. Mawachusetts: A Power Station, Waterford, Connecticut, Three-study in bio ecology. Ecol. Monogr. 17:261 294. Unit operational Studies 1986 1987. Dillon, CR. 1971. A comparative study of de NUSCO. 1989 Seagraw. Pages 105120 in primary productivity of estuarine phytoplankton Monitoring the marine environment of Long and macrobenthie plants. Ph.D. Dissertation. Island Sound at Mllisione Nuclear Powet i j Univ, of North Carolina. Chapel Hill.112 pp. Station, Waterford, Conneelieut.1988 Annual l ENDECO (Environmental Devices Corporation). Report. 1977. Postoperational Units 1 and 2, Orth, R.J. 1973. Benthic infauna of eclgraw, preoperational Unit 3 hydrothermal sur ey of Zostcra marma, beds. Chesapeake Sci.14:258 the Millstone Power Station. Report to 269. Northeast Utilities Service Company. Orth, RJ, 1976. The demise and recovery of Folk D.1974. Petrology of Sedimentary Rocks, celpraw, Zo3 rcra marma, in the Chetaptake - Hempshill Publishing Company, Austin, Texas. Ilay, Yuginia. Aquat. Bot. 2:141 159, 192 pp. Orth, RJ. 1977, The importance of sediment Keser, M., ILR. Larson, R.L Vadas, and W. stability in seagrass communtiles, Pages 281-McCarthy, 197a. Growth and ecology of 300 in 'll.C coull ed. Ecology of Marme Spartina ahcenifora in Maine after a reduction Benthos. ~ Univ. of South Carolina Prew, in thermal stress. Pages 420 433 in J.ll. Thorpe Columbia, SC and J. W. Olbbons eds, Energy and Orth, R.J., and K.A. Moore. 1981. Submerged Environmental Stress in Aquatic Systems. DOE aquatic vegetalion of the Chesar. cake Bay: [ust, Symposium Series (CONF 771114), National present and future. Trans. N. Am. Wildl. Nat. Technical Information Service, Springficid, VA. Resour Conf. 46:271 283. Klotz, R.L. and J.L Knight. 1973. The ceology Orth, R.J., and K.A. Moore. 1983. Chesapeake of eclgraw (Zoarcra maM. _ Report to Bay: An unprecedented decline in submerged Northeast Utilities Serviec Company.14 pp. aquatic vegetation. Scienec 222:51 52. Knight, J.L. and R.B. Lawton. 1974. Report on Orth, RJ., and K;A. Moore 19X6. Seasonal and the possible influence of thermal addition on year to. year variations in the growth of 20steta the growth of eclgrau (Zosicra marina) in marina L (celgraas) in the lower Chesapeake Jordan Cove, Waterford Connecticut. Report to llay. Aquat, Bot. 24:335 341. Northeast Utilities Service Company, Ostenfeld, CH.' 1905. Preliminary remarks on the Mann, K.H. 1973, Seaweeds. Their productivity = distribution and biology of Zostcra_ of the and strategy for growth. Science.182:975 981. Danish seas, Bot. Tidsskr. 27:123 125. McRoy, CP., and K W. Bridges. 1974. Dpamics Osterhout, W..l.V.1917. Tolerance of fresh water of r.eagrass ceomtems. Proc. Ist int. Congr.. by marine plants and its relation to adaptations. Ecol, the Hagut De Netherlands,'814 Sept. Bot. Gaz, 63:146 149 [ 1974. Peterson, - CO,Joh. 1891. Fiskens biologiske McRoy, CP,, and C McMillan.1977. Production, Forhold i Holback Fjord 1890.(91). Berce ecology and physiology of seagraues. Pages 53- Minist. Landbr. Fisk. dan. biol. Sin. 1:121 184. t 81 in CP. McRoy and C Helfferich eds. Peterson, COJoh.1918. The sea bottom and us Seagrass Ecosystems: A scientifle perspective. production of fish food. A survey of work done -Macci Dekker Inc. New York and Basel. in connection with the valuation of the Danish Milne, LJ., and MJ. Milne. 1951. The eclgrass waters from 1883 1917. Rep. Dan. biol. Sin. catastrophe. Sci. Am. 184:52 55, 25:1-62. Ecigrass 197 i d 4 0 i J l Phillips, R.C 1974. Transplantation of scayrusses the celgrau. Ecology 18:427 431, e' with special emphasis on celgrass, Zostcra Tha)ct. O.W., S.M. Adans. and M.W. laCroit l mariria L Aquaculture 4:161176. 1975. Structural and functional aspects of a Phillips. R.C 198a Responses of transplanted recently estabihbed Zostcra manna community. and indigenous Thalassin testudirunn Banks Ex Pages 518-540 in LE. Cronin ed. Recent Konig and #alodule wrighni Aschers, to Advances in Estuarine Research. Academic sediment loading and cold stress. Contrib. Mar. Press, New York, i Sci. 23:79 87. Thayer, O.W., W.J. Kenwotthy, and M S. Fonseca. Rasmussen, E.1973. Systematies and ecology of 1984. The ecology of eclgran meadows of the

_ the Isefjord marine fauna (Denmark). Ophella Atlantic coast

A comrnunh) profile.

11:1 495. FWS!OBS 84 02 147 pp. Rasmuwen, E. 1977. The wasting dhease of Tomlinson, P.D. 1974. Vegetative morphology celgrau (Zostcra marina) and its effect on and merktem dependente.the foundation of i environmental factors and fauna. Pages 151 in productivity in seagrawes. Aquaculture 4:107. CP. McRoy and C Helfferich, eds. Seagrass 13a Ecosystems: A selentific perspeethe. Marcel Tutin, T.O. 1942. Zosicia. J. Ecol 31 217 226. DeLLer, New York. 314 pp. Uphof J.CT. 1941. Italophylet Bot. Rev. 7:1 Renn CE.1934. Wasting dhease of Zostcra in 5K American waters. Nature, Lond. 134:416. - VAST. Inc.1972. Thermal suncy and dye study Roessler, M.A. 1971. Environmental change Milhtone Point, Connecticut, September, unociated with a Florida power plant. Mar. Nosember 1971. Report to Millstone Point Poll. Hu!!. 2.87 9lL Company. Roeuler, M.A., and J.C Zieman, Jr. 1%9, The Wted EJ.F., W.E. Odum, and J.C Zieman.1%9 i elfects of thermal additiont on the biota of innuence of scagrawes on the pnkluctivhy of southern Discayne Day, Florida. Pages 136 145 coastal lagoont Pages 495 502 in - A. Ayala in Proceedings of the .Ouli and Caribbean Celanarca and F.H. Phleger, eds. Coastal Fisheries Institute. Contrm. .No. 1865, 22nd Lagoons Universidad Nacional Aulonoma de ! Annual Session. _ Mexico, ciudad Universitaria, Meuco, D.R Roman, CT., and K.W. Able, 1988. Production Zieman, J.C Jr. 1970. The effech of a thermal ecology of eclgrass (Zo.rtera marina L) in a efnuent stress on the scarraues and macto. Cape Cod salt marsh estuarine system, algae in the vicinity of Turkey Point, Biscayne Massachusetts. Aquat. Ilot. 32:353 363. Day, Florida. phD. Diuertation, Univ. Miami. Seichell, W.A. 1929. Morphological and Coral Gables, Fla.129 pp. phenological notes on Zostern marina L Univ. Zieman, J.C Jr.1972. Origin of circular beds of Calif. Publ. Bot. 14:389 452. Thalarsia (Sperma tophyta: l lyd rocharit aceae)in Seichell, W.A.1935. Ocographic elements of the Southern Biscayne Bay, Florida, and their marine Dora of the North Pacifle Ocean. Am. relationship to mangrove hammocks. Bull. Mar. Nat. 69:560-577. Sci. 22:559 574. Short, FT.1988. Ecigrass4callop research in the Zieman, J.C Jr. 1982. The ceology of the Niantic River: Final report to the Waterford- scagraues of South Florida: A community East 1.yme Shellfhh Commission. November profile. U.S. Fhh and Wildlife Senice, 15,1988.12pp. FWS/ODS 82/25.124,26 pp. Short, F.T., LK Muchtstein, and D. Porter.- 1987, Zieman, J.C Jr., and RA Wetzel, 19Su Ecigrass wasting disease: cause and recurrence Productivity in seagrasses: Methods and rates. of a marine epidemic. Biol, But. 173:557 562. Pages 87116 in R.C Phillips and CP. McRoy - Short F.T/ B.W, lbelings, and C den Hartog. eds. llandbook of Seagrau Biology: An 1988. Comparison of a current eclgrass disease ecosystem perspective. Oarland STPM Press, 10 the wasting disease in-the 1930's. . Aquat. New York, NY. Bot. 30:295 304. Stauffer, R.C 1937. Changes in the invertebrate community of a lagoon after disappearance of -198 Monitoring Studies.1990 i__ __ _ . _ _ _ _ _ _ . - . _ _ _ _ _ _ _ _ _ _ . _ . _ _ _ . . _ - Contents M arine Woodbore r Studie s . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 201 I n t r od u c t io n . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 201 Materials and Methods ....................................... 201 Ex pos u r e Pa nel S t u dy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 201 Distribution Study . . . . . . . . . . . .......................... 202 Data Analysia ......................................... 203 Wa t e r Te mpe ra t ur e . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 204 Exposure Panel Study Results .................................. 204 Wa te r Te m pe ra t ure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 204 Fo uli ng S pe ci e s . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 204 Wood. boring S pe cies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20S Perce ntage of Wood. loss . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 213 Exposure Panel Study Discussion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 214 Distribution Study Results . . .................................. 216 Distribution Study Discussion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 216 Conclusions . . . . . . . ............................... ........ 218 R e fe r e n ce s Cit e d . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 218 1 Marifie Woodhorer Studies introduelloit three units wmbine prior to dischatpc into Long bland Sound through two quart) tuts 1 F h an j Marine wtu>dtxtrers in the vicinity of Milbtone trupacted site. The F1 and WP sites are located Nuclear Power Station (MNPS) include two approsimately 400 m and 1700 m hom the species of mollusks (Teredo nacalo, a native discharge cut, respeethcly, and are within t'ne shipworm, and T. bann hl, un immigrant) and two piedicted path of the disharge plume (NUSCO genera of crustaceans (Limnona, an isopod, and 19XS); these sites ate considesed to be potentially Chc/aro, an amphipod). These organi ms perform impacted. The llP and ON sites are located the important function of decornposing woody approximately .I and 7 km, respecthcly, hom the debth in the marine environment; however, when Millstone Quarry discharges and setse as our they attack wooden structures such as wharts, reference sites. At each site, sh knot hee pine boats, and lobster poh, they are a source of boards (23 4 x M.9 x l.9 cm) with one I,nc (oscled concern. Ileated c!fluents hom coastal power whh plexiglau were bolted to a klainlen stect rat L. stations hate been reporud to aucci prowth and whkh in turn was aHached to a stamiess steci , frame (Fig. 2h The panch at all sites wete reproduction of shipworms (e.g., Naylor 1965; Board 1973; Turner 1973), and to allow suspended frorn docks and postiloned 02 m hom estabihhment of immigrant populations from the boHom. warmer environments (Turner 1973; Dattelle 197(,; punch were deployed in February, May, and lloagland and Turner 1980). Further, finagland August, and were collected sh months later (in (1981,1983) suggested that the immigtant species August, Nosember and Februar)); the resuhed in could adapt to cold ambient -temperatures, and three exposure periodt Umh exposure period h ruuse increased destruction beyond thc hifluente of referred to as the month of deployment lo'lowcd the heated dbeharge. by the month of collection, ic., Feb Aug, Ma). Marine woodborer studies at MNPS were Nm Aug.Feb. conducted to evaluate whether operation of the Panch were procewed immediately aher power station has influenced the abundance, collection or ho/en for later proccaing. The activhy (amount of wood loo) or distribution of uncovered wood side of each panel was examined, wood boring species in the vicinity of MNPS. The and percentage of surface coser was eMimated for Expmure Panel Study mor.hm the abundance of organkms that occupied at least l'V of the panel ' fouling and wood. boring species, and quantifies surface (subjectively determined). Abundance wood loss. The Dhtribution Stt,dy monitors estimates for barnacles, Limnoria, Chelurn and densities of Teredo nacakt and T. banwhi at muuch were obtained by counting the number of various dktances from the power Mation. Thh organkms in sh, one inch by onc inch (M5 cm') report examines data collected during 1989 90, and subsamples, evenly dhiributeu between the upper compares these data to those collected during 3 and lower halves of the panel,11 an organism was unit and 2-unit operation at MNPS. observed on a panel, but not included in any of the sh subsamples, it was unigned a density value of Materials and Methods one. Following coverage estimation, panch were &posure Panel Sludy serared to temove fouung organklus and nuu)cd at the Northeast Utilities Non destructive Testing y n Berkn, le u ng rmhographs Woodborers and fouling organkms were "' " " #" monitored using six wooden paneisiubmerged at " "" #" E""# * "" E'" " five sites: White Point (WP). Fox bland (FI)' *""#" '# "" ^" "' # I#"" # D!ack Point (BP), Giants Neck (ON), and Effluent (EP)' (Fig.1). The EF site h located within the worms hom each sh were renmed hom Milbtone Quarry, where the effluents from all panch for WmWadon. Wpwonns D rum in t Marine Woodborers 201 ,-~ . - . _ . . . . - - . --_ C' ~ n ,,. Sites: f >posure Ponel Study ' I , h_. g i3 ' us g., me. r, p. p a  ; 3 /p* e^ ,. j , , , ,.. Distribution Study mo ,,, . - - e me ,. ( h norn; I }' [ll\ , \ f .,4 y \ , , /*

• k.

