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Marine Ecology Studies Related to Operation of Pilgrim Station Semi-Annual Rept Number 44,Jan-June 1994
	ML20149G938
Person / Time
Site:	Pilgrim
Issue date:	06/30/1994
From:	Richard Anderson; BOSTON EDISON CO.
To:	; MASSACHUSETTS, COMMONWEALTH OF
References
	BECO-94-109, NUDOCS 9411080234
	Download: ML20149G938 (110)
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p < Pilgrirn Nuclear Power Station ,

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' W. C. Rothert GeneralManager Technical October 26, 1994 BECo 94- 109 :

NPDES Program Operations Section (WCP) ;

Environmental Protection Agency P.O. Box 8127 '

Boston, MA 02114 ,

NPDES PERMIT MARINE ECOLOGY MONITORING REPORT

Dear Sirs:

In accordance with Part I, 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. 44 is submitted. This covers the ;

period from January through June,1994. ,

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Attachment:

Semi-Annual Marine Ecology Report No. 44 WCR/RDA/nas/ECOLRPT I

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080102 9411080234 940630 1 PDR ADOCK 05000293 R l PDR

, marineecologyItudief g Related to Operotion ofPilgrim/totion I SEMI-ANNUAL REPORT NUMBER 44 i

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BOSTON EDISON COMPANY LfCENSING DIVISION l g

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l MARINE ECOLOGY STUDIES RELATED TO OPERATION OF PILGRIM STATION SEMI-ANNUAL REPORT NO. 44 REPORT PERIOD: JANUARY 1994 TIIROUGH JUNE 1994 I DATE OF ISSUE: OCTOBER 31,1994 I

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I Compiled and Reviewed by:

llobert D. Anderson Principal Marine Biologist I

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1 Licensing Division l Boston Edison Company i Pilgrini Nuclear Power Station !

I Plymouth, Massachusetts 02360 l

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TABLE OF CONTENTS SECTION I

SUMMARY

ll INTRODUCTION 111 MARINE BIOTA STUDIES l IIIA Marine Fisheries Monitoring Semi-Annual Report on Monitoring to Assess impact of Pilgrim Nuclear Power I Station on Marine Fisheries Resources of Westem Cape Cod Bay, Project Report No. 57 (January - June 1994) (Mass. Dept. of Fisheries, Wildlife and Environmental Law Enforcement; Division of Marine Fisheries)

IIIB Denthic Monitoring Benthic Algal Monitoring at the Pilgrim Nuclear Power Station (Qualitative Transect Surveys). January 1994 - June 1994 (Science Applications International Corp.)

filC Entrainment Monitorinx l Ichthyoplankton Entrainment Monitoring at Pilgrim Nuclear Power Station, January l

- June 1994 (Marine Research, Inc.) l IllD Impjagement Monitating Impingement of Organisms at Pilgrim Nuclear Power Station: January - June 1994.

(Boston Edison Company)

IV Minutes of Meeting 81 and a Special Meeting (2/14/94) of the Administrative-Technical (

I Committee, Pilgrim Nuclear Power Station.

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SUMMARY

I Highlights of the environmet.tal surveillance and monitoring program results obtained over this reporting period (January - June 1994) are presented below. (Note: PNPS was in high operation I during this period.)

Marine Fisheries Monitoring:

1. Shrimp trawl catch from January - June 1994, outside Plymouth, Kingston, Duxbury Bay, recorded 16 benthic fish species with little skate (37.9%), winter flounder (32.2%), and windowpane (14.2%) composing 84% of the total. Mean catch-per-unit-effort (CPUE) for all species was 20.9 for all stations and 21.9 in Warren Cove. CPUE from January - June 1994 for commercially important winter flounder (9.1) was highest for all species at Warren Cove station, and the mean size winter flounder recorded there were 22 cm. Winter flounder stock assessment I work was performed to determine population parameters with 178 fish marked so far in 1994 (206 in 1993). Three recaptures have been recorded to date.

Techniques for sampling young-of-the-year winter flounder are being explored.

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2. In May - June 1994 fish observational dive surveys four species were observed in I the discharge area. Striped bass (88%) were the most numerous species seen, with tautog second (10%) in observational abundance. No fish showed abnormal behavior and no gas bubble disease symptoms were observed on routine i 1

observational dives. Most fish were in greatest concentrations in the path of the l

PNPS discharge, being observed most often in the denuded zone (98%).

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3. The April 24 - June 30,1994 shorefront sportfish survey at Pilgrim Station recorded 458 angler-trips. The PNPS thermal discharge attracted sportfish species with catches of striped bass (233), pollock (40) and bluefish (3) being recorded for l

a mean catch rate of 0.6 fish-per-angler-trip. '

4. Rainbow smelt egg restocking of the Jones River (Kingston), to mitigate for the I

high PNPS smelt impingement in December 1993, accounted for 600,000 fertilized eggs being transplanted for hatching to supplement the River's spawning I population of this species. This effort will be repeated in the early Spring 1995 El as l when 1,000,000 smelt eggs will be attempted to be stocked from other areas to the ,

Jones River.

5. The cunner tagging study concentrated on assessing tagging (Floy T-bar anchor I

tag)and mark / recapture for population estimation. Tagged cunner (510) were released in June 1994, and 273 were retained for fecundity and aging analysis.

Impingement Monitoring:

1. The mean January - June 1994 impingement collection rate was 3.34 fish /hr. The rate ranged from 0.43 fish /hr (June) to 10.63 fish /hr (April) with Atlantic silverside comprising 74.7% of the catch, followed by rainbow smelt, 7.6% and winter I flounder,4.5%.

