ML20205S299

Marine Ecology Studies Related to Operation of Pilgrim Station Semi-Annual Rept Number 53,Jan-Dec 1998. with

ML20205S299
Person / Time
Site:	Pilgrim
Issue date:	12/31/1998
From:	Alexander J BOSTON EDISON CO.
To:	ENVIRONMENTAL PROTECTION AGENCY, MASSACHUSETTS, COMMONWEALTH OF
References
53, BECO-5.99.015, NUDOCS 9904260173
Download: ML20205S299 (220)

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?(/d Boston Edison aacctwenovcompany April 12, 1999 BECo Ltr. 5.99.015 Mass. Department of Environmental Protection Regulatory Branch - 7th Floor One Winter Street Boston, MA 02108 NPDES PERMIT MARINE ECOLOGY MONITORING REPORT

Dear Sirs:

In accordance with Part 1, Paragraphs A.8.b & e, and Attachment A, Paragraph 1.F. of the Pilgrim Nuclear Power Station NPDES Permit No. MA0003557 (federal) and No. 359 (state),

Semi-Annual Marine Ecology Report No. 53 is submitted. This covers the period from J nuary through December,1998.

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Attachment:

Semi-Annual Marine Ecology Report No. 53 Pilgrim Nuclear Power Station, Rocky Hill Road, Plymouth, Massachusetts 02360 99042%173 981231 PDR ADOCK 05000293 R PDR J

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f' n LQjf9 a3areBoston cuenov coupAwy Edison April 12, 1999 BECo Ltr. 5.99.015 Planning and Administration (SPA)

U. S. Environmental Protection Agency P.O. Box 8127 Boston, MA 02114-8127 NPDES PERMIT MARINE ECOLOGY MONITORING REPORT l

Dear Sirs:

In accordance with Part 1 Paragraphs A.8.b & e, and Attachment A, Paragraph 1.F, of the Pilgrim Nuclear Power Station NPDES Permit No. MA0003557 (federal) and No. 359 (state), Semi-Annual Marine Ecology Report No. 53 is submitted. This covers the period from January through December,1998, d i i

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Semi-Annual Marine Ecology Report No. 53 Pilgrim Nuclear Power Station, Rocky Hill Road, Plymouth, Massachusetts 02360 f

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1 I 1 I MARINE ECOLOGY STUDIES RELATED TO OPERATION OF PILGRIM STATION I SEMI-ANNUAL REPORT NO. 53 REPORT PERIOD: JANUARY 1998 THROUGH DECEMBER 1998 DATE OF ISSUE: APRIL 30,1999 I l E

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TABLE OF CONTENTS SECTION I

SUMMARY

ll INTRODUCTION lil MARINE BIOTA STUDIES lilA Marine Fisheries Monitorino and impact Annual Report on Assessment and Mitigation of impact of the Pilgrim Nuclear Power Station on Finfish Populations in Western Cape Cod Bay, January - December 1998 (Mass. Dept. of Fisheries, Wildlife and Environmental Law Enforcement; Division of Marine Fisheries) lilB Benthic Monitorino and Imonet Benthic Algal Monitoring at the Pilgrim Nuclear Power Station (Qualitative Transect Surveys), January - December 1998 (ENSR Consulting and Engineering) lilC Entrainment Monitorino and impact Ichthyoplankton Entrainment Monitoring at Pilgrim Nuclear Power Station, January -

December 1998 (Monitoring) - (Marine Research, Inc.)

lllD Imoinoement Monitorino and imoact Impingement of Organisms at Pilgrim Nuclear Power Station: January - December 1998. (Boston Edison Company)

IV Minutes of Meeting 90 of the Administrative-Technical Committee, Pilgrim Nuclear Power Station l

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SUMMARY

Highlights of the Environmental Surveillance and Monitoring Program results obtained over this reporting period (January -December 1998) are presented below. (Note: PNPS was operating at high power level during most of January - December 1998).

Marine Fisheries Monitorino:

1. In the April - August / November 1998 shorefront sportfish survey at Pilgrim Station there were 1,877 angler visits and 1,553 fishes recorded for a catch rate of 0.83. Striped bass (72.3%) and bluefish (27.2%) dominated the sportfish catch. The presence of a strong thermal discharge component attracted fish during most of 1990 - 1998 which resulted in good sportfishery success compared with outage and low power years.

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2. During late August - December 1998 fish observational dive surveys, fish species were observed in the thermal effluent area. Striped bass and tautog were the most numerous fishes seen, being abundant in the Pilgrim discharge current. Striped bass observations peaked in early September while tautog were consistent throughout the summer into early November. Data from the dive and sportfish surveys reveal that certain species are attracted to either the elevated water temperatures (spring and fall) or current. This places them at risk of impact from temperature aberrations, chemical releases, and potential gas

[ bubble disease mortalities. As such, some form of direct visual monitoring is useful.

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3. Winter flounder tagging in tne Plymouth Bay vicinity to estimate adult population size and Pilgrim Station inipact has accounted Mr 22,470 fish with 896 (4.0%)

tag returns from 1993-1998, resulting in pool population estimation precision.

The 1998 population estimate based on an Area Swept Method (trawling) for the Plymouth Bay area was 264,812 adult winter flounder (age 3+). This equates to I roughly a 29% adult population impact from PNPS entrainment of 88,800,000 flounder larvae (77,428 equivalent adults) although area - swept estimate variability is high. Continuation of this study may not yield a more accurate or precise estimate of population size. More years of study to define the impact of Pi! grim Station on this species may not provide a definitive answer. Il i 1

4. Rainbow smelt egg restocking of the Jones River (Kingston) to mitigate the high PNPS smelt impingements in December 1993 (5,100 fish) /1994 (5,300 fish) accounted for 1,800,000 fertilized eggs being transplanted in 1994/1995. Once hatched, these eggs supplemented those produced by the river's spawning population of this species. Smelt impingement has the potential of impacting the local smelt population and was further mitigated in 1996/1997/1998 by improving the smelt spawning habitat in the Jones River to enhance egg survival, through the use of several dozen specially designed egg collecting trays. Future Jones l River and other local smelt spawning habitat enhancements will also consider improving water quality.

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Imoinnement Monitorina:

1. Th3 mean January - December 1998 impingement collection rate was-1.30 fish /hr. The rate ranged from 0.09 fish /hr (July) to 5.22 fish /hr (March) with Atlantic silverside comprising 51.6% of the catch, followed by winter flounder 13.1%, Atlantic menhaden 8.7% and rainbow smelt 6.8%. Fish impingement rates in 1989 - 1998 were several times higher than in 1984,1987 and 1988 when Pilgrim Station outages had both circulating water pumps off and reduced pumping capacity for long periods of time.

2. The March / April 1998 Atlantic silverside impingement accounted for 89% of this species' annual collection.

3. The mean January - December 1998 invertebrate collection raie was 1.11+/hr with blue mussel and sevenspine bay shrimp dominating. Longfin squid and green crabs accounted for 15% of the catch. Twenty-four American lobsters were sampled. The invertebrate impingement rates in 1989 - 1998 were similar to those recorded at Pilgrim Station during the 1987 and 1988 outage years, despite much lower circulating water pump availability in these outage years.

4. Impinged fish initial survival in the Pilgrim Station intake sluiceway was approximately 32% during stctic screen washes and 51% during continuous washes. Four of the dominant species showed greater than 50% survival overall.

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I Benthic Monitorina Three observations of the discharge, near-shore acute impact zones were performed during this reporting period. Denuded, sparse, and stunted zone boundaries were indistinguishable during September 1987 - June 1989 discharge surveys as a result of the PNPS extended shutdown. However, these surveys did note impact zone boundaries in fall 1989 - 1998 primarily because two circulating water pumps were in operation moct of the time resulting in maximum discharge current flow. The scouring impact area in 1998 varied from 1,437 m2 (March) to 2,469 m2 (October). Except for October, the 1998 denuded and total affected zones were fairly typical seasonally, despite heavy mussel settlement and high PNPS operating capacity.

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Entrainn ent Monitorina:

1.

A total of 40 species of fish eggs and/or larvae were found in the January -

December 1998 entrainment collections: 18 eggs, 40 larvae.

2. Seasonal egg collections for 1998 were dominated by yellowtail flounder, fourbeard rockling, American plaice and Atlantic cod (winter - early spring);

Atlantic mackerel and Isbrids (late spring - early summer); rockling/ hake, windowpane and labrids (late summer - autumn).

I 3. Seasonal larvae collections for 1998 were dominated by sculpin, rock gunnel and sand lance (winter - early spring); winter flounder, Atlantic mackerel and cunner (late spring - early summer); hake, rockling and cunner (late summer - autumn).

4. No lobster larvae were collected in the entrainment samples for 1998.

5. In 1998, an estimated 5.124 x 10' fish eggs and 8.821 x 108 fish larvae were entrained at Pilgrim Station, assuming full flow capacity of all seawater pumps.

On an annual basis, eggs were dominated b/ the labrid-Pleuronectes group and Atlantic mackerel, and larvae by winter flounder and cunner.

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6. On several occasions in 1998, " unusually abundant" ichthyoplankton densities were recorded including hake larvae for the most extended time period. This possibly reflects strong annual spawning production for the species involved.

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7. The mean annual losses attributable to PNPS entrainment for the adult stage of I

three abundant species of fish for 1998 were as follows: cunner 1,522,731; Atlantic mackerel 1, 082; winter flounder 5,473-77,428. None of these losses for cunner or Atlantic mackerel were found to be significant in the context of preliminary population or fishery effects, respectively. Comprehensive population impact studies are presently being conducted for winter flounder in the Pilgrim area.

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INTRODUCTION

8 l A. Scope and Obiective This is the fifty-third semi-annual report on the status and results of the Environmental Surveillance and Monitoring Program related to the operation of Pilgrim Nuclear Power Station (PNPS). The monitoring programs discussed in this report relate specifically to the Cape Cod l

Bay ecosystem with particular emphasit an the Rocky Point area. This is the fortieth semi-

,I annual report in accordance with the environmental monitoring and reporting requirements of

I the PNPS Unit 1 NPDES Permit from the U.S. Environmental Protection Agency (#MA0003557) and Massachusetts Department of Environmental Protection (#359). A multi-year (1969-1977) report incorporating marine fisheries, benthic. plankton /entrainment and impingement studies was submitted to the NRC in July 1978, as required by the PNPS Appendix B Tech. Specs.

Programs in these areas have continued under tra PNPS NPDES Permit. Amendment #67 l (1983) to the PNPS Tech. Specs. deleted Appendix B non-radiological water quality l

requirements as the NRC felt they were covered in the NPDES Permit.

The objectives of the Environmental Surveillance and Monitoring Program are to determine whether the operation of the PNPS results in measurable effects on the marine ecology and to evaluate the significance of any observed effects. If an effect of significance is detected, Boston Edison Company has committed to take steps to correct or mitigate any adverse

,I situation.

These studies are guided by the Pilgrim Administrative-Technical Committee (PATC), which was chaired by a member of the Mass. Department of Environmental Protection in 1998, and l whose membership includes representatives from the University of Massachusetts, the Mass.

Department of Environmental Protection, the Mass. Division of Marine Fisheries, the National Marine Fisheries Service (NOAA), the Mass. Office of Coastal Zone Management, the U.S.

Environmental Protection Agency, and Boston Edison Company. Copies of the minutes of the Pilgrim Station Administrative-Technical Committee meetings held during this reporting period are included in Section IV.

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B. Marine Biota Studie.s

1. Marine Fisheries Monitorina Marine Fisheries studies in 1998 focused on winter flounder population parameters to develop an understanding of PNPS impact on this indicator species. Population estimates and adult equivalency analyses were conducted on this key species to help assess the impact of PNPS larval entrainment. Winter flounder were studied by techniques including trawling and tagging. Cunner population impact efforts fere terminated in 1998 and rainbow smelt spawning enhancement continued on the Jones River (Kingston).

Finfish observational dive surveys were performed in 1998 for the Pilgrim Station thermal plume area. This monitoring involves periodic diving from May through October to document fish behavior and condition at various locations in the discharge area, and two discharge dives in late December to record any heated water, overwintering fishes.

Results of the marine fisheries monitoring during the reporting period are presented in Section Illa.

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2. Benthic Monitorina The benthic monitoring described in this report was conducted by ENSR Consulting and Engineering, Woods Hole, Massachusetts.

Qualitative transect sampling off the discharge canal to determine the extent of the denuded and stunted at;al zones was continued three times in 1998 (March, June, and September).

Results of the benthic monitoring and impact analysis during this period are discussed in Section 1118.

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3. Plankton hionitorina Marine Research, Inc. (MRI) of Falmouth, Massachusetts, has been monitoring entrainment in Pilgrim Station cooling water for fish eggs and larvae, and lobster larvae (from 1973-1975 phytcplankton and zooplankton were also studied). Information generated through this monitoring has been utilized to make periodic modifications in the sampling program to more efficiently address the question of the effects of entrainment.

These modifications have been developed by the contractor, and reviewed and approved by the PATC on the basis of the propram results. Plankton monitoring in 1998 emphasized consideration of ichthyoplankton entrainment and selected species adult equivalency analyses. Results of the ichthyoplankton entrainment monitoring and impact analysis for this reporting period are discussed in Section IllC.

4. Imoinaement Monitorina The Pilgrim Station impingement monitoring and survival program speciates, quantifies, and determines viability of the organisms carried onto the four intake traveling screens.

Marine Research, Inc. has been conducting impingement sampling with results being reported on by Boston Edison Company in 1998.

A new screen wash sluiceway system was installed at Pilgiim in 1979. This new sluiceway system was required by the U.S. Environmental Protection Agency and the Mass. Divisbn of Water Pollution Control as a part of NPDES Permit #MA0003557.

Special fish survival studies conducted from 1980-1983 to determine its effectiveness in protecting marine life were tsrinisted in 1984, and a final report on them appears in Marine Ecology Semi-Annua! Repc;t #23.

Results of the impingement monitoring and survival program, as well as impact analysis, for this reporting period are discussed in Section lilD.

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T Ij l C. Station Operation History PNPS was in a high operating stage during most of this reporting period with a 1998 I capacity factor (MDC) of 97.1%. Cumulative capacity factor from 1973-1998 is 56.0 %.

Capacity factors for the past 15 years a.a summarized in Table 1.

D. 1999 Environmental Proarams II A planning schedule bar chart for 1999 environmental monitoring programs related to the I operation of Pilgrim Station, shov.ing task activities and milestones from December 1998

- June 2000, is included after Table 1.

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I ANNUAL REPORT ON ASSESSMENT AND MITIGATION OF IMPACT OF THE PILGRIM NUCLEAR POWER STATION ON FINFISH POPULATIONS IN WESTERN CAPE COD BAY I Project Report No. 66 (January to December 1998)

I I By Robert Lawton, Brian Kelly, John Boardman, and Vincent Malkoski I

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I April 1999 I Massachusetts Department of Fisheries, Wildlife, and Environmental Law Enforcement Division of Marine Fisheries I 100 Cambridge Street Boston, Massachusetts 02202 I

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TABLE OF CONTENTS i I. EXECUTIVE

SUMMARY

j II. INTRODUCTION 5 III. METHODS AND MATERIALS 7 IV. RESULTS AND DISCUSSION I2 A. Physical Factors 12

1. Power Output-Thermal Capacity 12 1 2. Pump Operations 12 B. Finfish Species ofImportance 14

1. Rainbow Smelt 34

a. Background 14

b. Eggs and Larvae 14

c. Juveniles 15

d. Adults 15

2. Winter Flounder 16

a. Background 16

b. Eggs and Larvae 39

c. Juveniles 20

d. Adults 20

e. Movements, Migration and Fidelity 21

( 3. Other Species 32

4. Impact Perspective 36 V. CONCLUSIONS 41 ii r'

I m m i VI. ACKNOWLEDGEMENTS 44 VII. LITERATURE CITED 45 Il I

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LIST OF TABLES

l. Important indicator species ofTthe Pilgrim Nuclear Powcr Staten. 6

{

2. ' Summary of winter flounder mark / recapture data from western Cape 25 Cod Bayin the 1990s.

{

3. Tag returns by area for winter flounder (at large at least one month) recovered 26 dunng the non-spawning period (June-February) from 1993-1997 and (June-December) of 1998. Fish were marked in Areas 1-3.

4. Tag returns by area for winter flounder (at large at least one month) obtained 28 during the spring spawning season (March-May) from 1993-1998 of fish tagged in Areas 1-3.

5. Estimated abundance (post-stratified by depth) in numbers of winter flounder 29 (bottom area calculated at MLW), with 95% confuience limits, of winter flounder 2 280 mm (TL) and for pooled lengths estimated by otter trawl density extrapolations (adjusted for gear elTiciency) in the Pilgrim study area, spring 1998.

6. Mark-recapture model estimates, with 95% confuience limits, of absolute 31 abundance of winter flounder a 280 mm TL in the Pilgrim study area, spnng 1998.

7. Recreational bluefish catches reported by creel survey over three decades 36 at the Pilgrim Station Shorefront in relation to plant operation .

8. A summary of mechamcal impacts of Pilgrim Nuclear Power 37 Station on selected fmfish species and mitigation undertaken in the offsite waters of western Cape Cod Bay, iv i

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I LIST OF FIGURES Figure Eage

1. PNPS investigative area for rainbow smelt and winter floander, 7 January-December,1998.

2. A sphagnum moss filkx! collecting unit of the type used to collect 8 and incubate srnelt eggs (smelt shown above) in the Jones River.

3. Winter flounder with Petersen disc tag attached (tag not to scale). 9

4. Annual means and 26-year cumulative Mean Capacity Factor 12 (MDC Net %) for Pilgrim Nuclear Power Station,1973 through 1998.

5. Operational history of the two circulating seawater pumps at 13 i Pilgrim Station by month for the years,1983 through 1998.

6. Smelt egg densities within Zones A & B of the Jones River 14 habitat enhancement area,1998.

7. Division of Marine Fisheries winter flounder tagging area. 23

8. Recapture zones of winter flounder (Pseudopleuronectes americanus) 24 tagged in areas 1-3 by the MA Division of Marine Fisheries in the decade of the 1990's.

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I. EXECUTIVE

SUMMARY

The following are the 1998 highlights of study findings for selected species. Additional information can be found in the Conclusions section of this report.

Rainbow Smelt G

Rainbow smelt (Osmerus mordax) impingements of different magnitudes have occurred at Pilgrim Nuclear Power Station over the years of station operation. The smelt is considered an "important representative species" due to its abundance and recreational importance in the Plymouth, Kingston, Duxbury Bay (PKDB) area. Boston Edison Co. has funded the Massachusetts Division of Marine Fisheries (MDMF)in our remediation efforts to compensate for these impingement mortalities. Our overall goal has been to increase the number of adult smelt in the local population and thus ofTset power plant impact. ElTorts have included augmenting natural egg production and enhancing spawning habitat to optimize egg hatchout.

4 During the springs of 1994 and 1995, smelt eggs were obtained from two genetically isolated, wild, I anadromous Massachusetts populations: one from the Weweantic River, Wareham and the other from Back River, Weymouth and transpl cted into the Jones Ris er, a tributary to PKDB. Eggs were collected using our portable sphagnum moss-filled incubation trays, which provide ideal habitat for egg development and survival. We stocked ca.1.8 million smelt eggs into the Jones River. Larvae were expected to imprint on the waters of PKDB and return to the Jones River and its other tributaries to spawn when sexually mature. The stocking portion ofour project has been discontinued due to reduced egg production in our two " source" streams, with no other accessible supply of eggs to be found.

9 To address spawning habitat enhancement, we again used our egg collecting trays. Each spawning l season from 1994 to 1998, a number of trays were placed in the Jones River on the smelt spawning grounds, where spawning activity has consistently been greatest in past years. The trays were croplaced j in 1he memf_ _l, s,_1, __e ae _ ,_e ., egg hae, _ _plete.

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Unwanted fouling material was regularly removed from the trays to improve water circulation over the eggs.

04 We feel that improving water quality in the Jones River and other tributaries to PKDB is an important goal for the future. The MDMF will continue to place trays into the river during the smelt spawning period to continue husbandry practices. We also will monitor spawning activity and egg production densities, while conducting periodic checks to make sure the river is free of obstacles, such as fallen trees, that could hinder fish passage.

Winter Flounder S The PKDB and surrounding coastal waters are important spawning areas for winter flounder I

(Pseudopleumnectes americanus). In the PNPS study area, winter flounder exhibit fairly high fidelity to natal spawning grounds In general, they also undenake local seasonal movements which appear to l be temperature driven.

O in 1998, an estimated 88.8 million winter flounder larvae were entrained at PNPS, which equates to an ultimate equivalent loss of 77,428 adults from the local population. This is by far the highest flounder larval entramment recordea at the plant. Entramment was markedly up from last year, when 55.4 million 1

flounder larvae were entrained which equated to the equivalent loss of 47,087 adult flounder.

9 An estimated 1,493 winter flounder - mostly age 0 and age 1 - were impinged at PNPS in 1998.

e Only seven winter flounder reponedly were caught by anglers at the PNPS Shorefront in 1998. I 9 In 1998, we tagged 7,494 winter flounder with Petersen disc tags (light green in color), bringing the study total to 22,476 marked fish. As of the end of 1998,896 of the flounder tagged had been recaptured for a recapture rate of 4.0%. Tag returns by area for winter flounder recovered during the non-spawning period (June-February) from 1993-1997 and (June-December) of 1998 suggest that a I!

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large proportion of the flounder do not move far afield from the overall tagging area (Areas 1-3) after the spawning season (March-May). Tag returns by area recovered during the spawning period from 1993 1998 were primarily from Area 2 (72%). Our tag data reveal that most movements of winter flounder in the Plymouth area are restricted to relatively short distances, and there appears to be a fairly l

high fidelity in the local population.

I 9 Dmsity extrapolation, using the Area / Density Method, provides an estimate of the adult winter flounder population size (absolute abundance) for the study area of fish 2 280 mm total length (TL), i.e., age 3 and older adults,.which was 264,812 for 1998. This is substantially less than 1997, when adults in the study area were estimated at 321,831. The data suggest that total annual nortality was high.

O Population estunates of wint.:r flounder ibr the study area (fish 2 280 mm TL), obtained from a number of mark-recapture models, were considerably lower, being in the 100,00 range.

04 The recapture rate of tagg:d flounder is low, which affects the predictive value of mark / recapture population model estimators for abundance, while the variability in area-swept estimates is somewhat problematic. The equivalent adult loss because of entramment mortality in 1998 is estimated to represent approximately 29% of the number of adults in the local population, estimated by Area / Density methodology.

Other Soecies L

G Adantic silverside (Men /dia menidia) is typically impinged annually in high numbers (several thousand individuals), but no compensatory action has been taken because the species is short-lived and prolific.

( 6 Alewife (Alosapseudoharengus) impingement should continue to be monitored, as a large impingement incident of 13,100 juvenile alewives did occur in 1995.

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i e Striped bass (Morone scratilis), bluefish (Pomatomus saltatnx), winter flounder , and tautog (Tautoga onttis) were the species reported in the recreational catch at the PNPS Shorefront in 1998.

l e Striped bass and tautog dominated the SCUBA finfish sightings off PNPS, with small aggregations of cunner (Tautogalabrus adspersus) also obsen ed.

09 Data from the sportfish and underwater visual surveys reveal that some finfish species are attracted to l the thermal discharge at PNPS. This places them at risk from temperature aberrations, chemical releases, and potential gas bubble disease problems. As such, direct visual monitoring in the discharge area is helpful.

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II. INTRODUCTION The Massachusetts Division of Marine Fisheries (MDMF) power plant team has conducted field mvestigations to assess environmental efTects ofthe operation of Pilgrim Nuclear Power Station (PNPS). In some mstances, mitigative or remedial measures have been instituted to ofTset adverse impacts. This work was funded by Boston Edison Company (BECo) under Purchase Order No. LSP009438 in 1998.

In 1998, we focused on winter flounda (Pseudopleuronectes americanus) and rainbow smelt (Osmerus mordar), employing a suite of gear types, equipment, and techniques to sampic and, when appropriate, to undertake restorative measures. Descriptive statistics are summarized in tables or displayed in figures., and statistical procedures also are used.

From extensive field studies oft PNPS, it is evident that mechanical aspects of this station's operations, i.e., entrainment of fish eggs and larvae, and to a lesser extent, impingement ofjuvenile and adult fish, pose greater environmental threats than does the release of waste heat into the receiving waters.

The two finfish species ofparticular concem at present in the PNPS area are winter flounder and rainbow smelt (Table 1). The PNPS area serves as winter flounder spawning, nursery, and feeding grounds. This flatfish is a highly valued commacial and recreational species. Winter flounder lan ae have been entrained in relatively high numbers. Rambow smelt is valued as a recreational species in the nearby Plyniouth, Kingston, Duxbury Bay (PKDB) estuary Several incidents of relatively high smelt impingement have occurred at PNPS over the years.

Our objectives in 1998 were: (1) for winter flounder, to determine discreteness of the local population and estimate absolute abundance of the adult segment of the population; and (2) for rainbow smelt, to enhance the quality of spawning habitat in the nearby Jones River, a tributary to PKDB, where most of the local smelt population originates, by collecting their eggs on ideal substrate to improve survival.

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l Table 1. Important indicator species ofTthe Pilgrim Nuclear Power Station.'

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• Background Most Significant Source of fmpact Species as an Indicator Sources l Species ofImpact (Based on Results to Date) 3 Rainbow Sru,.

g r, s I,T/C Impingement - large incidents in December of'78,

'93,'94 Winter Flounder d, r, e, s I, E, T/C Entrainment - large number oflarvae collected (April-g May)

RIS- representative important species selected in the ongmal 316 (a and b) Demonstration Document and Supplement to assess Pilgnm Station impact (Stone and Webster 1975 and 1977).

d a dominant species in the Pilgrim area.

r-a local esident c-commercialimportance s- recreationalimportance

!-impingement E -entrainment T/C - discharge current effects: thermal'eurrent l

B

' Note: Indicator species selection rationale: these two species were selected because they have shown the most potential for impact otr Pilgrim Station and may be indicative of power plant induced stresses to other marine fish species.

This annual report includes a description of sampling design and methodology, together with findings, conclusions, and any recommendations. Progress achieved in asses.anent surveys and ongoing restorative projects was highlighted for these indicator species in the PNPS area.

In 1999, our efforts will again focus on winter flounder and rainbow smelt.

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III. METHODS AND MATERIALS The study area for 1998 is bounded in Figure 1.

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~ 5:V0 Figure 1. PNPS investigative area for rainbov smelt and winter flounder, January-December,1998. Depth strata are shaded difTerently.

I Rainbow Smelt i Eces and Imvae. We allowed rainbow smelt to spawn naturally over egg collecting units placed in the Jones River. Each collection unit (35.6 x 45.7 cm) was a weighted wooden frame, enclosed with chicken wire,

( and filled with unprocessed sphagnum moss which served as substrate for egg deposition (Figure 2). We deployed the egg trays into selected rifile areas of the upper Jones River smelt spawning ground. We inspected, seniced, and monitored these units every few days for egg deposition, developmen', and sunival. Fouling 7

I macro-algae were removed and discarded downstream of the spawning area. We endeavored to minimize egg disturbance and mortality on the river bed and on our trays during this process.

Following egg hatchout, larvae are carried downstream and into the waters of PKDB as they develop. When adults, they should home back to this estuary, ascending the Jones River and possibly other tributaries in this complex to spawn.

Juveniles. Three unusually large rainbow smelt impingement incidents have occurred at PNPS, in December, of 1978, '93, and '94. The majority of smelt ,

impinged were age-0 fish (juveniles). Impingement sampling data are collected by Marine Research, Inc. (see gig i i g i g M\\ \ \\ \1 Impingement section, this report).

Adullt Adult rainbow smelt (Figure 2) also are sm.a rag Tr.y impinged at PNPS (see impingement section) Figure 2. A sphagnum moss filled collecting unit of the type used to collect and incubate smelt eggs (smelt shown above)in the Jones River.

Winter Floun_dn Ecas and larvae. Data on these two life stages (primarily lan ae) are collected by Marine Research, Inc.

in their entramment sampling program at PNPS (see Entrainment section, this report).

Jm enilg. Juvenile wmter flounder are impinged at PNPS, with monitoring data also collected by Marine Research, Inc. (see Impingement section, this report).

Adults. Our objectives have been to detemune the discreteness (fidelity) of the local winter flounder population and to estimate absolute abundance. This information is being used to assess impact of flounder entrainment and impingement at PNPS.

During the winter flounder spawning season north of Cape Cod (March-May), some flounder may move in and/or out of PKDB (Figure 1), with evidence ofspawning both inside and outside this estuary. Flounder may I

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I agg egate in pre-spawning staging areas out in deeper water, with some moving into the estuary at night on a l

l flood tide to spawn in the shallows.

l We contracted two cuimscial fishing vessels in 1998 to sample winter flounder: one, the FN Frances Elizabeth, for tagging and recapture purposes, and the other, the FN Alosa, to estimate flounder density and to sample outside the tagging area for tag recaptures. The tagging study area was the same as last year and included the watas fnxn Humarock, Marshfield southeastward to the Mary Ann buoy, Manomet, from nearshore  !

(9.2 m MLW) out to the 36.6 m (MLW) depth contour (Figure 1).

Trawl gear on the FN Frances Elizabeth was unchanged I from 1997, namely, a Yankee otter trawl (21.9-m sweep and 15.8-m QM N- .. ,

headrope, which had a 15.2-cm stretch mesh and a 7.6-cm mesh e 7+r{,p ,N liner); it was fished with 12.8-m legs and 78.6-m ground cables. The (, _(

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trawl doors (#5 Bison doors) were of steel (1.5 m x 0.9 m and 181 kg -- a cach). Warp length varied with depth of water fished, ranging from 1;"F Q "5 f;W-C_

I EE 73.8 to 92.3 m. Measurements made while fishing indicated that the  % ,p,4 I door and net spread were approximately the same as in 1997. Trawl gy ~-

Figure 3. Winter flounder with Petersen disc tag gear on the FN Alosa consisted of a Yankee otter trawl (18.3-m attached (tag not to scale).

sweep and 12.2-m headrope, which had a 15.2-cm stretch mesh .nd a 4.5-cm mesh lincr); it was fished with 12.8-m legs and 73.2-m ground cables. The trawl doors (#63 Thiboron doors) were of steel (1.5 m x 0.9 m and 181 kg each).

I Winter flounder were enumerated, measured (TL), sexed, and assessed for maturity and reproductive state before being released near capture sites. In addition, aboard the FN Frances Elizabeth, flounder 2 280 mm TL were marked with green Petersen disc tags (Figure 3). Within the tagging area, fish have been marked at locations selected on the basis ofknown local flounder crimeadons (staging areas) primarily during the spring l

flounder spawning season (March-May) from 1993-1998. Data also were collected on net geometry and the trawl t

I '

I

I distance of each tow. Tow duration and distance on each boat averaged 30 minutes and 1.2 km, respectively.

s We generated independent estimates of population size via mark and recapture and by an a ca-swept approach (density extrapolation).

We estimated winter flounder population size (instantaneous absolute abundance) for 1998 using an arca/dcasity approach, based on density extrapolation over the total study area from five days of trawl area-swept sampling aboard the FN Alosa within the tagging area. As trawl gear efficiency in our sampling was unknown, we assumed it to be 50%. To estimate density, the number of winter flounder by tow (data transformed via in(x+1)) was divided by the area of bottom covered. Tow length was determined, and tow width was estimated from the trawl doors' spread on the bottom. Door spread is used as a measure of width because of the " herding" action caused by the sediment cloud generated by the doors and legs while towing. Catch per unit area was calculated for individual tows. The estimates computed for adult winter flounden (> 280 mm TL) and for all si7cs 2

pooled were doubled to reflect the assumed catch cfTiciency. Density estimates (number per m ) were multiplied by the total bottom acreage in the study area to obtain estimates of absolute abundance. Bottom area was determined using a dot grid and navigational charts. Acreage was converted to square meters.

We also estimated numbers of winter flounder >280 mm TL using several mark-recapture models

, utilizing sampling data collected aboard the FN Frances Elizabeth:

1 Closed population models -

single episode of tagging and one of recapturing = Petersen method; multiple markings = Schnabel method, Schumacher and Eschmeyer method, Mark method, and Open population model-multiple census = Jolly-Seber method.

For modeling estimates of absolute population abundance in 1998, except for the Pe%rsen method, we used our 1998 green tag recovery data for winter flounder at large 22 days and recaptured during our tagging period (30 March to 5 May 1998) for a total of 24 sampling days. For the Petersen method, we grouped the green tag ra:apture data into two periods for analysis - the first 24 sampling days (i.e., the tagging period) versus the last 3 sampling events (6 May to 8 May).

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( _ _ _ _ _ _ _ _ - _ _ _ - _ - -

I Other Fish Species Eces and Larvae. Egg and larval information for other finfish species entrained at Pilgrim Station were obtained by Marine Research, Inc. (see Entrainment section, this report).

Juveniles. We also collected data onjuveniles of several finfish species using SCUBA diving and fish potting. Impingement data were obtained from Marine Research, Inc. and BECo.

Adults (Same as forjuveniles) l I

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I I IV. RESULTS AND DISCUSSION I

A. PIIYSICAL FACf0RS

1. Power Outout-Thermal Canacity I Pilgrim Nuclear Power Station's capacity factor (MDC net percent) is an index of operational status that approximates thermal loading into the nearshore receiving waters of western Cape Cod Bay. This factor is relevant when assessing long-term thermal impact on marine organisms. By permit regulation, PNPS is allowed I a maximum discharge tranperature of 38.9 C and an effluent A T of 18 C above ambient. For the 26-year history ofplant operadons, the long-tenn mean MDC at PNPS is 56.0%, with annual averages ranging from 0.0%

(outage yers) to 97.1% in 1998 (Figure 4). The 1998 power output was an all time high for PNPS; for most months, the plant operated near 100%

capacity. Annual thermal capacity tur i cecon m 1H increased nearly 24.0% from 1997.