, p. .,, y (, / ,*>r: e , vs , j U - ".' y. : ,,,,, , . , i '4 33e a .- k , / O I,t,, , j \ i n lig, i I wam n or exp r. atti m ihe uane or the Mmu,u.e Nmicar twvr Nunon (Wl' = Mime l'omi. I'l = i m t.lan,l. t i a 1,muni - the Miliuonc Qo.ory shs hmge, lu' = litad l'iuni, (iN - omni Nc(L 1m m e.-e low m - the tranwci hnt ak,ng whath troul knes et HU m to IM m arc wt) ,90, and 10m m from the Milhtone Quarry cuts length were inliially claulfied as 7'rtrdo juveniles (Fig. 1). In May, five wooden exposure p meh because their pallets were not sufficiently were attached to each of three wire lobster pots on developed for accurale identification Decause a five lmt truwl line (Fig. 3A), and deployed on the adult T. barruhl were found only at IIF, Teredo tottom at each dhtance. Paneb were submerged juveniles tollected at WP, FI, DP and ON were for a shortM (0 month) cxposurc period during the claulfied as T. nacalis in data analyses of shipworm time of maximum shipworm settlement and growth abundance. Terrdo juveniles collected at EF were (May.0ct), and for a loncer (7. month) exposure uwigned to T, barrschi or T. navalis based on si/c duilng the period of minimum abundance (Oct. of the individuah and time of settlement. May). At the end of the May Oet exposure period, - Defore deployment, panels were dried at 80*C three panch hom cuch pot were collected and to constant weight. Alter collection and removal replaced with new ones; the remaining panels were of shipworms, panel fragments were acid stripped left to provide habitat for a source population. At in 10'N 11C1 to remove CACO, tubes deposlied by the end of the Oct.May exposure period, all panch the shipworms, soaked in freshwater, and dried to were femmed and replaced. constant weight. The difference in weight, Various subsampling schemes were used to expressed as a percentage of pre deployment provide an adequate number of shipworms for weight, was the measure of wood. low, identification, and to permit more accurate estimates of shipworm species abundance and D/JIr/hutio's Study ~ dktribution. For instance, when densities werc high (typleahy, May Oet exposure perloch), sh The Distribution Study was established to randomly chosen scellons, one from each of sh monitor distribution and abundances of Tercdo panch evenly distributed along a trawbkne at each nainlis and T. bortschi in the MNPS discharge distance, were used for shipworm counts and mixing zone by sampling panch placed 100,200, idenufication (Rp 3DL When dendlies were 202 Monitoring Studies,1WO 4 m -um v [G

n. Dg"s~n,% T%'%% " v.~ ",' , )'

,3 .......~. (7 ., .. n'. ')] A N d N, 7 2r$ g1 0(* " " W I &>  % i Qf g "~~ G l .. e \ g 3G *O \  ! ) S ~~ t. \ hg ? I'rutne end rm aumte owd for hoidmg saanonih. ' ~' 6a replanic cymure panu. hg 3 hagram or an equure panel traal hne uwd to sampk the dairibuuon or shipwotms in relanon to Ibe e muent 10Wer (blJy Oct,1988), rnore sections per panel dxharge point at H.e Mahtone Nuclear Power sianon (A (up to an entlic panel) were processed, When "8*N'ne or rise not.in poa .oih the i.< anon or the is pnc PaneN n Pine PaM $t"' wing the snuoni tot subs.nnewg) densities were minimal (all Oct.hlay esposure periods), all panels at each distance were collected and X. rayed, using the techniques described in the operadon n Ardt ata hom exposure 5 nce e ruan > reproem p umt Expmure Panel Study. Radiogtuphs helped to locate shipworms within panels resulted in more " E# ' " """ ' " """'"' "E" > '"' I I 989#'I ncludes hiay Nov 1989, Aug 1989 Feb IM and efficient proccuing, and provided a permanent record of shipworm densities, Fe Aug M expmum peh Data wek summar y npmum pcdod (Feb. To investicate whether Terrdo baruchi tarvac Aug, May Nm, Augfeb) and abundances were enter Long Island Sound from the quarry, a supplemcntal study was conducted hom blay to #* E"#d "* * *"f # E*'"'"E' "I '"' # ' "" E # "d hetober 1990 Two panels were placed just surfaces unfor nunter ohndWuah OdenMaNe beyond the fish barrier in the casternmost quarry aduhs and Menne9 per panch Fmung spp, cu t. Each pand was mounted in an open ended acept for barnacles and mussels were described one foot section of four inch PVC pipe, and onh_ by cmer data and were not reponed unlea suspended in an eddy to reduce current velocity average values for a taxon were 21% du;ing at over panel surfaces, and encourage larval leau one of the perioa in geestion O.c.,2. unit settlement. One panel was placed about 0.5 m operation, kunk operation, or cunent >carb The below hican Low Water, and the other about one cmcrages ofliving and dead foulers were combin meter deeper, 0.2 m from the bottom. These to aucu total recruhment of each species, and the panels were collected and processed in October effects that they had on woodborer abundance. } 9g Coserage by empty tests and basal plate remnants of barnacles was not assigned to a species Data Analysi, gumping, but repot ted as ' dead barnades? Abundances of barnacles and mussels were sposure panel data cohreted during 2 unit described by both coverage and density data = Wood boring tau were described by density data operation include observation:, frotn exposule gy periods from February 1979 to November 1981 and from February 1985 to February 1986. The Summarized data were presented two ways. Annual values for cos crape, density, and wood. loss sampling site at BP was established in August P strated in histograms (Figs. 510), while 1985, so data from this sitc represent only one . unit exposure period, Unit 3 began commercial tables were used to summarize and compare data hlarine Woodborers 203 l l l L ~ ~ -- .- - - - collected during 1989 90 with those averaged over considerably higher than either 2. unit or 3.umt perkWs of 2 unit (197946) and 3 unit o[wration averages from January through hlarch. Average (1986-4)). The Wilmon sigried rank test was ambient wtter temperature cycles were very similar used to evaluate differences between species in both operating periods, although the present abundances in the two operational periods when report year ( 1969 19W) w as somew ha t s typical. i.e., the speeles occurred in both periods and densit) very cold in December, and unusually warm in nyeraged 21 in at least one petitxl. Unless February and htarch. othcrue stated, the probabili:y level P=0.05 was Water temperatures at the ambient water shes used to establish statistical signTicance in all tests. (Lc., all sites neept EF) eshibited diurnal variability,especially in summer (time of maumum li'alcr 71>mperunue insolationb inercasing to peak temperatures of 2-3*C above average. At WP,an additional The source of water temperature data was the # " " " E '" " " "" *""" ""* of maimum tidal ebb, attributed to the MNPS Northeast Utilities Ensironmental Data Acqukition Network (EDAN) system, whkh d h 3eh opuim continually records a varicly of environmental Each sivmonth oposure period has a i  ; .  ; , 3 parameters at 15 minute interub. Ambient water being the warmest (2ri-2T C in the temperature was the average of temperatures recorded at the Unit I and 2 intake structures, and discharge and ITC under ambient conditions). dheharge temperature was the average of """E """ "I" " "" " ' " " " " " " * " I"I" "

• E" " ' " '" ' E' "' '" "} I U "'" ' ""

temperatures at the two quarry cuts. Daily averages were used to generate the mean *" N * " * #" *#' d *E' waters hase gener"Ih deercased. If

• E# '"'"'" "I I temperature and range for each cyxwure period; -

weekly averages were used to generate the ) temperature plots, f..oulm.g $.pecies Ternperature data at F1 and WP were recorded by thermistor probe / data lopper arrays attached to Fouling yeein, planis and ununah that grow the docks. Additional temperature data were singly or in colonin on npowe paneN are collected from various MNPS monitoring program nmnitored to awns their elleet on settlement and study sites (e.g., beach seines, celgrass stations) growth of woMxuers. During 198944 as in past during ahort term (7 day) deployment of portable ) cars, the species composition and relathe thermistor / recorder packages, and used to abundances of the fouling awemblages varied approtimate water temperature regimes at the gready arnong shn and apome periods. Total 1 npo ute panel sites. fouHng coverage ranged from 129 to 58's at Fl. from 2M1 to W1 at BP, from 50; to 359- at EF, Exposure Panel Study Hesults from l'X to 5'A at WP, and Ironi less than l'1 to 19't at GN during the three oposure periods sampled this year (Table 2 and Fig. 5). ilighest li'aler 71'mperature cover occurred in May-Nov, and lowest in Aug. Feb, at all stations escept FI where the opposite , Average weekly ambient and discharge water wn :rne. l temperatures during oposure panel studies are 4. prwrt 1, fouling patterns during 198940 were i presented in Figure ,l. Comparisons between 2- similm to those seen in other 3-unit operational unit and .tunit operational perhxh indicate that in ye,as, despite the unusually high cover of the winter and spring (December June), 3 unit 'olonial ectoproet bryoman Ekcira enarulen/a on c discharge temperatures tended to be 1 -( C Aug Feb panck at F1 (329) and a region.whle i warmer than those daring 2. unit operation- decrease in the similar species Cryptosula Further, the discharge has been a more iMr. "y palla3/ana throughout the year. Ilowever, total stable environment since Unit 3 start up, because coverage of fouling organisms at FI was hieher l simultaneous shut-down of all three units is rare. during 3-unit operation than during 2?unit During 19% discharge water temperatures were operadon (Table 2); fouling coverage at EF and 204 Monitoring Studies, lm 1 it .. _ . _ . . - . . . . . . . . . . . . . . . . . .. .. ~ .. . . . . . 40 35 ,...' + * 'p+ a G 30-

• G .

w Dischorge ct 25 q . . . . . 20; o  ;.MG , gf y . p . * * . . . ~ ~* . 1 15 '+ *

• 6 4, Ambient '

*w / \ /./* n ., s O. AVG 89 NovB9 FED 30 WAY90 AUG90 MAYB9 Fig 4 Aurage wecuy amtuent and dncharge Seawater temperatures for the curtrnt 6amphng year (o o o), and averages for 2 unit (---) and 3-unit ( ') operstkital penais. TAllLE 1. Seawater temperatures ('C) at the intakes (amtuent) and quarry cuts (dw:harge) of the Millstone Nu(lear 1%er Statnm dunng the three expmure perksh sampled in the Manne Woa.iturer Studies. 3' Unit 2-Unit leetkin 1989-90 Mat Ave Min Max A$e Min Max Perkxl Avc' Min l AMillENT: 9 9 22 17 8 22 May Nov 17 20 17 14 2 22 13 0 22 Aug l:eb 13 2 20 4 19 10 2 21 9 1 20 l'e b- Aug 10 DIScilAltGil. 33 27 14 34 26 8 35 May.Nov 27 17 Aug 17eb 24 14 33 24 8 34 23 0 35 20 7 32 1R 8 33 l'eb Aug 21 14 31 ' Average temperatures calculated using daily averages within each namphng perast Marine Woodborers 205 TAllt.E 2. Average percentages of nwer for fouhng capnisau un exesure pancis dunng the runent samphng ) ear (90, it.. May 1989 through August 1990K dunns 3-unit (3 U) getation and dunns 2 unit (2 U) geration. Aug-Fet. FetwAug May&w w 30 2U on 3U 10 P9 3U  ?-U IT Balomr c/wmrus 1.0 1.0 2.7 <1 3.3 38 14.2 10.5 11.4 Balse imlvmu <1 30 22.2 0 <1 9,9 1.5 2.8 11.8 Barythites kachii 0 0 2.$ 0 <1 0 0 0 0 Bugula spp <1 5,8 <1 10.0 11.0 <1 0 39 3.8 Cranosare verpnica 2.0 <1 0 0 0 0 <1 <1 0 Crepidula spp 0 <1 <1 <1 <1 <1 2.0 <1 <1 Coposula /wllariana 0 <1 <1 0 <1 1.3 0 0 <1 Dead flarnacles 1.8 46 16.7 0 7.2 3.2 38- 34 27.6 Ekrberia morma 0 <l 0 0 0 0 13 7 34 <1 Juvenile llarnacica <1 <1 1.0 0 <1 1.H <1 <l 10.3 I flehchondna spp. O <1 <1 <1 0 0 <1 0 1.4 ) Mraidium senile <1 <1 <1 <1 <1 2.8 <1 <1 <1 Affcak *pp. 0 0 0 1.1 <l 0 0 6.2 9 Mytih4 edulst <1 <1 1.6 0 0 0 0 0 0 la.iario crwea 0 0 1.3 0 0 1.3 0 0 <l me AM 14 4 4R$ 11 1  ?? v ?43 19 ? w? t..t v 11 Balama crrnatus <1 <1 <1 3.3 12.1 14.3 0 <1 <1 Italwu rbumrus <l <1 <1 <l <1 <1 2.2 <l 1.1 Bdlanus tryr<mua 1.7 1.0 <1 0 <1 1.0 3.2 1.1 2.1 lkeyllut schleuscri <1 <1 1.1 <1 <l <1 0 0 0 Bugula spo <1 <1 1.6 <l <1 <1 <l 2.1 1.8 C rpidula spp 0 <1 <1 2.2 <1 <l 0 0 0 Cryposula pallariana 16.0 34.9 e3 16.3 3.8 60 8.3 32.5 23.7 Dead llarnacien 43 1.1 <1 20.7 26.7 23 0 212 7.9 13.2 Decera cmstulmta 312 10 0 0 0 <1 <1 1.0 <l 0 Junnite llarnades 3.5 1.$ <1 <1 <1 ci <l cl 1.3 Ra!Ana spo 0 0 0 0 0 36 0 0 0 Sch/scrrlla ccrusa 0 2.6 0 <l <1 0 38 2.R 0 Semibalanus balamudes 0 0 0 EO 12 0 0 0 0 0 Soria sp <l <l 0 cl <1 <1 <1 <1 1.3 Total $ 7.7 $ 1.1 00 $0 $ $4 6 47 9 41 4 46 4 46 $ IIP Balaua cimana 0 0 0 <1 7.3 -* 0 1.3 - Balanus eburneus <l 2.0 0 0 <1 .. <1 1.6 .- Italanut imprmina <1 20 <1 <1 <l . <1 <1 . Boeyllus schlaueri <1 13 2.4 0 <1 - 0 <l - Codnan fhgilt 12.3 11.1 2L u 0 - 0 33 - Crepiduld spo 1.4 <l 0 <1 <1 - 0 <1 - Cryp<uula pallauam 12.3 24 4 - 4.0 <l <l - 6.8 18.0 - Dead !!arnades <1 <1 <1 l' 4.2 - <1 14 8 .. Ihrbesia ma*ma 0 2H 0 0 0 - 0 1.0 -- #ahchandria spp <1 <t 0 8.5 1.9 - <1 <l . RalAia sp 0 0 0 13.2 30 - 9 0 . Schimpwh reau 41 4$ <1 <1 2.3 - ' O.7 2K3 ... Semilulaw balanoides 0 0 0 29 8 US - 0 0 - Spinetst tutes <l el <1 <1 <1 - <1 1.1 - $0rld op <1 <l 0 0 <1 .. 2.2 <1 - Tnm ?A ? 49 1 tt? 4? 424 59 7 <19 6 206 Monitoring Studies,1990 t-i . . - . _ , , _. ... -_.m~,,_ , , , _ , , _ . , - - ~ . . -_. , , . - . - _ . . _ , . , - .#. l l l LOC sJaJogpoog SupejN i ui palaaps ajaw Aayi *(simi ssp,g) sJasoqpoow pataanoa uaaq sey sapads s!yi y3noyyn :(Jaroa l "3 a 'sapads Jatpo jo saaucpunqn ay) saajja una Soy <) luepunge Agensnun scw lj in v/ua/ni3n.o aaucu uop Jpyi pun 'saanpns pa3Jatuqns uo aaeds . usin/3 '0661.qad 3ny Wupna *spopad ainsodxa a[qcpcAn Joj ApApaajja os aiadiuoa spssntu pun AoN*Xely pue gaj $ny ay._Wupnp saacjJns sapeutcq asneaag sapads e Joj tuatutinjaaj jo pued uo luepunge isotu ajaw viv.ua vyaalotfrpS yi3uans ayi aJnscatu icyl aaunpunge jo saletupsa put vuu!rugud v/nsold0,3 micp funnoj aapcipuenb aJe '(Aysuap) stenppiput jo stunoa ay1 jo luauodtuoa Jo[ctu n si K ipipopad icuoscas 'isenuoa ul aaucpunqn jo sairtupsa arpaa[qns ojn 'ND le X iuo untutuoa aja.w ( dds up6);y inq 'ytwoJ3 puc luatuappas spyi Joj pappoJd aaeds pun anpiunnaytod 'sipsp/d uto snue/vy) aaiyi palpuy ayi of uopupJ u! *XJny[os pun [cluojo3 pun ?dg le $1 00 uututuna sc.w (SApt r!qsos!dS) atto y104 'stusiuc3Jo Junnoj ipt jo saaucpunge ay1 'id le A luo uotutuoa sc.w (viua/nmua usin/3) auo I Jfluenh Apsp3ajja una ettp Jasoa jo a30iuaajad tjij in djuo JaAoa %[ papaa3x0 (Unon vpuptynf AoN-fety ut palcad pue synpa rn/yQy "dds afoail y 9puar sun!ppiajy Al}ntaua3 snatunya JJ jo adnjaAna tuaalad $ny 'tMnitXit,1 IM.ilton tu,) 'typtMl Sap lOydliot)) Xp qaj u! palnad inensn ds vpf/vy pun sapeuscq 'spund painoj X iuotutuoa aAcq ya!yw nsn1 gg syi pnap ' Sap luntPp)q Snuv/Uqpua$ 'SnlunaD rnttop'(( ]Q Alpljpads oys panglysa inn) Wuflno) atuos spued uo JaAna ti papaaaxa JaAau pey y 'ajojaq uopnjado Itun g Supnp pascajaap No iN61 ArnN nl Joud paptiurs rou ww aus luiod FH13tHe parnpo ,ue unpa i > u$r0Lusad Joi unin pagtluenh Stro Jo tung atp tu.vuAtas $lrio,t, 90c c li i nI c tt n ei .it 99 on la p+u. 0 0 0 0 0 I> 0 0 0 EJf'totlefthj UlHt (f%ltHL1g l> W9 T6 i> I> [> l> r1 0 rrow Pusam/ontpy la 0 0 1> 0 0 11 0 0 'dde n/do/y E O O I> I> [> I> t> l> opetnetlapua4nt-1I t> i> l> 0 0 1> 0 0 dds nofwepiftsff 0 0 0 0 l> t. : 0 0 f, arpeuynaggl 0 l> l> 0 1> *> , 0 0 1> rswinivrus visnj;f I I> 13 9 91 t 1l t> gi 1> I> upeusrti pcMl St s: 9 t- 1> 1> l> t> n> t> Pun'witNE t inwtJU ) i, hl I> 0 6t l> 0 1> l> ajdtof wnipay o1 1> 0l l> I> l> t> t> t> dds tijdng/ 1> a 0 V: 0 0 WV 0 0 pnyips sntyaroy il f> 0 t> t> 0 i> l> 0 unpom/w! unertfny 1s u 0 l> t> I> 0 0 0 sn.nunq.s snurtry tt 0 0 6Vt Vi 0-l [> 1> 0 unnuse snunft>gt cl l+ t1 1> 0 0 \> aninspin.n vmorfest t> t> Nn c sc o 22 0i 9 9c l nc 0; t 41 8 t, gt (mu, >i it il l> 1> t> t> l2 1> vanw ofpenfonspy

0 0 l> I> l> t>

l> l> oixinett ainuer L I> I> IJI O O O t> t> t3 -dds vmipffttt/  ! il t> 1> l> t> 0 t> t> t> -ddu rupmnpynt; or t~ t 0 6 01 9w t> ft l> t> opeturti pv41 q L t. t (> 00 \> t> t? 09 l> t'uafw/p%/ r/nmidQJ j t.1 Is sI t, I w 0: il 9t dd< vidnt; ' rt t> 0 0 ft 0 0 0t t> 0 u.wfips snff.0p>gy l l1 0 0 *I l> 0 r1 1> t> rnrfwdwp rnunfcgg tis l> 0 6: 1> 0 t> 0 0 rn. nun.p emivp*gp 0 0 0 99 0 91 C t> 0 l> "UtWD rnut'#'u .lAs o; ,u oe o< - o., oe o-< i ., '"N - ("lN $ny4p l ip1 $ny (P, luna) O qiny; (range from 42! panel at GN to 494' panel at WP, y y"*"I Table 3). It, previous 3 unit operational years, e j" mussels were absent from ambient water sites in 40 g 1987 or 1988, but averaged 463 per panel in 1989 #$1 ah__ DM_. _. _ (NUSCO 19W), During 3. unit operation, barnacio and mussels were generally less abundant at EF than during the g Q ro.isiond 2 unit period. At Fl. abundances of Afytilus edults, R eo. . lla/ anus ctrnatus and juvenile barnacles were g 40 A' generally higher. Densities of foulers at WP and y (, _ . . , GN sites showed few changes in magnitude over g the two operating periods. R * * * "*'"' If'vod borins: Species l 0 so. hQ 9 o __ ._ _. The primary focus of the aposure panel study n on wood boring species because these alc the y organhms whose potential for property destruction W 00 wn,,, pomi b @M M M4M MWne WO g so growth rate, lecundity, recruitment success) are s a likely to be affected t ;.' elevated water , temperatures. In the Milhtone area, marine h *$ _.mEE rn . , woodboters are represented by one genus of mollusk (Terrdo) and two genera of crustaceans mo Gionis Neck @nuurria and Chr/ura), 'No species of Trtrdo a3 occur locally; the native shipworm T. narahs hat u been collected continually at all sites $1nce Q p sampling began, and the immigrant T /> art chi has 'o._b L . been collected continually at E F since 1975 $ill?!!! $$$$!!!!$ $$Y!IIe$$ (llattelle 1976). {- Avo-rto H F. rts-Auc H F-- uane -i Torrdo nurallt During the 198%) sampling . y 2-UNIT g 3-t> NIT g<5s year, the abundance of T._ nmalis continued to be highly variable, with highest densities occurring ut WP and GN (Table 4, Fig. 6). Densities (number lig. 5. Awrage penentage or ower for scuae foulmg organes. inc and dead components comtnned on expmure gunels collected of individuals per panel) at GN (252), ilP (38), and f rom tetwo. EF (33) Peaked in the Aug Feb exposure period, and at WP (~262) and F1 (34)- in May Nov, Densities in Feb Aug IWO were extremely low, this study to proude a quantitathe assessment of averaging less than one shipworm per panel. seasonal variability. Like cover estimates, densities Abundances of Tcredo narahs at all sites in the ' varied greatly among sites, exposure perin, and years 1989M . Aug Feb panels were Ihe highest jet (Table 3). For instance, on the Feb Aug panels 19W recorded for that exposure perk)d (Fig. 6); densities of Balanus errnatus ranged from "I to 16 per however, overall 3 unit densities were not panel at all sites except EF, where they were zero, significantly different from those during 2 unit Densities for this period in 1989 were also low (< ! 5; operation (Table 4). In contrast, densities during. NUSCO 1990); however, during 19688, Feb Aug 3 unit Feb Aug expnsure perhxb were lower than densities at ambient water sites averaged 151-482 during 2-unit operation. In May Nov pancis, (NUSCO 1989). Mussels, Alytilus cdulis, were most densities have significantly decreased at GN and . abundant in the Aug-Feb cxposure period; this year increased at WP during 3 unit operation, densities averaged 252 per panel at all sites except EF 208_ Monitoring Studies,1990 3 l TAllt.E 3. Average density per lunci(30 6 in#) for turnacien and tauucli during the current samphng Scar (90, ic. Wy IW9 thmugh August 1*f0), duringt 3-unit (3 U) nivration and durirgt 2-umt (2 U) operation SPI:0113 $1IE EXPOSURLs Pl.RIO!) Aug I eb l~cb Aug Mayh w ill 2 11 W 3 11 2 lt 89 lit 2 t! lialanus um;+itmc f .F 0 <l l1 0 <1 <1 0 <l o i l'1 0 0 0 0 0 3 0 0 (1 1 I llP <l <1 1 0 <l -' (1 l l l WP O <l 9 0 l$ 0 i <l i s1 GN <1 <1 <l 0 0 12 <! cl 0 IIalanus carnatus if 3 2 4 0 <1 0 0 0 0 l'1 14 12 3 ft 133' 13 11 cl (l Itr 0 0 0 7 113 0 in } %P 0 <1 <1 9 292 73 0 0 0 GN O 5 <1 16 , 4-1 101 0 0 si a llalanu.t rimmeus I:.I' 2 1 M <1 6' 10 13 6' 22 l'1 <1 (1 0 (1 2 <1 3 ci sI llP 4 5 0 0 $ -- cl 2 WP O O <1 0 <1 2h 0 <l h UN O n 0 <l el 3 0 0 5 llalanus kn/mnino 1:17 2 7 232 0 6' M $ t. ' ed I'l 23 ll 7 0 N 1 42 14 0 IlP 3 11 2 2 5 4 5 WP 3 1 32 0 <l 21 0 0 4 GN O 2 1 0 <1 6 0 <l 3 > Junnik llarnacles I;F 22 f. ' $9 0 44' 126 2 h liwi Fi 1241 407 H7 <l . 13 9 $8 l$ 10 llP 14 4 <1 0 25 - 2 <1 WP 101 29 29 2 38' 3tw 0 0 11 UN 37 67 46 1 31 4% 0 <1 19 Mallut rdulu l.F 9 6- 169 0 0 0 0 0- 0 l l'1 167 113 1 <l 4 <1 0 0 0 l'P _ 304 316 0 4 1 - 0 0 WP 494 289 l$0 <l 1 9 0 0 2  ? ON 42 11 4 0 e1 22 0 0 0 Semilialanus tulanoi.ics i .I' O O O <1 <l 0 0 0 a l'! 0 0 0 107 170 0 0 0 0  !!P O O O 305 253 .. 0 0 0 WP O O O 4 3 0 0 0 0 t GN O O O 2 20 0 'O O O lhe lit.uk hint sue was not sampled priorio May 1985.