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"""""""" " """""" """".133e)YEAR (1373 kl/m: * <> (155,000 gals / min)] DM M EMS withdraw water from an artificially Figure 4. Annual means and 26-year cumuladve Mean Capacity Factor (MDC Net %) for Pilgrim Nuclear Power Station,1973 through 1998.

created intake embayment that is bounded by breakwaters and rip-rap. Ihe cooling water cimulates through the plant condenser tubes before being discharged back into the waters of westm Cape Cod Bay with waste heat. At ebb tide, cfluent velocities can exceed 2.1 m/sec (7 fVsec) at the egress of the discharge canal. This I

12 I

results in scouring of the benthos and concomitant erosion of substrate along the bottom path of the discharge plume.

Throughout the operational history of PNPS, there have been station outages, when one or both circulating seawata pumps were not operated (Figure 5). Such periods have occurred aperiodically and generally have ba:n short-lived; however, extensive outages occurred in 1984 and from 1986-1988 (see Figure 4). During 1998, both circulating pumps were continuously operated throughout the year. The high operational status at PNPS resulted in a maximum withdrawal of cooling water for the two circulating water pumps. This,in turn, greatly enhanced the potential for entrainment impact at the plant this year (1998).

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B.FINFISH SPECIES OF IMPORTANCE 1 l

1. Rainbow smelt Backcround The goal of our 1998 rainbow smelt project was to enhance the quantity of qual habitat in the Jones Riva, a tributary to PKDB. We placed 69 egg collecting trays in th area of the Jones River for the period 24 March through 20 May,1998. The trays collec I

spawned, demersal, adhesive smelt eggs, providing an ideal habitat for egg pro sphagnum moss filling the trays provides a three dunensional depositional surface a micros:nvin..icit that offers protection for the developing embryos, re&ing ' egg tumover flow through the moss, canying away metabolic wastes and providing a continuous s

• lhe rainbow smelt spawning ground in the Jones River is comprised largely of hard s sand, and cobble). Natural aquatic vegetation which provides ideal substrate for eg a small portion of the spawning ground. Sutter (1980) reported smelt egg survival t on vegetation but only 1% on hard surfaces. Trays with sphagnum have consistently c than naturalhard abiotic bottom.

[tusvton. l ag seewieest wa Eces and Larvae ,\

The 1998 rainbow smelt egg set in the ^ ~

. ?III'iiN Jones River was the best in over a decade Areas , ijlh

~ ..Idm g p n M containing more than 50 eggs per square inch were ia kkk l considered to have heavy sets, while 20 to 50 per m . .i

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square inch were considered moderate sets, and <

'w Lpigit{!itly hf N 20 eggs per square inch were light sets. The y pgg Figure 6. Smelt .gg den.ity within Zon.s A4B of e

.nt .r. 29,s.

1s. aon.. a1.,,, n.eit.t ns.nc majority of available spawning habitat m Zone A and upper third of Zone B was utilized for egg 14 I

I deposition (Figure 6). This section of the rivcr generally was covered by moderate to heavy egg sets. Egg patches ofvarying densities also could be found throughout the lower two :hirds of Zone B and even down to the Route 6A bridge. Most ofour egg collecting trays in Zone A were covered with a single layer of eggs. With no major storms occurnng, conditions in the Jones River were favorable for successful spawning. The river was free of obstructions, and a good flow existed wd.h many riffle areas observed, which dispersed the eggs and prevented their aggregation in one area. The long idementous macro-algae, which likely reduce water flow to the developing eggs and have been a problem in years past, were not prevalent this year.

J venneg For the last six years (1993-1998), rainbow smelt Impingement at PNPS was estimated to total 25,697 fish. A representative sample ofimpinged fish was measured each year. Afler comparing lengths of these fish to the mean length at age for smelt from an earlier study of ours in the Jones River, we determined that the majority ofimpinged fish werejuveniles (ages 0+ and 1+ fish). Since smelt spawning runs in the Jones River generally have been depressed for many years, with the exception of 1998, these impingement incidents likely impacted population growth.

Adults A large aggregation of adult rainbow smelt was observed in the Jones River during two of our daytime trips to the river (14 and 17 April 1998). The fish were congregated in a pool in Zone A (Figure 6). Based on past observations, this is indicative of a relatively strong spawning run. These fish were likely males, with females moving onto the spawning ground during the nighttime hours (Lawton et al. 1990).

I During the 1998 spawning season, Eel River, Town Brook, and Smelt Brook (other tributaries in the PKDB complex) were in3vered weekly for egg deposition. We sampled areas of known spawning activity based I on past observations. Town Brook and Smelt Brook contained small patches oflight :gg sets. We did not find any eggs in Eel River for the second consecutive year. The majority of smelt spawning activity for the local PKDB smelt population again occurred in the Jones River.

I 15 x

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2. Winter Flounder Backcround Winter flounder range the northwest Atlantic from the Gulfof St. Lawrence to Chesapeake Bay (Bigelow and Schroeder 1953), being found in water temperatures between 0 and 27"C and salinities from 4 to 30 . They can form discrete, resident populations which undertake localized seasonal movements (Perlmutter 1947; Saila 1961; Howe and Coates 1975). Flounder movement and migration are apparently temperature driven (Pearcy I

1%2; McCrackm 1%3; Scarlett 1988; Powell, R.I. DEM, unpublished data). Some adults emigrate from shoal waters when water temperatures rise above 15 C and return as waters cool below this level. Other groups of winter flounder are resident, and, although an avoidance temperature of 24.4 C was reported by Meldrim and Gift (1971), their year-round occurrence has been documented in some estuaries (Olla et al.1969; Wilk et al.

1977) at water temperatures around 24 C. In addition, Phelan (1992) found adult winter flounder throughout the year in an ofTshore area of New York and New Jersey.

Based on a meristics' study, Pierce and Howe (1977) concluded that estuarine groups of winter flounder da not necessanly constitute separate genetic, biological units. A group may be comprised of an assemblage of adjacent estuanne spawning units that intemux, of which me may be more geographically isolated than others.

Homing patterns have been documented to some estuaries (NUSCO 1986; Black et al.1988; Scarlett 1988; 1

Phelan 1992; Powell, RIDEM unpublished data), and several tagging studies (Lobell 1939; Perlmutter 1947; I Saila 1%1; Howe and Coates 1975) have provided evidmce of high fidelity to specific embayments for spawning following offshore migrations in consecutive years. At the same time, rme winter flounder disperse to distant locations (Saila 1961; McCracken 1963; Howe and Coates 1975; Phelan 1992), and there may be a random I i l

search back for the natal spawning grounds (Saila 1961), following random food searches (McCracken 1963).

Phelan (1992) speculated that populations may be discrete only during the spawning period, with random temperature-related seasonal movements resulting in an intermix at other times of the year. If the search for natal spawning grounds has a randcen component to it, then some winter flounder may be found in non-natal locations 16 I

(

during the spawning season. From mark and recapture work in the inner New York Bight, Faelan (1992) purported that winter flounder there formed a dynamie assemblage, consisting of three reproductively discrete spawning sub-populctions: one that " homes" to na:al spawning grounds in the Navesink and Shrewsbury Rivers, a second consisting of an aggregation of generally sedentary fish found in Sandy Hook and Raritan Bays, and a third group found offshore, with all three capable ofinterm'xing.

In Maunchusetts, Lux et al. (1970), Howe and Coates (1975), and Pierce and Howe (1977) concluded from meristic and tagging work that, for management purposes, winter flounder consist of three stocis - one north of Cape Cod, another south and east of Cape Cod, and the third on Georges Bank. A comprehensive winter flounder mark and recapture program (more than 12,000 fish tagged at 21 locations) was conducted in Massachusetts during the 1960s by Howe and Coates (1975), who found that flounder migration generally encompassed relatively short distances; although, eensive movements of some tagged fish did occur. Flcunder dispersal, overall, was greater south of Cape Cod, where many areas are shoal (<l 8.3 m) with waters warming considerably during the summer Retums from release sites north of Cape Cod revealed that movement generally was more limited, with many tagged fish recovered in respective subarca release sites, even > ears later.

Winter flounder spawn principally at night when water temperatures are at or near the lowest (0 - 5 *C) for the year, occumng during late winter and early spring. Spawning occurs in estuaries (bays, rivers, harbors)',

I over shoals outside estuanes, and on offshore banks. It usually takes place in the shallows over firm bottom, e.g.,

gravel, sand, eelgrass, ard pelagic algae. The eggs are demersal and adhesive, and those that fall onto soft, fine sediments or onto algal mats are less likely to develop. Hatching occurs in about two to three weeks at water temperatures of 3-5'C. Larval stage duration generally is 4-6 weeks, and the pelagic larvae, which are relatively non buoyant, can move vertically in the water column, thus somewhat ofTsetting the effects of a difTusive

[ environment. Age-0 fish (juveniles) are more tolerant of higher water temperatures than are the adults, and they ofkn remam in estuarine nursery areas throughout their first year, age-1 fish may do the same (Buckley 1982).

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I' The PKDB estuary, not far from PNPS, is a local spawning ground for winter flounder, although spawning also occurs outside this estuary. The adult segment of the local population is exploited prior to the spawning season by a regulated commercial otter trawl fishery that is open from 1 November to 31 January, with a minimum legal fish size of 305 mm TL. In past years, this fishery was open into the spring, but declining flounder abundance prompted a mandated reduction in temporal efrort.

Spawning success, recruitment, and population coherence are maintained where physiography and oceanographic circulation enhance larval retention in specific geographic areas. Size of the spawning grounds and larval retention areas are limiting factors to absolute population abundance. Winter flounder population size is a function of the size of the physical system underlying larval retention. Large populations generally are found in large bays and on large offshore banks; whereas, smaller populations are associated with coastal ponds (lagoons) and smaller estaarine river systems (Howell et al.1992). Clearly, the magnitude of impact of a given mortality (power plant related or otherwise) is inversely related to the absolute abundance of the population afTected.

Habitat and water quality can be issues on inshore winter flounder spawning and nursery grounds because these areas typically are subject to anthropogenic alterations and environmental degradation. The various flounder life stages can be affected by dredging, filling of wetlands, toxicants, disease infestation, hypoxic conditions, and power plant-induced mortality. Direct mortality, loss of habitat, along with the loss of reproductive and growth potential can result. In addition to natural and fishing mortality, impingement and as airdred of winter flounder by power plants can substantially add to total mortality. lesses may be especially problematic when power plant intakes are located in or near spawning and/or nursery grounds (Normandeau I 1979), e.g., at PNPS. All life stages ofwinter flounder, at least seasonally, inhabit the artificial intake embayment at PNPS, which simulates a small cove.

18 I

Eces and Lan ae lhe larvae ofwinta flounder are much more susceptible to power plant entramment than are their eggs, which are demersal and adhesive. The benthi-pelagic larvae, especially the later stages, generally are more abundant near the bottom of the water cohann during the daytime and, thus, are vulnerable to entrainment as bottom water is drawn into the intake structure At PNPS, entrainment of winter flounder lan ae has ranged from an estimated 3.5 to 88.8 million annually over the last 19 years (1980 to 1998); the 1998 estimate was, by far, the highest recorded during this entire period. Larval entrainment was substantially up even from 1997 (55.4 million larvae), which 4q%ds the second highest annual entrauunent of the time series. The third highest value of this period was 29.8 million larvae, which was recorded in 1981. We pondered the cause for the large increases in larval entramment the last two years. From the Massachusetts Division of Marine Fisheries' (MDMF) coastwide spring trawl-survey time series, we find that the survey biomass index for the Gulf of Maine winter flounder stock dH not substantially increase in 1997, suggesting that flounder numbers were not particularly higher that year. Overall, their spring surveys show record high indices of recruitment of age-2 flounder since 1992. However, through 1997, we found no correlation between the number oflan ae entrained at PNPS and the surveyed number of age-2 fish, using a two year lag. Values for the 1998 MDMF spring sun cy were not available at this time i By way of comparison, the total number oflarval winter flounder entrained in 1996 and 1997 at the Millstone Nuclear Powa Station in Connecticut was estimated to be 53.9 million and 78.5 million, respectively, which represented the second and third lowest entrainment levels since three-unit operation began in 1986.

Larval flounder entrainment at the Brayton Point Power Station in Somerset for 1996-1998 was estimated at u

116.4 nulhon,96.9 million, and 49.0 million, respectively, which represent relatively low values for that power station; the 1998 value represents the lowest entrainment level ever at that plant.

Larval mortality due to entrainment at PNPS in 1998, assuming no sunival and using the Adult Equivalent Model with staged data, which assumes population equilibrium and no density-dependent 19 5

I compensation aquates to the total loss of 77,428 age-3 winter flounder. This estimated loss to the local population is 64% greater than last year's projected loss of 47,087 adults. Entrainment losses at the station for the last 12 years have ranged annually from 2,619 adults (1987) to this year's high of 77,428 adults. The equivalent adult estimates (stage specific) for entrainment at Brayton Point Station for 1996-1998 were 32,192, 35,806, and 23,419 age-3 winta floundcr, respectively. Gibson (1994) examined data for several winter flounder populations and found that afla accounting for adult mortality, recruitment rates were lowest in three populations (located in Mt. Hope Bay, Niantic River, and off Plymouth in western Cape Cod Bay) that are subject to entrainment by nearby power plants.

Delimiting the geographic extent of the local population was important to establish the source of flounder larvae entramed at PNPS. This power plant has been shown to entrain lan al winter flounder produced in PKDB and also larvae produced fnxn sites outside the estuary in westem Cape Cod Bay (Marine Research, Inc.1988).

Juvenilej hi 1998, an estunated 1,493 winter flounder were impinged at PNPS. All werejuveniles (ages 0 and 1).

Winter flounder were impinged during all seasons of the year, with the highest numbers collected in the month of April. The number impinged this year (1998) represents about 109 age-3 adults.

Juveniles tolerate water temperatures up to 27 C, but sublethal effects begin to appear at 20 C, with feeding inhibition evident at 24-27 C. This should precludejuveniles from the immediate discharge area in late summer, when temperatures can exceed these values.

Adults Direct mortality of winter flounder has been rare in the thermal plume off PNPS. When exposed to high El water temperatures, flounder probably vacate an area or try to avoid thermal stress by burying into the bottom which would be cooler than the overlying water (McCracken 1963; Olla et al.1969). Adult flounder can tolerate water temperatures up to 26*C, but above 22.2*C they become inactive and cease feeding. Occasionally during I ,

1 past summers, bottom water temperatures have approached 30*C at the mouth of the PNPS discharge canal.

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Stone and Webster (1977) predicted that adult winter flounder would be excluded by thermal stress from the immediate vicinity of the Pilgrim discharge during late summer and early fall, although this impact area is small, at most likelyless than 4,047 m 2, Seven winter flounder reportedly were caught by anglers at Pilgrim Shorefront in 1998. In the 1970s and early '80s, this species ranked among the top five sportfish angled in the recreational fishery off the power plant.

Movements. Micration. Fidelity and Abundance To assess the magnitude oflarval winter flounder entrainment at PNPS, we have conducted a tagging expenment ofsub-adult and adult winter flounder in the inshore waters of Western Cape Cod Bay / Massachusetts Bay. The ecological significance of man-induced mortalities (e.g., via power plant water withdrawal / discharge heat cfTects)is diflicult to interpre unless the mortality can be evaluated against some measure of the size of the true biological pyW afrected, while also considering natural mortality estimates. Our objectives have been to define movements, migration, and discreteness (i.e., fid:!ity to a spawning area) of the local population and to estimate its absolute abundance This sectioc relates to our analysis of observations pertaimng to the movements, migration, fidelity and abundance of winter flounder on coastal grounds north of Cape Cod.

'Ihe g&y fiel boundanes defining the region of the sample population for our tagging were defined for us by Eric Adams of M.I.T. employing an analytical, hydrodynamic model to predict spatial estimates of the origin of winter flounder larvae that are s abject to be entrained at PNPS. This simplistic model outputted the cumulative probability density function of entrained organisms (larvae) at the power plant that originate from different locations. The question oflarval transport was deemed analogous to the problem of computing the relative concentration of a contammant released at some origin at a constant mass moving in one direction by a current of constant magnitude.

From the FN Frances Elizabeth, we caught and tagged winter flounder, and recaptured tagged fish to determme fidelity and to estimate absolute population abundance employing mark and recapture models.

21 D

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I Between 30 March and 9 May 1998, we successfully completed 198 standard trawl tows within the study area and caught a total of 17,409 winter flounder for a mean catch of 87.9 fish per tow (CPUE). Of the 15,042 flounder sampled during the 171 tows used for tagging purposes,7,494 (2280 mm TL) or 49.8% were tagged, with a mean number tagged per tow of 43.8. It should be noted, however, that there were probably multiple recaptures of some smaller, untagged fish. In comparison, in 1997 we made 94 trawl tagging tows, sampling i1,792 winter flounder, of which 7,487 (2250 mm TL) or 63.5% were tagged. The mean CPUE was 149.2 winter flounder; whereas, the average number tagged in a tow was 79.6. The CPUE data suggest that relative abundance of winter flounder in the study area was considerably higher in 1997 than in 1998.

From 1993 to 1998, we marked / tagged 22,476 winter flounder during the spring spawning season from Humarock to Manomet Point (Figure 7) in Zones 1-3 (defined study area - Figure 8) of western Cape Cod Bay (Table 2). The number and nurumum size of fish marked or tagged by year was: 1993 - 206 fish (> 25 cm TL);

1994 - 245 fish (2 20 cm TL); 1995 - 2,047 fish (2 20 cm TL); 1996 - 4,997 fish (2 25 cm TL); 1997 - 7,487 fish (2 25 an TL); and 1998 - 7,494 fish (2 28 cm TL). All fish were released in the general vicinity ofcapture.

Tag nsurns came from commercial and recreational fishermen, fish processing plants, and our research efforts.

From the FN Alosa we collected catch data and recapture information inside and outside the collective tagging area (Areas 1-3) to determme fidelity and to estimate absolute population abundance via density e@ah B: tween 30 March and 8 May 1998, we sucerafully complcted 160 standard trawl tows, catching a total of 12,492 winter flounder for a mean CPUE of 78.3 fish.

The population of winter flounder in the emirons of Plymouth is demographically open and thus subject to immigration and emigration. Our analysis is based on winter flounder tag returns obtained with accurately ,

reported locations through 31 Deamber,1998 (Table 2). In some years, well over 50% of our tag returns came from commercial fishing catches.

Through December 1998,8% fish (with azurate return informahon) have been recaptured for an overall return rate of 4.0% (Table 2). A recapture rate of 2.8% was reported by Phelan (1992) from 7,346 winter 22 1

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flounder (218 an T.L.) tagged in the inner New York Bight in the late 1980s. In many fish mark and recapture f

programs, the percentage of returns ranges from 3 to 10% By way of contrast, over 30 years ago, Howe and Coates (1975) of the Massachusetts Division of Marine Fis ies, having tagged 12,151 winter flounder (gmerally> 200 mm TL) in the 1960-l%5 period (late March A i 'l) at 21 locations along the Massachusetts Table 2. Sununary of winter nounder naast/ recapture data fresu western Cape Cod Bay in the 1990s.

Tagging dates Sine- Nusnber Color of Recaptured through  % Recovery totallength tagged (Am. tag 31 Doc,1998 clipped)

Jan-May/Nov-Dec,1993 225 can (206) -

2 1.0 Mar May/Nov-Dec,1994 2200 sani 226 yellow 27 12.0 AprS,1995 2200 sani 2,066 yellow 86 4.2 Aprg,1996 1250 nun 4,997 red 191 3.8 Mar May,1997 3250 nun 7,487 blue 385 5.1 Mar May,1998 g200 musi 7,494 grues 205 2.7 Totals - 22,476 - 896* 4.0 a This asure does not lacende 88 tag returns fresu nah , w

plaats whm there wm '_= , "_; reportings of recapture locations, coast, obtained 4,440 tag returns through September 1971 for a remarkable overall finfish recovery rate of 36.5% One of the tagging locanons was Plymouth Outer Harbor, wluch is within our dermed study area, where in 1964 they tagged 500 winter flounder, of which 36.6% eventually were recaptured. It should be noted that their retums were compiled for a longer period of time following ficunder tagging.

'Ihe ovcrall tag return rate, to date, of 4.0% is disappointing for the number of fish tagged in the study area and is a limiting factor to our drawag infcrcnces from the subset of measurements obtamed from the sample population. We believe that the low return rate is due to the under-reporting of recaptures by commercial fishermen and the spatiot...yoral bans on commercial fishing in the inshore waters. The exclusion of commercial fishing from inshore waters at times during the year cfTectively removes a substantial source of 25 l-

recapture information. From anerMal comments, we have been told that some commercial fishermen did not return recapture information to us because they believe tle data will be used against them for management purposes Our ofraing oflucrative financial rewards the last two years, via lottery, aided somewhat in obtaining tag retums, based on our conversations with certain individuals reporting tags. The number of unreported tag returns is unknown; however, we suspect it to be sizable within the commercial sector.

Tag returns by area for winter flounder recovered during the non-spawning period (June-February) from 1993-1997 and (June-December) of 1998 (Table 3) must be interpreted with some caution because of the distribution of fishing effort off the Massachusetts coast, which, in turn, is dependent on seasonal flounder distributions and fishcry closures. It is clear that there was an unequal distribution of commercial fishing effort spatially. The highest numbers of recaptures, by far, came from Area 2, which was within the overall tagging Table 3. Tag returns by area for winter flounder (at large at least one month) recoveral during the non-spawning period (June-February) fran 1993-1997 and (June-December) of 1998. Fish were marked in Arves 1-3.

Area Number of Receptures Perrent of Total Rasptures 1 20 3.4 2 318 53.6 3 48 8.1 5 4 68 11.5 5 15 2.5 6 29 4.9 7 65 11.0 8 1 0.2 9 5 0.8 10 0 0.0 Other* 24 4.0 Totals 593

• Other: Newpoet, R.L (2), Steilwagen Bank (15), Highland Light (3), Georges Bank (3), Img Island, NY (1).

I 26 I

area. This suggests that a sizeable proportion of the flounder may not move far afield from the overall tagging area (Areas 1-3) aRcr the spawmng ==ari(March-May). Awareness of fishermen in this area of concentrations of fimmrier and numbers of tagged fish (including the two u. . di! vessels we contracted for tagging / recapture operations) may have contributed somewhat to recaptures from here. Relatively high .=apture numbersjust north (Area 7) and south (Area 4) of our overall taggmg area are similar, reflecting fish dispersal in both duectxes A small number of recaptures came from Area 6 off Provincetown, indicating an eastward movement of some fish. A few individuals traveled considerable distances, having been reported from Georges and Stellwagen Banks; the backside of Cape Cod (Highland Light); Gay Head, Martha's Vineyard; Newport, R.I.;

and long Island, N.Y. The greatest straight line distance from tagging area to recovery site was a remarkable 170 miles, accomplished by a 42 cm female in a span of 7 months and taken offlong Island, New York. n is evident that flounder were more broadly distributed geograplucally outside the spawning period.

Tag returns recovered during the spawning penod (March-May) from 1993-1998 (Table 4) also are influenced by the distributme and seasonality of fishing effort off the Massachusetts coast. Many of the recaptures in Area 2 are from our contracted vessel (s) dunng tagging operations There is limited commercial fishmg allowed in Areas 1 5 during this March-May penod based on state-m=~i=W spawning closures, while recreehonal water flounds fishmg does not open until May 1. Fidelity of the local flounder population has been somewhat difficult to assess based on the inherent areal biases associated with tag retum informaton However, aboard contracted vessel (s) we have recaptured high munbcrs of flounder in Area 2 (part of the tagging area) dunng the spawmng season (Table 4). Fish recowsed from Areas 6 and 7 (Massachusetts Bay) may have already spawned and thest moved off the local spawmng grounds Seventy-two percent of the total recaptures came from Area 2 during the spawning season Additonal information about fidelity of winter flounder to the study tagging area came from our other reseerdirocapture work *M from late March through early May,1998. A second contracted commercial fishmg vessel (F,V Alosa) made haphazard trawl tows (totahng 110) in Areas 4 and 5 (outside our taggmg 27 l .

Table 4. Tag returas by ana for winter fbmederist large at least one month) obtalmed during the spring spawning season i

(Marth-May) from 1993-1996 of fish tagged in Areas 13.

Area Number of Receptures Percent of Total Recaptures I

1 1 03 2 218 71.9 3 0 0.0 4 35 11.6 5 4 1.3 ,

6 16 5.3 7 27 8.9 8 3 0.0 9 0 0.0 10 0 0.0 W Other* 2 0.7 Totals 363

• 0ther: Stepwagen Bank (1), Highland Light (1) area) scarefung for tagged fish from past years of the survey. Only 2 tagged fish (at large at least one year) were recovered. We attempted trawling for tagged flounder north of the tagging area (Area 7), but untrawlable bottom limited the number of standard tows (3) we could successfully complete in this area. No tags were recovered.

The data strmgly suggest, nevertheless, that winter flounder return to (or never stray very far from) the locality I of tagging with high frequency in summary, the returns from our release sites show overall relatively limited (localized) movements, basically confined to inshore waters. Thus, our data support findings from earlier studies that most observed movements of winter flounder located north of Cape Cod are restricted to relatively short distances Finally, it appears there is fairly high fidelity and thus discreteness in the localized population within the Plymouth area, which imparts more impostance to entrainment effects of PNPS. Nevertheless, geographical isolation during the I

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flounder (t 18 cm T.L) tagged in the inner New York Bight in the late 1980s. In many fish mark and recapture

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programs, the percentage ofreturns ranges from 3 to 10% By way of contrast, over 30 years ago, Howe and Coates (1975) of the Massachusetts Division of Marine Fisheries, having tagged 12,151 winter flounder

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(gmerally2200 mm TL) in the 1960-l%5 period (late March-April) at 21 locations along the Massachusetts Table 2. Summary of winter flounder mart / recapture dets fran western Cape Cod Bay le the 1990s.

Tagging dates Sise. Number Color of Recepturwl through  % Recovery totallength tagaed (fin- tag 31 Dec,1998 clipped)

Jan-Msy/Nov-Dec,1993 125 cm (206) - 2 1.0 MarsMay/Nov-Dec,1994 1200 nun 226 yellow 27 12.0 April,1995 1200 nun 2,066 yellow 86 4.2 April,1996 2250 nun 4,997 red 191 3.8 Mar Msy,1997 1250 nun 7,487 blue 385 5.1 Mar-May,1998 1280mun 7.494 green 205 2.7 Totals - 22,476 - 896" 4.0

• Thh figure does not include 88 tag retures fresa fish processing plants where there were incomplete arportings of recapture locations.

coast, obtained 4,440 tag returns through September 1971 for a remarkable overall finfish recovery rate of 36.5% One of the tagging locatens was Plymouth Outer Harbor, which is within our def'med study area, where in 1964 they tagged 500 winter flounder, of which 36.6% eventually were recaptured. It should be noted that their returns were compiled for a longer period of time following flounder tagging.

'Ihe overall tag return rate, to date, of 4.0% is disappointing for the number of fish tagged in the study area and is a limitirg factor to our drawing infmmces from the subset of measurements obtained from the sample population. We believe that the low return rate is due to the under-reportmg of recaptures by conunercial fishermen and the spatio-temporal bans on commercial fishing in the inshore waters. The exclusion of commercial fishing from inshore waters at times during the year efTectively removes a substantial source of 25

I' recapture information. From anecdotal comments, we have been told that some commercial fishcrmen did not '

return recapture information to us because they believe the data will be used against them for management purposes Our ofTering oflucrative Tmancial rewards the last two years, via lottery, aided somewhat in obtaining tag returns, based on our conversations with certain individuals reporting tags. The number of unreported tag returns is unknown; however, we suspect it to be sizable within the commercial sector.

Tag retums by area for winter flounder troovered during the non-spawning period (June-February) from 1993-1997 and (June-December) of 1998 (Table 3) must be interpreted with some caution because of the distribution of fishing effort off the Massachusetts coast, which, in turn, is dependent on seasonal flounder distributions and fishery closures. It is clear that there was an unequal distribution of commercial fishing effrat I;patially, The highest numbers of recaptures, by far, came from Area 2, which was within the overall tagging

. Table 3. Tag naurus by ana for winter flounder (at large at least one month) recovered during the non-spawning period (June-February) frten 1993-1997 and (June-December) of 1998. Fish were marked in Areas 1-3.

Area Number of Receptures Perrent of Total Receptures 1 20 3.4 um 2 318 53.6 3 48 8.1 5 4 68 11.5 5 15 2.5 6 29 4.9 7 65 11.0 8 1 0.2 9 5 0.8 IG 0 0.0 Other* 24 4.0 Totals 593

'Other: Newport, R.L (2), Stellwagen Bank (15), Highland Light (3), Georges Bank (3), Long Island, NY (1).

i i 26 I

area. His suggests that a sizeable proporuon of the flounder may not move far afield from the overall tagging area (Artes 1-3) aller the spawrung season (March-May). Awareness of fishermen in this area ofconcentrations of flounda and numbas of tagged fuh (incluchng the two commercial vessels we contracted for tagging / recapture operations) may have contributed somewhat to recaptures from here. Relatively high recapture numbers just f

- north (Area 7) and south (Area 4) of our overall tagging area are similar, n:llecting fish dispersal in both duccmons. A small number ofrecaptures came from Area 6 off Provmcetown, uxhcating an castward movement of some fish. A few individuals traveled considerable distances, having been reported from Georges and Stellwagen Banks; the backside of Cape Cod (Highlaad Light); Gay Head, Martha's Vineyard; Newport, R.I.;

and Img Island, N.Y. The greatest straight-line distance from tagging area to recovery site wu a remarkable 170 miles, accomplished by a 42 cm female in a span of 7 months and taken offImg Island, New York. It is evident that flounder were more broadly distributed geographically outside the spawning period.

Tag returns recovered during the spawning penod (March-May) from 1993-1998 (Table 4) also are influenced by the distribubon and seasonality of fishing effort off the Massachneetta coast. Many of the recaptures in Area 2 are from our contracted vessel (s) dunng taggmg operabons There is limited commercial fishung allowai in Areas 1-5 during this March May pmod based on state-mandated spawning closures, while recreational wmta flounder fishmg does not open until May 1. Fidelity of the local flounder population has been somewhat difficult to asacas based on the inherent areal biases associated with tag return informauon However, aboard cor tracted vessel (s) we have recaptured high numbers of flounder in Area 2 (part of the tagging area) dunng the spawmng season (Table 4). Fish recovered from Areas 6 and 7 (Massachusetts Bay) may have already spawned and the moved off the local spawning gror.mds. Seventy-two percent of the total recaptures came from Area 2 dunng the spawning neaann Additional informahon about fidelity of winter flounder to the study tagging area came from our other research recapture work *~i from late March through early May,1998. A second contracted commercial fishmg vessel (F/V Alosa) made haphazard trawl tows (totahng 110) in Areas 4 and 5 (outside our taasmg 27

I Tolde 4. Tag neurus by area for whoser flounder (at large at least one month) obtalmed during the spring spawning season (Msirb-May) from 1993-1998 of fish tagged la Areas I 3.

Area Number of Receptures Percent of Total Receptures 1 1 0.3 2 218 71.9 3 0 0.0 4 35 11.6 5 4 1.3 6 16 5.3 -

7 27 8.9 )

I 8 0 0.0 9 0 0.0 10 0 0.0 l

Other* 2 0.7 Totals 303

'Other: Steilweya Bank (1), Highland Light (1) area) senithmg for tagged fish frtrn past 3 cars of the survey. Only 2 tagged fish (at large at least one year) were reayvered. We ="mmad trawling for tagged flounder natth of the tagging area (Area 7), but untrawlable bottom limited the number of standard tows (3) we could successfully complete in this area. No tags were recovered.

The data strongly suggest, nevertheless, that winter flounder retum to (or never stray very far from) the locality I1 '

of tagging with high frequency In summary, the returns from our release sites show overall relatively limited (localized) movements, basically confined to inshore waters. Thus, our data support fmdings from earlier studies that most obsen'ed I movements of winter flounder located north of Cape Cod are restricted to relatively short distances. Finally, it appears there is fairly high fidelity and thus discreteness in the localized population within the Plymouth area, l

which imparts more importance to entrainment efTects of PNPS. Nevertheless, geographical isolation during the I

'a i

e I

u

spawmng penod is not +:-g ' 2 in that there is some exchange with adjacent populations, with tagged fish being recaptured dunng this time interval in adjacent areas.

Density extrapalahnei(Area Swept Mahod), post stratificx! by depth, was used with data collected from 28 trawl tows made on the F/V Alosa over the penod of 25 to 29 April,1998 to estimate winter flounder population size : one estimate was for a segment of the flounder population 2 280 mm TL (age 3 and older considered to be adults) and the other for the entire wmter flounder population (all sizes) (Table 5), with areal measurements estimated for MLW.

Our unadjusted estimates ofwinkr flounder absolute abundance for the study area (see Methods section, this report) using arca-swept are 132,406 adults and 294,225 total winter flounder. These estimates assume a trawl gear efficancy of 100%. Trawl catch efficiency is vanable rather than a constant; we assumed it was more likely closer to 50%. Thus, we doubled the estimates and the adjusted values were 264,812 adults and 588,450 total flounds(Table 5). Last year's area-swept estimates for adult and total flounder abundance were higher at 321,832 and 905,031, respectively. This also suggests that abundance was down in 1998. Precision improved with post-stratified estimates of abundance In 1999, we will pre-stratify our standardized sampling M hadalogy based on depth prior to sampling, in a conunued effort to reduce the vanahan around our density estunates Gear selectivity is a factor, in that, the Table 5. Esthnesed sh==h (posteersetAnd by depth)in piumbers of winter flounder (bottoni eres calculseed et MLW). wish 95% confidence ihmies, of winter flounder a 288 mun (TL) ad for peeled lengths esehneemd by eteer erswl density entropolations (ed}as1ed for par efficiency) in the Pugrha seedy area, spring 1998.

Toeni Bosteni Area Numdwr of Upper Imer (equare nesters) flounder 95% CL 95% CL Fleender 247,391,497 264,812 286,825 242,799 a 280 nun TL AM Flounder 267,391,497 588,458 623,578 553,330 l

29-

1 FN Alosa used a 4.5 mm mesh cod-end which limits the retention of small fish; thus, an expanded estimate of abundance is biased toward larger fish. There is spatial variation in abundance of this species by depth (Lawton et al.1995), and we have not always distributed our sampling effort based on the relative areal sizes of each depth stratum. It is noted that the adult estimates for 1997 and 1998 are for a larger study area than used for the I previous two years. Based on a modeling prediction of the origin of winter flounder larvae potentially entramed, we expanded the study sampling area, substantially increasing areal coverage. Based on the modeling by Eric Adams of M.I.T.,it is predicted that winter flounder larvae entrained at PNPS can come from as far away as 17.7 I km. To repeat, our present study area encompassed from Humarock, Marshfield ath to Manomet Point, Manomet (Figure 1).

1 To gain perspective on the entrainment equivalent adult estimate, we compared it with population es.imates generated for the study area. These estimates came from two methods - trawl area-swept and mark.

recapture. First. a percent loss of adult winter flounder as a result oflarval entrainment was obtained using the I equivalent adult estimate (77,428) obtained from entrainment monitoring and the Adult Equivalent Model as l

related to the area-swept estimate of the ntunber of adults (264,812) residing in the3 stud an in 1998. The dult l

l loss berme ofentrainment corresponds to 29.2% of the adults estimated to be residing in the ed e ca during {

the 1998 winter flounder spawning season. Estimated adult stock reduction due to entramment in 1997 was 14.7%, based on an area-swept estimate of adult abundance However, it should be remembered that larvae of a givcn year will not attain adult status until age 3, so the actual effects of entrainment in 1997 ano 1998 won't be realized until winter floundx population edimata= for the pars 2000 and 2001 are generated.; the cfTect could

( be less or more than the current estimates A review by Marine Research, Inc. (1986) of winter flounder early-life studies at PNPS revealed that stock reductions of 0.7 - 2.2% (relative to a larger stock size back then) were l l

edima'M to be possible because ofplant opaat ons It is noted that back in the early 1980s, winter flounder were j

in greater abundance than at present. Given that coast-wide winter flounder populations have been severely l ire in recent pars by overfishing , PNPS entrainment may have added markedly to total mortality affecting 30 l

I

l this fairly discrete population in recent times. However, we know from our tagging data, fidelity is not 100 %,

with some mixing going on with other nearby sp wning units.

Population estimates for 1998 with mnfklenm limits, obtained from various mark-recapture models, are found in Table 6. As to the five tagging models used to estimate adult population size (fish 2 280 mm TL), the estimates range from 7.6x10* to 1.1x105 These estimates predict that abundance was down from last year (1.2x105to 5.2x105). All were hampered, however, as to predictive value because of the continued overall low number of tag returns; in fact, we could not use the Mark program model this year at all (not listed in Table 6).

The Petersen model is the simplest estimator but had a bias in that we did not know how many unmarked fish of Tatde 6. Mark-recapture anodel esthnstes, wkh 95% coandence ihnits, of stadute abundance of winter fkander a 280 nun TL in the Pilgr6n study area, spring 1995.

l F

Model Nuanber of Flounder lower Upper 95% CL 95% CL Pesenes 111,195 91,147 142,547 Schambel 92,659 82,597 105,514 Schuanacher 98,890 86,455 115,502 Captune 104,429 93,053 117,318 I Jolly Scher 76,259 54,744 106,266 I

a 280 mm TL were involved in multiple treaptures dunng the last 4 days of the study, when n o fish were tagged.

With the Jolly-Seber open population model, we could not generate an estimate unh high precision because of overall low recaptures and based on the chi square goodness-of fit test, model adequacy to parameterize the population was constrainesi Of the tagging models employed, the Capture model was preferred because it best fit the data; funhermore, it is the most conously used model for capture-recapture studies where capture probabilities vary only by time (although changing environmental conditions can afTect capture probabilities).

The estimated adult loss of winter flounder (77,428 fish) in 1998 because oflan al entramment (88.8 million larvae) at PNPS was companxi to the Capture mark /recrpture model estimate of spring 1998 abundance 31

I l

I l of adults in the local population. The entrainrr mt loss as a percent of estimated abundance of extant winter l1 flounder g 280 mm TL present in the study area during the 1998 spawning season was 74% (Capture nudel). l Intuitively, when examuung entrainment numbers for 1998 and the equivalent adult estimate, and comparing the latta to population estunates of adults obunned by area swept and the Capture model of tagging data, one would be concerned that the impact of PNPS, at the level of entramment that occurred in 1997 and 1998 was emlogmally signifwant to the local winta flounda populauon. We would deem the loss of over 77 thousand age-3 fish via entrainment by PNPS to be an important source of additional mortality to an already stressed population from overfishing.

In dusgc, we selected the Capture Model population predictive estimate which best fits the flounder )

data and umya entramment impact at PNPS to that at the Brayton Point Station. Gibson (1994), using data collected prior to the winter flounder stock decline in Mount Hope Bay in the mid-1980s, applied four methods l ofestunating population size, and generated an average population estimate of 378,957 fish (confidence limits Iji of 40,000 - 718,000). The average loss to entramment of 32,829 age-3 fish (unstaged approach) represented 82% of the Iowa confxlence limit of the absciute abund.- -maate and 5% of the upper limit. At PNPS, the population estimate for 1998 via the Capture Model s .' ;04,429 fish with confidence limits of 93,053 I17,318. The loss to entrainment of 77,428 age-3 fish (staged approach) amounted to 83% of the lower l confidence limit and 66% of the upper confidence limit.

3. Other Species Data on other finfish species were obtained from a cacci survey conducted at the PNPS Shorefront Recreation Area and by underwater SCUBA surveys in the thermal discharge area.

Creel Survey Unlike many past years, the access of recreational fishermen to the Pilgrim Shorefront was attenuated in 1998 because the area was closed to the public for nearly two months (28 August - 23 October ) while the I dischargejetties were being reconstructed. Therefore, the creel survey of shore-based anglers at the Shorefront I

I

was ennAnceM from 4 April through 27 August, and again from 24 October through 29 November, when the Shorefront closed for the season. A total of 986 anglers was inteniewed of the 1,877 anglers tallied during 121 sampling days over the split season This represented 56 fewer sampling days than last year. The goal was to obtain basic infonnauan on sportfishing activity, including fishing effort and locations, and gamefish catch over time. There were two data collectors, who were seasonal public relations personnel for BECo; they conducted the creelinventory in addition to other duties. We requested them to inteniew at least 10 anglers per day (5 in the mormng,5 in the afternoon). If there were 10 or less individuals, then each fisherman was represented in the census for that day. On days with greater than 10 fishermen, catch reports nye expanded to the total number I of fishermen based on the catch results of the 10 anglers interviewed. Only weekends were sampled in April, May, late-October, and November, while there was daily coverage June through 27 August.

It is clear that most of the fishing elTort wu expended in the thermal discharge area from off the two discharge canaljettics. Some effort was expended off the outer breakwater, with even less efTort off the rocky beach located north of the discharge canal. Anglers pnmanly sought striped bass (Morone saratilis) and bluefish (Pomatomus saltatrix), with not much directed effort for groundfish.

The overall monthly average number of angler trips per day to the Shorefront in 1998 was 15.5, while individual mordly averages ranged from a low of 3.5 in November to a high of 43.8 in May; the high values reported for May are probably innuencM by the fact that only weekends were sampled, when angler presence is Wantially greats Effort was relatively uniform from June through August, ranging from 12.6 to 15.7 angler visits in a day.

The recorded sportfish catch totaled 1,553 fish, comprising four species : bluefish, striped bass, winter flounder, and tautog (Tautoga onitis). The overall mean catch rate (i.e., catch per angler trip) was 0.83, with a monthly range of 0.0 (April) to 1.31 in October Reported catches were up from last year, when the overall mean catch rate was 0.34 fish per angler trip; the change in catch rate may be influenced by the manner in which data j _ _ ,_ (~, s _,~ 10 s b.sy ,1mg days) d th_mg e,_i_ f_

g 33

1 I'

applied to subsampled interview data. We believe that creel data recorded in past years may have under-represented the actual catch, as a limited number of the total anglers present on a busy fishing day were interviewed, with no adjustment made for the creel of fishermen not interviewed.

In 1998, the percent composition of the overall recreational catch was 72.3% striped bass,27.2%

bluefish, 0.4% winter flounder and 0.1% tautog. Highest monthly catch (pooled species) occurred in July at $24 E gl fish or 33.8% of the 7 month total, followed by June (416 fish - 26.8%) and August (305 fish - 19.6% ).

Winter flounder, which were not recorded in the sportfish catch oflast year, were caught in July (3 fish) l and August (4 fish). No Atlantic mackerel (Scomber scombnes) were reported for this year. I Striped bass dnminW the monthly totals of May, July, August and October, being caught in all months Il I

of the survey execpt April. The first striped bass was landed on 3 May, which is typical for their appearance in the sportfish catch at the Shorefront. Of the 1,122 striped bass reported to be caught at the Shorefront in 1998, 96.7% were sublegal as to the recreational size limit (< 71.1 cm TL). The highest monthly catches were made in July (40.0% of total striped bass catch), followed by June (19.2%) and August (18.8%). The overall catch rate, i.e., catch per day, averaged 9.3 striped bass, with monthly rates from May-October ranging from 7.2 to 17.9. 'Ihese catch rates were up substantially from last year. The seasonal catch of striped bass was similar in I. '

May and June, tnen improved in July, when bass were angled in all but four days. Catches declined somewhat in August, at which point the Shorefront construction closure occurred. For the 3-day sampling period when the l Shorefont re-opened in October, the catches were relatively high, followed by a rapid decline in November.

The total striped bass catch in 1998 was 76% greater than that recorded for 1997, even with the

]

construction closure. The reason for the catch increase is unclear, but a much more plentiful supply of striped bass along the Atlantic coast in recent years ostensibly should have resulted in elevated catches of this species at the Shorefront this year and last year. We already mentioned that the change in this year's sampling design may have contributed to higher values of fish being reported relative to past years. I I

I' Il l

The PNPS's warm water discharge has attracted striped bass over the years when the plant has been operating with both circulatmg seawater pumps in use. We obsen ed about a dozen " overwintering" striped bass in the discharge canal while SCUBA diving in Decxrnber 1998. These fish are susceptible to cold shock if PNPS was to experience an outage during the winter months. The most recent obsenational dive occurred in January of 1999 in the thermal discharge; we sighted about 40 striped bass residing there. A plant outage was planned for February 1999.

Bluefish were first caught on 24 May,1998 and were abundant in the catches of June-August and October. A total of 423 bluefish in a range of sizes was recorded at the Shorefront, with catches highest in June (47.3% of total). Catch rates (i.e., catch per day and catch per angler trip) matched up well with the monthly totals (excluding October, which was based on only three days of sampling): the former ranging from a mean of 2.3 fish per day in July to 6.7 fish per day in June, with the latter ranging from 0.10 fish per angler trip in July to 0.42 in June.

The 1998 bluefish catch at the Shorefront declined 43.6% from that in 1997. The reason for the decline is speculative, but may be partially the result of the Shorefront closing for nearly two months (September.

October) We also cannot rule out a real decline in bluefish numbers in the area. Nevertheless, it is readily evident that when PNPS is operatmg, the warm-water discharge current attracts and concentrates bluefish as well as striped bass, which is advantageous to sportfishermen Recreational bluefish catcles at PNPS have beer.

notable as to the number landed over the years when the station is operating. Conversely, power outages at the I Station have resulted in markedly reduced sportfish catches at the Shorefront (Table 7).

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I Table 7. Recrondmmel bhneemb catches repeeted by creed servey over three decades at the Puerhm Stades Sherefront la rienden to pimme operaden Year Nussber of Reported Fested Flamt Status

.l 1973 See * ;" ' -4)ctober

.- On-Ilme 1974 700 Sepesember-October Oudine 1975 14 Sepeesaber-October Off-thee 1983 1.200 Jame-Nevemeber On -Ilme 1995 2,200 Jume-Nevesaber On-ilme 1984 less them 100 ash Jesse-Nevensber Off-thee a ser Ihr two years 1.

1996 2,014 Jame4)ctober On -thee 1997 750+ June 4)ctober On-lhae 1998 423 Jamme-Noveanber* On-line

• Sinserfhint was cleend Angust 28- October 231998 due to cometruction.

I Observational Divine Undawata finfish dising obsavations proside us with sisual data on occurrence and general abundance of finfish in the imm~Ii='a area of the thennal effluent. From August through December, monthly SCUBA dives war mmpMaA, investigating the mouth of the discharge canal and the adjacent thermal discharge area. Small aggreganons ofcunner (Tautogolabrus adspersus) wac present outside the canal mouth throughout the summer and early fall. Striped bass wac the most mmmnnly obscrved species, with numbers peakmg in early September at 125 to 150 individuals per dive. Tautog were noted on all dives through early November, but following this they apparaitly had left the area as water temperatures declined. Their numbers ranged from 15 to 75 individuals 1 i

per dive.

4. Imoset Perspective l Winter flounder, rainbow smelt, cunner, alewives (Alosa pseudoharengus), and Atlantic silvmides (Men /dia menidia) have been negatively im= tad by PNPS operations (Table 8). The response of these species to perturbation may be illustrative of power plant induced stresses on other manne finfish in the area.

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Rainbow smelt in 1993 and 1994, rainbow smelt annual impingements at PNPS were relatively high - about 9,500 and 10,600 fish, respectively. Impingements of that magnitude are likely to be biologically important to the local smelt population. As a remedial measure to offset power station impact, we stocked over 1.8 million smelt eggs into the nearby Jones River (the major smelt spawning tributary in the area)over the years of 1994 and 1995.

From 1995 through 1998, we also have employed egg collecting trays containing artificial plant substrate (sphagnum) in this stream to enhance spawning ' Mtat for the purpose of optimizing egg survival to hatching.

This latter cfTort will be continued in 1999.

Entrainment of cunner eggs and larvae at PNPS has been high over the years. In 1997 alone, entramment was equated to the equivalent loss of an estimated 498,281 adults from the local population.

Edu numist of this magnitude would appear to be substantial, but the importance of this loss to the local cunner I population is unknown. We have geographically bounded the local population which included all major recruitment sources However, absolute abundance of the local population is difficult to determine because of logistics and financial constraints. Instead, for three years (1995 1997), we conducted recruitment studies to assess power plant effects of water withdrawals.

In 1995, cunner recruitment success appeared to be regulated primarily during the post settlement penod by compensatory processes (density-dependent mortality), with the plant's impact oflarval entramment likely being inconsequential. In 1996, plant impact was mconclusive; a number of storm events altered recruitment pattems at the taminatinn of sampling. In 1997, recruitment success again appeared to be mediated by post-settlement, density-dependent processes of predation and/or resource competition, with power plant impact of less importance. A difference in habitat at one of the sites (Discharge) increased survival there, resulting in higler recruit densities at the Durcharge reef by the end of the recruitment season This work was not continued in 1998 because of the findings of minimal power plant impact.

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1 Larval wmtar flounder entrainment in 1997 and 1998 was inordmately high at PNPS. It is not clear j whether an inmesse in the magstude ofentramment of water flounder larvae in 1997 and 1998ris w -.anive of higher egg abundance, naturally high larval abundance (perhaps M- of increased egg survival), or concentration oflarval densty resultag from the contnbution of transport via the physical processes of on-shore weds and water currents, or by localized spawning events. Perhaps it is an amalgam of several of these factors Entrainment mortalities of larvae at the present level are of great concem to MDMF, in the past, rearm operation of the circulating water pumps during the winter floun:ler spawmng period resulted in substantially lower larval entrainment (Lawton et al.1996).

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We estimated adult winter flounder population size in 1998 at 264,812 individuals by an area swept opproach (density extrapolation) using bottom trawl data. We had extended the study area in 1997 to include the recently estimated spatial range of the local population; however, much of the area is comprised of "untowable" bottom (i.e., rocky or otherwise unsuitable for trawling). As we are unable to sample within the l

I maire bosom study men, we was not able to determme the mean density of winter flounder on hard bottom. We I l

====wul it was the same as on trawlable bottom and calculasM population abundance by W% the average fish density over the atire study men. Entrunment in 1997 equated to a loss of 14.7% of the estimate of possible I i

adults in the area, while in 1998 the loss was estimated to have almost doubled at 29.2%

Mark-recapture data were used to adoress the question of population discreteness and to generate svinpesvimt estimates ofpopulatwwi size to corroborate with the density extrapolation estimate. The low number of winter flounder tag returns obtamed through the present time has hampered especially the latter objective.

Despite the low number of tag returns, there is evidence of a fairly high fidelity of the local population Using the Capture mark-recapture model , the estimate of population size (fish 2 280 mm TL) in 1998 was 104,429 fish, with entramment loss in equivalent adults being 74% of this absolute abundance estimate 39

I' Atlantic silversides l In 1994, there were two acute incdents ofimningwamt of Atlanbc silversdes at PNPS: 28-29 November

-5,800 fish and 26 28 C+-- -V- 6,100 fish. In 1998,it was the dnminant species and typically has led all other speces in numbers -fnfi No mn===*=y acuon has been taken because the silverside is a prolific, annual species with no commercial and only limited recreational value as bait. However, the silverside provides important forage for other piscivorous fish.

Alewife Arelativelyhigh: ; Jar.m of alewives occurred at PNPS on 8-9 September 1995 when an estimated 13,100 individuals died. The alewife is important as bait for the lobster fishery and for sportfishing, while its roe and flesh are used for human consumption. Employing a special publication of the American Fisheries Society (1992), we assessed the monetary value of this kill to be ca. 55,000.00. The MDMF negotiated with BECo for this sum of money which was granted for habitat rehabilitation (i.e., to help rebuild or repair a river herrmg fish ladder in the PKDB estuary situated on either the Jones River or Town Brook). Large impingements of alewives have been uncommon in recent years at PNPS, although it appears that the number of river hernng has dochned in the nearby Jones River run. Nevenheless, impingement monitoring should be continued at PNPS, so appropriate mitigative measures can be undertaken if wan anted.

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V. CONCLUSIONS Rainbow Smelt

1. To e -..;- =" for rainbow smelt impingement at PNPS, MDMF fonnerly stocked smelt eggs into the Jones Rivcr but contmues to work at improving spawning habitat. Restoration has been ongoing for the last five years.

2. After two years of egg stockmg (ca.1.8 million smelt eggs) into the Jones River, this effort had to be termmated because presently there is no good source ofeggs for transplantation.

3. For the last four pars, specially-designed egg collectmg trays have been placed on the Jones River smelt spawmng ground, which has resulted in an increased number of eggs being spawned on ideal substrate for egg survival. This work will continue into 1999.

4. Spawning tributanes shoukl be inaw*~i and cleared of any obstructions to fish passage each year before anadromous fish begin their spawmng runs. The DMF has helped with the removal of several tree snags from the Jones River last year and would lend assistance in the future when necessary.

5. In gmeral, we beheve our smelt restoraton efforts have been successful. We did move numbers of smelt eggs into the Jones River, and smelt have spawned over our collecting trays, with generally higher egg dmsities obuuned on the artificial habitat. However, we have not measured hatching success and, thus, do not know how many eggs set on the trays survived to the larval stage. We also have not addressed s_%=? larval survival or recruitment. On a positive note, the 1998 smelt run was the largest in over a M For the first time in sevcral years, large numbers of adult smelt were obsen'ed on the spawning grounds during the daytime, and egg rets throughout the spawning ground wcre very good.

6. A dochne in smelt populations has taken place throughout Massachusetts Bay and iri Quebec, Canada, as well. Causality for the wide-spread declines is conjectural, although there are obvious environmental I cuuuu, such as storm-water runofT, toxicants, nutrient loading, and sedunentation problems. These alteratens degrade water and habitat quality and are hkely linked to reduced smelt production. Future

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i rm=hrina efforts in the Jones River and other local smelt spawning streams should stress water quality WB issues in the respective watershed. This should be a priority in the future restoration of smelt pryhin=, and could include, for example, watershed runofTtreatment and efforts to purchase a " green belt" along a spawning river or stream to prevent development or environmentally detrimental land use.

Winter Flounder I j

1. The nearby location of winter flounder spawning (retention) grounds, the relatively limited movement 1

patterns of flounder north of Cape Cod, and the geographic bounds of the local population make this species especiaUy sensitive to cr.trainment and impingement at PNPS.

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2. In late summer, water temperatures in the immediate vicinity of PNPS's thermal discharge can exceed I the avoidance temperature (24*C) for winter flounder which would exclude them from this relatively small(~ 4,047 m )2 area of stress.

3. The record 88.8 million winter flounder larvae entrained at PNPS in 1998 equated to an equivalent loss of 77,428 adult winter flounder fmm the local population. This level of entrammcat should be of concern to the regulatory agencies.

4. In 1998, an estimated 1,493 winter flounder also were impinged at PNPS, with the majority being juverules impingement of winter floundcr at PNPS, as a source of mortality, is oflesser importance than entramment cfTects.

5. Our tag recovery rate (4.0%) is low, being hampered by the sporadic reportmg of tagged fish and the seasonal closure of the area to commercial fishing.

6. Our population estimate of winter flounder in the PNPS study area from post-stratified density extrapolation improved precision of the estimates, while estimates from mark-recapture models were ,

hampered by the low tag recapture rates. The magnitude of entramment impact of PNPS on winter

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flounder has been estunated by vanous methods Estimated impacts the last two years are of concern, and mitigation measures should be undertakca at the plant site and restoration measures (to be

( determmed) conducted in the essential fish habitat of the surroundmg waters.

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I, VI. ACKNOWLEDGEMENTS The authors thank Wayne and Dana Bassett of Canal Marine Fisheries, Inc. for donating the bait used during cunner trapping. Thomas Hoopes of MDMF produced the GIS map of flounder recapture areas. Robert

{

Dylan and Jack Sullivan of Boston Edison Company collected sportfish data at Pilgrim Shorefront. Al Hardy and his Agricultural Engmeenng class at Silver Lake Regional High School provided the labor to keep the Jones River smelt run obstructxx i free. Dave and Carole Arnold provided their vessel, Frances Elizabeth, which was used for the taggmg of winter flounder, while Jeff Good provided his vessel, Alosa, for winter flounder recapture operations. Gary White from Colorado State University assisted with technical expertise regarding population estunation using the MARK and CAPTURE tag recapture programs for winter flounder data. We appreciate the Euidance of Robert D. Anderson of BECo, W. Leigh Bridges of our Division, and nx:mbers of the Pilgrim Admuustrative-Technical Committee for their input on various studies and editorial comments on project reports mp_ I I

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VII. LITERATURE CITED 4 l l Anurican Fisheries Society.1992. Investigation and Valuation of Fish Kills. Special Publication 24 Bethesda, i Maryland % pp.

lg Bigekm, H.B., and W.C. Schroeder.1953. Fishes of the Gulf of Maine. U.S. Fish and Wildlife Senice Fishery J Bulletin. 53:577 pp.

'g Black, D.E., D.K. Phelps, and R.L. Lapan.1988. The effect ofinherited contammation on egg and larval winter g flounder, Pseudopleuronectes americanus. Marine Environmental Research 25:45-62.

i I Buckley, L.J.1982. Effects of temperature on growth and biochemical composition oflarval winter flounder, Pseudopleuronectes americanus. Mar. Ecol. Prog. Ser. 8:l 8 l-l 86.

Gibson, M.R.1994. Population dynamics of winter flounder in Mount Hope Bay in relation to operations at the Brayton Point Electric Plant. R.I. Division of Fisheries and Wildlife. Kingston, R.I.

Howe, A., and P. Coates.1975. Winter flounder movements, growth, and mortality off Massachusetts. Trans.  !

Amer. Fish. Soc. 104:13 29.

l Howell, P., A. Howe, M. Gibson, and S. Ayvazian.1992. Fishcry Management Plan for Inshore Stocks of Winter I Flounder (Pleuronectes americanus). Fisheries Management Report No. 21 of the Atlantic States Marine Fisheries Commission.138 pp.

I Lawton, R.P., P. Brady, C. Shechse , S. Correia, and M. Borgatti.1990. Final Report on Spawning Sea-Run Rainbow Smelt @merus mordar) in the Jones River and Impact Assessment of Pilgrim Station on the Population, 1979-1981. Pilgrim Nuclear Power Station Marine Emironmental Monitoring ,

Program Senes -Number 4: 33-43.

l L.wton, R.P., B.C. Kelly, V.J. Malkoski, and J. Chisholm.1995. Final Report on Bottom Trawl Survey (1970-I 1982) and Impact Assessment of the Thermal Discharge from Pilgrim Station on Groundfish. Pilgrim Nuclear Power Station Marine Environmental Monitoring Program Report Series - Number 7. 56 pp.

1 I Lawton, R.P., B.C. Kelly, V.J. Malkoski, J. Chisholm, P. Nitschke, and J. Boardman.19%. Annual Report on Assessment and Mitigation ofimpact of the Pilgrim Nuclear Power Station on Finfish Populations in Western Cape Cod Bay. Projcet Report No. 60 (Jan. Dec.1995). In: Marine Ecology Studies Related l

to Operatzn of Pilgrim Station, Semi-annual Report No. 47. Boston Edison Company, Braintree, MA.

Lobell, MJ.1939. A biologmal survey of the salt waters oflong Island,1938. Report on certain fisles. Winter flounder,Pseudopleuronectes americanus, New York Consen ation Department, Albany,28th Annual Report, Part I, Supplement 14:63-%.

Lux, F., A. Peterson, Jr., and R. Hutton.1970. Geographic variation in fm ray number in winter flounder, Pseudopleuronectes americanus (Walbaum), ofTMassachusetts. Trans. Amer. Fish. Soc. 99:483-512.

i Marine Research, Inc.1986. Winter flounder early life history studies related to operation of Pilgrim Station -

A myiew 1975-1984. Pilgrim Nucicar Pour Station Marine Er;vironmental Monitoring Program Report Ner No. 2. Boston Edison Company, Braintree, MA.

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I Marine Research, Inc.1988. Ichthyoplankton Entramment Monitoring at Pilgrim Nuclear Power Station, Jan.-

Dec.1988 (Vol 2). In: Marine Ecology Studies Related to Operation of Pilgrim Station. Final Report Boston Edison Company.

McCracken, F.D.1%3. Seasonal movements of the winter flounder, Pseudopleuronectes americanus (Walbaum) on the Atlantic coast. J. Fish. Res. Bd. Can. 20:551-586. E E

Meldrim, J.W. and J.J. Gift 1971. Temperature preference, avoidance, and shock exper.;ments with estuarme fishes. Ichthyological Associates, Inc. Bulletin 7. 75 pp.

Normandeau AsW,Inc.1979. New Havcn Harbor Ecological Studies, Summary Report 1970-77 (prepared for United Illummating Co.), New Haven, CT. 720 pp.

NUSCo (Northeast Utilities Service Company).1986. Winter flounder population studies, Section 7. In:

Monitoring the marme environment of Long Island Sound at Millstone Nuclear Power Station, a Waterford, Connecticut. NUSCo, Annual Report,1985, Waterford, Connecticut.

5 Olla, B.L., R. Wicklund, and S. Wilk.1%9. Behavior of winter flounder in a natural habitat. Trans. Amer. Fish.

Soc. 4:719-720.

Pearcy, W.G.1962. Ecology of an estuarine population of winter flounder. Bull. Bingham. Oceanogr. Collect.,

Yale Univ. I8(1):78 pp.

Perlmutter, A.1947. The blackback flounder and its fishery in New England and New York. Bulletin of the Bingham Oceanographic Collection, Yale Univ. 18(1):1-78.

Phelan, B.A.1992. Winter flounder movements in the Inner New York Bight. Trans. Amer. Fish.

Soc.121:777-784.

Perce, D., and A. Howe.1977. A further study on winter flounder group identification off Massachusetts. Trans.

Amer. Fish. Soc. 106(2):131-139.

Saila, S.B.1961. A study of winter flounder movements. Limnol. Oceanogr. 6:292-298.

Scarlett, P.G.1988. Life history investigations of manne fish: occurrence, movements, food habits and age structure of winter flounder from selected New Jersey estuaries. New Jersey Department of Environmental Protectum, Technical Series 88-20, Trenton, N.J..

Stone and Webster Engmeermg Corporation.1977. Supplemental Assessment in Support of the 316 Demonstration, Pilgrim Nuclear Power Station, Units I and 2. Boston, MA.

Sutter, F.C.1980. Reproductive biology of anadromous rainbow smelt, Osmerus mordar, in the Ipswich Bay area, Massachusetts M.S. Thesis, Univ. Mass., Amherst. 49 pp.

Wilk, S.J., W.W. Morse, D.E. Ralph, and T.R. Azarovitz 1977. Fishes and associated environmental data I collected in New York Bight, June 1974-June 1975. NOAA (National Oceanic and Atmospheric Adu--iian) Techmcal Report NMFS (National Marine Fisheries Service) SSRF (Special Scientific Report Fisheries) 716, 46 l I

I FINAL SEMI-ANNUAL REPORT Number 53 I

BENTIIIC ALGAL MONITORING AT TIIE PILGRIM NUCLEAR POWER STATION (QUALITATIVE TRANSECT SURVEYS)

January-December 1998 I

to BOSTON EDISON COMPANY Regulatory Affairs Department I Pilgrim Nuclear Power Station l

l Plymouth, Massachusetts 02360 l I l From ENSR 89 Water Street I Woods Ifole, MA 02543 (508) 457-7900 I

I 1 April 1999 I

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l TABLE OF CONTENTS EXEC UTIVE S UMMARY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . I 1.0 INTR O D UCTI ON . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 2.0 FIE LD STUDIES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 2.1 M ETH O D S . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 2.2 RES ULTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 i

2.2.1 MARCH 1998 TRANSECT SURVEY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 2.2.2 JUNE 1998 TRANSECT SURVEY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 2.2.3 OCTOBER 1998 TRANSECT SURVEY . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 2.3 D IS CU SS I ON . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .13 3.0 IMPACT ON ALGAL DISTRIBUTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 3.1 B A C K G RO UND . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .15.

3.2 QUALITATIVE TRANSECT SURVEYS: 1983- 1998 . . . . . . . . . . . . . . . . . . . . . . . . . 15 4.0 C ON CLUS I ONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21 5.0 LITERATURE CITED . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22 1

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I I LIST OF FIGURES Figure 1.

Location of Pilgrim Nuclear Power Station Qualitative Algal Survey Area . . . . . 3 Figure 2.

Design of Qualitative Transect Survey . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 Figure 3. Qualitative Algal Survey Data for 1998 Compared to Historical Baseline Data

.................................................................... 7 Figure 4. Denuded, Sparse, and Stunted Chondrus Zones and Dense Mussel Area O bse rved in M a rc h 1998 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Figure 5. Denuded, Sparse, and Stunted Chondrus Zones and Dense Mussel Area O bse n ed in J u ne 1998 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 Figure 6. Denuded, Sparse, and Stunted Chondrus Zones and Dense Mussel Area Obsened in October 1998............................................. 10 Figure 7.

Results of the 1998 Qualitative Transect Surveys of the PNPS Acute Impact Z'one off the Discharge Canal taken in March, June, and October 1998 .. 11 Figure 8. Monthly PNPS Capacity Factor (solid lines) and Circulating Pump Activity (black bars at 100% = 2 pumps; at 50% = 1 pump; at 0% = 0 pumps) Plotted I Figure 9.

for the Period 1983 Through December 1998.............................

Arca of the Denuded and Totally Affected Zones in the Vicinity of the PNPS 16 1

I I Efiluent Canal Plotted with the Monthly PNPS Capacity Factor (MDC for the Period 1983 Through 19 9 8 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .17. . . . ). . . .

I TABLE Table 1. Qualitative Algal Survey Data for 1998 Compared to Historical Baseline Data . . 7 APPENDIX I Appendix A. Quality Control (QC) Protocol for Qualitative Transect Surveys at PNPS O u t fa ll A rea . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 4 I

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SUMMARY

l His report presents results of qualitative surveys of benthic algae performed in 1998 in the area of l

thermal efiluent from the Pilgrim Nuclear Power Station (PNPS). The report summarizes the impact of the I PNPS on algal distributions near the discharge canal. At the request of the Pilgrim Administrative-Technical Committee (PATC) Benthic Subcommittee, three field surveys were planned for 1998. These field studies were conducted in March, June, and October and included transect surveys designed to map algal cover in

I the area of water outflow. These investigations constitute the most recent phase oflong-term monitoring of thermal effluent effects on the benthic algal community within andjust offshore of the PNPS discharge canal. Field survey techniques were identical to those used in prior years. Starting in 1996, data from each seasonal survey were compared to the historical baseline (maximum measurements recorded prior to the

.I 1996 survey year) for that season. Measurements greater than 15% above the historical baseline trigger a report to the (PATC) Benthic Subcommittee for review.

The qualitative transect studies performed to evaluate the Chondrus crispus (Irish moss) community )

indicate that from October 1995 through March 1998 (with the exception of December 1996) the sizes of the denuded and totally affected areas in the thermal plume were larger for each season surveyed than in earlier surveys when the power plant was in full or nearly full operation (1983,1985,1989-1995). In 1998 the denuded and totally affected areas measured in March were only slightly larger than the historical spring maxima, while in June they were well within those seen in the earlier surveys. Although the Chondrus denuded and totally affected zones were much larger than historical maxima in the fall survey, they were much reduced in size compared to those seen in the fall of 1997. A dense cohort of newly settled blue mussels (Mytilus edulis) was already in place by March 2 and covered a yet larger area by June. Dense congregations of mussels were still present over much of the affected area in late October even extending beyond the sparse and stunted Chondrus zones.