• Significant difference (Pc005) twtween 3 unit and 2 unit densitics, atmrd.ng to a Wilcoxon signed rank test I

hlitfil10 WOOdIX)f 0TS 2(N 1 i I TAllt.li 4 Awrage dennH3 of 7 credo namlo in npuutc pmch suhatted durmg itw cuttent umpling gas Chi. 4 e , May 19x9 Auguo 1944. durmg T utut (3 t 4 and during 2.unH (211) operation sill! I APostmli PI Riol) Aug i ob lcb Aug Me h w 3 tl 2 11 W 3 il 2 11 89 1U 20 1.l# mton 312 16.8 B5 02 0 $' I$ 20 0 N2 un n' 52 21 7 21 1 IW tt ,84 5 24 9 lb k ll % 13 5 l'1 nwan 24 3 10 2 45 0.7 02' 15 4 340 lh b 143 cv jab 21.3 20 2 ttf 2 $0) 32 0 AU 13 % 14 ? HP mean 37.5 135 63 00 02 > 21:4 ll 4 cv 79 23 s 2tN .t .i t 7 Iv V IS A WP nwan 189 0 39 4 373 op kg M3 262 0 169 4* 6? ? cv vt IV 4 25 7 Ja2 322 *4 14 1 22 8 GN rnean 231.8 917 74 0 02 47' l i k t. 413 67f 2 te, I cv 78 21) .ta l HMu Rn2 lhJ 14 4 I?O v2

• Coelluicnt of garialshly (Mandard estor of the nwan, dwided by liw mean and mutuplu d 69 Hki)

' Sigminant dilletetwc between 3 tJmt stid 2 tinit denutwa (P(003) neutedmg to a Whenon signed tank AcM

• co' could not be sakuhted twcauhe the mean w tern
• lilath Pomt 6ite was not sampled poor to May IWS l .

i . Tant 1; 3. Awenge deneir or imdo 6,nu hi in nr.ote lanci oinicied dunne ihr coneni umphng gar tw, i t.. My tw9 Ayuu l 1940, dunng 3-unH (3-ll) and durms 2' unit (2 L1) opetauon. i - l smi tmrost eni. PPuloo L Ang i eb l'ob Aug M9 Nm 90 3 tl 2.L } W 3 11 2 11 N9 't11- 2>l 1117 nwan 46 0 1233' 14 0 33 2 17 0' L2_ 2'#17 20n N' 10 0 - . cv 13k 15 7 J&l 77 4 JS b M6 17 8 lh 2 H3 l

• Cuellicient or varialslity (stanJ.trd crYor of nu mean, diuded by the nwnn and muhipiwd by 100).

j Lgailwant difference twsween 3 LinH and 2 lti i denstwn (Pc004), accordmg to n Wamon ug:ncd tunk tot Trredo barricht. This immiglant shipworm has to peak in May Nov at all sites except EF, where been found consistently in large numbers within~ higher densities occurred in Feh Aug. Densities the Millstone quarry (EP) discharge waters since were lowest during Aug Feb, and were below 1975, - During 19893>0, T, burnch/ was found in 25/ panel at all sites. In general, densities in 19M9-enth exposure period, in densities ranging from - 90 were similar to thme reported for other 3 unit' 'Tll/ panel in May Nov to 33/ panel in Feb Aug operauanal years (Fig. 8). The highest dentitics Gable 5). Densities of T, barochi at EF in all occurred at WP and UN (702 and Wi per panel, three exposure periods were higher during 3 unit respectively), There has been a pencral trend of operation than during 2 unit operation (Table 5, decreased abundnce of Linmoria during 3 unit - FigE 7).- In November - 1989i--one individual operation, relative- to densitics in - the 2 unit - identified as T. bortscht (confirmed by Dr.'R.D.' operational period, especially in the. Feb Aug Turneri pets, comm.) was . collected at ON. The exposure period (Table 6). At the fear sites for imp!! cations of discovering the tropical immigrant w hich we can make comparisons, Linmorin shipworm at a reference iite will be discussed later, abundanceduring3 unitoperationwauignificantly , lower at FI, WP and GN, and significantly higher Limnoria spp, in 1989MI,abundanees continued at EP. 210 Monitoring Studies,1990 ._.____a._.._____..._____.__._____.________.______... M' 2bO< [f flutt;l FOO < ts30, [tflutfit 1 200 20po . l 1 f.0 t90 tW S000 50 WO . o .s . . ah E ,..1- . c . .. . a==% =4 _a==== 3N< f c. : l$ 10hd WD ' Ivi1610nd g 2W< ;WO 4 g 2 n. ia 2300 g tLD 'f00 p yo. 2 ifKo < %M 4 8:50< 0._.t4 m M _ M, a. _. f J af d- E . 5 0 o > a==m- *- # ~ *#d4 e====AE l m n [ VW< [Octl lhnt

• WD (Mack Pmnt f3 t 7tX) no. ,

noo < 2000 g 1% tbOO< Q 109 A ina0 g e,a . ir MO - y 0.-._ M - . L- j t =====. - - - - - - - _ arm.ma., P E l no w t, point

• Moo. mvte Omnt 2M -

2'004 . l 2M 7300 #.# 1 y( 1% .i ib30' . 100 j ,- t090, .a m - ., r . .._ . - . a -== # - - ,- . l kO- Csonts Neck- y FOO . G,0nts f 4ec h 2n 5 290 200 $ 29004 StD, yy t Wp . tog, $ r 1(no. M. $ $004 - =f ' f': r - - - O. - dm==<=.==~ c _ .- , 7 BOSS 8689 780 9 01 gs68489

i. 7 8 9 0 7856$8809 1808P6889 788Be6P89 78BSSe8Ab 901067890 9066676v0 90lb67890 $0itt,Fe90 totttrese H A004(D -d 6-- t t 0- nvG -( H uaf-yN -( l- A4-f l0 --4 H t t D AUG --( t- uai , W)v H Q 2. t:hl g F Uh!! g dD g& Q, uN1 g1 (3d g1 V hg . 6. AWrage numeriod abundance of the 6hi[morm, Trrrdo staruhi, in nemure juncts wnctied in 19N-lWO hg K Average nuniental abundance of Hic MlWs, laniniusa w ,

m expmure pinels miletted dunng 14N IWO XC<[fhuent C "E. Chrluru terrbruin, Chelurids remained a minor

j. gg component of the wood boring community sampled tiy

+ w our p.inct study (Fig. 9). During l>894), this o f- - m .-.n ?eeeaeea9 7eeeaaae9 7eeeeaeao amphipod wm ody abusnt during May Non 9o1567e9o eoiS67eoo eotS67e90 maximurn dernity (39])aneO occurred at WP pable H Auc-#Ie -( F rie- Aua -.( H un-ww .-i 7). ,There has been a general trend of decreasing l abundance during 3 unit operation, but statistically g ; - um 3 .h oun gm g npa significant dllferences between 2 unit and ' 3 unit l'ig. 7. Ascrage numeric 4d abundance of the sinperm, Irredo . periods occurred only at WP ill Feb Aug and May-banuhi, m expmure omek dunng 1979 Iwo Nov. 9 Marine Woodborers 211 v i 9 i TAlllE k Averege dctmfy of lintthusa 6pp in t.tpteure pincts (vilected dutwg the curicht samphng ) car ('MI. i c., May 1989 August 1990L during 3 unit (3 U) and during 2,un6t (2-11) operanon. hr!E IWPostfRl! Pt:RIOD Aug I'eb I tb Aug May -Nm wi 3- U 2,1f 90 3 L1  ?.D tiv 3-ti 2.t t I l' mean 3.4 10.4 11 14 4 $5 7' 9.0 0k O.7 16 . b cv' 300 N' 6 34.3 41.? ;34 279 lino ed h 42 ' l l'1 rnean 0.0 22' 26 1 $3 6 26.I' 127 9 IWU 187 0 14$ 9 sr 67.3 3%3 lK 5 la2 2rto l t. t 16 9 )?) llP mean 14 4 9.

• 30 fel 6 MIR -- ' lM 7 IW3 cv 468 JL3 IV2 74 3 276 26 0 274

%P mean 24 t+ 27.1 914 391 4 2W6' $199 702 1 SMO 7 1910.4 tv 33.3 13 0 25 4 Lfs  !!1 vy nv 12 4 Its 'ON mean 18 7 M.5' 1515 187 6 14't h' $67.5 am o $st2' 40 4 cv 41.3  !!3 1V4 41] l11 17: Iko  !!v .M ? # Gicffwicnt of variabihty (standard error t4 the sucan, dnkled 15 ttic mean aiid iniuluplied ty 100)

• Lgmucant differen<c betacen 3 LInti and 2-llrut denstuca (P< 0 05). attording to a % skien signed rank tesi.
• Cr coukt not be calculated becauw the mean was tcro,

' liluk Pomt site was not sampled pror to May 19M$. TAllt.fi 7. Average density of Clutwa siwbru*ti ci4tsticd during the turient wisuphng scar (90, M.sy 19e Augunt 19N11. durisig 3.umi (3.ll) and durms 2. unit (2.Ll) eleranon. MIE I,Xi'OSUlti; PERIOD Aug-l'cb fch Aug May Ntn 40 3U 2 U. 90 31) 2.ll 89 3 ll 2.ll 1:F mean 00 '00 0.0 00 0.0 00 00 00 sto cc* . I' ~ l'l mean 00 00 00 00 02 -00 2.$ 0.7 00 cv . M2 Th2 M3 4%) llP mean 0.0 0.0 0.0 00 0.1 - 00 (t 2 . cv . . 69.3 J 1(Kto WP. mean 0.0 0 04 0.8 08 24' 17.6 .W l ' 70 0*. '870.9 cv . 10GO $l17 lik)0 .i7. 6 41.4 4kh. lU l 24.7 GN mean 1.7 _ 1.3 2.3 00 0.0 0.9 . ' 74 51.3 100 8 cv likt0 566 66 0 by ? 63.8 24 3 09 1

• Orthcient of vanatwhty (standard error of the mean. divided ty the mean and muluphed l'y llE4
• cv could not be calculated treause the mean was teru 5 ilixL Pinnt site was not sampled prior to May 1985.
• Significant difference twsween 3. Unit and 2.LJnit denuurs (P<0 05), according to a Wdcoxon signed r. ink test.

i. -212 Monitoring Studies,1990

_ _ _ _ _ ~ . . . - . _ . _ . ._ _ - . . _ _ _ _ _ __ _- . . - . _ __ _ _ _____. _ _ _ ~ - _ _ . _ . . . . - - . _-- ~. ~ . . - . - - _ . . - - - - . . - - . - - . - - - . . - . - - i I g i.fnvent ' (invent

on w, 1500, 1000 40-we , ?o oaw ww  :. ==.4.~ O m. .J . -- -_ -

xxo F o. y,lond 8 mo E a. .i 7200 g g' J t %% .  % TL r - A- ' N, 74H L.m.  ! . .. ... - - - . - - -. - - - . m. b l

• thock Pe. int Aco - Diock Point 2!o0 D so, NOC . "O' N wa ,

T _ _ m - _... b y "( es WMe Point r Wh+te Point , 40 noo , 20 t500, -

o. 2mm. ~ . .m== % ,

t000 no < 0 - .ana - .. .r2 anneme ., Grants Neck e.o Giants Neck , yyyo o da .t' . t. ~ i sz . 78eeBesee 7etennese zeeeeeeep uno . 90io67890 9 0 t o t, 7 e 9 0 901567e90 > too , F-. Auc-rin -1 F- r te. AuG --.i F.- uruth ~1 0--- ~ ~ = = = = = - 7eassess9 788spesas 7aeeneeas 901567590 901s61 890 S0tbe7890 g . F - Ax. a t e -.4 F tto- Aoc - { H u4Nov a 7,gy ggg gg lig 10 Autage winid-he (as a pcrientage of weight hat) hom y ; eM - g 3-UNd g <lu $ UifRO capwure pincts colicord dunng l'49 twu I ip 9 Ascrage numencal abundance or the amphipal. Clwlura n,iwam, in exp use pinci. co'lenca dunns ivw i'm 79,11) and F1 (14 and 16'1). Wood low in Feb.Aug Petrentage of it'uod. loss "'*I"'O I'" 'h"" "'"U *" #**0 "" h"' conshtently been very variable among sites, exposure submerged wuod (e.g., our exposure panels) may be periods. and years (Fig.10). Despite such variability, when overall 3. unit and 2 unit oIierational periods ar'e deltraded by a variety of physical and biological factors; however, the most significant losses in our compared, wood. loss at EF has been signtficantly study hase been attributed to woodborer activity, greater during 3. unit operation in all exposure periods During 1989-90, as in past years, wuod. loss peaked (Table 8). Wood. loss in the May Nov period has during the May Nov and Aug Feb exposure perhxh: decreased from 64 to 31% at GN during 3 unit largest losses were observed at WP (66 and $40i), EF " P# '" ' I""' (36 and 559f) and GN (17 and 54%; Table 8). Less wood was lost in these two perksds at ilP (10 and l [ l Marine Woodborers 213 l 'I Alit.l: 8 Awrage omt kms (n the pertentage ut weight hot) per rys.murt pinti tot tinar tulletted duting the t uttnd umphng year (90, t c., Mn lWV August twa0), during 3 unn (3-LI) and during ? und (; 11) otrtahan ME l APo%lIRt P1 kluD ALgItb lib-Aug Ma3Nn W 3 tl 2-l! W 3 11  ? ll 89 3 ll 2 t) ! IF turan 34 6 445' 19 e eg n i' 1; w, 3 44 ;' 3: 3 cv* IV V: 158 13 7 ?J Ja3 l44 I: 3 1: 1I tucan li 7 1,7 86 08 30' I4 lik 11 4 12 8 <t lit ! 14