The annual capacity factor at PNPS for 1958 was 97.1%, higher than in any previous year. In comparison to 1996, the year with the second highest MDC (90.5%), the Chondrus denuded and totally affected zones in March and June were smaller but by the time of the fall survey were larger than in 1996.

Ilowever, none of the 1998 areal measurements, excepting an insignificantly larger totally affected zone in the spring of 1998, were as large as those in the comparable 1997 season. He Chondrus denuded and totally affected zones surveyed in the outfall area in 1998 seem to have rebounded from the anomalously large expanses measured in 1997, reinforcing the idea that the dredging operation that took place during the summer of 1997 may have had a noticeable impact on the affected Chondrus zones.

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I I.0 INTRODUCTION I,

The presence of hundreds of square meters of seafloor where the regionally abundant red alga, Chondrus crispus, is unnaturally absent, even in the presence of suitable substrata, provides evidence that '

the PNPS nearfield discharge area is affected by elevated temperature and high current velocity, causing bottom scouring, of the cooling water outflow. To study this acutely impacted area, a qualitative diver transect study was designed to map the effects of the thermal effluent on nearby algal distributions. SCUBA divers perform seasonal transect surveys to measure the extent of denudation and other reductions in size or density of the algal flora, particularly Chondrus crispus, in the nearfield discharge area.  ;

This report represents a continuation oflong-term (25 yr) benthic studies at (PNPS) designed to monitor the effects of the thermal effluent. The 1998 monitoring program consisted of three qualitative undenvater su veys of algal cover in the nearfield thermal plume of the effluent within and beyond the f

discharge canal (Figure 1), performed in March, June, and October. Currently, no quantitative assessments of benthic flora or fauna are being made. Beginning in 1996, reports have been prepared after each seasonal  !

l survey to compare the collected data with an historical baseline that tabulates, for each parameter, the  !

maximal sizes measured prior to the 1996 survey season (1983 through February 1996). This Semi-Annual Il!

I Report includes seasonal qualitative observations, tabular and graphical comparison of these data with historical baselin s, and a summary of the potential impact on algal distributions caused by PNPS. Work was performed under Boston Edison Co. (BECo) Purchase Order LSP009647 in accordance with requirements of the PNPS NPDES Permit No. MA 0003557.

PNPS is a base-load, nuclear-powered electrical generating unit designed to produce 670 megawatts of electrical energy when operating at full capacity. The condenser is cooled by water withdrawn from Cape l Cod Bay and subsequently returned to the Bay via an open discharge canal designed to dissipate heat through rapid mixing and dilution of the outflowing water. Two circulating water pumps produce a maximum water 2 d flow of approximately 20 m s The PNPS cooling system may affect the benthic community in three ways: ,

1) by warming ambient waters (aT=18'C),2) through chemical discharge (mainly Cl ), 2 and 3) by seabed scouring from the rapid (- 2.1 mps at low tide) flow regime. High temperature and chemical discharges may stress the algal community so that species composition and community structure change, with the extent of such change depending upon season and local oceanographic conditions. A high current velocity directly affects the benthos by actually removing benthic organisms and inhibiting settlement and recolonization; where there is intense bottom scouring, rock surfaces may support fewer and smaller macroscopic organisms than normally would be present.

2 I

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Location of Pilgrim Nuclear Power Station Qualitative Algal Suney Area.

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2.0 FIELD STUDIES l\

2.1 METHODS The qualitative algal survey is performed by SCUBA divers in the same location and with the same techniques that have been used since the present monitoring program began, approximately 17 years ago.

'Ihe effluent area is surveyed by two or three SCUBA-equipped biologists operating from a small boat. For all 1998 suneys, the divers were able to launch their boat from the fishermen's launching site within the PNPS facility. For the qualitative transect survey, underwater visual observations are made along the axis of the discharge canal. A line is stretched across the mouth of the discharge canal (Figure 2). A weighted central transect line (CTL), marked at 10-m intervals, is then attached to the centt r of this line and deployed along the central axis of the canal to a distance of 100 m offshore, where it is anchored. Using a compass, divers extend a measuring line at least 45-m long and marked at 1-m intervals, perpendicular to the CTL at each 10-m mark. A diver swims along this third line, recording changes in algal cover from the CTL through the denuded, sparse, and stunted Chondrus areas, until the algal cover looks normal. A large boulder, nearly exposed at mean low water, is used as a landmark by dive teams and serves as a visual fix for proper alignment of the CTL. To ensure consistency among surveys, the divers make sure that the boulder is always located at 65 m along and just to the north of the CTL.

The terminology established by Taxon (1982) and followed in subsequent years uses the general abundance and growth morphology of Chondrus crispus to distinguish between " denuded" and " stunted" zones. The denuded zone is the area in which Chondrus occurs sparingly and only as stunted plants restricted to the sides and crevices of rocks. In this area, Chondrus is found on the upper surfaces of rocks only where the microtopography of the rock surfaces creates small protected habitats. In the stunted zone, Chondrus is found on the upper surfaces of rocks but is noticeably inferior in height, density, and frond development compared to plants growing in unaffected areas. In 1991 the divers began to discriminate between a stunted zone and a " sparse" zone. The sparse zone is an area with normal-looking Chondrus plants occurring only at very low densities. The control zene begins at the point where Chondrus height and density are fully developed. The dive team must keep in mind while taking measurements that the shallow depths northwest of the discharge canal hamper normal Chondrus growth. In addition to evaluating extent and condition of algal cover, the divers record any unusual recent events in the area, such as the occurrence of unusually strong storms, and note the location of any distinctive algal or faunal associations.

I 4

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I I

yAnchor and Line Figure 2. Design of the Qualitative Transect Sun'ey.

r' I

Since the April 1996 survey, Quarterly Progress reports have been submitted to BECo. These reports I

tabulate areal results of each SCUBA survey and compare them to previously measured maximal sizes of Chondrus denuded and totally affected zones, as well as other parameters, for that season. Particular attention is paid to changes in the sizes ofimpacted regions that exceed earlier results (prior to 19960 by more than 15%, in which case a written report is to be submitted to the PATC Benthic Subcommittee. Table 1 and Figure 3 summarize these comparisons for 1998. The quality control (QC) protocol for the 1998 benthic algal monitoring program is included as Appendix A.

2.2 RESULTS Qualitative transect surveys of acute nearfield impact zones began in January 1980 and were conducted quarterly since 1983 through 1997. This frequency was reduced to three suneys for 1998 that were performed on March 2, June 11, and October 28, bringing the total number of surveys conducted 72.

Results of surveys conducted from January 1980 to June 1983 were reviewed in Semi-Annual Report 22 to BECo (BECo,1983). A summary of surveys conducted between 1983 and 1997, including a review of the four performed in 1996, was presented in Semi-Annual Report No. 51 (BECo,1998). The present report summarizes the March and June 1998 surveys, presents detailed results of the October 1998 survey, and discusses long-term trends.

Figures 4 - 7 show the results of the 1998 transect surveys. in the figures, the denuded zone is essentially devoid of Chondrus crispus, while sparse zones have normal looking Chondrus that is sparsely distributed and stunted zones contain smaller than normal Chondrus plants. Dislodged jetty boulders encountered by the divers along their transects are indicated. The landmark boulder (at 65-m) is plotted in all figures as are positions of other common algal and faunal species observed. A large area, densely covered byjuvenile mussels, was observed during each survey and delineated.

2.2.1 MARCH 1998 TRANSECT SURVEY The denuded and sparse Chondms zones observed on March 2,1998, immediately offshore of PNPS, are shown in Figure 4. The denuded area (1437 m2 ) was 23% smaller than in spring 1996 and 14% smaller 5 than in March 1997 but was still larger than measured during all other previous spring surveys. The totally 2

affected srea (2112 m ) was 40% smaller than it had been during the previous survey in December 1997,1%

la.ger than in the 1997 spring survey, and 4% larger than measured in April 1983, the historical spring baseline for the total affected zone (Table 1). The denuded region extended 93 m offshore along the CTL and, as often seen before, was asymmetrically distributed with 56% of the denuded area north of the line.

6 I)i Ii

Talile 1. Qualitative Algal Survey Data for 1998 Compared to IIistorical Base.line Data.

Spring Summer Fall Measurement March ilistorical Percent June llistorical Percent Oct. liistorical Percent 1998 Baseline Change 1998 Daseline Change 1998 Baseline Change i (Date) from (Date) from (Date) from Baseline Baseline Baseline TotalDenuded Area 1437 1321 +8% 1738 1835 -5% 2469 2043 +21%

(m') (3/91) (6/90) (10/95)

Total Affected Area 2112 2029 +4% 2136 2135 +0% 3112 2348 +33%

l (m') (4/83) (6/90) (10/95)

Maximal Distance of 93 94 (3/91) l% 92 105 -12% 100 103 +0%

Affected Area from (6/92) (9/90, Discharge Canal (m) 10/95)

Maximal %idth of 34 40 (4/83, -15% 42 39 +8% 54 42 +29%

l Affected Area (m) 3/84) (6/84) (10/94) l 3500 ; 120 3000d- _ . _ . . A- - - - . - - . . ;;. : : r= q 100

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- 4 . . Maximal Distance-1998 - -A - Maximal Distance-Baseline  ;

_ - C- Maximal Width-1998 --G--Maximal Width-Baseline I

Figure 3. Qualitative Algal Survey Data for 1998 Compared to IIistorical Baseline Data.

7 L

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M::':<:.:::6 M g l Figust 6. Denuded, Sparse, and Stunted Chondrus Zones and Dense Mussel Area Observed in October 1998. B 10 g

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11 m

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Other algae present included: Enteromorpha, Fucus, Corallina and, further offshore, Ascophyllum. In 1

contrast to 1997, an extensive set of the blue mussel, A&tilus edulis, had already occurred, a phenomenon perhaps accelerated by our anomalously warm winter. Juvenile mussels,1-5 mm in length, were common

]

(outlined by M's in Figure 4) and responsible for the almost complete epiphytization of Chondrus. Other invertebrates included: many Asterias forbesii, a mussel predator; Littorina littorea, the common periwinkle; one blue crab, Callinectes sapidus; and the colonial anemone, Epi:oanthus incrustatus. No Gsh or lobsters were seen.

2.2.2 JUNE 1998 TRANSECT SURVEY I Results of the divers' sun ey for June 11,1998 are mapped in Figure 5. The Chondrus denuded zone and totally affected areas were smaller this summer than observed during the past two summer surveys. The j

2 denuded zone (1738 m ) extended 92 m offshore along the CTL, was 21% larger than three months earlier l l

in March,31% smaller than in June 1997 and 5% less than the June 1990 summer historical baseline of 2

1835 m (Table 1). In contrast to the pattern seen during most prior surveys, the denuded zone extended much farther to the south than usual with three-quarters of the denuded zone south of the CTL. The sparse 2

and stunted Chondrus zone (398 m ) was 41% smaller than in March 1998 and 73% smaller than in the 2

previous June. The total affected area (2136 m ) was only 1% larger than in March 1998, nearly half the size 2

as measured the previous June, and the same size as the 1990 historical summer baseline (2135 m ). Very few algal plants were seen. Mussels carpeted the area so thickly than even identincation of Chondrus plants could be verined only after the mussels were removed. The region with 100% mussel coverage (outlined by M's in Figure 5) was very nearly coincident with the totally affected Chondrus area. Dense aggregations ofjuvenile (5-10 cm in diameter) star 6sh, Asteriasforbesii were seen. Other invenebrates present included:

rock crabs (Cancer borealis), green crabs (Carcinus maenas), and spider crabs (Libinia sp.). Winter flounder (Pseudopleuronectes americanus) and a school of striped bass (Morone saratilis) were seen.

2.2.3 OCTOBER 1998 TRANSECT SURVEY Figure 6 shows the results of the transect survey conducted on October 28,1998. For most parameters, the 1998 measurement.s exceeded the 15% target limit (Table 1). However, the surveyed areas were not as large as measured during the 1997 fall survey and the divers were able to inspect the entire area.

2 The area of the denuded zone (2469 m ) was much larger (42%) than in June 1998, a not unusual event, and 21% larger than the October 1995 baseline. The pattern of denudation had reverted to the more usual 12 I

l situation, with most of the affected area (two-thirds) north of the CTL, thus, reversing the unusual pattera seen in June.

The areas of the sparse and stt.nted Chondrus zones totaled 6432 m in October, smaller than in the fall of 1997 but approximately the same as seen in the fall 19962 (636 m ). The total affected area in October was 3112 m2,10% larger than measured in June 1998, and 33% larger than the historical 2baseline (2348 m )

established in October 1995. The totally affected area extended out along the CTL to 100 m (the same as the baseline); the maximal width of the affected zone was 54 m at the 50-m mark on the CTL (29% larger than the baseline). Besides Chondrus the only other macroalgae noted were C. purpureum and Gracilaria spp. growing close to the CTL out to the 60 m mark.

Mussels had disappeared from the portion of the CTL closest to thejetties, but were present in a narrow band along the CTL between the 40-m and 50-m marks, and abundant (20 cm in length) in a wide area even extending beyond the Chondrus affected zone from the 70-m to 95-m marks on the CTL (outlined by M's in Figure 6). The most unusual invertebrates seen were a number of the colonial tunicates, Diplosoma spp. This is an invading species and has been noticed for about the last two years on the pilings of the WHOI dock in Woods Hole. A few specimens had been seen in the BECO dive area on earlier occasions but the numbers present in October were much greater especially from the 70-m to 100-m marks on the CTL. Other invertebrates observed included: starfish, amphipods, green and rock crabs, and anemones. No fish or kelp were seen.

2.3 DISCUSSION The configuration of the Chondrus crispus denuded zone, that can extend seaward even farther than 100 m beyond the discharge canal, is readily apparent to SCUBA divers and easily mapped from the qualitative transect survey. Stunted and sparse zones are sometimes less obvious, but the sparse zones observed in 1998 were delineated without difficulty. For the March 1998 survey, the sizes of the denuded end totally affected zones were slightly larger than the historical maxima (+8% and +4%, respectively),

while in June, both areal measurements fell well within those surveyed when the plant was in full or nearly full operation and within the 15% target limit when compared to the historical baseline (maximum measurements recorded prior to the 1996 survey year). For the October 1998 survey, the areas of the denuded and total affected zones were much smaller than in the fall of 1997 but still large compared to the baseline. The denuded zone was the third highest ever measured (after the 1997 summer and fall surveys) and the totally affected area was the second largest measured during a fall survey when the plant was in full or nearly full operation. By March 1998, an extremely dense mussel mat was already present, much earlier 13

I l

in the year than in most earlier surveys. By June, this mat, composed ofjuvenile mussels 5 to 30 mm in Ii length, provided nearly 100% coverage over the entire C/mndrus affected region. This mussel mat phenomenon has been seen during every June survey since 1990, except for 1991. The areas of the denuded and totally affected zones were again greater in June than in March, the usual trend when early summer growth of Chondrus is adversely affected by high mussel settlement. In October 1998, even though the mussel mat was somewhat reduced in size, the denuded and totally affected Chondrus areas were still very large, exceeding the lustviical baseline by 21% and 33%, respectively.

The highest ever annual capacity factor at PNPS for 1998 (97.1 %), coupled with summer temperatures, probably was reflected in the size increase of the Chondrus affected zones seen in October I over those measured .in June. The decrease in the June and October 1998 areal measurements when compared to those delineated in the same seasons in 1997 may reflect a recovery from the additional stress placed on the system last year from the summer-time dredging operation that took place in the plant intake area in 1997.

1 I

Ii 1 l

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I I

I I

" E I

1 3.0 IIISTORICAL IMPACT OF EFFLUENT DISCHARGE AT PNPS ON ALGAL DISTRIBUTION

3.1 BACKGROUND

Historically, operational conditions at the PNPS have provided opportunities to assess long-term trends associated with impacts on the benthic community. Plant operations have included consecutive years ofhigh operation as well as times when there were complete shutdowns, sometimes for prolonged periods.

The longest outage in the history of the plant began in April 1986 and continued until March 1989. During this period the benthic community associated with the ef0uent canal and nearby areas immediately offshore experienced reduced current velocity as the use of circulating pumps was restricted to one or none (Figure 8). In addition, the discharge water remained at ambient temperature. As a consequence. the benthic community normally afTected by these efDuent parameters recovered, so that by 1988 there was essentially no difference between the control stations and the areas near the discharge canal.

Studies conducted after the power plant resumed electrical generation at full operating capacity, with the consequent thermal discharge and consistent use of one or both circulating pumps, assessed the impact of plant operation on a benthic environment that had returned to near ambient conditions. Quantitative faunal and algal monitoring studies, and qualitative transect surveys were conducted through 1991. In 1992, community studies of the benthic algae and fauna were discontinued. From 1992 through 1997, the monitoring program consisted of quarterly qualitative surveys of the discharge area. For 1998, three seasonal (spring, summer, and fall) qualitative surveys were performed.

PNPS operated at it's highest ever capacity in 1998. Figure 8 shows the monthly dependable capacity (MDC) factor and circulating water pump operation of PNPS since 1983. The percent MDC is a measure of reactor output and can be used to estimate thermal loading to the marine environment. A maximum MDC value of 100% approximates, with some seasonal variation, the greatest allowable increase (18' CAT) in ambient temperature for effluent water discharged to Cape Cod Bay. In 1998, the monthly dependable capacity factor was greater than 97.0 % for 8 months and never less than 92.5%.

I 3.2 QUALITATIVE TRANSECT SURVEYS: 1983-1998 Results of the qualitative transect surveys from 1983 through 1998 are summarized in Figure 9. The total acute impacted area (denuded, sparse, and stunted), the area of the denuded zone only, and the monthly PNPS capacity factor (MDC) are plotted. The difference between the denuded and total acute impact zones represents the area of the sparse and stunted zones.

15

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I, A lag in recovery time in the acute impact zone during and following the 1984 PNPS power outage I

was reported in Semi-Annual Report No. 27 (BECo,1986). Evidence of this slow recovery included a decrease in the area of the total acute impact zone that began in mid-1984 (5 months after the cessation of power plant operations) and continued through mid-1985. Between December 1984 and December 1985, the total affected area was the smallest recorded between 1983 and 1986, indicating a delay in recovery in response to the absence of thermal discharge and reduced circulating water pump operation in 1984. This delay phenomenon also held true when the situatie, was reversed, so that the size of the acute impact zone began to increase only 6 to 9 months (September to December 1985) after the resumption of thermal effluent discharge and normal circulating water pump operation. These results confirmed a delay of 6-9 months between the causal factors (cessation or resumption of thermal effluent discharge and normal pump operation) and associated responses (decrease or increase in size of the acute impact zone). In 1987, in response to the 1986-1989 outage, increased recolonization of the denuded and stunted zones by Chondrus made zone boundaries diflicult to distinguish (no areal differences could be discerned from September 1987 througn June 1989). As in summer 1984, the large size reduction of the denuded zone between December 1986 and June 1987 was primarily the result of the shutdown of the circulating water pumps in late Februar'3 1987 that continued into the summer (BECo,1988). Apparently, water current scouring is a greater stress to algal colonization than elevated water temperature. Generally, scouring denudes the substratum, whereas elevated temperature results in stunted growth (Bridges and Anderson,1984).

In 1988, low circulating water pump activity caused few scouring effects. The 1988 transect surveys showed such an increase in recolonization of fomierly denuded and stunted zones by Chondrus, because of the continuing outage, that divers could not detect zonal boundaries or make area measurements. In March and June 1989, divers were still unable to detect boundaries of denuded or stunted zones (BECo,1990). In September and December 1989, presumably in response to increased PNPS operations with resultant thermal effects and scouring of the acute impact zone, boundaries began to be redefined and area measurements were made of the total impact zone.

During 1990, boundaries between the stunted and denuded zones became even more clearly defined and areal measurements of both zones were made. The denuded and total impact zones in June 1990 were the largest measured since 1983 (BECo,1991). The dramatic increase in total affected area that occurred between April and June 1990 had not been seen before. The typical pattern seen prior to 1990 was that during spring, with warmer temperatures and increased sunlight, algal growth flourishes, and the impact area declines even in years when the power plant is operating at high capacity. The pattern in 1990 appeared anomalous until, more recently, a correlation was made between the appearance of enormous numbers of 18 I'

juvenile mussels and the occurrence oflarge denuded and total affected zones. The divers noted remarkable numbers ofjuvenile rnussels during the June 1990 dive. Thus, it would appear that the large affected zones result, at least partly, from damage suffered by the Chondrus plants due to the massive settlement ofmussels.

In 1991, the boundaries of the acute impact zone remained well-defined, except that in June there was no true stunted zone but only an area described by the divers as " sparse", that is, where the algal plants grew normally but were thinly distributed. From March to June, the total affected area and the Chondrus denuded zone decreased in area, a return to the typical pattern seen before 1990 (BECo,1992). This decrease in area continued through the October survey, perhaps aided by the power plant outage from May into August. There was a slight increase in the affected area in December.

During 1992, the divers were unable to discern a Chondrus stunted region. Except for June, they noted zones containing normal but sparsely distributed Chondrus plants. An enormous set of mussels that had reached 0.5 cm in length by June, totally obliterated the boundary between the denuded and sparse areas.

Parallel to results seen in 1990, the areas of the denuded and total acute impact zones in June 1992 were larger than any seen (except for 1990) since 1983, and the dramatic increase in total affected area that occurred between April and June 1990 occurred once again in 1992. Thus, the pattern seen in 1990 can no longer be considered anomalous but may be related to oceanographic conditions that lead to a large settlement of mussel larvae and consequent damage to Chondrus plants (BECo,1993).

In 1993, the June mussel set that hampers Chondrus growth was not as dense as those that occurred in 1990 and 1992, so that the denuded zone was smaller in June than it had been in April, the opposite of the situation seen in 1990 and 1992 (BECo,1994). The area of the denuded zone in September was slightly larger than it had been in September of 1990 and 1992, but the denuded zone in December was much larger than in previous years. In addition, the total affected area in December was the largest seen since 1983, rivaling the areas measured in the summers of 1990 and 1992; this may be partly due to the very early winter date (Dec. 2) of the survey and partly to damage imposed by a heavy infestation of the encrusting bryozoan, Membranipora membranacea.

In 1994, the denuded and total affected Chondrus areas in all four seasons were similar in size to those found during prior surveys (since 1989) at times of full or nearly full power plant operation (BECo, 1995). The dense mussel settlement seen in June obscured the boundary between the denuded and sparse / stunted regions and damage caused by the mussels to the Chondrus plants contributed to the enlargement of both Chondrus zones between the April and June surveys. The three-month fall power plant outage (September through November) appeared to have had no effect on the size of either the denuded or l total affected Chondrus zones.

19 W

in 1995, the sizes of the denuded and total affected Chondrus areas were within the ranges seen in I

earlier surveys only for the early May and late June sun eys (BECo,1996). The impacted areas in October 1995 and February 1996 were much larger than those measured during any earlier fall and winter surveys and most closely approximated the impacted areas seen in September and December 1993. The two-month (April /May) spring power outage appeared to have no effect on the size of the Chondrus affected areas seen in May or June. Ilowever, the high plant operating capacity in effect from June 1995 through February 1996, in c onjunction with a high mussel set in June, may have contributed to the largest fall and winter denuded and totally affected Chondrus zones seen since the current monitoring program began in 1983.

In 1996, the sizes of the uenuded and totally affected Chondrus areas continued to increase over his:orical baseline measurements (1983 through February 1996) for the first three surveys, in December, the denuded zone declined in size to less than the winter historical baseline but was still the second largest ever observed in winter (BECo,1997). The large Chondrus denuded and totally affected zones seen in each survey since October 1995 may be due to a combination of the high plant capacity that was in effect for the 18 montis Aarting in July 1995 (mean = 92.6%), high summer water temperatures, and extremely dense settleme .t by mussel larvae in late spring that totally covered, possibly damaging, the algal plants.

In 1997, the sizes of the denuded and totally affected Chondrus zones were again larger than historical baseline measurements. In March 1997, the impacted areas were the second largest ever measured in spring. For the remaining three seasons, the areas of the denuded and totally affected zones were the largest ever seen for the corresponding season. The sizes of the denuded and totally affected zones in 1997 were extraordinarily large, larger than in 1996 for three surveys, and appeared not to track the reduction in the annual plant capacity factor from 90.5% in 1996 to 73.4% in 1997 that resulted from a two-month spring power outage. Turbidity from the dredging operation that took place from mid-June until the end of August, in conjunction with dense settlement byjuvenile mussels that occurred sometime between March 28 and June 22, high summer water temperatures, and a moderately high 1997 power plant capacity, probably caused many Chondrus plants to die back to their holdfasts, yielding very large affected Chondrus zones.

In 1998, some recovery apparently took place in the outfall area compared to the very large denuded ard totally affceted Chondrus zones seen in the summer, fall, and winter of 1997. The areal measurements taken in March were somewhat higher than the historical maxima, but those made in June were well withm g

those seen in previous surveys when the plant was in full or nearly full operation. The sizes of the Chondrus EI der 2uded and affected zones did increase dramatically between the June and October surveys, probably as i a consequence of warm summer water temperatures combined with the extremely high plant capacity (97,1%) in effect in 1998, the highest seen in the history of plant operations.

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

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4.0 CONCLUSION

S e

The denuded and totally affected Chondrus areas of the acutely impacted region off PNPS for the March survey were smaller than seen in the 1996 and 1997 spring surveys, although still larger than the historical baseline values (for each season, the largest area measured between 1983 and the 1995 survey seasons).

e The Chondrus denuded and affected zones measured during the June 1998 surveys 3 were within the range seen in prior surveys when the plant was in full or nearly full operation. Some parameters were less than historical baseline values.

Mussels settled earlier than usual so thatjuvenile mussels were common over the

^

entire length of the CTL by March 2,1998. The timing of this ' set' may have been acceleratea by our anomalously wann winter.

o The areas of the denuded and total affected zones were greater in June than in March 1998, the usual trend observed when early summer Chondrus growth is adversely affected by high mussel settlement.

I e The denuded and totally affected Chondrus areas increased dramatically between the June and October surveys, probably as a consequence of warm summer water temperatures combined with the highest plant capacity (97.1 %) seen in the history of plant operations.

e in spite of the increase in size of the denuded and totally affected Chondrus zones between June and October, they were much smaller in October than they had been in the fall of 1997, indicating a recovery from the additional stress placed on the system from the dredging operations that occurred during the summer of 1997.

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r I I 5.0 LITERATURE CITED I Boston Edison Co.1983. Marine ecology studies related to the operation of Pilgrim Station. Semi-Annual Report No. 22. Boston, MA. I Boston Edison Co.1986. Marine ecology studies related to the operation of Pilgrim Station. Semi-Annual Report No. 27. Boston, MA.

Boston Edison Co.1988. Marine ecology studies related to the operation of Pilgrim Station. Semi-Annual Report No. 31. Boston, MA.

Boston Edison Co.1990. Marine ecology studies related to the operation of Pilgrim Station. Semi-Annual Report No. 35. Boston, MA.

Boston Edison Co.1991. Marine ecology studies related to the operation of Pilgrim Station. Semi-Annual Report No. 37. Boston, MA.

Boston Edison Co.1992. Marine ecology studies related to the operation of Pilgrim Station. Semi-Annual Report No. 39. Boston, MA.

Boston Edison Co.1993. Marine ecology studies related to the operation of Pilgrim Station. Semi-Annual Report No. 41. Boston, MA.

Boston Edison Co.1994. Marine ecology studies related to the operation of Pilgrim Station. Semi-Annual Report No. 43. Boston, MA.

i Boston Edison Co.1995. Marine ecology studies related to the operation of Pilgrim Station. Semi-Annual Report No. 45. Boston, MA.

Boston Edison Co.1996. Marine ecology studies related to the operation of Pilgrim station. Semi-Annual Report No. 47. Boston, MA.

l l

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I Boston Edison Co.1997. Marine ecology studies related to the operation of Pilgrim station. Semi-Annual Report No. 49. Boston, MA.

l Boston Edison Co.1998. Marine ecology studies related to the operation of Pilgrim station. Semi-Annual Report No. 51. Boston, MA.

Bridges, M'.L and R.D. Anderson.1984. A brief survey of Pilgrim Nuclear Power Plant effects the marine aquatic environment, p. 263-271. In: J. D. Davis and D. Merriman (eds.)

Observations on the ecology and biology of western Cape Cod Bay, Massachusetts,289 pp.  !

Springer-Verlag. (Lecture Notes on Coastal and Estuarine Studies, Vol.1 I).

l Taxon.1982. Benthic studies in the vicinity of Pilgrim Station. In: Marine Ecology Studies Related to Operation of Pilgrim Station. Semi-Annual Repon No.19.

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I l APPENDIX A I

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\

l Quality Control (QC) Protocol for Qualitative Transect Surveys at PNPS Outfall Area 1 Field Operation Planning I Field equipment is organized by the scientist in charge of dive operations; for 1999, the chief diver will be Mr. Erich Horgan of the Woods Hole Oceanographic Institution. Mr. Horgan has been a diver or I chief diver on four quarterly surveys at the PNPS outfall site since April 1996. The survey equipment includes a boat and associated safety equipment; anchor and line; buoy and diver safety line; SCUBA gear, i

1 incluchg a collecting bag; 100-ft kevlar line to be deployed across the mouth of the discharge canal; grapnel l to aid in tying off the kevlar line tojetty boulders; the weighted 100-m central transect line (CTL), marked at 10-m mtervals; two 30-m measuring tapes; compass; clipboard; data sheets on plasticized paper; two #1 l

pendis.

Every attempt will be made to perform the one dives between mid-September and mid-October as scheduled. Windows of opportunity, considering times of high tide (less current for the divers to contend with) and other commitments for both boats and personnel, will be blocked out in advance. Enough leeway will be planned to allow some flexibility for bad weather days.

2 Pre- and Post-dive Briefines

'Ihe chief diver and ENSR data manager, Isabelle Williams, will hold a pre- and post-dive briefing.

The pre-dive briefing (may be made by telephone) will be the opportunity for determining the dive schedule, for reviewing data collection, and for informing the dive team whether or not any additional observations are requested. At this time, emphasis will be placed on the importance of the divers exploring the limits, and defining them, of the entire affected area so that a comprehensive survey map can be produced. The post-dive briefing (in person) will give the chief diver the opportunity to tell the data manager his immediate impressions about the region surveyed and whether any problems were encountered that need to be corrected.

3 Data Collection A diver swimming perpendicularly away from the CTL, along the measuring line, records the distance away from the CTL line that changes in algal cover occur, from denuded to sparse and/or stunted Chondrus areas, and from sparse and/or stunted Chondrus to normal-looking Chondrus. Positions of other algal species, especially Gracilaria, a warm-water indicator, and kelp (Laminaria), a cold water indicator, 24

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are noted. Positions of animals, including mussels, starfish, crabs, and fish, and any unusual activities are I

also indicated.

For 1999, detailed observations will be made of Chondrus, including notes on robustness, color, occurrence of epiphytes, and qualitative descriptions of density and height. The divers will look for the presence of Phyllophora, the second dominant algal species in this community, throughout the survey area; if necessary, they will collect an algal sample from the normal Chondrus zone for examination in the laboratory. Particular attention will be paid to the boundaries of the high-density mussel array that may persist from ti.e spring or summer settlement.

A sample blank data sheet is shown. A separate sheet is used for the north and south sides of the CTL. As the diver swims away from the CTL, distances and notes are recorded on the data sheet from left to right. For ease in working in an underwater environment algal cover is coded as indicated on the data sheet: 1 - denuded; 2 - stunted; 3 - sparse; 4 - normal. Codes for mussel cover are M1 - very dense; M2 -

separated clumps; M3 - absent. i

(

4 Data validation The diver recording data during the field survey is responsible for reviewing his work at the end of the survey to ensure that the data are complete and accurate. The chief diver will submit to the data manager the original field notes and a survey report, previously reviewed for accuracy and completeness by other members of the dive team, that includes the data on the total extent of the denuded and stunted Chondrus

)

zones as well as a general description of the area surveyed, including notes on flora and fauna observed. The data manager is responsible for reconciling data in the submitted field repon to those recorded on the original data sheets. The data manager will discuss any questions that may arise with the chief diver. The data  ;

i manager is responsible for constructing maps based on the survey data and for calculating the total areal extent of the denuded and totally affected Chondrus regions. All calculations performed by hand are checked for accuracy. The data manager is responsible for proof-reading the final computer-generated maps I'

against the original maps for accuracy. All reports generated by the data manager will be reviewed by the ENSR Project Manager, Dr. James Blake.

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5 Obsenation ne data manager will plan to accompany the divers on the 1999 field trips. She will be be on hand to accept any samples collected during those dives and to hear immediately the impressions of all divers about the conditions of the outfall area, as well as ensure that the entire affected area has been surveyed.

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T 6 Meetines The project and/or data manager will attend full Administrative-Technical Committee and Benthic Subcommittee meetings when appropriate. This will help ensure communication between ENSR, the field team, and the A-T Committee so that the quality of the benthic survey will be maintained as guided b Committee.

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Il Date:

Wind:

Divers Down @:

I Divers Up @: E Visibility:

E CTL(m) NORTH / SOUTH CHONDRUS 30 1 DENUDED g 2 STUNTED E 3 SPARSE g 40 4 NORMAL E MUSSELS 50 M1 V. DENSE M2 CLUMPS l M3 ABSENT 60 l I 70 I{

80 l

90 l .

NORMAL CHONDRUS i 100 ROBUSTNESS COLOR

>100 EPIPHYTES HEIGHT l

COLOR g Qualitative Transect Survey Field Data Sheet.

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1 I ICHTHYOPLANKTON ENTRAINMENT MONITORING AT PILGRIM NUCLEAR POWER STATION JANUARY - P"CEMBER 1998 i

Submitted to Boston Edison Company Boston, Massachusetts I

by Marine Research, Inc.