• 21 3 M3 ist 3) k 11 3 ri u 14 v tiP tur.w 20 1 8A 42 00 2.8 > 10 2 12 5 cv  ?) IN T 32 M 51 14 3 Ili WP mean 54 3 ;ti 17.1 00 30' 1.3 646 32 1 411 cv A2 13 4 l2 4 14 0 270 l? in 3v l bN menn ' $4 2 23 9 241 0$ 40 31 17 0 30 9' ott cv 37 the 26 7 100 0 21 s 2n 0 40 11 < Ju
• Coemtient or unibihty (suindard retor er Hit turen, dnnled t3 the mean and mulophed by 100)

' $sproficant dillerrnce betwern 3 L.Init and 2 tinit densitus (P(0 04), strosdmg to a Wikmon signed tanL tet,t 'er tould tiot liv talruldted btvause the mean was reto , ' lHuk Piunt tite on nol h.impled Pflot to Md) 19M3> w(mdborers are lacking. For instance, oserall loullnp coverage in the May.Nov esposure period I'yxnure l'anel Study I)iscussion during 2 unit operation at WP and GN (2rt and 21% respecthcly; Table 2) were not significantly Fouling communities in the htilhtone arca, and different from those during 3. unit operation (23 the specks compthing them, exhibit high spatial and 11'7v ). Ilowevet, user the sarne time 4 pan, (among $11cs) and temporal (umong exposure woodterer density increased at WP (from to to periods and years) variability. Fouling species 169 per panel; Tuble *l) and decreased at GN could affect settlement and sunivalof woodborers (from 236 to 67). Woodborers are controlled in several ways; possible mechanisnn include 1) more by physical (e.g., severe winters, availability pre emptive competition (prior settlement of of wtxxl) and biological (e.g., fecundity, resistan(c fouling; species could_ limit space available to to disease, larmi mortality) factors than by subsequent woodtvrer settlement), 2) predation settlement inhibition caused by interactior,s with (Illter Iceders, e.g., barnacles and tunicates, muld fouling organbmt ' Ingest or dkrupt woodborer larvac), or_3) Linmoria spp, and Chr/ura irrrbrans can be r smothering (fast growing colonial species, i.e., significant contributors to _ wood. low (Menries encruulng bryotoans, tunicates and sponges, could 1957; Nair 1462; Kuhne 1971), but have not been overgrow the siphon openings of established important in our study. 'lypically, crustaceans woodimrerr,, especially juseniles). Heavy fouling require a full year to effectively coloni/c and reach and large limnorid populations on wtxxl surfaces peak ubundances (>4(KO/ panels;llattvile 1978) on have been shown to reduce woodboret recruitment paneb. In our six month cymsure periods, (Weiu 1948; Turner 1906; Nair and Saraswathy abundances seldom exceeded ifx0/ panel (many of 1971; Hoagland 1983); however, the effect is these, juveniles not included in the 1978 data) and dependent on the retailve abundance and timing of wood. loss attritsuted to Limmvia and Chchtra has-ihe settlement. Our 6 month exlmure per!cds do usually been less than 5'E Of these two genera of not allow the development of a ' mature' foulin8 crustaceans, Limnoria continue to be more community (cf. Recolontration Studies in the abundant; Chr/ura rarely exceeded densities of two Rocky Intertidal section of thh report), so it h not per panel. Even though Linmoria can recruit to surprising that consistent relationships t etween panch as adults during every exposure period

• coverage by fouling species and density of sampled and they brood thcir young to a juvenile 214 Monitoring Studies,1990

i stage prior to release, their small si/c and a review. We cannot determine how much each of l relathcly low fecundily (compared to shipworms) these factors contributes to the sariability of hical makes them less destructi e than shipworms <wer shipworm populationt a sh month period. Thk 3 car, as in the past, Despite the variability in Trrnlo moula seasonal patterns of wood loss closely resemble abundance among years, seasonal (within ) car) those of shipworm abundance, and show no patter 6 of recruitment are ser) conshtent. Other relationship with crustacean distribution, rewatchers base reported that pedneligers begin 7~rredo norahs b nathe to the coastal waters of settling in June and continue 10 sueeruf uth invade northeastern United States, and common in wood through October (Orase 1928. Imai et al. temperate seas worlJuide (Turner IW6). Locally, 1950, Scheltema and 'Iruitt 1956; Krntensen 1979, I nain/n b found at all sarnpling sites; densities Rh hards et al.1980, Ibt ahim 198); lloagland 1953, are high at WP and ON (where docks are flillman et al.19X5; llillman and llellmore 196% supported by untreated oak pilings), and lower at in our studies, we base found that htile i F1 and ilP (where pihngs are treated with copper recruittnent of T naraht occurs before Augusi l ' chromated arsenate (CCA) preservalh e), (evidctwed by s er) low densities in I'ch. Aug ) Dernities are aho low at EF, where T narahs panch; Table ,th and no succewful settlement l l larcae from the source populations must paw (neurs atlet October (evidenced by the ubseme of I

through the MNpS cooling water sptem and T narakt in Nov-May panch at ambient water  ;

experience a fairly limited time (30 min) for sites, sampled 1979-89. NU5CO 1990) ' settlement before pauing through the discharge Ternlo harn da ha semitropical _ shipworm I cuts back into Long Island Sound; in addition, common from Texas to Soutn Carolina (Turner  ! l._ those indhiduals that do settle on panch must IW6; Abbott 1978). In 1971, un nolated  ! compete with I baruchi for wmnl resources. population of thn shipworm was reimtled in The number of shipworm larvae that settle on thermally enhanced areas sunounding Opter panch at our samplint sites rnay be related to the Creek Nuclear Power Station, New Jersey (Turner j: sI/c of nearby source popu!ations (adults). For 1973; Richards et al.1980, lloagland 1981). In example, the recent decline in abundanec of Tcrolo 1975,it was found in the warm water diwharge at narahs in the May Nov exposure perhxl at GN MNPS (Dattelle 1976). The presence and i appears to be related to a general deterioration of persistence of thk shipworm within the MNPS nearby pilings, whkh limits wood resources for effluent is clearly related to power plant operation. ! adult populations and reduces the quantity of With the start up of Unit 3 (April 1986), larvac released in the immediate vicinity, in abundances of I bornch/ hase increased by a contrast, recent maintenance of the dotk at Wp factor of 9 to 20, and wood loss by a factor of 2 to has provided fresh substrata for a large source 5. The sucecu of this population b attributed to population, whleh could contribute to the high T moderation of ellluent temperature extremes and

narolif densities obser ed in 1989 90. At sites with to increased availabilhy of food resoureck in the CCA treated pilings (DP and Fl), lower densities form of sawdust and wood chips used by Unit I to of shipworms in panch might be related to plug pinholes in condenwr tubes (NUSCO 1989, leachate from the treated pilings that makes the _ 1990).

Yleinity unattractive or toxic to'setlling larvac Tcredo bartsch/ has a generation time as short as (NUSCO 1990). A large number of phpical and sh weeks (cf. hham and Tierney 1953; Turner and biologleal- factors' hase been shown - to affect Johnson 1971), IL, larvac can settle, woodlmrer recruitment, c.g., watet temperature . metamorphose, and grow into adults capable of and salinity-(Krbtenwn 1%9), currents (Doochin releasing larvac in 1.5 months. These larvae are and Walton Smith 1951),foulingorganisms(Weiss brooded by the parent to a late stage of 1948; Nair 1962; Turner 1(X6; lloagland 1983), development (pediveliger), w hich can invade wood abundances of Limnoria (Battelle 1977); bio, immediately upon release (Isham and Tierney attractants (Culliney 1975; l-lillman et al.1987), 1953; lloagland 1981). Once mature, under illumination (hham et al.1951), or water depth favorable conditions,- I barnchi produces larvae (Grave 1928; Edmondson 1942; Nair 1962; continually. In the MNPS quarry, since Unit 3 NUSCO 1990); see Nalt and Saraswathy (1971) for - began operation, there have been few excunions of  ! Marine Woodborers 215 I i i I water temperatures atawe 35'C or below 5'C Distribution Stud) Hesults (i.e., unfavurable conditions; Iloagland 1463), even one additional generation per ) car could account 1b study was designed to awess the ability of for the observed inercases in T barruhl densities Adpmums to seule in the MNPS clauent mihng and www.1 loss at EF during 3 unit operation. mne, at diuanas of un 2m,5N and ino m  ; 'ne difference in destructive potential between from the quarry cuts. During the Oct lux 9.Ma) Tetrdo baruchi and T. narahs can be illustrated as iw c9,sure perned, no settiemetu of 7ernlo follows: if one T. narahs individual recruits to a occurred ut any distance. During hiay Oct 1989, piece of wm1 at the beginni g of the larval settlement of T. narah5 was 4Wpanel at IN m, settlement season, by summet it can prmluce many 117/ panel at 2m m, 34& panel at $m m, and larvac. However, these larvae (straight hinge 374, panel at 1(kki m (TaNe 4L A pattern of veligers) requite 2,3 weeks of planktonic. hlyher densities at SW m has been conshtent since development, and it is very unlikely that they will 142 (Fig.1It by contrast, the highest dernitt in remain in the vicinity of the original piece of 19S5 occurred at im m and dechned knearly woh woodc On the other hand, one I barrnhi dntance from the quarry cuts. Individual can produce larvae (pediveligers) that The high abundance of Ternlo naruht at im m are able to re infest the original womi. Therefore, in 19X5 is consiJered un anomah, induced by N ut the high degree of wood loss at WP, uttributed to 2 und water circulation. This view point n

7. taar,@, regulics a large, widopread source supponed by the collection of 14 T banuhr m the '