Falmouth, Massachusetts I

i April 1,1999 l

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TABLE OF CONTENTS SECTION PAGE I EXECUTIVE

SUMMARY

l II INTRODUCTION 3 III METHODS AND MATERIALS 4 IV RESULTS ANDDISCUSSION A. Ichthyoplankton Entrained - 1998 13 B. Notification Plan 18 C. Multi-year Ichthyoplankton Comparisons 19 D. Ichthyoplankton Entrainment Impacts - General 41 E. Ichthyoplankton Entrainment Impacts - Specific 44 F Lobster Larvae Entrained 53 V LITERATURE CITED 54 APPENDICES A and B (available upon request) l PLATE I Plankton net streaming in the discharge canal at Pilgrim Station for the collection of fish eggs and larvae (lobster larvae are also recorded).

A single, six-minute collection can contain several thousand eggs t.nd larvae representing 20 or more species.

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LIST OF FIGURES FIGURE PAGE 1 Entrainment sampling station in PNPS discharge canal. 5 2 Dominant species of fish eggs and larvae found in PNPS ichthyoplankton samples during the winter-early summer season. Percent of total and summed monthly means for all species are also shown. 14 p 3 Dominant species of fish eggs and larvae found in PNPS ichthyoplankton samples during the late spring-early spring season. Percent of total and summed monthly means for all species are also shown. 15 4 Dominant species of fish eggs and larvae found in PNPS ichthyoplankton samples during the late summer-autumn season. Percent of total and summed I monthly means for all species are also shown. 17 5

l Mean monthly densities per 100 m' of water in the PNPS discharge canal for the eight numerically dominant egg species and total eggs,1998 (bold line). Solid lines encompassing shaded area show high and low values over the 1982-1997 period.

f 27-32 6 Mean monthly densities per 100 m' of water in the PNPS discharge canal for the thirteen numerically dominant larval species and total larvae,1998 (bold line). Solid lines encompassing shaded area show high and low values over the 1982-1997 period. 33-40 7 Estimated numbers of fish eggs entrained at PNPS by species or group,1998. 42 8 Estimated numbers of fish larvae entrained at PNPS by species or group,1998. 43 9 Numbers of equivalent adult winter flounder estimated to have been lost to entrainment at PNPS, 1980-1998. 58

. 10 Numbers of equivalent adult cunner estimated to have been lost to entrainment at PNPS, 1980-1998. 59 11 Numbers ofequivalent adult Atlantic mackerel estimated to have been lost to entrainment at PNPS, 1980-1998. 59 ii

LIST OF TABLES TABLE EAG]l 1 PNPS ichthyoplankton entrainment notification levels for 1998 by species category and month. See text for details. 9-12 2 Species of fish eggs (E) and larvae (L) obtained in ichthyoplankton collections from the Pilgrim Nuclear Power Station discharge canal, January-December 1998. 60-61 3 Ichthyoplankton densities (number per 100 m' ofwater) for each sampling occasion during months when notably high densities were recorded, January-December 1998. Densities marked by + were unusually high based on values in Table 1. Number in parentheses indicates percent of all previous values during that month which were lower. 62-66 4 Species of fish eggs (E) and larvae (L) collected in the PNPS discharge canal,1975-1998. 67-69 t

5 Numbers oflarval winter aounder entrained at PNPS annually by stage, 180-1998. Number and weight of equivalent age 3 adults calculated by two methods is also shown. 70 6 Ares 514 commercial landings and Mr.ssachusetts recreational landings from inland waters (pounds), 1982-1997. 71 7 Numbers of cunner eggs and larvae entrained at PNPS annually,1980-1998. Numbers of equivalent adults are also shown. 72 8 Numbers of Atlantic mackerel eggs and larvae entrained at PNPS annually, 1980-1998. Numbers of equivalent age 1 and age 3 fish are also shown. 73 LIST OF APPENDICES APPENDlX l A* Densities of fish eggs and larvae per 100 m5 ofwater recorded in the PNPS discharge canal by species, date, and replicate, January-December 1998.

l B* Geometric mean monthly densities and 95% confidence limits per 100 m2 of water for the dominant species of fish eggs and larvae entrained at PNPS, January-December 1981-1998.

• Available upon request.

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1 SECTION I EXECUTIVE

SUMMARY

Sampling of entrained ichthyoplankton at PNPS followed the revised protocol initiated in April 1994. In January, February, and October through December three samples were taken every other week each month, weather permitting. From March through September single samples were taken three times every week in conjunction with the impingement monitoring study.

A total of 40 species were represented in the 1998 collections, two above the 23-year mean .

of 38 species. Numerical dominants during winter-carly spring included yellowtail flounder, American plaice, fourbeard rockling, and Atlantic cod eggs along with sculpin, sand lance, and rock gunnel larvae. During the late spring-early summer season numerical dominants included tautog/ cunner and mackerel eggs, along with larvae of the cunner, winter flounder, mackerel, f

rockling, hake, radiated shanny, and menhaden. During late summer-autumn, collections consisted primarily of tautog/ cunner, windowpane, and rockling/ hake, among the eggs as well as hake, rockling, cunner, Atlantic herring, windowpane, tautog, and menhaden larvae.

Comparisons ofichthyoplankton densities over the 1975-1998 time series suggested that Atlantic mackerel eggs, windowpane eggs, Atlantic menhaden larvae, and Atlantic herring larvae were entrained in relatively high numbers in 1998 consistent with overall trends in fish stocks. Larval winter flounder were also entrained in high numbers in 1998 for the second straight year although stock size estimates have varied without trend over the past nine years. Similar results were obtained for tautog and cunner larvae and, while stock size information is lacking for cunner, estimates for j tautog indicate low stock abundance. Larval hake were also numerous in PNPS samples in 1997 and 1998, both nearly double the previous high. Like tautog, stock size estimates suggest that abundance is relatively low.

Unusually high entrainment densities, as defined under PNPS's notification plan, were identified on a number occasions in 1998. These involved tautog/ cunner eggs, Atlantic menhaden eggs and larvae as well as the larvae of Atlantic mackerel, winter flounder, fourbeard rockling, hake, silver hake, tautog, cunner, and radiated shanny. The hakes displayed the most protracted period of high densities with unusually high numbers being recorded on 21 occasions in June, July, and 1

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September. Among larval tautog densities all but one in July exceeded the notification level for that month with four of those exceeding all previous July observations.. j Estimated numbers of eggs entrained by PNPS during 1998 rangcd from 918,000 for searobins to 4,342,000,000 for tautog/ cunner and totaled 5,124,000,000 for all eggs combined.

Corresponding values for larvae ranged from 831,000 for seasnail to 370,218,000 for cunner, totaling 882,183,000 for all larvae combined.

Entrainment of winter flounder, cunner, and Atlantic mackerel, was examined in more detail dating back to 1980 using the equivalent adult (EA) approach. Winter flounder estimates for 1998 were 5,473 and 77,428 age 3 adults based on two suites of survival values, the highest yet observed -

because larvae were very abundant at PNPS during May and June of the 1998 season. These values were compared with estimates of commercial and recreational landings as well as local population estimates determined by trawl and mark-recapture. Recent, dramatic declines in commercial flounder landings reduce the value of that variable as a measure of EA impacts. The 1998 EA estimate from the larger staged approach amounted to 29% of the local area-swept population estimate and 75%

g of a mark-recapture estimate. A respective EA estimate for numbers of cunner eggs and larvae entrained in 1998 amounted to 1,522,731 fish. Comparable values for 1980-1997 ranged from 113,048 to 2,353,607 adult fish. The mean cunner EA value for the 1980-1998 time series (428,119) represented less than one percent of an estimate of the number ofcunner spawning in the PNPS area.

For Atlantic mackerel EA estimates of 2,633 age I fish or 1,082 age 3 fish were obtained for 1998.

Average values of4,214 and 1,732 age 1 and 3 fish, respectively, were obtained over the 1980-1997 time series. Each of these values represented less than one percent of the commercial mackerel landings for area 514 which encompasses Cape Cod Bay and Massachusetts Bay. They also represented 0.08% of an estimate of the number of mackerel spawning in the PNPS area.

No lobster larvae were collected in 1998 for the third straight year. The total dating back to 1974 remains at 13.

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I SECTION II INTRODUCTION I

This report summarizes results ofichthyoplankton entrainment sampling conducted at the Pilgrim Nuclear Power Station (PNPS) from January through December 1998 by Marine Research, Inc. (MRI) for Boston Edison Company (BECo), under Purchase Order No. LSP009085, in E

5 compliance with environmental monitoring and reporting requirements of the PNPS NPDES Permit (U.S. Environmental Protection Agency and Massachusetts Department of Environmental I Protection).

In an effort to condense the volume of material presented in this report, details ofinterest to some readers may have been omitted. Any questions or requests for additional information may be dirxted to Marine Research, Inc., Falmouth, Massachusetts, through BECO.

Plate I shows the ichthyoplankton sampling net being deployed on station in the PNPS discharge canal approximately 30 meters from the headwall.

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I SECTION III METHODS AND MATERIALS Monitoring Entrainment sampling at PNPS, begun in 1974, had historically been completed twice per month during January and February, October-December; weekly during March through September; in triplicate at low tide. Following a PNPS fisheries monitoring review workshop in early 1994, the sampling regime was modified beginning April 1994. In January, February, and October through December during two alternate weeks each month single samples were taken on three separate occasions. Beginning with March and continuing through September single samples were taken three times every week. During autumn and winter months when sampling frequency was reduced, sampling was postponed during onshore storms due to heavy detrital loads. The delayed sample was taken during the subsequent week; six samples were ultimately taken each month.

To minimize costs, sampling was linked to the impingement monitoring program so that collections were made Monday morning, Wednesday afternoon, and I riday night regardless of tide (see Impingement Section). All sampling was completed with a 60-cm diameter plankton net streamed from rigging mounted approximately 30 meters from the headwall of the discharge canal (Figure 1). Standard mesh was 0.333-mm except from late March through late May when 0.202-mm mesh was employed to improve retention of early-stage larval winter flounder (Pleuronectes g

americanus). Sampling time in each case varied from 8 to 30 minutes depending on tide, higher tide requiring a longer interval due to lower discharge stream velocities. In most cases, a minimum quantity of 100 m' of water was sampled although at astronomical high tides it proved difficult to collect this amount even with long sampling intervals since the net would not inflate in the low current velocity near high tide. Exact filtration volumes were calculated using a General Oceanics Model 2030R digital flowmeter mounted in the mouth of the net. Near times ofhigh water a 2030 IC! rotor was employed to improve sensitivity at low velocities.

For the most part sampling followed the sample design, however sampling was not completed on January 21, February 25, May 11, August 28, October 12, and October 14 due to stormy seas.

Sampling under such conditions results in such heavy detrital loads that processing the samples is all but impossible. (In the past when storm samples have been processed, ichthyoplankton has been 4

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-~

gVe[,

,, ,4-r-  : ,1 e. .

7 J+ h wh F  ;

• w, k y%.T MwAEN.h.Nh(k3M g h - g , +j N'h~CQ ' *

~

q ,p, f k

,.., ~~

, r- 4 4

,p .,

• ~

, 'Y g

<- -:: 4

, ano  ?

i' k *

,ef

~ ,r

.q

, e

. . J . .

(, _ f c" Plate 1. Plankton net streaming in the discharge canal at Pilgrim Station for the collection of fish eggs and larvae (lobster larvae are also recorded).

A single, six-minute collection can contain several thousand eggs and larvae representing 20 or more species.

5

I uncommon.). Sampling was also not possible on April 17, July 24, or August 7 because condenser backwashes were underway.

All samples were preserved in 10% Formalin-seawater solutions and returned to the laboratory for microscopic examination. A detailed description of the analytical procedures appears in MRI (1988). As in past years, larval winter flounder were enumerated in four developmental stages as follows:

Stage 1 - from hatching until the yolk sac is fbily absorbed (2.3-2.8 mm TL).

Stage 2 - from the end of stage 1 until a loop or coil forms in the gut (2.6-4 mm TL).

Stage 3 - from the end of stage 2 until the left eye migrates past the midline of the head during transformation (3.5-8 mm TL).

Stage 4 - from the end of stage 3 onward (7.3-8.2 mm TL).

Similarly larval cunner (Tautogolabrus adspersus) were enumerated in three developmental stages:

Stage 1 - from hatching until the yolk sac is fully absorbed (1.6-2.6 mn. TL).

Stage 2 - from the end of stage 1 until dorsal fin rays become visible (1.8-6.0 mm TL).

Stage 3 - from the end of stage 2 onward (6.5-14.0 mm TL).

Samples were examined in their entirety for larval American lobster (Homarus americanus).

When collected these were staged following Herrick (1911).

Notification Provisions When the Cape Cod Bay ichthyoplankton study was completed in 1976, provisions were added to the entrainment monitoring program to identify unusually high densities of fish eggs and larvae. Once identified and, if requested by regulatory personnel, additional sampling could be conducted to monitor the temporal and/or spatial extent ofthe unusual occurrence. An offshore array of stations was established which could be used to determine whether circumstances in the vicinity of Rocky Point, attributable to PNPS operation, were causing an abnormally large percentage of

)

ichthyoplankton populations there to be entrained or, alternatively, whether high entrainment levels simply were a reflection ofunusually high population levels in Cape Cod Bay. The impact attributable to any large entrainment event would clearly be greater ifichthyoplankton densities were particularly ,

high only close to the PNPS shoteline. In past years when high densities were identified, additional entrainment sampling was reouested by regulatory personnel and the unusual density in most cases 6

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was found to be of short duration (<2 days). With the change in 1994 to Monday, Wednesday, Friday sampling the temporal extent of any unusual density can be more clearly discerned without additional sampling effort.

Until 1994 " unusually abundant" was defined as any mean density, calculated over three replicates, which was found to be 50% greater than the highest mean density observed during the same month from 1975 through to the current year. Restricting comparisons to monthly periods damped the large seasonal variation so readily apparent with ichthyoplankton. Starting with 1994

" unusually abundant" was redefined. On a month-by-month basis for each of the numerically dominant species all previous mean densities over three replicates (1974-1993; to be updated each year) were examined and tested for normality following logarithmic transformation (Ryan and Joiner 1976). Single sample densities obtained from 1994-1997 were added to the pool within each month.

Where data sets (for example, macke el eggs taken in June) fit the lognormal distribution, then

" unusually large" was defined by the overall log mean density plus 2 or 2.58 standard deviations.'

Log densities were back-transformed to make them easier to interpret, thus providing geometric means. In cases where data sets did not fit the lognormal distribution (generally months when a l species was frequently but not always absent, i.e., many zeros occurred), the mean and standard deviation was computed using the delta-distribution (see for example Pennington 1983). The same mean plus standard deviation guideline was applied.

The decision to rely on 2 standard deviations or 2.58 standard deviations was based on the relative importance ofeach species. The more critical criterion was applied to species ofcommercial, recreational, or biological interest, the less critical to the remaining species (i.e., relatively greater densities were necessary to trigger notification). Species of commercial, recreational, or biological interest include Atlantic menhaden (Breroortia tyrannus), Atlantic herring (Clupea harengus),

Atlantic cod (Gadus morhua), tautog and cunner (the labrids; Tautoga onitis/Tautogolabrus adspersus), sand lance (Ammodytes sp.), Atlantic mackerel (Scomber scambrus), windowpane I

' Normal distribution curve theory states that 2.5% of the measurements in a normally distributed

[ population exceed the mean plus 1.% standard deviations (= s, we roundal to 2 for simplicity),2.5% lie below the mean minus 1.% standard deviations. Stated another way 95% of the population lies within that range and 97.5%

lies below the mean plus 1.%s. Likewise 0.5% of measurements exceed the mean plus 2.58s,99% lie within the range of the mean

• 2.58s, 99.5% lie above the mean + 2.58s.

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I (Scophthalmus aquosus), American plaice (Hippoglossoides platessoides), and winter flounder.

Table 1 provides summary data for each species of egg and larva by month within these two categories showing the 1998 notification level.

A scan ofTable I willindicate that, in cases where the long-term mean amounts to 1 or 2 eggs or larvae per 100 m', the critical levelis also quite small. This situation occurred during months when a given species was obviously uncommon and many zeros were present in the data set with an inherent small standard deviation. The external reference distribution methodology of Box et al.

(1975) was also employed. This procedure relies on a dotplot of all previous densities for a species within month to produce a reference distribution. Densities exceeding either 97.5 or 99.5% of the reference set values were considered unusually high with this procedure.

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Table 1. PNPS ichthyoplankton entrainment notification levels for 1998 by species category and month. See text for details.

Densities per Long-term Mean + Mean +

100 m' of water: Mean' 2 std dev. 2.58 std.dev.

January LARVAE Atlantic herring2 0.2 1 Sculpin Rock gunnel 0.8 1.4 Sandlance 2 5 11 February LARVAE Atlantic herring2 0.1 0.8 Sculpin 2 65 Rock gunnel 4 99 Sandlance 2 16 29 March EGGS American plaice: 2 3 LARVAE Atlantic herring 2 0.9 1.3 Sculpin 17 608 Seasnails 0.6 1 Rock gunnel 10.7 723 Sandlance2 7 164 Winter flounder 2 0.4 0.7 April EGGS American plaice2 3 32 LARVAE Atlantic herring2 1 2 Sculpin 15 391 Seasnails 6 10 Radiated shanny 3 6 Rock gunnel 4 142 Sand lance 2 21 998 Winter flounder 2 7 12 9

7-I Table 1 (continued).

Densities per Long-term Mean + Mean +

100 m' of water: Mean' 2 std.dev. 2.58 std.dev.

May EGGS Labrids 2 36 3514 Atlantic mackerel: 18 4031 g Windowpane2 9 147 g American plaice 2 2 15 LARVAE g Atlantic herring 0.7 1.1 g Fourbeard rockling 2 5 Sculpin 3 4 E<

Radiated shanny 7 236 m Atlantic mackerel 2 1.8 3.5 Sand lance2 37 59 g Atlantic mackerel 2 4 5 Winter flounder2 9 123 Seasnails 7 208 June EGGS g Atlantic menhaden2 10 16 Searobins 3 4 Labrids: 958 21599 Atlantic mackerel 63 3515 Windowpane 2 27 261 American plaice 2 1 2 LARVAE Atlantic menhaden 2 6 10 Fourbeard rockling 9 634 Hake 0.3 1 Cunner2 6 265 g Radiated shanny 1 15 g Atlantic mackerel 2 91 155 Winter flounder2 7 10 m 1 EGGS Atlantic menhaden2 2 4 Labrids: 615 13349 Mackerel 9 16 Windowpane2 12 156 to i

Table 1 (continued).

Densities per Long-term Mean + Mean +

100 mS -ofwater: Mean' 2 std.dev. 2.58 std.dev.

hllX LARVAE Atlantic menhaden 2 2 3 Fourbeard rockling 6 9 Hake 0.7 1 Tautog: 2 2 Cunner: 7 318 Mackerel 2 3 August EGGS Searobins 4 6 Labrids 2 23 936 Windowpane: 15 136 LARVE Atis.ntic menhaden: 0.4 1 Fourbeard rockling 6 10 Hake 2 4 2

Tautog 16 2.2 Cunner2 lb 15 September EGGS Labrids: 2 3 Windowpane2 11 159 LARVAE Fourbeard rockling 4 6 Silver hake 2 1 2 Hde 5 9 Tautog2 1 2 Cunner2 1 2 October EGGS Atlantic menhaden 2 2 6 Windowpane: 1 2 LARVAE Atlantic menhaden2 2.3 4 Fourbeard rockling 1 16 Hake 1 2 11 L

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Table 1 (continued).

Densities per Long-term Mean + Mean + I 100 m' of water: Mean 8 2 std.dev. 2.58 std.dev.

November j LARVAE 2

Atlantic menhaden 0.4 1 Atlantic herring2 4 g gi pecembsr LARVAE Atlantic herring2 2 3 I

' Geometric or Delta Mean.

2 Species of commercial, recreational, or biological interest for which more critical notification level will be used.

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SECTION IV RESULTS A. Ichthvoolankton Entrained - 1998 Population densities per 100 m' ofwater for each species listed by date, station, and replicate are presented for January-December 1998 in Appendix A (available upon request). The occurrence of eggs and larvae of each species by month appears in Table 2. Ichthyoplankton collections are summarized below within the three primary spawning seasons observed in Cape Cod Bay waters:

winter-early spring, late spring-early summer, and late summer-autumn.

Winter-early spring soawners Ganuary-Aorilj Many species spawning during this season employ a reproductive strategy which relies on demersal, adhesive eggs not normally entrained. As a result, more species are typically represented by. larvae than by eggs during winter-early spring. Considering the season as a whole,9 species were represented by eggs, yellowtail flounder (Pleuronectesferrugineus), American plaice, fourbeard rockling (Enchelyopus cimbrius), and Atlantic cod being numerically dominant (Figure 2). Yellowtail eggs first appeared in the collections early in April at which time they represented 46% of the month's total with a geometric mean density of 8 per 100 m' ofwater. American plaice eggs appeared at l'ow densities in February and March, then increased in number in April when a geometric mean density of 4 per 100 m' accounted for 24% of the month's total. A single rockling egg was collected in February with the remainder of the seasonal total being taken in April. During that month they accounted for 19% of all eggs with a monthly geometric meau density of 3 per 100 m' of water.

Atlantic cod eggs were present in the collections each month reaching a high geometric mean density of 2 per 100 m'in February. That density accounted for 77% of the month's egg catch.

Larval collections during the winter-early spring season contained 19 species of fish.

Numerical dominants consisted ofsculpin (Myorocephalusspp.), sand lance, and rock gunnel (Pholis gunnellus). Sculpin, a group actually consisting of three species, represented 16% of the January catch,72% of the February catch,48% of the March catch, declining to Ib. in April. Respective monthly geometric mean densities for the group as a whole amounted to 0.2,13,18, and 9 per 100 m' of water. Among the three species oflarval sculpin the gmbby (M. aenaeus) was most abundant over the season as a whole accounting for 96.5% of the group total. The shorthorn sculpin (M.

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I scorpius) followed at 2.5% and the longhorn sculpin (M. octodecemspino. sus) at 1%. Larval sand lance were collected throughout the January-April period accounting for 33% of the seasonal total and reaching a peak monthly geometric mean density of 19 per 100 m' of water in April. Rock gunnel were also collected throughout the period adding 14% to the seasonal larval total. They reached a peak geometric mean density of 7 per 100 m' of water in both February and March.

I Winter - Early Spring I january- April Eggs Larvae ven omier Al

$MN " s.nd tenoe AH other ' 'g{

x 33 5 % ]

12 5 %

Fourbe.rd rocklms Ad cod R a Wasar Domder I

Sum of monthly means = 48.7 Sum of monthly means =201.4 evbw===nP88P4 g Figure 2. Dominant species of fish eggs and larvae found in PNPS ichthyoplanktot samples during the winter carly spring season.1998. Percent of total and summed g monthly means for all species are also shown. 3 Late Sprina-Early Summer (May - Julv)

Egg and larval densities, particularly among species with pelagic eggs, typically increase during this season along with expanding day length and rising water tempenture. Considering both eggs and larvae together,18 species were represented in May, increasing to 21 species in June and 24 species in July. Numerical dominants included tautog/ cunner, and mackerel among eggs and l

cunner, winter flounder, mackerel, fourbeard rockling, hake (Urophycis spp.), radiated shanny (Ulvaria subbifurcata), and Atlantic menhaden among the larvae (Figure 3).

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Late Spring - Early Summer Season May - July Eggs Larvae nuin on,,r *"'"8"'d" /~- 4

"** An aun n

7.0% ~

u.

57%

\_- Mg ng-'  ?,";

Sum of monthly means -7742.0 Sum of monthly means = 1224.7 Figure 3. Dominant species of fish eggs and larvae found in PNPS ichthyoplankton samples during the late spring - carly summer season 1998. Percent of total and summed monthly means for all species are also shown.

Tautog/ cunner eggs accounted for 26% of the May total, 95% of the June total, and 94%

of the July total. Respective monthly geometric means were 52,1297, and 269 per 100 m' Based on a study completed at PNPS in 1975 and 1976 (MRI 1978a), over 90% of tautog/ cunner eggs taken in the PNPS area are believed to have been spawned by cunner. Mackerel eggs contributed an additional 59% to the May total and 1% to the June total with monthly geometric means of 1% and 11 per 100 m'. Mackerel eggs were not present in the July collections.

Cunner larvae first appeared during the week ofMay 25 accounting for less than 1% of the month's total catch. They increased in number in June with a geometric mean density of 14 per 100 m' accounting for 50% of the larvae collected. In July they reached a mean density of 136 per 100 m' while accounting for 59% of the catch. Larval winter flounder were the overall numerical dominant in May when they contributed 45% to the month's total with a monthly geometric mean of28 per 100 m'. In June they accounted for 18% ofthe tota' with a mean of12 per 100 m'. Larval flounder were present into the first week of July but overall they contributed little to that month's 15

I catch. Larval mackerel first appeared in mid May and continued to appear in collections until mid July. They contributed 21%,15%, and 0.3% to the three respective monthly totals with geometric monthly means of3,8, and 1 per 100 m' ofwater. Fourbeard rockling which occur nearly year round in egg and/or larval form contributed an additional 4, 6, and 9% to the May, June, and July catch with monthly geometric means of 5,10, and 32 per 100 m'. Hake larvae were collected from late May through the month ofJuly. Monthly geometric means of 0.2,2, and 17 per 100 m' represented 0.2, 2, and 10% of the three respective month's catch. Radiateo shanny declined in number through the season. They accounted for 24% of the May total with a geometric mean of 13 per 100 m',4% of the June total with a geometric mean of 4 per 100 m', and 0.2% of the July total with a geometric mean of 0.5 per 100 m' Lastly, larval menhaden first appeared in latc May and increased in number through June into July. Overall they contributed less then 1% of the May catch,1% of the June catch, and 8% of the July catch. Monthly geometric means amounted to 0.03,2, and 28 per 100 m' respectively.

Late Summer - Autumn Soawners (August - December)

This season is typically described as one where a marked decline in both overall ichthyoplankton density and number of species occurs. Considering egg and larval stages combined, 20 species were taken in August,19 were taken in September, followed by 9 in both October and November dropping to 6 in December. Numerical dominants included tautog/ cunner, windowpane, and rockling/ hake among the eggs, hake, rockling, cunner, Atlantic herring, windowpane, tauteg, and, g

menhaden among the larvae (Figure 4). Tautog/ cunner eggs, presumably primarily cunner, accounted 5 for 64% of all eggs taken in August with a geometric mean of 28 per 100 m'. Their numbers declined into September when they accounted for 6% of the month's total with a geometric mean of 1 per 100 m'. Small numbers of these eggs were occasionally taken through the remainder of the seasonal period. Windowpane eggs are reported under the Paralichthys-Scophthalmus group because they cannot be distinguished from fourspot flounder eggs. Because windowpane larvae are far more abundant then fourspot larvae in PNPS collections, the majority of the grouped eggs are assumed to be in fact windowpane. These eggs occurred from August through the first half of October accounting for 20%, 63%, and 8% of those three monthly totals; geometric monthly means were 37, 17, and 0.4 per 100 m' respectively. Rockling and hake eggs were entrained from August through 16 I i

Late Summer- Autumn Season August - December Eggs Larvae

(

~w RocklargMs_ 45 3 uh - ,e =

- 47,.

25 m aj g ,q 70% 71%

, Sum ofmonthly means =291.58 Sum of monthly mear.s =102.13 Figure 4. Dominant species of fish eggs and larvae found in PNPS ichthyoplankton samples during the late summer - autumn season 1998. Percent of total and summed monthly means for all species are also shown.

October with monthly combined geometric means ranging from 2 tol6 per 100 m' and percent contribution ranging from 14 to 40%. Based on collection ofspecifically identifiable late-stage eggs, l hake appeared to be somewhat more abundant than rockling.

< Among the larvae, hake were collected in August at a mean density of 4 per 100 m',

increasing in September to a mean density of 7 per 100 m'. While absent from the October collections a small number appeared in November at a mean density of 0.6 per 100 m'. These densities accounted for from 10 to 69% of those three monthly larval totals. Larval rockling paralleled hake in being collected during August, September, and November. They accounted for 13, 5, and 3% of those three monthly totals with respective geomet.ric mean densities of 2,2, and 0.2 per 100 m'. Cunner, ranking third among the seasonal dominants, were present in samples from August and September at monthly geometric mean densities of 3 and 0.5 per 100 m'; these densities accounted for 19 and I % of those monthly totals. Larval Atlantic herring, originating from the fall spawning season, appeared onlyin November and December. Respective geometric mean densities 17 r

I of I and 2 per 100 m' accounted for 48 and 64% of those monthly collections. Windowpane, like hake and rockling appeared regularly in August and September, skipped October, and reappeared in November. With respective geometric means of 1,2, and I per 100 m' they represented between 5 and 14% of those monthly tctals. Larval tautog were regularly present in August and September l only, accounting for 4 and 5% of those monthly totals with geometric means of I and 2 per 100 m','

Lastly, menhaden larvae were taken each month of the seasonal period except for December. They accounted for 4% or the August catch with a geometric mean of0.7,1% of the September catch with a geometric mean of 0.4,20% of the October catch with a geometric mean of 0.5, and 8% of the November catch with a geometric mean of 0.5 per 100 m' B. Notification Plan Ichthyoplankton densities reaching the unusually high level during the 1998 sampling season occurred on a number of occasions. These involved Atlantic menhaden and cunner eggs and larvae as well as the larvae of fourbeard roc'kling, hake, silver hake, tautog mackerel, radiated shanny, and winter flounder (Table 3). Since winter flounder densities recorded during the first three weeks of May were based on 0.202-mm mesh samples they were scaled downward using mesh conversion factors for stage I and 2 larvae to make them comparable to past 0.333-mm mesh based densities.

Among the above species, the hakes displayed the most protracted period of high numbers with unusually high densities of larvae being recorded on 21 occasions during June, July, and September.

On two of the occasions in June and four of the occasions in July hake densities exceeded all previous densities for those respective months dating back to 1975. In particular a density of 248 larvae per 100 m' was recorded on July 27 exceeding the previous July high of 50 per 100 m' by a factor offive.

Among tautog densities all but one in July exceeded the notification level for that month. Four of those (38 to 269 per 100 m') exceeded all previous July observations,29 per 100 m2 being the previous high. Menhaden larvae did not exceed all previously recorded densities on any occasion in July 1998 although eleven ofthe thirteen observations were high enough to exceed the notification level.

Additional notification level densities are mentioned in the nert section.

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C. Multi-vear Ichthvonlankton Comnarisons A master species list for ichthyoplankton collected from the discharge canal at PNPS appears in Table 4; the years during which each species was represented is indicated for 1975 through 1998.

A total of 40 species were represented in the 1998 collections, two above the 23-year mean of 38 species.

Appendix B (available upon request) lists geometric mean monthly densities along with 95%

confidence limits for each ofthe numerical dominants collected during each year dating back to 1981.

Geometric means are reported because they more accurately reflect the true population mean when the distribution ofsample values are skewed to the right as is commonly the case with plankton data.

Generally low values obtained for both eggs and larvae during April-June 1984 and 1987 were shaded because low through-plant water volumes during those months probably affected densities of ichthyoplankton (MRI 1994); shaded values were omitted from the discussion below. Entrainment data collected from 1975-1980 remain in an outdated computer format requiring conversion before geometric mean densities can be generated. These years were therefore excluded from Appendix B

( but are discussed in the multi-year comparisons if noteworthy.

To help compare values over the 18-year period, egg data were plotted in Figure 5 for those species whose combined total represented 90% or more of the 1998 egg catch. For this figure cod and pollock eggs were combined with the Enchelpopus-Urophycis-Peprilus group, and labrids and yellowtail flounder were combined with the labrid-Pleuronectes group. For each category shown, the highest monthly geometric means obtained from 1981 through 1997 werejoined by solid lines as were the lowest monthly geometric means, and the area between was shaded, indicating the range of

) these values. Monthly geometric mean values for 1998werejoined by a solid line. Alongside each j plot is a bar graph showing annual abundance indices for each year. These were generated by integrating the area under each annual curve using trapezoidal integration2 . One set ofbars was based on geometric monthly means and the other, longer time series, on arithmetic monthly means (1975-1998). Appendix B and Figure 6 contain corresponding data for the 13 numerically dominant species of fish larvae, those accounting for 99% of the 1998 catch, as well as total larvae (all species combined). As mentioned for eggs, low values obtained for both eggs and larvae during April 2

Curve integrauon results in units of(Numbers x days) per 100 m' of water.

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I through August 1984 and 1987 were flagged in these figures and omitted from the following discussion.

In many cases densities of fish eggs and larvae vary considerably from year to year. For example, over the l'7-year geometric mean time series the highest annual abundance index divided by the lowest for Atlantic menhaden eggs amounted to 292. In spite of such pronounced variation, no consistent upward or downward trend was apparent over the time series for many species such as menhaden and windowpane eggs, sculpin and rock gunnel larvae. Following are noteworthy observations concerning the multi-year time series. Since densities ofeach ichthyoplankton species rise from and fall to zero over the course of each respective occurres.ce season, inter-year comparisons are often conveniently made within monthly periods.

Atlantic menhaden eggs were relatively abundant at PNPS on three occasions in June and five occasions in July 1998 based on the notification program criteria (see above). In spite ofthese observations the annual index ofabundance for menhaden eggs was not remarkable.

The geometric mean index ranked 7* over the 1981-1998 period and the arithmetic index l

ranked 11* over the 1975-1997 period. While egg abundance was not remarkably high in 1998, larval menhaden abundance was considered so for the second straight year. The annual geometric mean abundance index (984) ranked second behind .1997 (1145) dating back to 1981 and the arithmetic index (1893) ranked third behind 1997 (2801) and.1981 (2708).

Menhaden are coastal migrants which travel in schools that can often be quite dense. For example, the great variability in numbers of eggs taken at PNPS probably reflects not only numbers of adults in the surrounding waters but variability in the distance from PNPS at which spawning takes place. Spawning stock biomass increased from 1993 through 1995 (Cadrin and Vaughan 1997) which is consistent with the observed increase in egg and larval densities in 1997 and larval densities alone in 1997 and 1998.