popunctlan, w herem the comparable level of wood-same panch (i e., im m in 10X5h T. bartwhi has loss at 19 tesults from a very localized population of T harnehl-not been found in any dhiribution study panel since 1955,despite the persistent dense population The signhPanec of the eullection of one traide the hillhtone Quarry 'lo address the individual of Tonki hnernhi from a ON panel in question of whether T barnchi larvae were leasing November IV89 eannot be determined at thh time. the quany, a supplemental study, using panch There are several possible mechanbms by w hleh I lastened just outside a fish barrier in the new bartschi could be introduced to Giants Neck; these quarry cut, was performed from May Oct 1991 Include, but are not limited to, transport of larvae Although only the bottom panel has been or juveniles from the population in the Milktone completely processed, lid adult T. bartichi, nearly Quatry, transpott of larvae or juveniles from 4W juveniles, and almou 100 recendy selfcd unknown source ',tischarges (e.g., a warm water pediveliger larvae were counted. Of the adults, discharge elsewhere in inng bland Sound or lM were bnxxling late-Mage scHger lanac. farther away), or dispersal from a population that has adapted to ambient water ternperatures. laboratory studies at Milktone (19S2 M4) have Distribullon Stud) Discussion shown that summer ambient water temperatures can support the production, settlement and growth TN Diuribution Study was initiated in May of T barnehi pediveligers, and that adults can 1985, to assess the abundances of shipworms, and tolerate 2 C temperatures for at least two weeks. to document the distribution al Tmdo narahs and These observations imply that I bartwhi may exi i T bortschi in the MNPS thermal mNng mne. outside the MNPS quarry, in small, patchy Data Itom this study support and con tilement populations, normally limited by prolonged results from the Expmure Panel Study in several For instance, both studies show e/treme exposure to cold water during the winter months. Prior to this yer.r we have had no evidence that I ariability in settlement for 7errdo thh was occurring. However, winter water navahi, whh virtually all recruitment occorring temperatures in 1989-90 were unusually mild, hom late summer to early autumn (Aug Oct), and seldom falling below 4 C, Future monhoring will negligible recruitment in winter and t pring, determine whether I bartschi at an ambient water Minimal settlernent occurred in Oct May site 6 a unique event, or the first observation of a distribution study panch ($$! panel); October newly establist.ed population, apparendy represented the last month in which larvae are capable of successful settlerrent because recruitment has never occurred in Nav May 216 Monitoring Studies,1990 i I l l TAlfLI? 9 Denusy or Irredo nmla (musnberipanet)in telahon to distance from the quarty Cuh. Mill 6 tune Nutkar P,mer Matson. M AW0 li X P O s tf H L p i, H t O D May,0ct Oct M,i> 19838 19 % IVM7 IVM 1989 CD64 IVd 19N7 IVe IVMV lW tt*L Ho m 601 121 N IS 4N IS9 0 3 5 1 0 1.8 l 200 m J - -- 19 117 78 . - 0 0 U.0 5to in  !;6 634 110 13V NM 335 0 I O O O 0.2 1010 m 3'A $2$ St M 274 268 0 0 t 0 0 0.2 1 6td 505 4H sr. et 22) 0 IJ 20 0 0 l *the 1983 cxpmure p,tnod extended trorn May to November. ' *lhe 19% npmtae penal extended from Nmember to May, 'The distance or 2to m was not sampled unut IVM, the ascrage desaoy al this datance in tuAcd on only tw yeart IVM and 1989 , 10 he colnotent, the 2(O in datantc salues were not induded in ihn nicrage. "~~ temperature, low dScharge velocity (NUSCO wwnm, mw . w ,us. 1987). Others have reported that h4h currents g could udverscly affect shipworm recruitment  != ~.. - J.* (Doochin and Walton Smith 1951). [ ~%p '- '%, Laboratory studies of Trtcdo navala conducted & ~w , at Northeast Utilities Environmental laboratory [" / o ,,,, (NUEL) in 1983 and 1984 showed that individuali o - grown in undiluted effluent water and in a 3:1 g* i*s mixture of ambient and dhcharge water released , g W i d' . , pedhreligers earlier, over a longer period, and in e_hr."'. . . - _., 21.__..Z...] greater numbers than did individuah reared at .-w ..y u .* 7 ambient water temperatures (NUSCO IVAlj. rmwet r%m eou tuu"tm" * . lig il. The May Oci denunci nr the shipworm,7eredo runw/u, reproduction and growth were extended in the in pancia piaced Ho,2m son and Inu m from the Quarry vicinity of the discharge of a power plant in Wales, cun (nun 1983 io 1989 UK. This pattern of enhanced settlement in the discharge mising mne h further supported by the exposure panels at ambient water sites. This higher abundances of shipworms collected at 5(K)- seasonal pattern of t,hipwurm abundance is 1(KK) m relative to those at other sites f.ampled consistent with that reported by other researchers during the Exposure Panel Study, and by the (Orave 1928; imal et al.1950; Scheltema and observed increase in T. navalis densities at WP Truitt 1956; Kristensen 1979; floagland 1983; (17m m imm the dhcharges) during 3mnit Hillman et al.1985; llillman and Dellmore 1989). operation. Data from both the Exposure Panel and Trredo barr3 chi, a non native shipwoun, was aho Distribution Studies show high year to year studied at NUEL in 1983 and 1984. Tbh variability; e.g., panch at 5(X) m in 1986 collected shipworm reproduced throughout the year in 654 shipworms / panel, but in 1987, only 110/ panel. undiluted dheharge water. In a 3:1 mixture of l Despite 1,uch annual variability, the consistent ambient and discharge water and in 1(k)% ambient - pattern of peak abundances occurring at 5(K) m, water, T bartschl released smaller numbers of noted since 1986, implies that cicvated water pediveligers than did those in 1(W discharge temperatures may enhance ettPment.-but that water, but this shipworm euuld survive and become - high water velocity may be inhit'! ting settlement reproductive under atnblent water conditions nearet the dheharges (NUSCO 1989,1990). The -(NUSCO IVA)). Dense settlement of T. barr3 chi anomalously high recruitment seen at ifK) m in on the special panch placed in the quarry cut 1985 represents 2-cut 2 unit operation, i.e., high indicate that larvae are exiting the quarry and Marine Woodborers 217 .. _ _ .. _ .a._ _ ._ _ _. .c. _ _ _ _ _ . . . _ . _ _ _ . - _ _ . . _ _ _ _ _ _ _ . _ . _ _ l entering 1.ong Island Sound, Mthouyh to date, im indicate that populadons of thh shipwurm exist in , catablished populanons have been found beyond areas of long Island Sound other than the MNPS ) the undiluted MNPS discharge. quarr). Trredo bartschi brood their young to a late stage Data from the Dhtribution Study, specineally of development (pediveliger Stape) before releasing the relationship between shipwotm recruitment them. These pediveligers are capable of imrnediate and dktance from the quarry cuts, support the settlement and burrowing (1 sham and Yicrney supposition that settlement of Terrdo naial/A h 1933, Turner and Johnson 1971; Hoagland and related to direct or indirect effects of the 3. unit Turner 198&, Hoagland 1983). For thh reason, thermal plume. Also, the collection of sescral thh immigrant shipworm has been able to sustain hundred T. barr3 chi, rtpresenting all stages of a resident population in the Milhtone Quarry, development,jast outside the quarry indicates that where discharge water has a transit time of less larvac are entering the MNPS discharge mhing than 30 minutes (NUSCO 19S3). Thh life hhtory tone and 1.ong bland Sound. Further monitoring strategy not only results in rapid destruction of will determine whether these larvac can estabibh womi in close proximity to Ibc parental stock popuhtioni ciscwhere in the Milhtone area, or if (Turner 1973; lloagland and Turner 19MO, the occurrence of T. bartschi at GN in 19w was a i lloagland 1983), but contributes to the patthy unique event. dktributions of their populations pechenik et al. l (1979) reported that the larvae of Lymher l(cierences Ciled pedicellatus, a shipworm with a life hhtory similar to that <4 7 bartsch/, were clearly adapted for Abbou, R.T.1974. American Shelhi The marin-buildir g up local shipworm populations rather Mollusca 01 the Atlantic and Pacific Coasts of ! than vor long range dhpersal. These life hhtory North America,2* ed. Van Nostrand Reinhold

charneteristics are entirely comktent with the j Co NY. rM pp. l dhtribution of T. barracht observed in the MNPS  !!attelle (Columbus lab., W.F. Clapp lab ). 1976.

repon. Ihpnute Paneb. Pages Al A20 in A monitoring program on the ecology of the Conclusion 5 marine emironment of the Millstone Point, 3 Connecticut area. As submitted to Northeast i , During 1989.90, local fouling comtnunities Utilities Service Company. Annual Report, l continued to eshibit high spatial and ternporal 1975. Report No.14673. variability. Iloweser, shipworm abundances Dattelle (Columbus lab., W.F. Clapp 12b). 1977. wntinued to be etmtrolled more by physleal and Expwure Panch. Pages Al.A43 in A !- biological factors (e.g., severe winter condillons, monitoring program on the ecology of the t uvallability of wood sutwtrata, variation in the marine environment of the Millstone Point, { source population) than by settlement inhibition Connecticut area. As submitted to Northeast j caused by interactions with fouling organkms or Utilities Service Company. Annual Report, l Limnoria inlestations. 1976. Report No.14748. Shipworm abundances have aho exhibited some Battelle (Columbus Lab., W.F. Clapp 1.ab). 1978. changes during 3 unit operation. Increased thpwure Panch. Pages Al A25 in A densities of Terevlo nacalis at WP suggest that the monitoring program on the ecology of the MNPS effluent may be enhancing the recruitment marine environment of the Milhtone Point, of larvae to this site, increased dernities of T. Connecticut area. As submitted to Northeast hartschi at EF, and associated wmd low were Utilities Service Company. Annual iteport, attributed to the moderation of water temperature 1977. Report No.14892. cxtremes in the quarry, and to the increased Board, P.A.1973. The effects of temperature and availabliity of food resulting from more frequent . Other factors on the tunnelling of Lyralus use of wood chips to bhsek small leaks in pedicr/ lams and Terrdo navnlis, Pages 797 805 condenser tubes at Unit 1. However, due to the in Proc. 3d int. Contr. on Marine corrosion and distance between MNPS and GN, the appearann - Fouling, Natt. Dur. Std., Gaitherburg, Maryland, of T. bartschi at thh reference site in 1990 may U.S.A. 218 Monitoring Studies,1990 ~ - _ _ _ _ , _ _ _. _ - _ _ _ . _ _ _ _ _ . _ , _ _ _ _ _ _ _ _ . _ _ _ _ _ _ _ _ _ _ . _ Culliney, JL 1975. Comparative larval Australian liarbours. Aust. J. Freshwater Res. dnelopment of the shipworms llanAia pddi 32:591-604. and Trtrdo narolis. Mar. Illot. 29:245 251. Imai, T., M. Ilatanaka, and R. Sato. 1950. Doochin,11., and F.O. Walton. Smith. 1951. Breeding of marine timber.borer, Te redo mo ula Marine boring and fouling in relation to velocity L. in tanks and its use for antiloring tests. I of water currents. Bull. Mar. Sci. Ouli Carib. Tohoku J. Agricult. Res. 1:l % 208 l 1:l%.208 Isham, LIL and J.O. Tierne).1953. Some aspects l Edmondson, C.H. 1942. Teredinidae of flawall. of the larval development and metanmrphosis 01 II.P. Dishop Mus., Occ. Papers. 17:47 150. Terrdo (l.3mlut) prdicr/ lata DcQuatrefagn G ras e,11.)l. 1928. Natural history of shipwurm, Dull Mar. Set Gulf and Caribbean. 2:574 589 7rrnlo navalis, at Wmds Hole Mawachusetts Isham, LD., F.G. Walton. Smith, and V. Sprinyer. Biot DuH. Woods llole, 55:2Nb282, 1951. Marine borer attack in relation to Hillman, R.il, and C.l. Delmore. 1989. Annual conditions of illumination. Ilull. Mar. Sci. Gulf report for the period December 1,1987 to and Caribbcan.1:46 63. Nmember 30, 1988 on study of wom!borer Kristensen, E.S. 1%9. Attacks b) Terrdo nam /o , populations in relation to the Oyster Creek L in inner Danish watets in relation to Ocnerating Station. As submitted to GPU environ.nental factors. Vidensk. MedJr dansk l Nuclear Corporation. Hattelle Ocean Sciences. naturh. Foren. 132:199 210.  ! Dusbury MA. 9 pp. Append. A and D. Kristensen E.S. 1979 Observations on gtowth ' lifilman, R.E., C,l. Belmore, and R.A. McGrath. and life cycle of the shipworm Teredo narn/a l 1985. Antiual report for the period December L(Divalvia, Mollusca) in the Isefjord, DenmarL.  ! l,1983 to November 30, 1984 on study of Ophelia. 18:235 242. womlborer populations in relation to the Oyster Kuhne, H. 1971. The identiHcation of Wood. i Creek Generating Station. As submitted to boring crustaceans Pages 66-88 m E.D.O. Jones OPU Nuclear Corporation. Ilattelle, New and S.K. Eltringhom (eds) Marine borces, funyt England Marine Research Laboratory Report- und fouling organisms of womi. Proc. OECD 148 pp. ~ Workshop, March 1968. Organi/ation for liliiman, R.fl. C. Werme, and M.J. Kennish. Economic Cooperation r.nd Dnelopment. -1987, Setting of larval shipworms Terrda. Paris, France, barnchl Clapp stimulated by malle acid and Menties, ILJ. 1957 The marine borer Family woodborer metabolites. Technical report to Limnoridae (Crustacea, Isolmda). Bull. Mar. Environmental Controls Department, OPU Sci. Gulf and Caribbean. 7:101 200. Nuclear, Forked River, NJ. 25 pp. Nair, N.11. 1962. Ecology of marine fouling and floagland, K.E.1981, Life history characteristles wmxi boring organisms of western Norway.

and physiological tolerances of 7'eredo barachi, Sarsia. 8

1 88.