Atlantic cod eggs were typically collected in low numbers at PNPS during winter months from 1975-1987 (5 per 100 m' of water for example). Following 1987 they became uncommon particularly during January and February. None were taken either month in 1993 or 1994 and only one was taken in 1995. In 1996 collections rose to three eggs, all taken I

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in February. The gadidae-Glyptocephalus group in general showed a significant decline from 1975 to 1993 (p<0.001), based on a nonparametric sign test, which is consistent with the downward trend reported for Atlantic cod and witch flounder stocks apparently resulting, at least in part, to overexploitation (NOAA 1995, NFSC 1998). Annual geometrk mean indices suggest the decline has ended if not reversed, at least locally, since values for 1994 through 1997 appear stable at about three times the low value recorded in 1993 (39) and the

, 1998 geometric index (149) was the highest since 1989 (158).

Eggs of the fourbeard rockling and closely related hake (grouped in the early developmental stages with far less common butterfish as Enchelyopus-Urophycis-Pepri/us ; MRI 1988) have been uncommon in recent years. Trend analysis using the longer-term arithmetic time series indicated that a significant downward trend occurred from 1978 through 1996 (p =

0.05)in spite of a moderate catch in 1995. Any suggestion of a reverst.1 in 1995 was erased by the 1996 value which was similar to values observed from 1992 to 1994. In spite of relatively high densities in April 1997, the 1997 indices (3819 and 1621) represented but a slight improvement over 1996 (2889 and 1299). The 1998 indices (5078 and 2687) suggest an upward trend is undenvay. Fourbeard rockling dominate within this grouping based on late-stage egg .a well as larval collections. Since this a small bottom fish with little or no commercial value, stock size data are not available with which to compare trends. Hake on the other hand contribute to the commercial bottom fishery, and stocks in the Gulf ofMaine and northern Georges Bank are considered to be underuploited. Stock abundance of red hake on southern Georges Bank and in Massachusetts waters are relatively low according to the Northeast Fisheries Center survey index (NOAA 1995).

Searobin eggs (Prionotus spp.) were relatively abundant at PNPS from 1983 through 1987.

Relative to that period of time numbers have been low with 1998 particolarly so. The geometric curve index for 1998 (26) ranked second to last ahead of only 1990 (24) and the locyr arithmetic time series (53) ranked last dating back to 1975. Massachusetts Division ofMarine Fisheries resource survey trawls showed relatively high abundance during the late 1970's through the mid-1980's followed by a sharp decline through the early 1990's (McBride et al.1998). These data appear to be reflected in the PNPS larval data.

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I Tautog/ cunner eggs, composed primarily of cunner (Scherer 1984) appeared to be in a I

downward trend from the late 1970's through 1994 although a sign test failed to confirm it using the conventional 95% significance level (p = 0.055). In contrast the arithmetic and geometric indices both showed an increase in density in 1995, the geometric index continuing to rise in 1996. The 1995 arithmetic index appeared exceptionally high and disproportionate to the geometric value due to a single high density in June (37,282 per 100 m' ofwater) which greatly skewed the arithmetic mean for that month. The 1997 indices declined from 1996 but remained well above the low values observed in 1990,1991, and 1994. Indices rose again in 1998, the geometric value nearly equally the 1996 index. The arithmetic index was disproportionately high due to two high densities in June. The downward trend noted through1 ' 994 is consistent with finfish observations in the PNPS area as well as impingemen collections at the Station (Lawton et al.1995). Changes in sampling protocols at PNPS have negated the ability to monitor general cunner population trends beyond 1994 which in the past were sampled by gill net, trawl, and diver surveys. Numbers impinged appeared to systematically decline from 1980 through 1992 (annual totals dropped from 116 to as low '

as 2 in 1988), then increase from 1993 (104) through 1995 (288). They remained high in 1996 (211) which appeared to roughly parallel the egg abundance data. The impingement total for 1997 (39) and 1998 (76; see Impingement Section) represented a substantial drop relative to the preceding four years and appeared out of step with the ichthyoplankton collections.

1 Eggs of the yellowtail flounder were also relatively abundant in April 1997and again in 1998.

While early staged eggs of this spec;

. e similar to and grouped with the labrids, they are believed to account for all eggs of that type collected in April since the labrids are not likely l{

l to spawn until May. The geometric mean density for that month in 1997 was 4.6 per 100 m', increasing to 7.7 in 1998, both exceeding the previous high of 1.8 per 100 m' noted in 1983 (Figure 5). Stock assessment information shows a slight increase since 1994, perhaps explaining the increase in egg abundance (NFSC 1998).

While mackerel egg densities declined a 1997, they increased in number in 1998, continuin to show that they have clearly been more abundant since 1988 when compared to the 1975 n

i I

through 1987 period. A sign test using the arithmetic index time series supponed this upward trend (p<0.006). Mackerel eggs typically display a sharp peak in their abundance curve oRen with one or two very high densities. For example in May 1995 a single density 8

of 19,203 eggs per 100 m was recorded on May 26, dropping to 557 eggs per 100 m' on the 29*. The second highest density occurred on June 9 at 4,754 per 100 m'. Due to these brief sharp peaks, arithmetic and geometric indices are oRen quite far apart (Figure 5).

Entrainment of high densities of mackerel eggs over the past decade is consistent with a dramatic rise in stock biomass attributable to reductions in foreign fishing and under exploitation by U.S. fishermen (Overholtz 1993, NOAA 1995, NFSC 1996)

• Windowpane eggs, assuming, based on larval collections, that they predominate within this egg group, have increased from 1994 through 1998. The annual geometric index for 1997 (3144) was essentially equal to 1996 (3147) but the upward trend continued in 1998 (4553).

Over the entire 24-year time series the arithmetic index for 1998 (6634) ranked fourth. In general these eggs have not shown wide variations in number, at least not compared with l other species regularly entrained. Consistent with the recent egg collections, current l l

abundance indices for windowpane, based on Massachusetts Division Of Marine Fishenes spring and fall surveys, suggest that stocks increased steadily from 1991 through 1996 1

(Steve Correia, MDMF, personal communication).

For American plaice eggs, the arithmetic time series shows a more or less steady decline from 1978 to 1986 followed by a steady increase through 1995. While 1996 represented a drop in overall abundance,1997 and 1998 turned upward again. Patterns ofegg abundance

appear to follow, in a general way estimates of finfish abundance According to the Northeast Fisheries Center survey results for Massachusetts (NFSC 1996), plaice were at relatively low abundance levels in the mid 1980's, when egg entrainment was also at its lowest, then rebounded following the production of a strong year class in 1987. They again declined from 1989 through 1993 and, while the finfish series does not yet run to 1997 or 1998, they appear to have begun to increase again.

Atlantic herring larval abundance indices have proven valuable in management of herring stocks on Georges Bank, Nantucket Shoals, and in the Northeast Atlantic in general (see for 23

I example, Smith and Morse 1993). The stock was seriously depleted during the 1970's.and collapsed on Georges Bank in 1976 (Anthony and Waring 1980, Smith'and Morse 1993).

The stock has increased more or less steadily since 1986 following reductions in fishing pressure. Presently the Atlantic coast stock is increasing in size, projected to continue doing so through into the year 2000, and considered to be extremely underutilized (NFSC 1998).

Larval collections at PNPS from 1994 through 1997 reflect the general increase in stock size, the geometric index for those four years ranking among the top five. Although numbers dropped in 1998 the geometric index (143) remained among the top ten over the 1981-1998 time series (Figure 6)..

Fourbeard rockling larvae were abundant in 1998 particularly in hily when the monthly geometric mean of 32 per 100 m' exceeded the previous July high dating back to 1981 of 8

6 per 100 m . Overall the annual geometric mean index of 1620 exceeded the previous high of 1086 recorded in 1989. The arithmetic index (2945) ranked second behind 1977 (5001).

l As mentioned above under eggs, the rockling is a small bottom fish with little or no l

commercial value and stock size data are not available with which to compare trends.

Larval hake were abundant in 1997 and again in 1998. Respective geometric mean indices amounted to 994 and 932, both exceeding the previous high of 514 recorded in 1985.

Arithmetic means for the two most recent years ranked second and third dating back to 1975. Relatively high larval densities in 1998 were clearly reflected in the notification I program mentioned above. Data available through 1995 suggest that hake ~ stocks in Southern New England have declined by about 50% since the late 1960's and surveys in Massachusetts waters confirm that abundance is relatively low (NFSC 1996). High larval abundance at PNPS in 1997 and 1998 may indicate production of a strong year class or simply reflect a localized spawning aggregation.

Larval seasnail (Liparis atlanticus) were uncommon at PNPS in 1998, the geometric index (32) amounting to less than half the previous low recorded in 1992 over the 18-year geometric time series and the arithmetic index also ranked last over the 24-year series. Since these fishes typically reach a length ofless than 6 inches and they have no commercial or I

I I

i l

recreational significance no stock size data are available with which to compare the larval abundance.

In spite ofunremarkable egg abundance in 1998, larval cunner and in particular lar el tautog were relatively abundant in PNPS entrainment samples. Both species were particularly abundant in July exceeding the previous high mean density for that month (Figure 6). High densities were often identified in July under the notification program. The 1998 geometric index for tautog (801) ranked well ahead of the previous high observed in 1989 (324) and represented the fourth straight year ofincreasing abundance. The arithmetic index for tautog (1,647) also ranked well ahead of the previous high (800) recorded in 1980. The geometric index for cunner (4,742) ranked ahead of the previous high recorded in 1981 (3,828)while the arithmetic index (17,518) ranked second behind 1981 (25,901). Current stock size data j for cunner are not available but tautog are believal to be overfished and at very low levels (NFSC 1996). Perhaps two seasons of relatively high larval abundance will result in one or j two strong year classes which will help rebuild the local stock.

.- L.arval radiated shanny were relatively abundant during the 1998 season. The annual i ~ geometric mean index of 554 ranked fourth over the 18-year time series dating back to 1981 and the arithmetic index ranked second dating back to 1975. In general shanny have been abundant in PNPS collections since 1989. Since this is a small, rather inconspicuous bottom fish, relatively little is known ofits habits and data are not available concerning population trends.

l

• Laival winter flounder densities were relatively high throughout their occurrence period in  ;

1997 and again in 1998. In 1997 larvae were particularly abundant in April and May while l in 1998 they were particularly abundant in May and June. The annual geometric mean curve L index for 1998 (1271) was exceeded only by that for 1997 (1800). Owing to three large  !

densities in late May, early June. ranging from 283 to 814 larvae per 100 m' water (see Table

~ 3), the 1998 arithmetic curve area was considerably greater than the geometric index and in fact exceeded all previous years dating back to 1975 (Figure 6).

Larval winter flounder abundance in the Mount Hope Bay section ofNarragarisett Bay was average to somewhat below average in 1997 (40* and 50* percentile by two abundance 25 l

I indices) while in Niantic Bay, Connecticut, abundance was relatively high (2"' out of 15 I years; Dale Miller, Nonheast Utilities Service Co., personal communication). In spite of the differences in 1997 between these areas, in general larval flounder abundance has been found to be correlated between these two locations (NUSCO 1997), suggesting that widespread regional signals exist. For the 1975 through 1998 period no comparable correlation was j detected between Mount Hope Bay and PNPS larval flounder abundance (Pearson  ;

correlation coefficient, r = -0.1%, p = 0.359). Since Cape Cod appears to serve as a faunal barrier (see for example Anraku 1964, Davis 1984, Scherer 1984), regional signals may dissolve or weaken across that barrier. Stock abundance based on the Massachusetts Division Of Marine Fisheries spring, northern stock assessment appears to have been relatively stable since 1988. From that time through 1997 trawl estimates have varied without trend from 10 to 15 kg per tow, down from a high of 29 per tow in 1983. There is no evidence in that time series to suggest why particularly large numbers oflarvae would be present in PNPS waters in 1997 and 1998. Hopefully the high larval abundance will result l

in production of a strong year class although this is unlikely to be observed until they recruit ,

to trawl surveys.

I :

Ii ll l g

I I

I u

I I

l I

I Figure 5. Geometric mean monthly densities per 100 m' of water in the PNPS discharge I canal for the eight numerically dominant egg species and total eggs,1998 (bold line). Solid lines encompassing shaded area show high and low values over the 1981-1997 period.

Brevoortia tyrarmus Labridae-Pleuronectes Gr'idae-Glyptocephalus Scomberscombrus l Enchelyopus-Urophyvis Paralichthys-Scophthalmus Peprilus Hippoglossoidesplatessoides Prionotus spp.

Total eggs To the right are plotted integrated areas under the annual entrainment abundance curves for 1975-1998. An asterisk aiove 1984 and 1987 marks the two years when values may have been low due to low through-plant water volumes from April-August. An asterisk above 1976 indicates abundance value may be low due to absence of sampling during January-late April; see text for clarification. Light bars represent indices based on monthly arithmetic means, solid bars (1981-1998) indices based on monthly gerimetric means.

s 27

E Brevoortia tyrannus Eggs igo 2000 i

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Month

[D Nghtco es1998}

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32 I

1 Figure 6. Geometric mean monthly densities per 100 m' ofwaterin the PNPS discharge canal for the thirteen numerically dominant larval species and total larvae, 8(bold line). Solid lines encompassing shaded area show high and low values over the 1981-1997 period.

Brevoortia tyrannus Tautogolabrus adspersus Clupea harengus Ulvaria subbifurcata Enchelyopus cimbrius Pholisgunnellus Urophycis spp. Ammodytes sp.

Myoxocephalus spp. Scomberscombrus Liparis spp. Pleuronectes americanus Tautoga onitis Totallarvae To the right are plotted integrated areas under the annual entrainment abundance curves for 1975-1998. An asterisk above 1984 and 1987 marks the two years when values may have been low due to low through-plant water volumes from April-August. An asterisk above 1976 indicates abundance value may be low due to absence of sampling during January-late April; see text for clarification. Light bars represent indices based on monthly arithmetic means, solid bars (1981-1998) indices based on monthly geometric means.

33 1

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l D. Ichthvoolankton Entrainment Imoacts - General Ichthyoplankton entrainment at PNPS represents a direct negative environmental impact since fish eggs and larvae passing through the station are subjected to elevated water temperatures, shear forces, and periodic chlorination. In effect PNPS operates as a mechanical predator increasing overall mortality rates in western Cape Cod Bay. When PNPS is not on line, elevated temperature is not a factor but fish eggs and larvae may still be subjected to mechanical forces and periodic chlorination when circulating seawater or salt service water pumps operate. Although sunival has been demonstrated for some species of fish eggs at PNPS such as the labrids (45%; MRI 1978) and winter flounder (73%, n = 11;MRI 1982) and among larvae at other power plants (0-100% initial survival depending on species and size; Ecological Analysts 1981), entrainment mortality is conservatively assumed to be 100% in all PNPS assessments.

To place fish egg and larval densities recorded in the PNPS discharge canal, expressed as numbers per 100 m' of water, in some perspective in relation to amounts ofwater utilized by PNPS,

) they were multiplied by maximum plant flow rates over each respective period of occurrence. This was completed for each of the numerically dominant species as well as total eggs and total larvae.

Mean monthly densities were multiplied by 17,461.44, the full load flow capacity ofPNPS in 100 m' units per 24-hour day, then by the number of days in each respective month they were collected.

Values for each month in which a species or species group occurred were then summed to arrive at a seasonal entrainment value in each case (Figures 7 and 8). For cunner, mackerel, and winter flounder, egg and larval totals were calculated using individual densities and mesh adjustment where I appropriate as part of an adult equivalent analysis (see next section). Among the eight numerically dominant groups, numbers of eggs entrained ranged from 918,500 for searobins (Priormtus spp) to 4,341,665,000 for the labrids. Corresponding values among the thirteen numerically dominant larval species varied from a low of 831,000 for seasnail to a high of 370,217,000 for cunner. For all eggs and all larvae combined, values amounted to 5,124,176,000 and 882,183,000 respectively. These totals state the extent to which large quantities of eggs and larvae can be entrained by the circulating seawater system at PNPS during a single year; based on the assumption of 100% mortality all are lost

- to the local population.

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E. Ichthvoolankton Entrainment - Specific Estimated numbers of eggs and larvae entrained annually at PNPS were examined in greater 3 detail for three species of fish using the equivalent adult procedure (EA, see Horst 1976, Goodyear l

1978, for example). Somewhat arbitrarily this review dates back to 1980 so that with the addition

)

of 1998,19 years are included. The adult equivalent methodology applies estimated survival rates to numbers ofeggs and larvae lost to entrainment to obtain a number of adult fish which might have entered the local population had entrainment not occurred. The consequences, ifany, of the loss can then be considered if the size of the extant population is known or numbers can be compared with commercial or recreational landings.

Many assumptions are associated with the EA procedure. The fish population is assumed to be in equilibrium, therefore in her lifetime each female will replace herself plus one male. It is also assumed that no eggs or larvae sunive entrainment and that no density-dependent compensation occurs among non-entrained individuals. The later two assumptions result in an overestimation of plant impacts. As pointed out earlier, numbers of eggs and larvae entrained were determined using the full-load-flow capacity of the plant. This value was used even if the station was out ofservice and less than full capacity was being circulated. In those cases the adult equivalents are conservatively high.

Since plankton densities are notorious for deviating from a normal distribution but do generally follow the lognormal, geometric mean densities more accurately reflect the true population mean. For data which are skewed to the right such as plankton densities, the geometric mean is always less than the arithmetic mean (see Figures 5 and 6). In calculating total entrainment values for the adult equivalent methodology we chose to use the larger arithmetic mean for all sampling dates preceding April 1994 when three replicate samples were taken per sampling occasion to lend ,

additional conservatism to the assessments. Beginning with April 1994 each individual sample density was utilized so that no averaging was necessary.

In summary, four opportunities were chosen to overestimate the impact of PNPS '

. All eggs and lanae were assumed killed by plant passage regardless of thermal load. '

. No density-dependent sunival compensation was assumed to occur, PNPS was assumed to operate at full-flow capacity year round.

44 I

a Mean entrainment densities were overestimated by the arithmetic mean for sampling dates when three replicates were taken.

The three species selected were winter flounder, cunner and Atlantic mackerel. Flounder were chosen because of their commercial and recreational value as well as their importance in PNPS ecology studies. Cunner were selected because they are abundant in entrainment samples and in the local area and PNPS finfish studies have been focusing on that species which appeared :o be in a I

declining trend from 1980 to 1994 (Lawton et al.1995). Mackerel were included because they are abundant among the ichthyoplankton entrained, both eggs and larvae being removed irom the local I population, and they are commercially and recreationally valuable.

Winter Floundsr The annuallarval entrainment estimates were converted to equivalent numbers ofage 3 adults, the age at which flounder become sexually mature (Witherell and Burnett 1993, NOAA 1995).

Numbers of stage 1 and 2 larvae collected prior to 1995 were scaled upward by 1.62 to correct for mesh extrusion (MRI 1995). Two sets of survival values were used. The first set followed NEP (1978) using data from Pearcy (1962) and Saila (1976). Briefly, this consisted of dividing the total number of entrained larvae by 0.09 to estimate the number of eggs which hatched to produce that number oflarvae. The number of eggs was then multiplied in succession by 0.004536, an estimate of survival from a newly hatched egg to day 26; 0.2995, survival from day 27 to metamorphosis; 0.03546, survival ofjuveniles from 3 to 12 months; 0.3491, survival from 13 to 24 months; and finally 0.33, survival from 24 to 36 months. The second approach followed larval stage-specific survival rates (S) derived by NUSCO (1993) as modified by Gibson (1993a). These are as follows:

S (stage 1) = 2.36E-01 S (stage 2) = 1.08E-01 S (stage 3) = 1.54E-01 1 S (stage 4) = 6.23E-01 S (age 0) = 7.30E-02 S (age 1) = 2.50E-01 1 S (age 2) = 4.77E-01 In using the stage-specific rates it is recognized that NUSCO employs different morphological stage criteria than those used at PNPS (NUSCO 1998). However a comparison of samples from both studies showed stages to be quite coniparable until larvae approach metamorphosis, a size not often l

45 I

I collected because these individuals begin to assume a benthic life style. Although small numbers are entrained each year, flounder eggs were ignored because they are demersal and adhesive and not i generally impacted by entrainment. I Recently Rose et al. (1996) presented information on a population dynamics model for winter flounder consisting of separate young-of-the-year and adult components. The young-of-the-year model includes survival rates for eggs, larvae, early and late juveniles stages. Since the model is designed to mathematically represent numbers ofindividuals as they develop from one stage to another, it is difficult to apply their survival rates to the mixed age pool oflarvae entrained at PNPS.

All individuals would need to be converted to a common starting point such as newly hatched eggs as is done with the unstaged approach. By using a value of 0.09 to step back from mixed-age larvae to hatched eggs, the rates utilized by Rose et al. produce approximately twice as many fish as the staged survival values provided above. Since the staged survival values were adjusted by Gibson (1993a) to provide an equilibrium population the Rose et al. values likely overestimate EA values in this instance.

The general, unstaged larval survival values produced an adult equivalent value of 5,473 age l

3 fish for 1998 (Figure 9, Table 5). The stage-specific values produced an EA total about fourteen times higher at 77,428 age 3 individuals. Based on a weight of 0.6 pounds per fish (Gibson 1993b),

l these values convert to 3,284 and 46,457 pounds, respectively. Comparable values for 1980 -1997 ranged from 535 to 3,414 fish (mean = 1,397 fish, 838 pounds) for the general approach and 2,624 to 47,087 (mean = 10,601 fish,6,361 pounds) for the staged approach. EA totals for 1984 and 1987 were omitted here because both circulating seawater pumps were off for most of the larval winter flounder seasons during protracted maintenance outages. There is some indication that ichthyoplankton entrainment is disproportionately low when only the salt service water pumps are in operation (MRI 1994). Values for 1998 using the unstaged general approach represented the second consecutive record high year exceeding the notably high value for 1997 (3,414 fish) by 60%.

Values based on the staged approach also exceeded the previous high recorded in 1997 (47,087) by 64%. The relatively high EA values noted in 1998 are directly attributable to the unusually high number oflarvae entrained. The large differences between the two sets of survival estimates clearly I

I I

show how relatively small variations in survival values when applied to large numbers oflarvae can result in relatively large variations in adult numbers (see Vaughan and Saila 1976 for example).

Over the 1982 through 1997 period an annual average of 1,557,365 pounds (s.e. = 275,125 pounds) of flounder were landed commercially from NOAA statistical area 514 which covers Cape Cod Bay and Massachusetts Bay (Table 6). Based on a weight of 0.6 pounds per fish, the average estimated loss of 685 or 6,361 pounds of equivalent adults from PNPS entrainment over a similar time frame represents 0.04 or 0.4% of those landings. Area 514 commercial landings declined sharply after 1993 from1,057,211 pounds that year to 16,788 pounds in 1995 and only 1,79F pounds in 1997 (Table 6). The precipitous drop is attributable to increased fishing restrictions and stock declines. EA values for 1994 through 1998 alone appear quite high compared to the reduced commercial landings and in fact the unstaged values for both 1997 and 1998 exceed the commercial landings for 1997.

Winter flounder also have considerable value as a recreational species. Based on NOAA records' an annual average of 978,255 fish (s.e. = 317,368) weighing an average of about one pound each were landed from Massachusetts inland waters over the 1981-1997 period (Table 6). More recently (1990 -1997) recreational landings have been well below earlier years because of stock declines and area closures consistent with commercial landings; an annual average of 120,253 fish (s.e. = 11,722) were reported landed in the state from inland waters during that more recent period.

These fish were also apparently smaller, weighing an average of 0.72 pounds each. Unfortunately these landings are compiled by state within distance from shore areas (inland, <3 miles from shore,

> 3 miles from shore) and the number of fish taken from a more appropriate area such as Cape Cod Bay are not available. Arbitrarily adding 20,000 pounds of recreationally-caught flounder to the 1994-1997 Area 514 commercial landings would bring the respective totals for those four years to 348,706,36,788, 22,961 and 21,798 pounds. The PNPS entrainment EA values from the unstaged approach for those years then amount to 0.2,1.4,3.0, and 9.4%, respectively. The 1998 unstaged estimate of 3,284 pounds represents 15% of the 1997 landings estimate. For the staged larvae I approach the four vrJues range from 2.1 to 130%, respectively with the 1998 value of 46,457 pounds representing more than twice the 1997 landings estimate. Clearly the decline in commercial landings after 1994 suggest that those values are no longer a realistic measure of PNPS EA losses.

8 Recreational landings data were obtained via the internet at http:// remora. ssp.nmfs. gov /mrfss.

47

I' Massachusetts Division ofMarine Fisheries (DMF) personnel made estimates of the number l of adult winter flounder (>280 mm TL - age 3+) in a 106 square mile area in the vicinity of PNPS using area swept by a commercial trawl and using several mark and recapture models in 1997 and l 1998 (see Section Illa, this report). While reliable estimates oflocal population size are difficult to make, they can provide realistic numbers with which to compare EA values. Landings data typically represent numbers caught over a very large area or as displayed by the most recent commercial landings can be subject to catch restrictions or changes in fishing effort which make them less useful.

The DMF area swept estimate equaled 321,832 adults based on gear efficiency of 50% with confidence limits ranging from 271,000 to over 373,000 fish. DMF's mark-and-recapture study was limited by disappointing tag returns. Estimates ranged from 115,000 to 520,000 adults depending on the model employed. EA estimates for 1997 using the unstaged survival values amount to 1.1%

of the area swept estimate and 3.0% of the low mark and recapture estimate. The 1997 EA estimate '

from the staged approach amounted to14.6% of the area swept estimate and 40.9% of the low-end mark-recapture estimate. Fewer fish were collected in 1998, providing a comparable area-swept estimate of 264,812 adults and best mark-recapture estimate of 104,429 fish (see Section IIIA).

Comparing the 1998 unstaged EA estimate to these values provided proportional losses of 2.1 and 5.2%, respectinly. The staged estimate amounted to 29.2 and 74.1%, respectively.

As mentioned earlier, two consecutive years of relatively high larval flounder entrainment at a time when local area stock size shows no sign ofincreasing remains unexplained.

Cunner Goodyear's (1978) basic procedures were used to estimate equivalent adult values. This method converts numbers of eggs and larvae to numbers of fish at age of sexual maturity which occurs for approximately half the pooulation at age 1 (P. Nitschke, University of Massachusetts, Amherst, personal conununication).

Assuming all labrid eggs were cunner eggs in PNPS entrainment samples (Scherer 1984),

cunner larva: egg ratios were determined from PNPS samples to provide cn estimate ofsurvival from egg to larva. Mesh correction values were first applied to both eggs and larvae. Presented in MRI (1998) these were 1.24 for eggs taken from 1980-1995,1.14 for eggs taken in 1995, and 1.10 for eggs taken in 1997. The 1997 value was used for 1998. Larval cunner mesh values applied were 1.16 for stage 1 and 1.28 for stage 2, irrespective of year. From 1980 to 1998 the larva / egg ratio 48 I

ranged from 0.001284 to 0.128812 and averaged 0.030480; 1984 and 1987 were excluded because of extended circulating seawater pump shutdown. Average lifetime fecundity was calculated from fish collected in the PNPS area by Nitschke (1997). He provided numbers of eggs produced at age in the second order form:

Log F = [2.891 log A)-[1.355 log A ]2 + 3.149 where F = fecundity at age A Tge-specific instantaneous mortality necessary for calculation of average lifetime fecundity was calculated from fish trap collections made from 1992 - 1997 (Brian Kelly, Massachusetts Division Of Marine Fisheries, personal communication, MRI 1998). Average instantaneous mortality rates for the PNPS area collections from 1992 through 1997 using this approach were as follows:

Age 3 = 0.286 Age 7 = 0.653 Age 4 = 0.342 Age 8 = 1.463 Age 5 = 0.645 Age 9 = 0.728 Age 6 = 1.260 Utilizing data from Serchuk and Cole (1974) for age I through 5 cunner collected with assorted gear, a survival rate of S = 0.605 was obtained (Z = 0.5025) which appars comparable to the PNPS values. Age 1 and 2 fish appeared less abundant in the PNPS coiiections than age 3 fish (MRI 1998), suggesting they were not fully recruited to the trap collections, perhaps due to their small size or behavior. Fish older than age 10 were rarely taken both because they are uncommon and because they can exceed the maximum size susceptible to the fish traps. In the absence of additional information an overall mean value ofZ = 0.831 was substituted for age 2 and age 10.

Based on the PNPS area fecundity study (Nitschke 1997), 50% of age I females were assumed to be mature; complete recruitment was assumed by age 2. Following Goodyear (1978),

an average lifetime fecundity of 21,656 eggs per female at age I was calculated (MRI 1998).

Utilizing the survival estimate for eggs to larvae and average lifetime fecundity, a survival estimate fer larvae to adult of 3.03E-3 was obtained. Converting numbers of eggs to larvae utilizing the larvae / egg ratio and then converting numbers oflarvae to adult produced an estimate of 1,522,731 cunner potentially lost to entrainment effects in 1998. Comparable values for 1980-1997 ranged from 113,048 to 2,353,607 adults averaging 474,279 (s.e. = 119,048) over the 19-year period (Figure 10, Table 7). The high value of 2,571,973 recorded in 1981, attributable to high egg and exceptionally 49 l

1 I

high larval densities, skewed the mean EA value; without that high value a mean of 363,730 (s.e. =

46,855) was obtained. I Cunner have no commercial value and little recreational importance (although many may be II taken unintentionally by shore fishermen) so that current landing records are not available. To shed some light on their abundance in the PNPS area, calculations were performed to estimate the number i

of adult cunner which would be necessary to produce the number of eggs found there. The PNPS area was defined by Cape Cod Bay sampling stations 2,3,4,7,8 (MRI 1978b), the half-tide volume j

)

ofwhich was estimated by planimetry from NOAA chart 1208 at 22,541,000 100 m' units. Labrid egg densities were obtained at those stations on a weekly basis in 1975 and they were integrated over time (April-December) using the mean density of the five stations. The integrated values were multi-plied by 1.40 to account for extmsion through the 0.505-mm mesh used in that survey (MRI unpublished data), then by the sector volume. Based on the 0.333/0.202-mm mesh data collected from the PNPS discharge stream from 1994 through 1997, additional upward scaling might be appropriate; however specific data for towed samples with 0.202-mm mesh are not available and an estimated value was net applied. Omitting this step likelv led to an underestimate of the number of l

eggs produced and therefore to an underestimate of the number of adults spawning in the area. The resulting value was divided by 2.2, the estimated incubation time in days for cunner eggs (Johansen 1925), then divided by 30,230, an estimate of mean annual fecundity per female derived from Nitschke (1997) and MRI 1998). Lastly the resulting value was multiplied by 2 assuming an even sex ratio. These calculations resulted in an estimated production of 6.899E12 eggs by an estimated 207,473,000 adult fish. The loss of1,522,731 adults in 1998 due to PNPS operation represents 0.7%

of the estimated spawning stock. The annual mean loss of 529,461 fish, including 1981 and 1998, represents 0.26% of the stock estimate.

MDMF personnel have chosen cunner as an indicator species for PNPS impact investigations.

Taggmg studies were conducted during the 1994 and 1995 seasons to estimate the size of the cunner population in the immediate PNPS area. Minimum tagging size and therefore the minimum size fish enumerated was 90 mm TL. Estimates were highly localized since individual cunner have a very small l 2

home range measured on the order of100 m orless (Pottle and Green 1979). Estimated population '

size for the outer breakwater and intake areas combined were 7,408 and 9,300 for the two respective i years. Combining upper 95% confidence limits produced totals of 10,037 and 11,696 fish,  !

$0 I.

respectively. Since the upper confidence limit total is only 0.003% of the egg based population estimate, it is clear that eggs must arrive at PNPS from areas removed from the immediate vicinity of the Station. A hydrodynamic modeling study completed by Eric Adams of MIT (see also section III.A) predicted that 90% of the cunner eggs and lanae entrained at PNPS come from within about 5.5 miles ofPNPS to the nonh down to White Horse Beach, about one mile to the south of PNPS.

[

This area extends further to the north than the area 2,3,4,7,8 used in the above egg estimates. The number ofeggs entrained indicate that cunner must be abundant in these waters.

Atlantic Mackerel Procedures outlined by Vaughan and Saila (1976) were used to derive a survival rate for mackerel eggs to age I fish. This procedure utilizes the Leslie matrix algorithm to estimate early survival from proportion mature, fecundity, and survival within each age class assuming a stable population. Fecundity for Atlantic mackerel was obtained from Griswold and Silverman (1992) and Neja (1992). Age-specific instantaneous mortality was obtained from Overholtz et al. (1988) and NOAA (1995). A maximum age of 14 and maturity schedules were obtained from NFSC (19%).

Since two fecundity profiles provide two egg to age I survival values: 2.2772E-6 for Griswold and Silverman,2.3039E-6 for Neja, values were averaged (2.2906E-6). The observed average ratio of f eggs to larvae for PNPS of 0.09143 (1980-1998) provided a larva-to-age I survival rate of 2.5053E-

5. In calculating larvae / egg ratios 1981,1984, and 1987 were omitted,1981 because larvae were more abundant then eggs and 1984 and 1987 because both circulating seawater pumps were off for the mackerel egg and larval seasons during protracted maintenance outages. A mesh adjustment l factor of 1.12 was applied to the egg data based on mesh comparison collections completed from 1994 through 1997 (MRI 1998). No mesh adjustment wasjustified for larvae. According to NOAA (1995,1996) stock biomass consists of fish age I and older while fish completely recruit to the spawning stock by age 3. Therefore, adult equivalent values are shown for both age groups (Figure 11, Table 8). Age 3 individuals were estimated using an instantaneous mortality rate ofM = 0.52 for age I fish and M = 0.37 for age 2 fish (Overholtz et al.1988). These values provide annual survival f

rates of S = 0.595 and 0.691, respectively.