u shipworm intrmluced into Iwo temperate zone Nair, N.D., and M. Saruswathy.1971. The biology nuclear puer plant effluents. In 3rd int. Waste of wood.lmting teredinid molluscs. - Adv. Mar. Heat Meetings Proc. 14 pp. Biol. 9.335 509 Hoagland, K.E.1983. Ecological studies of wood. Naylor, E.1965. Effects of heaied emuents upon boring bivalves and fouling organisms in the marine and estuarine organisms. Adv. Mar. Alcinity of the Oyster Creek Nuclear Generating Diol 3:63 103. Station, Final Report, September 1976 - NUSCO (Northeast Utilities Senice Company). December 1982. U.S. Nuclear Regulatory 1983. Milhtone Nuclear Power Station Unit 3 Commission,' Washington, D.C. NRC FIN environmental relmrt. Operation license stage. -118138. 173 pp. Vol.1 4. Hoagland, K.E., and R.D. Turner. 1980 Range NUSCO. 1987 : Rocky intertidal Studies.- Pages etttnsions - of - teredinids -(Shipwurms) and 146 in Monitoring the marine environment of polychatta in the vicinity of a temperatesone lamp Island Sound at the Milblone Nuclear nuclear generatinptation, Mar, Biol, 58:55 64. Power Sta tion, Wa terford Connecticut, Summary . Ibrahim, J.V. 1981. Season of settlement of a of studies prior to Unit 3 operation. Annual number of shipworms (Mollusca: Divalvia) in six reimrt,1986 Marine Woodturers 219 . - . . . _- = -- - - . .. NUSCO. 1988. Hydrothermal Studies. _ Pages 323 354 in Monitoring the marine environment of l ang ' Island Sound a+ Millstone Nuclear Power Station, Waterford, Connecticut. Annual report,1987. NUSCO 1989. Exposure Panet Program. Pages _209 235 in Monitoring the marine environment of Long Island Sound at Millstone Nuclear Power Station, Waterford, Connecticut. Annual report,1988. NUSCO. 19m Marine woodborer, Pages 221242 in Monitoring the marine environment of Long Isla.id Sound at Millstone Nucicar Power Station, Waterford,Conneethul. Annual report,1989. Pechenik, J.A., F.E. Perron, and R.D. Turner. 1979. The role of phytoplankton in the diets of adult and larval shipworirn, l,yrodus pedicellatus (Bivalvia: Teredinidae). Estuaries, Short Papers and Notes, 2:58 60. Richards, B.R., C.I. Belmore, R.E. Hillman, and N.J. Maciolck. 1980. Annual report for the pcriod December I,1978 to November 30,1979 on woodborer study associated with the Opter Cieck Generating Station. As submitted to Jersey Central Power and Light Company. Report No.14968 (Battelle).- Scheltema, R.S., an'l R.V. Truitt. 1956, The shipworm Terrdo navalis in -Maryland coastal waters. Ecology, 37:841 843. Turner, ' R.D. 1966. A survey and illustrated catalogue of the Teredlaidae (Mollusca: Bivalvia). The Museum of. Comparative Zoology, Harvard University, Cambridge, MA. 265 pp. Turner, R.D.~ 1973. In the path of a warm salhe effluent. Am. Malaeol. Union Bull 39:36-41. Turner, R.D., and A.C. Johnson.1971. Biology t,f marine wood. boring molluse . Pages 259-301 in E.B.0, Jones and S.K. Eltringhom (eds) Marine borers, fungi and fouling organisms of wood. Proc. OECD- Workshop, March '1998. Organization for Econo.nic Cooperation and Development. Paris, France. - Weiss, C.M. 1948. An- observation on the lnhibition of marine wood destroyers by heasy fouling accumulation. Ecology. 29:120. 220 Monitor;ng Studies,1990 Contents Be n t h ic I n fa u n a . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 223 I n t r od u c t i o n . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 223 Materials and Methods ....................................... 223 Da ta An alysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 224 Multiple Regression Analysis . . . . . . . . . . . . . . . . . . . . . . . . . 225 Model Selection Procedure . . . . . . . . . . . . . . . . . . . . , . . . . . 225 Cumulative Data Analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . 226 S pecies Dive rsity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 226 Cluster Analysis .................................. 226 I n t e rt idal Re sults . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 227 Sedimentary Environment . . . . . . . . . . . . . . . . . . . . . . . . . . . 227 General Community Composition . . . . . . . . . . . . . . . . . . . . . 228 Community Abundance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 228 Numbe r of Species . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 229 Community Dominance . . . ......................... 230 Dominant Taxa . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . , 232 Cumulative Abundance Curves . , . . . . . . . . . . . . . . . ..... 235 Species D ive rsity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 236 Cluster Analysis .................................. 236 D is cu s sio n . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 237 Conclusions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .................. 238 - S ub t id al Res ul ts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 239 Sedime ntary Environment . . . . . . . . , . . . . . . . . . . . . . . . , . . 239 General Community Composition . . . . . . . . . . . . . . . . . . . . . 239 Community Abundance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 241 N u mbe r o f S pecies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 242 Community Dominance . . . . . . . . . . . . . . . . . . . . . . . . , . . . . 242 D om i n a n t Taxa . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 243 Cumulative Abundance Curves . . . . . . . . . . . . . . . . . . . . . . . 250 S pe cies Dive rsity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 250 Cluster Analysis ... .............................. 252 Discussion . . . ............................................. 252 Conclusions . . . . . . . . . . . . . . . . . . . . . .......................... 254 References Cited ................................... ...... 255 llenttile Infauna intrixtuction Eleftheriou 1989). Long-term studies are needed because temperate infaunal conununities tan Benthic inlaunal communities include numerous exhibit large natural nuctuations in abundance and species of worms, clams and crustaceans which lise species composition in response to short and long. in or near the surface of t, oft bottom subtidal term climatic conditions (Boesch et al.1976, Flint sediments and intertidal sand beaches. These 1985; Jordan and Sutton 1985) and to variations in organisms provide a source of prey for invertebrate such biological factors as con petition and and vertebrate species including demersal fishes predation (Levinton and Stewart 1982; Woodm (Richards 1963; Moeller et al.1985; Wat/in 19%; 19S2; Kneib 1988). Ilorn and Gibson 1988; Commito and Boncavage Objectives of the Millstone infaunal studies base 1989). The sediment reworking resulting from the been to characteri/c localinfaunal communities in burrowing and tube buihling activities of infaunal terms of abundance and species compmuon, communities also contribute to nutrient recycling quantify natural spatial and temporal patterns in from the sediments to the water column community structure and abundance and to iJennify (Goldhaber et al.1977; Aller 1978; Gaston and changes in these communities which might be the Nasci 1988). result or anstruction and operation of the MNPS Infaunal communities are often examined to To date long-term studies have ideniihed area-measure the innuence 01 man's activities on wide shJts in ciganism abundance and species aouatic systems. The use of these communities to ~ composi'an that were apparently the result of as ess the direction and extent of anthropogenic natural wents. In addition, studies base quantilied disturbance has several advantages. First, benthic local impacts on infaunal communities related to communities can reDect environmental conditions Unit 3 Intake construction (NUSCO 1987) and 3 over extended periods of time rather than just at unit operations (NUSCO 198Sa). the time of sampling (Wanvick et al. 1990). Second, because of their relatisely sedentary Materials an<l Metlio<ls nature,infaunal species can reflect even small scale disturbances which are more typical of human Infaunal communities in the vicinity of MNPS induced impacts (Reish 1973). Lastly, many were sampled quarterly (September 14S9, studies have described the structural and functional December 1989, March 1990 and June 1900) at changes in beathic communities following three intertidal and four subtidal stations (Fig.1). disturbance (Boesch and Rosenburg 1982; Young The Giants Neck stations (GNI, GNS), 2.5 km and Young 1982; Gaston and Nasci 198S; Regnault west of MNPS power plant, are beyond the area et al.1988; Rees and Eleftheriou 19S9; Warwick et expected to be affeeled by power plant operations al.1990). Results of these and numerous other and thus serve as our reference stations. The studies proside a general framework 10 identify intake subtidal station (INS) is located 100 m environmental impacts of human acti ,:s on seaward of the Mllistone Unit 2 and Unit 3 intake marine benthic systems. structures, and is exposed to potential scour Studies on subtidal and intertidal infaunal produced by inflow of cooling water. The effluent communitics have been performed in he vicinity subtidal station (EFS), located approximately h)0 of Millstone Nuclear Power Station (MNPS) since m offshore from station discharge into Long Island 1968, although variations in sampling design and Sound,is exposed to increased water temperatures, collection procedures allow direct comparisons scour, and any chemical or heasy metal additions among data collected since only 1979. The need to the cooling water discharge. The Jordan Cove for long term data to distinguhh between natural stations (JCl, JCS), and the White Poim (WPI) and human. induced changes in inf: unal station are located 500 km and 1500 km, communities has been well established by respectively, cast of Millstone station and can be numerous researchers (Holland 1985; Nichols exposed to plant induced water temperatures of 0.8 1985; Holland et al.1987; Warwick 1988; Rees and to 2.2"C above ambient, principally during ebb tide i Benthic Infauna 223 l v ) / J '\ \ ~ North 0: ' mi ( ,f (%.$)' ( } ' Niante Dw ) b{ inh q C 5 , p f EFS *N % ,., f ' N .'> f Y GNI ' ,y g ( .0 Q ,,o ,m, GNS v I?ig.1. Map or the Milstone Point area showing the kcation or infaunal sand samphng stations (jct. JCS

• Jordan Cove intertidal and subtidal stations; WPl = White Point intertidal station; ITS = rimuent subuda! stauon; INS = Intake subtidal station; GNI. UNS =

Giants Neck intertidal and subtidal stations). (NUSCO 1988b). that were too small to be quantitatively sampled by 2 At each station, ten replicate samples (0.0078/m our methods (e.g., nematodes, ostracods, copepods, coch) were collected using a hand held coring and foraminifera) were not sorted from san.ples. ' device 10 cm diameter x 5 cm deep. At subtidal Grain size end silt clay was determined on a 3.5 cm s',ations, SCUBA divers randomly sampled within diameter x 5 cm core, taken at the time of infaunal 3 m of each station marker. Each samp!c was sampling, using the dry sieving method (Folk placed in a 0.333 mm mesh Nitex bag and was 1974). brought to the surface. Intertidal samples were collected at approximately 0.5 m intervals along Data Analyses the water line at mean low water, When returned to the laboratory, samples were This report presents results from September . fixed with al10% buffered formalin / Rose Bengal 1989. June 1990. hereafter referred to as the 1990 solution and after a minimum of 48 h, organisms report year. Data collected in 1990 were compared were 00ated from the sediments onto a 0.5 mm to previous 3 unit operational years (19861989) mesh sieve and preserved in-70% ethyl alcohol. and to t .0 entire 3. unit operational period (1986 Samples .wcre examired . -using dissecting 1990) as well as to the 2 unit operational perh>d microscopes (10x) and organisms sorted into major extending from 1980 through 1985. Should power groups (annel;ds, arthropods, mollusas, and others) plant impacts occur the; are expected to cause foi later !dentification to the lowest practical taxon identifiable shifts in abundance and species and counted, Oligochaetes and rhynchocoels were richness and/or shifts in dominance structure treated as taxonomie units because of the (Boesch 1973; Oden 1979; Persson 1983; Jordan difficulties associated with identifying these and Sutton 1985). organisms to a lower taxonomie level. Organisms 224- Monitoring Studies,1990 pg 7y ..--. , , . . -- , Mtiltiple Regression Analyses Climatic Euremes fDeviations) - Additional explanatory variables were created to represent Multiple regression techniques were used to unusual climatic conditions which occurred during minimit e the temporal variation in community the sampling period. liigh or low deviations (i.e., abundance, number of species and the abundance extremes) were derived for wind, rain, water and of numerically dominant taxa attributable to air temperature data and determined as the fluctuations in sediments, reproductive or difference between the quarterly mean or daily recruitment cycles, or climatic conditions. This value and the 13 year mean (1977 90) for that technique was used to improve the sensitivity of quarter. Deviations based on quarterly means comparisons of animal abundances and species reflect the effects of longer term extremes (e.g., an during the 2 and 3 unit operational periods. unusually cold winter), while those based on dail) Analyses were based on average quarterly values tend to remove the effects of shorter term abundance data after in tx+ 1) transformation and episodic events (e.g., stonw Daily deviations species number collected from September 1979 were averaged and also summed in each sampling i- through June 1990. Explanatory variables used in quarter to assess cumulatise effects. the regression analyses were as follows: Sedimentary Parameters Sediment mean grain Precipitation - Daily precipitation records site and silt / clay content were obtained as part of compiled by the U.S, Weather Bureau at the the monitoring studies ar'l these quarterly values Groton Filtration Plant. Groton, CT were obtained were included as expla . ory variables in the from June 1976 through June 1990. Values to the multiple regression models, nearest 0.01 inch were used as ' rain" data. Reproductive Recruitment Component Infaunal Water and Air Temperatures - Ambient water organisms in the Millstone area e.shibit annual temperatures (at the intake structures) and air peaks in abundance, often reflecting the seasonal temperatures (recorded at the 33 foot level of the nature of reproduction and recruitment cycles or Millstone meteorological tower) were obtained periods of favorable climatic conditions. Spectral from the Northeast Utilities Environmental Data analyses of quarterly data showed annual geles in l Acquisition Network (EDAN). Daily averages of community abundance and number of species. To l 15 minute-values were calculated for the period account for this periodicity, harmonic terms (l_orda June 1976 to June 1990, 9nd Salla 1986) having a period of 1 ) car, were included as explanatory variables in the repression Wind Speed and Direction - Wind speed and models, directlan (at the 33 foot level of the Millstone In all, 32 variables were used during initbl meteorological tower) were extracted from the model selection steps. These included two EDAN-database for each 15 min interval from sedimentary parameters, iwo seasonal /reproducth e June 1976 to June 1990. These values were used components and seven climatic variables, each of to calculate a wind index, which was wind speed which had four values representing daily and weighted according to wind direction. A quarterly high and low extremes, navigational chart of the sampling area was used to calculate site specific, wind directional weighting Afodel Selecdon Procedure coefficients. The directional weight ranged from 0, when wind could not influence the station, to 1. The quarterly abundance and species number when wind induced waves could directly affect the data were detrended using a linear regression area. The wind index was then computed by model. If no significant linear trend was evident, multiplying the directional weight by the wind residuals were created by subtracting the quarterly speed. Because the effect of wind was assumed to mean from the 10-year mean. A step. wise Inultiple be cumulative, daily averages were derived using regression was then applied to the residuals to only wind index values greater than 0- identify explanatory factors and combinations of factors whose regression coefficients were significantly different from vero (p50.05). Thh Denthic Infauna 225 0991,seidutS gnirotinoM 622 evitalumuc gnittolp yb detcurtsnoc ere'v )sevruc

alumrof eht gnisu detaluclac ecnanimod k(sevrucecnadnubaevitalumuc.egnahc tneiciffeoc ytiralimis- sitruC yarB eht no desab ssessa dna erutcurts ytinummoc eziretcarahc oT saw sraey/snoitats revo axat fo secnadnuba eht ni .

_ evruc ytiralimiS .sesylana eht ni dedulcni dna detaluclac )0991-6891( tl'ru 3 eht dna evra c )58-0891( tinu 2 saw )09 6891( !xkrep tinu-3 eht gnirud noxat ' eht ,evruc 0991 eht neewteb sretemarap A dna hcae rof ecnadnuba egareva,noitidda nI .)09-6891( x cbt ni)5003p( secnereffid tnacifingis rof tset ot raey tinu.3 hcae ni secnadnuba launna no dna )58 desu erew stset t elpmas owT .sdohtem noisserger 0891( doirep tinu 2 eht gnirud ecnadnuba egareva raenil non gnisu sdoirep lanoitarepo tinu 3 dna-no desab erew seuqinhcet sesylana retsulC tinu 2 eht rof yletarapes atad ot dettif neht saw noitcnuf ztrepmoG ehT setacilper sa gnivres sraey sesylanA retsulC htiw raey lanoitarepo )09-6891( tinu 3 h:ae dna raey lanoitarepo )58-0891( tinu 2 hcae ni snoitcarf .xedni siht fo sisab ezis niarg ylretrauq gniloop yb detcurtsnoc erew - eht no tcapmi tnalp gniterpretni ni dezingocer sevruc owt ,noitidda nI .0991 rof noitats gnilpmas eb tsum saib sihT .seiceps ot deifitnedi ton erew hcae rof sevruc tnemides evitalumuc tcurtsnoc yeht esuaceb )smsinagro latot eht fo %08 revo ot desu erew sthgiew tnemides lanoitcarF rof detnuocca semitemos taht spuorg(sleocohcnyhr dna _ seteahcogilo dedulcxe snoitaluclac ytisreviD .detubirtsid ylneve erom semoceb . ,)is91 seiceps gnoma slaudividni fo rebmun eht sa htimS dna reparD( ylchtcepser ,sretemarap epahs dna nonacol =n dna # .ecnadnuba ro thgiew evitalumuc latot = a ,I emit sesaercni dna eno ot orez morf seEnar ssennevE ta ecnadnuba sweeps ro thgiew tnemides ehtalumuc=,C erehw . -)7791 )* ap -(pac a ,C uoleh( tnadnutla yllauqe era seiceps lla nehw ytmcnd mumm.m lacneroeht eht sineserper dna s 2*"I"anil erehw :swollof sa si noitcnuf ztrepmoG ehT .egnar lanoitavresbo eht nihtiw )cilobarap susrev i T"g" depahs-s( tniop noitcenni na tuohtiw ro htiw atad j "" evitalumuc 10 ot ytilibixelf eht sedivorp erutaef detaluclac saw ytisresid f o tnem<pmoc ssenneve nA sihT .)1891 htimS dna reparD( tniopdim a tuoba cirtcarmy:ylirassecen to,r era taht atad evitalumuc mcP$ ebircsed nac hcihw noitcnuf a ,noitcnuf htworg ro rNmun-3 dna .n u os ua ror hauamdni ro reemun ztrepmoG eht gnisu dessessa ylevitatitnauq erew latot= N ,nicepi

• i eht fo laudmdm ro rebmun ,n erehw erutcurts ytinummoc lanuafni dna stnemnorivne N NJ yratnemides laditretni dna laditbus ni segnahC j

b4 b 7, .w sesylanA ataD evitalumuC tedni noitamrofni nonnahS eht gnisu detaluclac saw noitats hcae ta ytisrevid seicepS .rebmun seiceps dna ecnadnuba eht ni segnahc launnaretni )50 05p( tnacifingis yfitnedi ytisreviD seicepS ot desu erew setairavoc tnacifingis rof detsujda snaem no stset t esigriaP . .srebmun seiceps ,sdoirep lanoitarepo tinu.3 dna ecnadnuba ni secnereffid launna rof tset ot eht dna doirep tinu 2 eht fo esoht ot sevruc 0991 desu neht erew sesylana suoiverp eht ni tnacifingis - erapmoc ot desu erew )500sp( stset t elpmas-owt dnuof srotcaf eht gnidulcni sledom ecnairavoC 1 ;esruc hcae gnibircsed sretemarap evired .seiceps detceles fo secnadnuba dna -seiceps ot desu saw noitcnuf ztrepmoG ehT .)7891.la te fo srebmun ,ecnadnuba ytinummoc ni ytilibairav kciwraW ,6891 kciwraW( seitinummoclanuuforcam - devresbo gnibircsed ledom tseb eht sa detceles fo erutcurts eht ni stfihs gnissessa fo snaem saw 2r eht dezimixam dna rorrc-crauqs naem eht a sa detseggus neeb sah sevruc ecnanimod k fo deziminim taht ledom ehT .ezis elpmas eht nevig nosirapmoC .)assicsba( knar s'noxat afo mhtiragol ,detamitse ylbailer eb dluoc naht sretemarap etout laru tan eht susrev )etanidro( ecnadnuba egatnecrep gnittif tsniaga draug ot nesohc saw level ytilibaborp I b=' .n & {,,; I { (X,

• X) o 4 4 .

I ' where Xgabundance or attribute i ai enuly j and j , ,,l f ,,' l Xpabundance of attribuit i ut entity L g ; , J s < wl \f(s,jb,\:tl 7 , , n , Based on these similarities, a clustering algorithm y ,J ,- ,, incorporating a flexible sorting strategy (l.ance and w . i Williams 1%7), (#= 0.25) was . used to form

• I

~ ^ , " " ~ , " " " ' ' ' ' ' " ' station groups at decreasing similarity and the "'m' results were presented as a dendrogram. ,,7.- - - . - l ~. - ! Intertidal Results i I ~ w i!h . : ) , , i Sedimentary Environment  ! LO  !, 5 / ,=! i ' . I Sediments at the three Millstone sandy beach  ! i II ,- k -/h [7 stations during 1990 were categorized as medium I a Qj ~ N g - ' /. , I to coarse sands with low silt / clay content. Particle sizes ranged between 0.33 and 0.48 mm at both ^" ' ,t . Ji, j '( h -j GN and WP and from 0.49 to 0.94 mm at JC (Fig. d" i N' _j,, _t 2), Of the three beaches sampled, sediments at JC " " " " ' " " ' " " " " " " " ' " " " " " " " exhibited the largest seasonal shifts, a pattern typical of this area since the study began. At all 'i--- --- ~ ~ ~ - ~ r stations, the. silt / clay component of intertidal , ,,1 Og ,  ! " " " ~ ' " ,. sediments was low throughout .1990 and usually , !- -represented less than - 0.5% of ' the sediment - . . = l fractional weights. Particle size ranges and silt / clay !F p i:

content of sediments at GN and WP in 1990 were i A , l' ;

- generally similar to previous sampling years. At JC, ka \ j\ / 't'pV V ,Nl "V \"V0 , ,,, y , , particle sizes comprising beach sediments were 'l a typical of those observed over both 2 and 3 unit j-operational years. Silt / clay content of sediments m , _, , m_ , .m , _,, , m . ., co!!ceted at the JC station in 1990 was similar to - ' " " " ' " " ' " " * " ' " " ' " " " " ' " " " " that observed during other 3 unit. years (1986- .1989), but generally lower than values obsersed Mg. 2. Quanerty mean grain size (mno and sai<tay conteni - during the 2 unit period. (a or sedimenu at M M onc inienidal sianom from Comparisons of cumulative sediment curves for Sepicmber 1979 June 19% each of the monitoring stations (Fig. 3) indicated . . sigmficantly different f. rom the 2-unit years, but not the temporal stability of the sedimentary environment at GN and 'WP..versus ~ tempmal from the - 3 unit curve. Overall, sediments ! variability at JC. For both GN and WP, there d'*".ribing the entire 3 unit period (1986-90) were were no significant differences, based on t-test significantly different from those otwerved in the 2-comparisons of parameters representing the 1990 unit period. Th.is shift was due to the decreased sill / clay c ntent. along with an increased sediments and ' those representing sediments obtained in the 2-unit period (1980 85) and over - E"""""'*"I*

• 5" "

the entire 3-unit period (1986-90). In addition, sedimentary characteristics over the entire 2- und

3. unit operational periods were not significantly different. ' Al JC, sediments during 1990 were Benthic Infauna 227 l

l c t yvt+ - .vt r . _ , - , , , . . _ , ._ , _ _ _ _ _ _ _ . _ _ _ _ _ . _ _ _ __ _ _ _ . _ _ _ _ _ _ _ _ _ _ _ _ . _ . _ _ _ _ _ _ _ _ _ _ __ _ _ _ _ _ _ _ .. , - _ , rhynchocoels, which were not identified to species,

w. m e polychaetes accounted for the majority of the

"".0% < species at GN and WP,559; and 69G , rcspectisely ,( [ (Table 1). Arthropod species were abundant at JC / (530i) and GN (409). The highest number el pd g individuals was collected at JC (3,S27), of which y / oligochactes comprised 93G of the total. At GN / and WP, oligochaetes accounted for less than 20'i [S r} of the total individuals. Polychaetes anJ gf0 thynchocoels were the abundant taka at GN anJ ,t _ .. . _. . 7 - WP, together they accounted for greater than SO'; ~+' of the total number of indiviJuals collected at each  % . _ _ . station. o- - 3 The numbers of species and individuals collected tr.;'T . 6 at all intertidal sand stations during 1991 were y u - o. . e lower than those repor.ed in the 2-unit and in y prior 3. unit 3 ears. For example, the total number ., of species collected at a!! stations (3S) was below t the rance of totals reported for both Sunit (l* [, . [~ 1985) imd 3, unit (1986-19S9) peiiods (55 73) Similarly, the tolt,. nuniber (5,111) ol' indniduals  ! collected during 17M was below the range of all years (9,532 40,651) ewept 19S9 Within the major groups, there were also lower numbers 01 , _y individuals. The total number of oligochaete3 m,o / collected at JC during IVM was 3,56S, well below .q P.".Ok u ~i ~ f [ the average for 2-unit (9,099) and 3. unit (6,433) periods. Fewer polychaetes were collected in 1990 'l  ! at GN (167) and WP (455) than in the 2. and 3- !y unit p,:riods, Arthropods were the only group at ;j /g n [ l/ GN that occurred in higher numbers during 19%) than during 2-unit years and previous 3-unit years. 1, A ". .l Community Abundance a_' ., . w y._ __ The range of mean quarterly abundance (per core) at intertidal stations during 19)O was 0 23 at Mg .i Cumulame cunes tused on fracuonal weights of sedimenu concried during IWO, and during the IWu tW5 (.. GN, 28-10S at JC and 5-28 ai WP (FiS . 4). - umo and tutWo (3-unio operanonal penods ai Mat 3 tone flighest macrofaunal abundance occurred in imenid..I staanns. September at GN and WP and in March at JC; abtndance was lowest in June at GN and JC and Generni Community Composition W December at WP. (Fig. 4). From 1979 to 1990, there has been no significant trend in infaunal There were 5.01I individuals enumerated and 38 community abundance evident at any intertidal species identified at the three intertidal stations. station. Based on t test comparisons, the 1990 during 1990. The taxa present were similar to abundance at GN was significantly lower than that previous years, however, there were changes in the in 19SO,1987 and 19SS; at JC 1990 was lower than number of species within major groups and total that in 1985; at WP the 1990 average abundance community abundance. The GN community had was significantly different from those in 1982 and the most species (20) while fewer were collected at 1984. A comparison of the 3- and 2 unit average JC and WP (15). Excluding oligochaetes and abundance revealed no significant difference at GN 228 Monitoring Studies,1990 T Ant,lt 1. Numtwr of slwucs (S), numt cr of indmduah (N) and the nintnt ouan to the total indmJaah (9 ) lor t.,t h nupt lawn oihcoed at Mdhtone miettsdal stattom m lWO with nicans and uactikirmt of uruNht) isir 1 ll ut i operational scan (l'N, %n and 2 t hat oprational ) tan (1940 85) 1990 UN, w piso ss S '< N MIAN CY' M1AN (T MIAN (T Mt .\N (T t,um sa Poh cluet a ii 55 0 167 M4 17 17 ' 1104 T2 5 1% ll. 1N Ik l Ohr s hacia ll*a is 5 Fi Hs .'s ' 3t s Mi dluwa 1 50 I2 2 2s % 5 29 h 1 .I l 1 37 3 Arthro;ula 4 40 0  % 14 9 4 NI 24 on 2 s 18 1 2s .=4 l4 h) rk ha t ecla 21N 37.0 194 93 4l0 45 'l otal 20 $w 24 142 1%n 27 o ## 12 s 2005 12 . . lard m n we Polytucta 5 31\ 1 47 3s (S 14 h 15M M2 10 2100 ls 4 Ohpwhacia WM 93 2 61 H 28 3 m r ve 2to Malldw.I 2 ll3 1 <l S d.h 42 17 h 5 7. 4 170 tel I Ar thropria M 53'l M 10 12 10 9 52 14 1 15 12 4 30% 45 3 Hb)rkhmwla  ?! 14 7% 86 \1 W2 ' l'ot al 15 M27 3n 149 81M 27 1 4L 38 1 ppu t is 2 Whoe Pomt Polytuota l1 m8 4M h55 12 7. 4 64M kl l 1? 90 v21 ]79 OhpiChael3 7h It 2 97 27.1 ,W b l '2 Monuwa 1 6. 2 9 13 2 31 2 *! 475 4 25 n n inn Arthrop sia 3 18 8 4 ( l 5 177 7 16.1 3 :s n  ? 21.3 14 hym hecoeta + 149 2tA T 4t> kn 504 Ito ^! ot al 15 695 19 73 1tl7 18 o 22 11.7 17ai 14 2 'CN. = (Standard I-:f rot- Mean) s 100 or JC .At WP, however, the 3, unit average multiple regression analpes, abiotic variantes abundance was significantly lower than the 2. unit accounted for 35';-69'?; of the total variation at average abundance. intertidal stations. Analpis of covariance and t-test comparisons of menn3 indicated that there was Number of Species no significant dilrerence between the mean number of species in 1990 and that in any previous year at During 1990, the rance in number of species per W P. At GN, the 1990 mean was significantly core at intertidal statio'ns was L5 (GN),2 5 (JC) lower than that from lim 6-1987. <\t JC, mean j and 3-7 (WP; Fig. 5). Highest values occurred in number of species in 1981,1983,1985,1986,1988 hlarch at GN and WP and September at JC; lowest and 1989 were signiikantly higher than the IWO value3 were noted in March (JC), December (GN) value At WP, the number of species was and December / June at WP. From 1979 throuch significantly higher during the 2 unit operating -1990 thele was no significant trend in quarterIv period; no such operating period differences were obsersed at GN and JC, average number of species at ariy station. In Benthie Infauna 229 -. ~- - - , . . n_~._.~ n.~....---.- . - . ~ ~ - - . . _ ~ . - - _ . . . - - - gg .ewww e-wa <e6 e-- +-v.m.. gq m.,q. g . w .m_.r_- r.3.m., w w s w,=,< . -~ s.e s m E.W3 Nf 5% On44eI8kM4 . e . e . ," $- - . . us y* . . .~. .. . . , -r C *  ! 6e . . 0 . . ,, , i .' l \ j %. , f\. g' l - \ ~ . , . ...s . ,, 1., . V - .}}