PNPS entrainment equivalent adult estimates for 1998 amounted to 2,633 age i fish or 1,082 age 3 fish. Corresponding age i values over the 1980 through 1997 time series ranged from 483 (1982) to 12,349 (1989) fish with an average of4,214 (s.e. = 846). Age 3 values ranged from 199 51

I l

l l

to 5,077 with an annual average of 1,732 (s.e. = 348) individuals. Data from 1984 and 1987 were omitted here because values were unusually low as described above for the larvae / egg ratio calculations. Converting numbers offish to weight using 0.2 and 0.7 pounds per individual (Clayton et al.1978) resulted in an estimated average annual loss including 1998 of 824 pounds (s.e. = 174 pounds) or 1186 pounds (s.e. = 237), respectively (1984 and 1987 excluded). Weight values for 1998 alone were 527 pounds of age 1 fish,757 pounds of age 3 fish.

According to NOAA statistical records, an annual average of360,203 pounds (s.e. = 91,879) of mackerel were taken commercially from statistical area 514 over the years 1982-1997. For PNPS the loss of an average of 1,050 pounds of age 1 fish (1980-1997,1984 and 1987 omitted) amounts to 0.3% of those landings and the loss of 2,368 pounds of age 3 fish, 0.7%. In addition to commercial :andings, mackerel have considerable recreational value. For example, over the years 1981-1997 an average of 763,865 fish (s.e. = 138,862) were landed in Massachusetts by fishermen working inland waters and within three miles of shore. These fish had an average weight of about l

one pound. Unfortunately these landings are available only by state and therefore the portion attributable to Cape Cod Bay is not known. Arbitrarily adding 200,000 one-pound fish to the l

commercial landings brings the harvest total to 560,203 pounds and the mean PNPS EA total to 0.2 and 0.4%, respectively.

Calculations performed to estimate the number ofadult cunner which would be necessary to produce the number ofeggs found in the PNPS area also completed for Atlantic mackerel. Mackerel eggs occurred at Cape Cod Bay stations 2, 3,4, 7, and 8 from early May through early July in 1975.

Integration over time using the mean density of the five stations produced an estimate of 1.3529E12 eggs. This total included a mesh correction factor of 1.95 to account for extrusion through 0.505-mm mesh (MRI unpublished data). The resulting value was divided by 4, the estimated incubation time in days for mackerel eggs (Sette 1950), then divided by 319,978, an estimate of mean annual fecundity per female for age 3 fish from Cniswold and Silverman (1992) and Neja (1992). Lastly the resulting value was multiplied by 2 assuming an even sex ratio. These calculations resulted in an estimated production of 3.382El I eggs by an estimated 2,114,052 adult fish. The annual mean loss

(1980-1988; 1984,1987 omitted)of1,694 age 3 fish due to PNPS entrainment represents 0.08% of that value.

l 52 I

i I

l F. Lobster Larvae Entrained No lobster lanae were found in the 1998 entrainment samples, the total, dating back to 1974, p remaining at 13. Following is a tabulation of previous collections:

1997: none found.

1 1996: none found.

1995: 1 larva - stage 4-5, July 28.

1994: none found.

1993: 1 larva - stage 4-5, July 21.

1991-1992: none found.

1990: 2 larvae - 1 stage 1, June 26; I stage 4 August 23.

1983-1989: none found.

1982: I larva - stage 1 on June 14.

1981: 1 larva - stage 4 on June 29.

1980: none found.

1979: 1 larva - stage 1 on July 14.

1978: none found.

1977: 3 larvae - I stage 1, June 10; 2 stage 1, June 17.

1976: 2 larvae - ! stage 1, July 22; I stage 4-5, August 5.

1975: 1 larva - stage 1, date unknown.

1974: none found.

The lobster larvae collected in 1976 were obtained during a more intensive lobster larvae program which employed a 1-meter net, collecting relatively large sample volumes, in addition to the standard 60-cm plankton net (MRI 1977). Both larvae taken in 1976 were collected in the meter net; none 3 were found in the routine ichthyoplankton samples.

During the three-season Cape Cod Bay neuston study for larval lobster begun in 1974, larvae I were found from May through September at monthly mean densities ranging from 0.2 (September) to 3.8 per 100 m' (July; Matthiessen and Scherer 1983). Considering that a minimum of roughly 10,500 m5 of water were sampled during these months each year, larval lobster must indeed be rare in the PNPS circulating water system.

53 s

r SECTION V l

LITERATURE CITED l

Anraku, M. 1964. Influence of the Cape Cod Canal on the hydrography and on the copepods in l Buzzards Bay and Cape Cod Bay, Massachusetts. I. Hydrography and distribution of l copepods. Limnology and Oceanography 9:46-60.

i Anthony, V. and'G. Waring. 1980. The assessment and management of the Georges Bank herring fishery. Rapp. P.-V. Reun. Cons. Int. Explor. Mer. 177:72-111.

Box, G.E.P., W.G. Hunter, and J.. Ht.nter. 1975. Statistics for Experimenters. John Wiley & Sons, New York. l Cadrin, S.X. and D.S. Vaughan. 1997. Retrospective analysis of virtual population estimates for Atlantic menhaden stock assessment. Fishery Bulletin U.S. 95:445-455.

, Clayton, G., C. Cole, S. Murawski and J. Parrish. 1978. Common marine fishes of coastal l Massachusetts. Massachusetts Cooperative Extension Service, Amherst, Massachusetts.

231p.

Davis, J.D.1984. Western Cape Cod Bay: hydrographic, geological, ecological, and meteorological l backgrounds for environmental studies, pl-18 In: J.D. Davis and D. Merriman (editors). g Observations on the Ecology and Biology ofWestern Cape Ce d Bay, Massachusetts. Lecture g Notes on Coastal and Estuarine Studies. Volume II. Springer-Verlag, New York.

Ecological Analysts,Inc.1981. Entrainment survival studies. Research Report EP 9-11. Submitted to Empire State Electric Energy Research Corporation, New York.

Gibson, M.R. 1993a. Population dynamics of winter flounder in Mt. Hope Bay in relation to l operations at the Brayton Point electric plant. Rhode Island Division Fish and Wildlife, West Kingston, R.I.

.1993b. Stock assessment of winter flounder in Rhode Island,1992: A report to the RI Marine Fisheries Council. Rhode Island Division Fish and Wildlife. Res. Ref. Doc. 93/1.

l Goodyear, C.P.1978. Entrainment impact estimates using the equivalent adult approach. U.S. Fish and Wildlife Service, Biological Service Project. FWS/OBS-78/65. 14p.

Griswold, C.A. and M.J. Silverman.1992. Fecundity of the Atlantic mackerel (Scomber scombms) in theNorthwest Atlanticin 1987. Journal ofNorthwest Atlantic Fisheries Science 12:35-40.

Herrick, F.H. 1911. Natural history of the American lobster. Bulletin U.S. Bureau of Fisheries 29:149-408.

54 I

i

Horst, T.J.1975. The assessment ofimpact due to entrainment ofichthyoplankton. In: Fisheries and Energy Production: A Symposium. S.B. Saila, ed. D.C. Heath and Company, Lexing-ton, Mass. p107-Il8.

Johansen, F.1925. Natural histocy ofthe cunner (Tautonolabrus adsoersus Walbaum). Contribution to Canadian Biology new series 2:423-467.

Lawton, R.P., B.C. Kelly, V.J. Malkoski, and J. Chisholm. 1995. Annual report on monitoring to assess impact of the Pilgrim Nuclear Power Station on selected finfish populations in western Cape Cod Bay. Project Report No. 58 (January-December 1994). IIIA.i-77. h: Marine Ecology Studies Related to Operation ofPilgrim Station, Semi-annual report No.45. Boston Edison Company.

Marine Research, Inc. 1978a. Entrainment investigations and Cape Cod Bay Ichthyoplankton Studies, March-December 1977. Ill.C.2-34-38. h: Marine Ecology Studies Related to Operation of Pilgrim Station, Semi-annual Report No. I1. Boston Edison Company.

1978b. Entrainment investigations and Cape Cod Bay ichthyoplankton studies, March 1970-June 1972 and March 1974-July 1977. Volume 2, V.1-44. h: Marine Ecology Studies Related to Operation of Pilgrim Station. Final Report. July 1969-December 1977.

Boston Edison Company, 1982. Supplementary winter flounder egg studies conducted at Pilgrim Nuclear Power I Station, March-May 1982. Submitted to Boston Edison Company. 4p.

1988. Entrainment investigations and Cape Cod Bay Ichthyoplankton Studies, March-December 1987. III.C.1-6-10. h: Marine Ecology Studies Related to Operation of Pilgrim  !

Station, Semi-annual Report No. 31. Boston Edison Company .

1994. Ichthyoplankton entrainment monitoring at Pilgrim Nuclear Power Station January-December 1993. Volume 2 (Impact Perspective).III.C.2i-27. M: Marine Ecology Studies l Related to Operation ofPilgrim Station, Semi-annual report No.43. Boston Edison Company

. 1998. Ichthyoplankton entrainment monitoring at Pilgrim Nuclear Power Station January-December 1997. h: Marine Ecology Studies Related to Operation ofPilgrim Station, Semi-annual Report No. 51 Boston Edison Company.

Matthiessen, G.C. and M.D. Senerer. 1983. Observations on the seasonal occurrence, abundance, and distribution oflarval lobsters (Homarus americanus) in Cape Cod Bay. p41-46 M: M.J.

Fogarty (ed.). Distribution and relative abundance ofAmerican lobster, Homarus americanus.

larvae: New England investigations during 1974-79. NOAATechnical Report NMFS SSRF-775. ,

I McBride, R.S., J.B. O'Gorman and K.W. Able.1998. Interspecific comparisons of searobin (Prionotus spp.) movements, size structure, and abundance in the temperate western North Atlantic. Fishery Bulletin 96(2):303-314.

Neja, Z. 1992. Maturation and fecundity of mackerel, (Scomber scombrus L.) in Northwest Atlantic. Acta Ichthyol. Piscatoria 22(1):125-140.

Nitschke, P.C. 1997. Assessing factors that influence cunner (Tautogolabrus adsper.ms) reproduction and recruitment in Cape Cod Bay. Masters thesis, University ofMassachusetts Amherst.

NFSC (Northeast Fisheries Science Center). 1996. Report of the 21st Northeast Regional Stock Assessment Workshop (21st SAW). Stock Assessment Review Committee (SARC) consensus summary ofassessments. Northeast Fisheries Science Center Reference Document 96-05d. 200p.

l 1998. Report of the 27th Northeast Regional Stock Assessment Workshop (27th SAW).

Stock Assessment Review Committee (SARC) consensus summary of assessments.

Northeast Fisheries Science Center Reference Document 98-15. 350p.

NOAA(National Ocear.ic and Atmospheric Administration).1995. Status ofFishery Resources off the Northeastern United States for 1993. NOAA Technical Memorandum NMFS-NE-108.

140p.

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Overholtz, W.J.1993. Harvesting strategies and fishing mortality reference point comparisons for the Northwest Atlantic stock of Atlantic mackerel (Scomber scombrust Canadian Journal of Fisheries and Aquatic Science 50:1749-1756.

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49p.

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l 56 I

l

[

Pennington, M. 1983. Efficient estimators of abundance for fish and plankton surveys. Biometrics f 39:281-286.

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57 r

i

I Winter Flounder Equivalent Adult Summaly I 1980

, l l 1982 Unstaged Approach Age 3 Fish 1984 1986 1988 1990 l 1992 W

im  !

im 1998 l

0 1 2 3 4 5 6 '

Thousands I

I Winter Flounder 1980 Equivalent Adult Summary l

Staged Approach 1982 3

Age 3 Fish g 1986 1988 .M 1990 1992 1994

j 1996 1998 5

0 20 40 60 80 Thousands Figure 9. Numbers ofequivalent adult winter flounder estimated to have been lost to entrainment at PNPS, 1980-1998. l 58 I

Cunner Equivalent Adult Summary 1950 i i 1982 i 1984 1986 1988 I*

i I

1992 I 1994 I  !  !

1998 0 500 1000 1500 2000 2500 nousands i Figure 10. Numbers ofequivalent adult cunner estimated to have been lost to entrainment at PNPS, 1980-1998.

I Atlantic Mackerel Equivalent Adult Summary 1980

!= Age i Fkh 1 1983 1984 1985 l 1986 i i 1987 1988 1989 I

1990  ! i 1991  ! i 1992 l 1993

[ l=

l= ,  !

0 5 10  !$ 20 Thousands c:WikenstWraphsWs98.pr4 Figure 11. Numbers ofequivalent adult Atlantic mackerel estimated to have been lost to entrainment at PNPS, 1980-1998.

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Table 3. Ichthyoplankton densities (number per 100 m' ofwater) for each sampling occasion during months when notably high densities were recorded, January-December 1993. Densities marked by + were unusually high based on values in Table 1. Number in parentheses g indicates percent of all previous values during that month which were lower. E Atlantic mackerel larvae' Winter flounder larvae May 1 0 May 1 1.8/1.1 4 0 4 52.8/32.6 6 0 6 10.8/6.7 8 0 8 7.3/4.5 11 STORM 11 STORM 13 0 13 2.7/1.7 15 0 15 25.6/15.8 18 0 18 19.8/12.2 20 16.8/15.0 + (96) 20 16.1/9.9 22 0.9 22 49.9/30.8 g 25 88.4 + (l00) 25 6.7 g 27 377.6 + (100) 27 573.8 + (100) 29 1.3 29 283.2 + (100)

Previous high: 59 (1996) Previous high: 148 (1974)

Notification level: 4 Notification level: 123 June 1 16.8 June 1 58.2 + (97) 3 1.6 3 813.5 + (100) 5 112.4 5 39.1 +(96) 8 304.0 + (94) 8 18.5 + (92) 10 49.7 10 18.8 + (92) 12 2.8 12 52.7 + (97) 15 0 15 22.8 + (92) 17 0 17 1.0 19 0.8 + (95) 19 16.3 + (92) 22 362.2 + (95) 22 0 24 3.2 24 14.3 + (89) 26 0.8 26 9.3 29 20.0 29 2.7 Previous high: 2700 (1981) Previous high: 154 (1996)

Notification level: 155 Notification level: 10 8

0.202 mesh densities adjusted to 0.333 mesh. Both are shown as follows: 0.202/0.333.

l\

l Table 3 (continued).

Atlantic menhaden EGGS LARVAE June 1 11.5 0 3 10.1 0 5 2.0 0 8 1.5 2.3

10 32.9 +(94) 0 12 20.4 + (88) 0 15 1.9 0 17 0 0 19 0 0 22 799.7 + (100) 3.3 24 11.9 17.5 + (89) 26 5.9 4.2 I 20 2.7 13.3 + (88)

Previous high: 425 (1997) 496 (1997)

I Notification level: 16 10 July 1 6.6 + (94) 41.1 + (98)

I 3 6

13.7 + (96) 1.5 12.7 + (96) 75.4 + (99)

I 10 8 5.8 7.0

+ (93)

+ (94) 54.7 29.0

+ (99)

+ (96) 13 3.I 27.9 + (96) 15 0 94.8 + (99) 17 0 96.5 + (99) 20 0 40.3 + (98) l 22 24 0

Backwash 101.8 Backwash

+ (99) 27 0 5.6 + (90) 29 0 2.7 31 0 102.1 + (99)

Previous high: 59 (1978) 124 (1974)

Notification level: 4

{ 3

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i-

Table 3 (continued).

I Hake larvae June 1 0.9 July 1 22.5 + (99) 3 0 3 0.7  ;

5 2.0 + (95) 6 62.7 + (100) )

8 0 8 18.7 + (99) 10 0.7 10 7.0 + (98) ,

12 2.1 + (95) 13 176.7 + (100) 15 0 15 28.1 + (99) 17 0 17 0.9 19 0 20 12.7 + (98) 22 18.0 + (100) 22 3.7 + (97) 24 0 24 Backwash l, l 26 2.5 +(97) 27 248.4 + (100) 29 50.6 + (100) 29 2.0 + (93) 31 194.1

+ (100)

Previous high: 5 (1981)

Notification level: 1 Previous high: 114 (1990) gl Notification level: I gl Sept 2 48.3 + (94) 4 1.9 g 7 7.5 g' 9 51.1 + (94) 11 292.4 + (99) 14 No sample Silver hake larvae 16 19.9 + (86) Sept 2 14.1 + (98) 18 5.5 4 0.0 21 1.4 7 0 23 0 9 1.8 25 2.8 11 6.7 + (95) 28 17.7 + (85) 14 No sample 30 2.9 16 1.3 18 1.8 Previous high: 327 (1997) 21 3.4 + (92)

Notification level: 9 23 0 25 2.2 + (86) 28 0 30 r Previous high: 32 (1975)

Notification level: 2 I

64 I

Table 3 (continued).

Radiated shanny larvac Fourbeard rockline larvae June 1 7.1 July 1 96.8 + (99) 3 12.4 3 2.2 5 52.8 + (99) 6 80.2 + (99) 8 0 8 108.0 + (99) 10 0 10 8.1 12 90.0 + (99) 13 41.9 + (98) 15 13.3 15 114.1 + (100) 17 0 17 27.3 + (95) 19 8.5 20 66.9 + (99) 22 0 22 17.6 + (91) 24 0.8 24 Backwash 26 25.2 + (95) 27 78.2 + (99) 29 0 29 19.1 + (91) 30 79.9 + (99)

Previous high: 262 (1996)

Notification level: 15 Previous high: 114 (1990)

Notification level: 9 Labrid eeen Cunner larvae June 1 195.7 June 1 18 3 165.5 3 0 5 1774.7 5 2.0 8 2181.9 8 27.0 10 863.9 10 64.5 12 7173.6 12 0 15 551.6 15 0 17 228.7 17 0 19 36017.2 + (100) 19 3.1 22 10186.4 22 2215.6 + (100) 24 792.2 24 178.2 26 1184.5 26 34.5

'29 1860.3 29 239.9 Previous high: 37282 (1995) Previous high: 1249 (1981)

Notification level: 21599 Notification level: 265 65

r I'

Table 3 (continued).

Tautue larvae Cunnner larvae (continued)

July 1 5.3 + (87) July 1 156.4 3 1.5 3 10.1 6 48.4 + (100) 6 893.6 + (99) l 8 37.5 + (100) 8 134.0 10 12.7 + (97) 10 165.6 13 89.9 + (1000 13 796.8 + (99) 15 268.6 + (100) 15 1464.0 + (99) 17 16.4 + (98) 17 418.9 + (98) 20 19.8 + (98) 20 112.5 22 17.6 + (98) 22 113.8 24 Backwash 24 Backwash l 27 22.3 + (99) 27 127.0 29 9.5 + (94) 29 17.0 31 25.3 + (99) 31 140.5 Previous high: 29 (1990) Previous high: 2163 (1981)

Notification level: 318 Notification level: 2 Sept 2 1.5 Sept 2 4.5 + (91) g 4 0.9 4 1.9 5 7 1.3 7 7 1.3 9 5.3 + (95) 9 0 11 0.8 11 4.5 + (91) 14 No sample 14 No sample 16 1.9 16 0.6 18 11.0 + (98) 18 0 21 1.4 21 0 23 0 23 0.9 25 1.1 25 0 28 5.9 + (95) 28 0.7 30 0 28 0

~-

Previous high: 19 (1996) Previous high: 14 (1996)

Notification level: 2 Notification level: 2 I

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I! Table 5. Numbers oflarval winter flounder entrained at PNPS annually by stage, 1980 - 1998. Number and weight of equivalent age 3 adults calculated by two methods is also shown. l Number Of Larvae Entrained Equivalent Age 3 Adults Stage Year 18 28 3 4 General Staged Number Pounds Number Pounds 1980 8,694,456 12,714,822 7,317,129 0 1,771 1,063 7,443 4,466 7,606,942 19,133,121 3,073,126 43,304 4,689 1981 1982 2,706,834 6,724,795 11,583,134 425,011 1,841 1,322 1,105 12,643 2,813 l{ m 1983 1,933,453 2,246,172 7,558,534 260,350 740 793 444 7,969 7,586 4,781

                                                                                                                          )

1 1984 248,082 0 7,570,145 516,247 514 308 9,128 5,477 l 1985 1,039,001 2,312,789 8,025,452 130,786 710 426 7,643 4,586 l 1986 5,397,403 5,783,669 3,963,747 77,005 939 563 4,365 2,619

                                                                                                                          ]

1987 0 437,608 3,088,405 0 217 130 2,619 1,571 1988 1,995,968 1,656,376 15,079,960 511,009 1,187 712 15,558 9,335 1989 1,668,823 5,755,240 2,224,675 39,114 597 358 2,624 1,574 1990 643,683 1,155,404 6,846,718 33,002 535 321 6,016 3,610 1991 3,471,022 3,908,488 5,188,056 37,717 777 466 4,%6 2,980 1992 873,660 876,914 7,034,690 26,192 543 326 6,i14 3,668 E g 1993 1,595,700 3,540,750 4,934,952 88,617 626 376 4,958 2,975 1994 1,034,617 6,433,716 13.060,373 172,606 1,276 766 12,446 7,468 1995 1,632,907 2,820,023 8,826,496 375,857 842 505 9,699 5,819 19 % 504,810 5,818,499 11,329,855 995,127 1,150 690 15,395 9,237 1997 2,225,634 9,537,788 41,484,016 2,126,280 3,414 2,048 47,087 28,252 Mean 2,404,055 5,047,565 9,343,859 325,457 1,056 633 10,076 6,045 I s.e. 578,064 1,140, % 8 2,067,069 122,466 173 104 2,368 1,421 1984,1987 Omitted 2 Mean 2,689,057 5,651,160 9,845,682 333,874 1,142 685 10,601 6,361 , s.e. 614,157 1,200,337 2,292,345 136,105 183 110 2,626 1,576 1998 5,099,963 20,202,973 58.546,916 4,904,482 5,473 3,284 77,428 46,457 I i Mesh factor = 1.62 applied to Stages I and 2 prior to 1995.  ! 2 See text for details. l t l 1 I 70 l 1 I'

I I i Table 6. Area 514 commercial landings and Massachusetts recreational landings from inland waters for winter flounder (pounds), 1982-1997. I 1982 Conamnercial (pounds) 3,830,162 Recreational (pounds) 4,146,553 Total (pounds) 7,976,715 I 1983 2,936,176 874,245 3,810,421 1984 2,558,483 839,561 3,398,044 1985 2,450,319 1,858,645 4,308,% 4 1986 1,667,938 708,677 2,376,615 I 1987 1988 1989 1,739,664 1,846,171 1,8 % ,609 568,822 729,200 1,163,315 2,308,486 2,575,371 3,059,924 1990 1,737,733 139,641 1,877,374 5 1991 1992 1,520,470 1,326,646 67,659 85,256 1,588,129 1,411,902 1993 1,057,211 147,287 1,204,498 I 1994 1995 1996 328,706 16,788 2,%) 71,403 43,362 69,871 400,109 60,150 72,832 1997 1,798 69,893 71,691 5 I I I I I 1 I )I y

I Table 7. Numbers of cunner eggs and larvae entrained at PNPS annually, 1980 1998. Numbers of equivalent adults are also shown = ' Cunner Eggs Larvae Equivalent g Stage 1 Stage 2 Stage 3 Total Adults E 1980 3,257,891,776 76,282,260 40,480,032 4,229,248 120,991,540 667,485 1981 6,576,294,915 316,245,739 256,567,950 3,508,876 576,322,566 2,353,607 1982 2,010,779,150 6,351,445 3,187,760 597,356 10,136,561 216,418 1983 5,895,329,347 10,%1,646 27,571,530 3,955,802 42,488,978 673,201 1984 1,766,764,864 0 176,682 1,029,352 1,206,034 166,823 1985 2,021,886,071 17,182,039 20,392,615 2,307,617 39,882,271 307,573 g 1986 1,493,653,289 4,419,092 22,197,318 297,368 26,913,778 219,494 g 1987 4,465,564,080 40,247,222 314,474 248,738 40,810,434 415,062 1988 1,539,089,318 2,290,972 2,624,077 2,461,452 7,376,502 164,492 1989 4,469,416,004 34,100,052 15.224,141 2,863,938 52,188,130 570,900 1990 1,336,048,112 65,705,970 62,378,298 44,014,528 172,098,797 644,849 1991 675,000,390 5,790,172 3,701,490 7,243,966 16,735,627 113,048 1992 2,174,661,078 0 1,186,819 1,605,055 2,791,875 209,299 1993 3,235,317,207 148,674 7,178,133 7,923,303 15,250,109 345,004 1994 1,558,253,667 0 5,545,977 4,440,095 9,986,072 174,169 j 1995 4,116,491,874 7,961,638 29,910,748 9,257,792 47,130,178 522,981  ! 1996 2,807,124,109 3,765,455 8,094,509 5,558,849 17,418,813 312,029 1997 1,718,289,.; 6,444,923 51,895,511 41,294,559 99,634,994 460,586 Mean 2,839,880,8 4. 33,216,517 31,034,892 7,935,439 72,186,848 474,279 Std Dev, 1,660,270,370 74,242,592 59,254,322 12,902,781 133,801,355 505,078  ! count 18 18 18 18 18 18 sa 391,329,479 17,499,147 13,966,378 3,041,215 31,537,282 119,048 Median 2,098,273,575 6,398,184 11,659,325 3,732,339 33,398,025 328,516 Geomean 2,421,129,559 8,911,803 3,252,772 27,076,301 352,116 Without 1981 Mean 2,620,091,768 16,567,739 17,768,242 8,195,825 42,531,805 363,730 Std. Dev, 1,415,945,969 23,566,038 19,090,312 13,251,044 46,933,901 193,187 count 17 17 17 17 17 17 sa 343,417,341 5,715/44 4,630,081 3,213,850 11,383,143 46,855 Median 2,021,886,071 6,351,445 8,094,509 3,955,802 26,913,778 312,029 Geomean 2,282,920,458 7,313,548 3,238,303 22 618,677 314,886 1998 4,34 If,64,826 104,908,332 211,248,501 54,060,618 370,217,451 1,522,731 I E I' n g I'

I l Table 8. Numbers of Atlantic mackerel eggs and larvae entrained at PNPS annually, 1980 - 1998. Numbers of equivalent age I and age 3 fish are also shovm. Total Nuneber EntraineJ Equivalent Adults Year Eggs Larvae Age 1 Age 3 , 1980 81,599,432 22,293,108 745 306 1981 183,959,791 320,135,5 % 8,442 3,471 1982 108,234,931 9,388,143 483 199 ll lu 1983 1984 148,616,621 22,486,619 41,333,673 78,315 1,376 53 566 22 i l 1985 1,867,648,438 45,711,343 5,423 2,230 l 1986 219,488,066 58,333,520 1,%4 808 1987 71.222,294 215,561 169 69 i l 1988 2,663,608,568 3,401,489 6,186 2,544 l 1989 4,673,915,938 65,562,469 12,349 5,077 I 1990 2,313,416,455 4,627,282 5,415 2,226

 "              1991         479,761,865      66,009,482         2,753       1,132 1992         377,610,764        8,086,393        1,068         439

,l l 1993 1,801,378,418 8,325,789 4,335 1,782 l3 1994 520,917,221 1,767,609,278 3,419,299 1,279 526 ! 1995 197,689,693 9,002 3,701 g 1996 1,507,370,682 70,947,053 5,230 2,150 1997 316,% 9,390 25,778,062 1,372 564 Mesa 1,062,545,265 52,852,015 3,758 1,545 s.c. 296,892,824 19,268,231 833 343 'g Mesa 1,189,506,616 59,440,150 4,214 1,732 g w/o 1984,1987 i s.r. 310,913,433 20,518,466 846 348 l lI 1998 530.017,006 56,622,648 2.633 1,082 l E I l l l I

APPENDIX A*. Densities offish eggs and larvac per 100 m$ ofwater recorded in the PNPS discharge canal by species, date, and replicate, January-December 1998.

                                                                                      *Available upon request.

l APPENDIX B*. Geometric mean monthly densities and 95'4 confidence limits per 100 m' of water for the dominant species of fish eggs and larvae entrained at PNPS, January-December 1981-1998. Note the following: g When extra sampling series were required under the contingency sampling regime, 3 results were included in calculating monthly mean densities. Shaded columns for certain months in 1984 and 1987 delineate periods when I sampling was conducted with only salt service water pumps in operation. Densities recorded at those times were probably biased low due to low through-plant water flow (MRI 1994).

                    *Available upon request                                              .

I s [ t L s

IMPINGEMENT OF ORGANISMS AT PILGRIM NUCLEAR POWER STATION (January - December 1998) E Prepared by- [I If a f, Robert D. Anderson Principal Marine Biologist B I I I Regulatory Affairs Department Boston Edison Company I April 1999 I I ]

h I I I I I Herring suNana /A,1,;f .1m Ateware h E Smcit n ii n n x 1 x W I c...e, I commonly l' h fNenide , Impinged species I I I I I I,

l TABLE OF CONTENTS I Section Title Paae .I 1

SUMMARY

1 2 INTRODUCTION 2 3 METHODS AND MATERIALS 5 4 RESULTS AND DISCUSSION 7 4.1 Fishes 7 4.2 Invertebrates 17 g 4.3 g,se S , ., 2, 5 CONCLUSIONS 23 6 LITERATURE CITED 25 I I I I I I I g I

LIST OF FIGURES Fioure Pace 1 Location of Pilgrim Nuclear Power Station 3 2 Cross-Section ofIntake Structure of Pilgrim 4 Nuclear Power Station 3 Trends of Intake Water Temperature, and Number of Fish Captured 12 by month from Pilgrim Station intake Screens for the Five Most Abundant Species Collected, January-December 1998 I I I I I I I I I iii

LIST OF TABLES Table Paae 1 Monthly Impingement for All Fishes Collected From Pilgrim Station intake 8 Screens, January-December 1998 2 Species, Number, Total Length (mm), Weight (gms) and Percentage for 9 All Fishes Collected From Pilgrim Station impingement Sampling, January-December 1998 3 Annual Impingement Collections (1989-1998) for the 10 Most Abundant 10 Fishes From Pilgrim Station intake Screens During January-December 1998 4 Approximate Number and Cause for Most Notable Fish Moralities at 13 ' Pilgrim Nuclear Power Station, 1973-1998 5 Impingement Rates per Hour, Day and Year for All Fishes Collected 15 From Pilgrim Station intake Screens During January-December 1998 6 Impingement Rates Per Hour, Day and Year for All Fishes Collected I 16 From Pilghm Station intake Screens During 1979-1998 7 Monthly Means of Intake Temperatures ( F) Recorded During 18 Impingement Collections at Pilgrim Nuclear Power Station, 1989-1998 8 Monthly Impingement for All Invertebrates Collected From Pilgrim Station 19 I Intake Screens, January-December 1998 9 Survival Summary for the Fishes Collected during Pilgrim Station 22 Impingement Sampling, January-December 1998. Initial Survival ' Numbers are Shown Under Static (8-Hour) and Continuous Wash Cycles I I I I, w g I'

SECTION I i

SUMMARY

l l Fish impingement rate averaged 1.30 fish / hour during the period January-December 1998, which is considerably lower than most recent years partially because of no large impingement 'I incidents. Atlantic silverside (Menidia menidia) accounted for 51.6% of the fishes collected 1 l l tollowed by winter flounder (Pleuronectes Americanus) at 13.1%. Atlantic menhaden (Brevoortia tyrannus) and rainbow smelt (Osmerus mordax) represented 8.7 and 6.8%, l respectively, of the fishes impinged. The peak period was MarcNApril when fish impingement was dominated by Atlantic silversides. This time period is typical for high silverside impingement. Initial impingement survival for all fishes from static screen wash collections was approximately 32% and from continuous screen washes 51%. At 100% yearly (January-December) operation of Pi: grim Nuclear Power Station (PNPS) the 1 estimated annual impingement was 11,426 fishes. The PNPS capacity factor was 97.1% during 1998. I The collection rate (noihr.) for all invertebrates captured from January-December 1998 was 1.11 +. Blue mussel (Mytilus edulis) and sevenspine bay shrimp (Crancon septemspinosa) were most numerous. Longfin squid (Lolico pealei) and Green crab (Carcinus maenus) accounted for 10.0 and 5.3%, respectively, of the invertebrates impinged and enumerated. Mixed species of algae collected on intake screens amounted to 1,980 pounds. ,I I I I

                                                 ~' -

I

SECTION 2 INTRODUCTION Pilgrim Nuclear Power Station (lat. 41 S6' N, long. 70*34' W) is located on the northwestern shore of Cepe Cod Bay (Figure 1) with a licensed capacity of 670 MWe. The unit has two I circulating water pumps with a capacity of approximately 345 cfs each and five service water pumps with a combined capacity of 23 cfs. Water is drawn under a skimmer wall, through vertical bar racks spaced approximately 3 inches on center, and finally through vertical traveling water screens of 3/8 inch wire mesh (Figure 2). There are two traveling water screens for each circulating water pump. This document is a report pursuant to operational environmental monitoring and reporting requirements of NPDES Permit No. 0003557 (USEPA) and No. 359 (Mass. DEP) for Pilgrim Nuclear Power Station, Unit 1. The report describes impingement of organisms and survival of fishes camed onto the vertical traveling water screens at Unit 1. It presents analysis of the relationships among impingement, environmental factors, and plant operational variables. This report is based on data collected from screen wash samples during January-December 1998. l I! I I I I I I I 's I I q% l E

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SECTION 3 METHODS AND MATERIALS Three screen washings each week were performed from January-December 1998 to provide data for evaluating the magnitude of marine biota impingement. The total weekly collection time was 24 hours (three separate 8-hour periods: morning, afternoon and night). Two collections represented dark period sampling and one represented light period sampling. At the beginning of each collection period, all four traveling screens were washed. Eight hours later, the screens were again washed (minimum of 30 minutes each) and all organisms collected. When screens were being washed continuously, one hour collections were made at the end of the regular sampling periods, and they represented two light periods and one dark period ori a weekly basis. Water nozzles directed at the screens washed impinged organisms and debris into a sluiceway that flowed into a trap. The trap was made of galvanized screen (3/8-inch mesh) attached to a removable steel frame and it collected impinged biota, in the screenhouse, shortly after being washed off the screens. Initial fish survival was determined for static (8-hour) and continuous semenwash cycles. Variables recorded for organisms were total numbers, and individual total lengths (mm) and weights (gms) for up to 20 specimens of each species. A random sample of 20 fish or invertebrates was taken whenever the total number for a species exceeded 20; if the total collection for a species was less than 20, all were measured and weighed. Field work was conducted by Marine Research, Inc. Intake seawater temperature, power level output, tidal stage, number of circulating water pumps in operation, time of day and date were recorded at the time of col!ections. The collection rate (#/ hour) was calculated as number of organisms impinged per collecting period divided by the total number of hours in that collecting period. Beginning in 1990, if all four intake screens are not washed for a collecting period then the number of fishes collected is increased by a proportional factor to account for the unwashed screens, as requested by the Pilgrim Administrative-Technical Committee. Common and ) scientific names in this report follow the American Fisheries Society (1988,1989,1991a and 1991b) or other accepted authority when appropriate. i I I I-I I I I I I I I I I I SECTION 4 RESULTS AND DISCUSSION 4.1 Fishes in 575 collection hours, 750 fishes of 36 species (Table 1) were collected from Pilgrim Nuclear Power Station intake screens during January - December 1998. The collection rate was 1.30 fish / hour. This annual impingement rate was relatively low compared to most recent years primarily because of previous, large impingement incidents of Atlantic silverside (Menidia menidia) and/or rainbow smelt (Osmerus morday) and alewife (Alosa pseudoharenaus). Atlantic silverside was the most abundant species in 1998 accounting for 51.6%% of all fishes collected, followed by winter flounder (Pleuronectes americanus) at 13.1% (Table 2). Atlantic menhaden (Brevoortia tyrannus) and rainbow smelt accounted for 8.7 and 6.8% of the total number of fishes collected and identified to lowest taxon. Atlantic silverside occurred most predominately in monthly samples from March and April. Hourly collection rates per month for them ranged from 0 to 4.53. Silverside impinged in March and April accounted for 89% of all this species captured in impingement collections from January-December 1998. They averaged 98 mm total length and 4 grams in weight. Their impingement indicated no relationship to tidal stage or diel factors. They are usually the e dominant fish in the annual impingement catch being the most abundant species caught in seven of the last ten years. Impingement histories of abundant species impinged at Pilgrim Station in 1998, over the past 10 years, are documented in Table 3. Winter flounder were relatively prevalent in April and December samples, indicative cf this species' juvenile stage movements. It has been one of the more commonly impinged fish over the years. /

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l Table 2. Species, Number, Total Length (mm), Weight (gms) and Percentage For All Fishes Collected From Pilgrim Station impingement Sampling, January -December 1998 Length Mean Weight Mean Percent Of Speicies Number Range Range Range Weight Total Fish Atlantic silverside 387 70-135 98 2-9 4 51.6 g Winter flounder 98 39-277 77 - - 13.1 Atlantic menhaden 65 46-90 66 '[ Rainbow smelt 51 70-157 107 1-7 3 8.7 1-21 7 6.8 Windowpane 25 47-291 87 - - 3.3 I Lumpfish 19 31-80 43 1-12 3 2.5 Grubby 17 50-90 62 2-7 3 2.3 Alewife 13 68-118 89 2-12 5 1.7 Blueback herring 8 66-96 82 2-5 4 1.1 Atlantic herring 7 42-275 98 0.2-170 27 0.9 Hake spp. 6 60 117 73 1-10 3 0.8 Atlantic cod 5 53-67 57 1-3 2 0.7 Cunner 5 46-108 83 1-16 11 0.7 Little skate 5 357-485 423 - - 0.7 Red hake 4 68-137 93 2-13 5 0.5 Threespine stickleback 4 36-62 50 1-5 2 0.5 Radiated shanny 3 78-130 97 4-18 9 0.4 Tautog 3 75-132 96 5-41 18 0.4 Atlantic tomcod 2 120-130 125 12-19 16 0.3 Butterfish 2 40-53 47 1-2 2 0.3 Rock gunnel 2 67-148 108 1-9 5 0.3 Sand lance sp. 2 122-156 139 6-11 8 0.3 Spotted hake 2 76 76 3 3 0.3 Striped kill l fish 2 75-85 80 6-7 7 { 0.3 White perch 2 92-100 96 9-12 10 0.3 Atlantic moonfish 1 50 50 2 2 0.1 Bluefish 1 685 685 - - 0.1 Fourbeard rockling 1 74 74 2 2 0.1 Fourspot flounder 1 163 163 - - 0.1 Longhorn sculpin 1 328 328 - - 0.1 Northem searobin 1 170 170 37 37 0.1 Scup 1 190 190 94 94 0.1 Silver hake 1 71 71 2 2 0.1 Smallmouth flounder 1 52 52 1 1 0.1 Striped cusk-eel 1 192 192 29 29 0.1 Summer flounder 1 365 365 - - 0.1 j-ji998. doc 1

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l Atlantic menhaden were prevaient in August / September samples and have been most abumdant in the early fall period, ranking third in 1986/1991/1997 and second in 1989/1990. Generally, it has been one of the less impinged fish over the years. Rainbow smelt were abundant in February impingement collections and have been most prevalent in the late Fall / Winter period in the past, ranking first in 1978,1987 and 1993 in total numbers impinged. In 1978,1993 and 1994, large impingement incidents involving smelt occurred during December. Monthly intake water temperatures and impingement rates for the five dominant species in 1998 are illustrated in Figure 3. There were no small fish impingement incidents (20 fish or greater /hr.) at Pilgrim Station in 1998. There were no large fish impingement incidents (1,000 fish or greater) in 1998 on intake screens. Most large fish impingcment mortalities have occurred while both circulating water pumps were operating. Fifteen large fish incidents have been documented since Pilgrim operation in 1973, and most (11) have involved impingement as the causative agent (Table 4). However, at least in two of these, the possibility of pathological influence was implicated as indirectl/ contributing to the mortalities. They were the Atlantic herring (tubular necrosis) and rainbow smelt (piscine erythrocytic necrosis) impingement incidents in 1976 and 1978, respectively. I Fish impingement rate at Pilgrim Station has been shown to be related to the number of circulating water pumps operating, in general (Lawton, Anderson et al,1984b). Reduced pump operation has lowered total impingement, particularly during the April to mid-August 1984 and portions of the mid-February to August 1987 periods when no circulating water pumps were operating for extended time frames. The significance of this relationship is supported by the 1

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Table 4. Approximate Number and Cause for Dominant Species of Most Notable Fish Mortalities at Pilgrim Nuclear Power Station, 1973-1998 9 Date Species Number Cause April 9-19,1973 Atlantic menhaden 43,000 Gas Bubble Disease August / September,1973 Clupeids 1,600 Impingement April 2-15,1975 Atlantic menhaden 5,000 Gas Bubble Disease August 2,1975 Atlantic menhaden 3,000 Thermal Stress August 5,1976 Alewife 1,900 Impingement November 23-28,1976 Atlantic herring 10,200 Impingement August 21-25,1978 Clupeids 2,300 Thermal Stress December 11-29,1978 Rainbow smelt 6,200 Impingement March / April,1979 Atlantic silverside 1,100 Impingement September 23-24,1981 Atlantic silverside 6,000 Impingement July 22-25,1991 Atlantic herring 4.200 Impingement December 15-28,1993 Rainbow smelt 5,100 Impingement November 28-29,1994 Atlantic silverside 5,800 Impingement Decernber 26-28,1994 Atlantic silverside 6,100 Impingement Rainbow smelt 5,300 Impingement September 8-9,1995 Alewife 13,100 Impingement radmisc/ chart 98

f'ct thit totil fish impingsm:nt and r t3 of fish impingsm:nt w:rs sev:ral times lower in 1984 and 1988 (low-pump operation years) than in 1989 - 1998, despite a greater number of collecting hours in 1984 and an average number of hours in 1988. In 1987, far fewer collecting i hours were possible when both circulating pumps were off than in these other years which limits comparisons to them. However, total fish impingement rates in 1984,1987 and 1988 were several times lower than in 1989-1998 when at least one circulating pump was more consistently in operation. Although there were brief periods in 1994 and 1995 when no circulating water pumps were operational, mixed results were noted regarding the effect on impingement of pump operation, possibly influenced by conditions causing large impingement incidents each of these years. Projected fish impingament rates were calculated assuming 100% operation of Pilgrim Nuclear Power Station, under conditions at the times of impingement, during the period January-December 1998. Table 5 presents hourly, daily, and yearly impingement rates for each species captured (rates are rounded to significant figures). For all fishes combined, the respective rates were 1.30,31.30 and 11,426. The yearly rate of 11,426 is below normal and only 57% of the last 20-years' (1979-1998) mean annual projection of 19,911 fishes (Table 6). This was considerably lower than most recent years' rates which were the highest yearly fish impingement rates since 1981 and which greatly exceeded the historical annual average partially because several large impingement incidents inflated yearly projections. Relatively high impingement rate years offset low impingement years, and they may be attributed to population variances of the dominant species and/or extreme meteorological or o,~~ational conditions influencing species' behavior and vulnerability. Over the past 20-year period (1979-1998), Pilgrim Station has had a mean impingement rate of I 2.27 fishes /hr., ranging from 0.13 (1984) to 10.02 (1981) (Table 6). Anderson et a!. (1975) documented higher annual impingements at seven other northeast power plants in the early ' I olj I

Table 5. Impingement Rates Per Hour, Day and Year For All Fishes Collected From Pilgrim Station intake Screens During January - December 1998. Assuming 100% Operation of Pilgrim Unit 1* Rate / January- Dominant Months Species Rate /Hr. Rate / Day December 1998 Of Occurrence Atlantic silverside 0.67 16.15 5,896 April Winter flounder 0.17 4.09 1,493 April Atlantic menhaden 0.11 2.71 990 August / September Rainbow smelt 0.09 2.13 777 February Windowpane 0.04 1.04 381 April Lumpfish 0.03 0.79 289 May Grubby 0.03 0.71 259 April Alewife 0.02 0.54 198 April Blueback herring 0.01 0.33 122 April Atlantic herring 0.01 0.29 107 April /May Hake spp. 0.01 0.25 91 June Atlantic cod 0.01 0.21 76 May Cunner 0.01 0.21 76 December

           -Little skate                    0.01                0.21                76     July Red hake                         0.01                0,17                61     November Threespine stickleback            0.01                0.17                61     January Radiated shanny                  0.01                0.13                 46     March / April Tautog                           0.01                0.13                 46     January Atlantic tomcod                  0.003               0.08                 30     November / December Butterfish                       0.003               0.08                 30    April /May Rock gunnel                      0.003               0.08                 30    April /May Sand lance sp.                   0.003               0.08                30     November Spotted hake                     0.003               0.08                30     April Striped killifish                0.003               0.08                30     September / November j        White perch                      0.003               0.08                30     December
 )        Atlantic moonfish                0.002               0.04                15     October Bluefish                         0.002               0.04                15     October Fourbeard rockling               0.002               0.04                15     April Fourspot flounder                0.002               0.04                15     June Longhom sculpin                 0.002               0.04                 15     December Northem searobin                0.002               0.04                 15     June
 )        Scup                            0.002               0.04                 15     June Silver hake                     0.002               0.04                 15     December
        . Smalimouth flounder             0.002               0.04                 15     April Striped cusk-eel                 0.002               0.04                 15     August Summer flounder                  0.002               0.04                 15     May Totals                           1.30               31.30          11,426

• Rates have been rounded to significant figures.

radmis/ chart 98

I Table 6. Impingement Rates Per Hour, Day and Year For All Fishes Collected From Pilgrim Station intake Screens During 1979-1998, Assuming 100% Opers' ion of Pilgrim Unit 1* Dominant Species Year Rate /Hr. Rate / Day RateNear (RateNear) 1979 3.24 77.69 28,280 Atlantic silverside g (20,733) g 1980 0.66 15.78 5,769 Cunner (1,683) g 1981 10.02 240.42 87,752 Atlantic silverside g (83,346) 1982 0.93 22.39 8,173 Atlantic silverside (1,696) 1983 0.57 13.65 4,983 Atlantic silverside (1,114) 1984+ 0.13 3.13 1,143 Atlantic silverside (185) 1985 1.14 27.46 10,022 Atlantic silverside (3,278) 1986 1.26 30.34 11,075 Atlantic herring (3,760) 1987+ 0.28 6.74 2,460 Rainbow smelt (682) 1988+ 0.27 6.48 2,372 Atlantic silverside (586) 1989 0.80 19.30 7,045 Atlantic silverside (1,701) 1990 1.70 40.74 14,872 Atlantic silverside (4,354) 1991 3.38 81.14 29,616 Atlantic Herring (22,318) 1992 0.63 15.22 5,572 Atlantic silverside (2,633) 1993 2.78 66.78 24,375 Rainbow Smelt (9,560) 1994+ 5.97 143.18 52,259 Atlantic silverside (36,970) 1995+ 5.87 141.00 51,464 Alewife 5 u (26,972) 1996 3.11 74.64 27,318 Atlantic silverside g (16,153) 5 1997 1,43 34.29 12,514 Atlantic silverside 1998 1.30 11,426 (5,814) g 31.30 Atlantic silverside Wl (5.896) , Means 2.27 54.55 19,911

• Rates have been rounded to significant figures.

+No CWS pumps were in operation 29 March - 13 August 1984,18 February - 8 September 1987, g 14 April- 5 June 1988, 9 October - 16 November 1994 and 30 March - 15 May 1995. 3 I,

1970's. Stupka and Sharma (1977) showed annual impingement ra;es at numerous power plant locations for dominant species, and compared to these rates at Pilgrim Station were lower than at most other sites. Recently, Normandeau Associates (1996) compared fish impingement at several marine power plant intakes which demonstrated Pilgrim rates to be among the lowest with the exception of incidents that involve one or two species occasionally. However, in terms of the number of fish species impinged, Pilgrim Station displays a greater variety than most other power plants in the Gulf of Maine area (Bridges and Anderson,1984a), perhaps because of its proximity to the boreal-temperate zoogeographical boundary presented to marine biota by Cape Cod. Monthly intake water temperatures recorded during impingement collections at Pilgrim Station were above normal during most of 1998 compared to the mean monthly temperatures for the 10-year interval 1989-1998 (Table 7). During the first half of 1998, with the exception of June, water temperatures were higher than this 10-year period. Overall 1990/1995/1997/1998 disp!ayed relatively warm water temperatures, 1987/1989/1991 1994/1996 were average years, and 1988/1992/1993 were cold water years. Pilgrim Station intake temperatures approximate ambient water temperatures. However, a dominance of colder water species (i.e., Atlantic silverside, winter flounder, and rainbow smelt) appeared in impingement collections during 1998, with the warmer water species Atlantic menhaden also being well represented. h 4.2. Invertebrates in 575 collection hours,641+ invertebrates of 12 species (Table 8) v.vre recorded from Pilgrim Station intake screens between January-December 1998. The annual collection rate was 1.11+ invertebrates / hour. Blue mussel dominated, being caught only in August. l - _ _ _ _ _

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Sev nspine b y shrimp (Craaon septemspinosa) w:rs capturrd in grart:st numbers in I'! March / April and were 75% of the enumerated catch. Longfin squid (Lolico pealei) and green j crab (Carcinus maenus) represented 10.0 and 5.3%, respectively, of the total invertebrates  ! impinged. Unlike the fishes, the 1987 and 1988 invertebrate impingement rates were comparable to 1989 - 1998 despite relatively low circulating water pump capacity available in 1987 and 1988. I A noteworthy occurrence was the collection of so many blue mussels during 1986-1989. This 1 could be an effect of the Pilgrim Station outage during the late 1980s (reduced power level in 1989) which precluded the use of regular thermal backwashes for macrofouling control and the j migratory / adhesive abilities of mussels. In 1990 - 1998 several thermal backwashes were performed and blue mussel impingement was relatively minor for those years. During 1998 5j W! aggressive biofouling control activities included three effective thermal backwashes during the months of April, July and September. l Longfin squid were the third most abundant invertebrate impinged, peaking in August. Green crabs were fourth, being most represented in Octc,ber. Twenty -four specimens of the commercially important American lobster were captured in 1998 ranking them fifth. This equals 366 lobsters impinged on an annual basis at 100% operation of Pilgrim Station, under conditions at the times of impingement. This is considerably less than in 1991-1994 and is ) more comparable to the number of lobsters impinged in most previous years. The lobsters ranged in size from 27-74 mm carapace length and were impinged mostly in September. Approximately 1,980 pounds of mixed algae species were recorded during impingement sampling, for a rate of 3.44 pounds /hr. This equates to 15 tons of algae annually on Pilgrim l intake screens. This rate is considerably higher than the low flow 1984, and 1988 outage 1 years, comparable to 1989-1992 and 1994-1997, and much lower than 1993 which experienced very adverse meterological conditions of high winds and coastal storms (particularly in j l December).

4.3 Fish Survival Fish survival data collected in 1998 while impingement monitoring are shown in Table 9. Continuous screenwash collections provided the fewest numbers of fishes and revealed an overall survival rate of approximately 51%. Fishes collected during static screen washes fared worse showing a survival rate of 32%. As in previous years, the lower initial survival rate for static screen washes was influenced by the low initial survival of Atlantic silverside which were impinged in abundant numbers. As illustrated in 1993-1998, fishes have a noticeably higher survival rate during continuous screen washes because of reduced exposure time to the effects of impingement. However, reduced intake currents in 1984, associated with limited circulating water pump operation, may have been a factor in higher static wash survival then because of less stress on impinged individuals; although this wasn't apparent from 1987 and 1988 limited pump operation results. Among the ten numerically dominant species impinged in 1998, four demonstrated initial survival rates of 50% or greater. Grubby showed 82% survival, winter flounder 86%, alewife 8%, Atlantic silversidc 26%, windowpane 72%, rainbow smelt 22%, Atlantic herring 0%, Atlantic menhaden 5%, lumpfish 63%, and blueback herring 12%. Some of these high survival percentages may be explained by the robustness and durability of some of the species that were sampled during screenwashes.

I Table 9. Survival Summary for the Fishes Collected During Pilgnm Station lmpingement Sampling, January-December 1998. Iniital Survival Numbers are Shown Under Static (8-Hour) and Continuous Wash Cycles Number Collected Number Survivina Total Lenath (mm) Static Cont. Speicies Washes Washes Static Cont. Mean Range Atlantic silverside 350 37 80 22 98 70-135 Winter flounder 56 42 43 41 77 39-277 Atlantic menhaden 33 32 2 1 66 46-90 Rainbow smelt 14 27 2 9 107 70-157 Windowpane 21 4 14 4 87 47-291 Lumpfish 17 2 11 1 43 31-80 Grubby 16 1 13 1 62 50-90 Alewife 11 2 0 1 89 68-118 Blueback herring 8 0 1 - 82 66-96 Atlantic herring L 1 0 0 98 45-275 Hake spp. 4 2 0 0 73 60-117 Atlantic cod Cunner 2

                                     ?            2 3            0            1          57         53-67 g 2            1          83        46-108 W Little skate                      4             1            1           0          423       357-485 Red hake Threespine stickleback 4            0             0            -

93 68-137 g 3 1 3 1 50 36-62 5 Radiated shanny 2 1 2 1 97 78-130 Tautog Atlantic tomcod 2 1 2 1 96 75-132 g 0 2 - 2 125 120-130 3 Butterfish 2 0 0 - 47 40-53 Rock gunnel Sand lance sp. 2 0 0 2 1 - 108 67-148 g 2 139 122-156 g Spotted hake 2 0 0 - 76 76 Striped killifish 2 0 0 80 75-85 g White perch Atlantic moonfish 1 1 1 0 96 92-100 g 1 0 0 - 50 50 Bluefish 1 0 685 1 - 685 g Fourbeard rockling Fourspot flounder 1 0 1 - 74 74 g 1 0 1 - 163 163 Longhorn sculpin 0 1 - 1 328 328 g Noithern searobin Scup 1 0 0 0 0 170 170 g 1 - 190 190 Silver hake 1 0 0 - 71 71 Smallmouth flounder 1 0 0 - 52 52 Striped cusk-eel 0 1 - 0 192 192 Summer flounder 1 0 0 - 365 365 8 All Speicies 574 176 181 90 Number (% Surviving) (31.5) (51.1) ij1998. doc

                                    ---_____-__________---__---_____------_-_-__-_---._.--_-_-U

SECTION S CONCLUSIONS

1. The average Pilgrim impingement rate for the period January-December 1998 was 1.30 fish / hour. The impingement rates for fish in 1984,1987, and 1988 were several times lower than in 1989-1998 becausc of much reduced circulating water pump capacity during the former years.

2. Thirty-six species of fish were recorded in 575 impingement collection hours during 1998.

In 1989-1998 several times the nurnber of fishes were sampled as compared to 1984 and 1988, despite more collection hours in 1984 and an average number of hours in 1988. This illustrates the importance that the number of circulating pumps operating has on the quantity of impinged organisms. Substantially less collecting hours for portions of 1987 precluded its comparison with other years. I 3. At 100% yearly operation the estimated maximum January-December 1998 impingement rate was 11,426 fishes. This projected annual fish impingement rate was much lower than most recent years' rates because of several impingement incidents during the past few years.

4. The major species collected and their relative percentages of the total collections were Atlantic silverside, 51.6%; winter flounder,13.1%; Atlantic menhaden, 8.7%; and rainbow smelt, 6.8%.

i I 1

5. The peak in impingement collections occurred during March / April when 89% of the annual catch of Atlantic silverside occurred.

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6. Monthly intake water temperatures, which generally reflect ambient water temperatures, were higher for 1998 than the ten-year monthly averages for the period 1989-1998, with the exception of June-October, which were lower than normal.

7. The hourly collection rate for invertebrates was 1.11+. Blue mussel dominated in August.

I Sevenspine bay shrimp were second because of relatively large early spring collections. Longfin squid ano green crab were 10.0 and 5.3% of the enumerated catch. Twenty-four American lobsters were collected which equates to a potential 1998 impingement of 366 , lobsters.

8. Impinged fish initial survival was approximately 32% during static screen washes and 51%

during continuous washes for pooled species. Of the ten fishes impinged in greatest numbers during 1998, four showed initial survival rates of 50% or greater. I I' I I I I I I SECTION 6 LITERATURE CITED American Fisheries Society.1988. Common and scientific names of aquatic invertebrates from the United States and Canada: mollusks. Spec. Pub. No.16: 277 pp.

 'I                 .1989. Common and scientific names of aquatic invertebrates from the United States and Canada. decapod crustaceans. Spec. Pub. No.17:77 pp.

1991a. A list of common and scientific names of fishes from the United States and Canada. Spec. Pub. No. 20: 183 pp.

                 .1991b. Common and scientific names of aquatic invertebrates from the United States and Canada: cnidaria and ctenophora. Spec. Pub. No. 22: 75pp.

I Anderson, C.O., Jr., D.J. Brown, B.A. Ketschke, E. M. Elliott and P. L. Rule.1975. The effects of the addition of a fourth generating unit at the Salem Harbor Electric Generating Station on the marine ecosystem of Salem Harbor. Mass. Div. Mar. Fish., Boston: 47 pp. Briges, W.L. and R. D. Anderson.1984a. A brief survey of Pilgrim Nuclear Power Plant effects upon the marine aquatic environment, p. 263-271. In: J. D. Davis and D. Merriman (editors), Observations on the ecology and biology of western Cape Cod Bay, Massachusetts,289 pp. Springer - Verlag. (Lecture Notes on Coastal and Esturaine Studies, Vol.11). Lawton, R. P., R. D. Anderson, P. Brady, C. Sheehan, W. Sides, E. Koulokeras, M. Borgatti, and V. Malkoski. 1984b. Fishes of western inshore Cape Cod Bay: studies in the vicinity of the Rocky Point shoreline, P. 191-230. In: J. D. Davis and D. Merriman (editors), Observations on the ecology and biology of western Cape Cod Bay, Massachusetts,289 pp. Springer-Verlag. (Lecture Notes on Coastal and Esuarine Studies, Vol.11). a

I I Normandeau Associates.1996. Seabrook Station 1995 environmental studies in the Hampton - Seabrook area: a characterization of environmental conditions during the operation of Seabrook Station. Section 5.0 - Fish. Northeast Utilities Service Company: 103 pp. I Stupka, R. C. and R. K. Sharma. 1977. Survey of fish impingement at power plants in the United States Vol. Ill. Estuaries and Coastal waters. Argonne National Lab.: 310 pp. Radmisc/impgJan I I I I I I 1 I I I I I l l

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                                                                                                                           -5      9 DIRECTOR Fax: 508-563-5482 MEMORANDUM TO:             Members of the Administrative-Technical Committee, Pilgrim Power Plant 1

Investigations FROM: Brian Kelly, Acting Recording Secretary

SUBJECT:

Minutes from the 90th Meeting of the A-T Committee DATE: September 22,1998 The 90th meeting of the Pilgrim A-T Committee was called to order by Chairman Szal at 9:55 AM on September 15,1998, at the National Marine Fisheries Service lab in I Narragansett, Rhode Island. Minutes of the 89th Meeting I Bob Maietta motioned to accept the minutes of the last meeting, while Jack Parr seconded the motion, which was carried unanimously. Pilgrim Station Status Uodate Bob Anderson noted that 1998 is shaping up to be a record year for Pilgrim I Station regarding power output capacity. There is a planned refueling outage slated for April 1999. The sale of Pilgrim Station should occur in early October 1998. Final nuclear license transfer will take an additional 6-12 months, pending NRC approval. The new owner may want to build another generating unit at the present Pilgrim site. 1999 Marine Fisheries Monitoring (outlined in DMF's August 26,1998 memorandum) Bob Lcwton mentioned that he felt strongly that the restoration / enhancement pad of the upcoming Division of Marine Fisheries (DMF) work is the most important part of his proposal, and the means ofprocuring and setting aside the funding for these efforts are critical. Regarding field work, Bob described the proposed effort of continuing smelt restoration using egg trays in the Jones River and by monitoring smelt spawning in several I other tributaries of Plymouth, Kingston, Duxbury Bay. Several A-T members requested that DMF monitor the Jones River obstruction cleanup rendered by students from Silver i Lake Regional High School, so as to maintain the physical / biotic diversity of the stream while maintaining unobstructed passage for spawning smelt. The winter flounder abundance study was presented next, with DMF proposing a 1 M

I stratified, area swept, bottom trawl survey, with Adult Equivalent model numbers resulting from plant entrainment [ generated by Marine Research, Inc. (MRI)] to be compared to the index of adult abundance. There was considerable discussion regarding the Adult Equivalency model, the rationale for post-stratifying the trawl survey, Eric Adams' hydrodynamic modeling oflarval flounder dispersal in the Pilgrim area, and the utility of this survey. Overall, the Committee felt that there was a need for estimating adult flounder abundance in the Pilgrim area. l Lastly, Bob outlined the observational SCUBA dive schedule for the discharge area. Bob mentioned that with his proposed work, BECo would save approximately 90 thousand dollars as compared to last year. Jack Parr motioned that the proposed 1999 l field work be done as outlined by DMF (sole-source). Geny Szal seconded the motion, which passed unanimously. Jack Parr also recommended to the Committee that regarding upcoming review processes at other plants that, when possible, regulatory agencies should be involved in the collection or the oversight of the collection of monitoring data, in order a to insure quality control and assurance. Bob then outlined DMF sampling programs that have not been summarized in the 3 final report series, with his recommendation of which reports should have priority as far as their utility and value. Bob Maietta motioned that the Committee accept the DMF g 3i recommendation of writing three final reports in 1999 - cunner recruit surveys, winter flounder population study, and rainbow smelt restoration. Jack seconded the motion, gi which passed unanimously. Jack also requested that DMF produce a one page W comment / fact sheet on each of the other DMF studies that will not have a final report done on them, noting each study's merit from a general utilitarian approach (e. g., potential value to perform a similar monitoring study at other power plants). Lastly, the Committee had a lengthy discussion on the proposed pilot restoration / enhancement program for Pilgrim. It began with Jack discussing the Essential i Fish Habitat (EFH) Amendment to the Stevens-Magnuson Fishery Conservation and Management Act, which concentrates on habitat protection and conservation, with the role of the regional Fisheries Management Councils as custodians of this section; habitat is defined as that essential for all fish life stages. As power plant impacts (entrainment, l impingement and thermal) are mentioned in this document, power companies must now realize that EPA, as a permitting agency, must meet the Fisheries Management Council EFH mandate here, which has regulatory backing. Bob Lawton then followed with the DMF restoration / enhancement proposal, 1 which would appear to fit in well with the new EFH mandate. Bob Anderson noted l concerns of BECo due to increased electric utility competitiveness and hence cost l considerations in the industry from deregulation. Bob Maietta and Jack Parr noted that in light of the amendment to the Stevens-Magnuson Act, the timing is appropriate to seek El 3! some type of restoration / compensation /remediation fund from utilities. Jack mentioned i that consent decrees, basically negotiated settlements between utilities and regulatory 3' agencies as part of the permitting process, have been agreed upon in some environmental B restoration / enhancement cases. The Committee decided that a letter addressed to BECO regarding this issue will be drafted by Gerry Szal and Jack Parr to be signed by Jane I Downing, who is the Director of the Massachusetts Office of Ecosystem Protection at the  ; EPA Boston office. In that letter will be a requested dollar amount for proposed ' I

restoration / enhancement. This is partiallyjustified by the fact that DMF has reduced substantially its 1999 monitoring budget. Jack noted that regulators may be reaching the point where when a NPDES permit comes up for renewal, EPA may decide to adjust up or down monitoring efforts, request restoration / enhancement, and evaluate the ( effectiveness of respective restoration efforts. IV. 1999 Benthic Monitoring Program Bob Maietta motioned to accept the proposed benthic monitoring program by ENSR which includes onc qualitative transect discharge dive in September and a multi-year final benthic impact analysis report outlined in ENSR's August 26,1998 memorandum. The motion was seconded by Gerry Szal, which then passed unanimously. V. 1999 Impinnement and Entrainment Monitoring Mike Scherer reviewed Pilgrim Station monitoring proposed by MRI. Mike also discussed the statistical power / cost analyses done by MRI regarding impingement and entrainment sampling at Pilgrim Station. The Committee felt the current level of impingement and entrainment sampling (three times a week) is acceptable for now to monitor potential plant impact. Jack asked Mike to generate statistical power versus rate of population charige graphs for him for several species. The Committee discussed g:neral entrainment monitoring requirements for other plants in their upcoming relicensings. Bob Maietta motioned that MRI continue sole source with the proposed 1999 entrainment/ impingement work at Pilgrim Station as outlined in MRI's August 28 1998 memorandum. The motion was seconded by Gerry, which passed unanimously. VI. Other Business Bob Anderson motioned that BECo not have the discharge barrier net in place in 1999 unless requested to do so in an emergency. Gerry Szal seconded the motion which passed unanimously. A discussion of past menhaden kills at the plant and the utility of banier nets ensued. VII. The meeting adjourned at 3:15 P.M. L

Ii PNPS A-T Committee Meeting Attendance September 15,1998 Gerald Szal, Chairman Mass. DEP, Worcester Robert Anderson Boston Edison Company Carolyn Griswold NMFS, Narragansett Robert Lawton Mass. DMF, Pocasset Robert Maietta Mass. DEP, Worcester Jack Pan US EPA, Lexington I Michael Scherer MRI, Falmouth Richard Zeroka Mass. CZM, Boston Brian Kelly Mass. DMF, Pocasset Acting Recording Secretary I I I I I l I! l I' I, 1 I 1

PILGRIM NUCLEAR POWER PIANT I ADMINISTRATIVE-TECHNICAL CCHKITTEE September, 1998 l I I I Robert D. Anderson Boston Edison Company Pilgrim Nuclear Power Station Jack Paar U. Agency S. Environmental Protection 600 Rocky Hill Road New England Regional Lab I Plymouth, MA 02360-5599 (508) 830-7935 FAX (508) 830-8575 Surveillance and Analysis 60 Westview Street Lexington, MA 02173 (781) 860-4604 I ( W. Leigh Bridges MA Division of Marine Fisheries Nicholas Prodany State Office Building U.S. Environnantal Protection Agency 100 Cambridge Street Region 1, Industrial Permits Section .I Boston, MA 02202 (617) 727-3194 JFK Federal Building Boston, MA 02203 (617) 565-3507 -lW Carolyn Griswold National Marine Fisheries Service Rick Zeroka 28 Tarzwell Drive MA Coastal Zone Management Narragansett, RI 02882 I 100 Cambridge Street, Floor 20 (401) 782-3273 Boston, MA 02202 j (617) 727-9530 l John Boardman j I MA Division of Marine Fisheries Gerald Szal 50A Portside Drive DEP-Division of Watershed Management Pocasset, MA 02559 627 Main Street, 2nd Floor (508) 563-1779 Worcester, MA 01608 I Robert Lawton MA Division of Marine Fisheries (508) 767-2789 50A Portside Drive OTHER CONTACTS I Pocasset, FW 02559 (508) 563-1779 x 118 Dr. James Blake/Izzie Williams ENSR Consulting and Engineering I Robert Maietta DEP-Division of Watershed Management 627 Main Street, 2nd Floor Worcester, MA 01608 89 Water Street Woods Hole, MA 02543 (508) 457-7900 FAX (508) 457-7595 l I (508) 767-3793 Dr. Martha Mather Derek Mcdonald Marine Biofouling Control Corp. l j' MA Coop Fish & Wildlife Unit .l l ie Holdsworth Hall University of Massachusetts (508) 888-4431 Amherst, MA 01003 Dr. Michael Scherer lg (413) 545-4895 Marine Research Inc. Fa m uth Heights Road lE i 4 Falmouth, MA 02540 I I lll b}}