2. For April 1994, when the fish impingement rate was 10.63, Atlantic silverside accounted for 88% of the fishes collected. Fish impingement rate was notably higher in 1989-1994 than in 1988 (0.30), primarily because Pilgrim Station had much less circulating water pump capacity than normal that year.

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.I 3. The mean January - June 1994 invertebrate collection rate was 2.39+/hr with jellyfish (undetermined numbers), sevenspine bay shrimp (71.1%) and American l _

lobster (8.0%) dominating the catch. Sixty-nine American lobsters were caught.

4. Impinged fish initial survival at the end of the Pilgrim Station intake sluiceway was approximately 71% for static washes and 84% for continuous washes I Benthic Monitoring I

April and June 1994 mappings of the discharge efiluent, near-shore acute impact zones were performed. Negligible Chondrus growth in the denuded zone was evident for both April (1,065m 2) and June (1,222m2) indicating continuing impact since the 1986 - 1988 PNPS outage. In June a dense mat of blue mussels blanketed large portions of the Lhondrus sparse / stunted zones as was also apparent in June of 1990 r.nd 1992, possibly because of consistent thermal discharge during I these periods.

I lintrainment Monitoring:

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1. A total of 24 species of fish eggs and/or larvae were found in the January - June 1994 entrainment collections: 9 eggs,21 larvae.

I 2. Egg collections for January - April 1994 (w'mter-early spring spawning) contained fourbeard rockling, Atlantic cod, American plaice, winter and yellowtail flounder eggs. May and June (late spring - summer spawning) egg samples were most representative of Atlantic mackerel and labrids.

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5 Larval collections for January - April 1994 were by rock gunnel, grubby and sand lance. For May and June larvae, sand lance, fourbeard rockling, winter flounder and radiated shanny dominated.

4. No lobster larvae were collected in the entraiament samples for January - June Il ,

l 1994.

5. On several occasions unusually high densities of ichthyoplankton were found, involving sand lance, Atlantic herring, sculpin and radiated shanny larvae, as well as both the eggs and larva of Atlantic menhaden.

6. Winter flounder entrainment sampling, net mesh size efliciency comparisons were conducted showing 0.202 mm mesh significantly more efficient in capturing stage 2 larvae than 0.333 mm mesh. Also, the current entrainment sampling plan ,

was shown to be relatively powerful in detecting annual abundance changes of winter flounder.

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INTRODUCTION A. Scope and Objective I

This is the forty-founh 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 Western Cape Cod Llay ecosynem with panicular emphasis on the Rocky Point area. This is the thirty-second semi-annual report in accordance with the environmental monitoring and reporting requirements of the PNPS Unit i NPDES Pennit from the U.S. Environmental Protection Agency

(#MA0003557) and Massachusetts Division of Water Pollution Control (#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 been continued under the PNPS NPDES permit.

Amendment #67 (1983) to the PNPS Tech. Specs. deleted Appendix B non-radiological water quality requirernents as the NRC felt they are covered in the NPDES Pennit.

I 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 situation I These studies are guided by the Pilgrim Administrative-Technical Committee (PATC) which was chaired by a member of the Mass. Division of Water Pollution Control in 1994 and whose membership includes representatives from the University of Massachusetts, the Mass. Division of Water Pollution Control, 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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I B. Marine Biota Studies l

1. Marine Fisheries Monitoring A modified version of the marine fisheries monitoring, concentrating on indicator species I

populations' impacts, is being conducted by the Commonwealth of Massachusetts, Division of Marine Fisheries (DMF).

l The occurrence and distribution of primarily cunner and winter flounder around Pilgrim l

Station and in adjacent areas are being determined. Population parameters and related life ~I history statistics are being studied to address Pilgrim Station impacts from entrainment of 1

ichthyoplankton, and impingement of juveniles and adults.

I Smelt eggs will be stocked in the Jones River (Kingston) in March / April 1995, as was done in 1994, to mitigate for the large impingement of 5,000+ rainbow smelt on Pilgrim Station intake screens in December 1993.

A finfish observational dive program was initiated in June 1978. SCUBA gear is utilized on biweekly dives from May-October (weekly mid-August to mid-September) at 6 stations in the PNPS thermal plume area.

Results of the marine fisheries monitoring during the reporting period are presented in I

Section Illa.

2. Henihic Monitoring The benthic monitoring described in this report was conducted by Scientific Applications International Corporation, Woods Hole, Massachusetts.

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Physical thennal plume analyses are being conducted to rccommend the most applicable future benthic studies to be perfonned. Qualitative transect sampling off the discharge canal to determine the extent of the denuded and stunted zones is conducted four times a year (March, June, September and December). Results of the benthic monitoring reported during this period are discussed in Section IIIB.

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3. Elankton11onitoring Marine Research, Inc. (MRI) of Falmouth, Massachusetts, has been monitoring entrainment in Pilgrim Station cooling water of fish eggs and larvae, and lobster larvae (from 1973-1975 phytoplankton and zooplankton were also studied). Figure 1 shows the entrainment contingency sampling station locations. Infonnation generated through these studies has been utilized to make periodic modifications in the sampling program to more efficiently address the question of the effect of entrainment. These modifications have been developed by the contractor, and reviewed and approved by the Pilgrim A-T Committee on the basis of the program results. Plankton monitoring in 1994 emphasized consideration of ichthyoplankton entrainment and selected species adult equivalency analyses. Results of the ichthyoplankton entrainment monitoring for this reporting period are discussed in Section IIIC.

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

January 1979, Marine Research, Inc. has been conducting impingement sampling with results being reported on by Boston Edison Company.

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l A new screen wash sluiceway system was installed at Pilgrim in 1979 at a total cost of approximately $150,000. This new sluiceway system was required by the U.S. !

Environmental Protection Agency and the Mass. Division 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 terminated in 1984, and a final report on them appears in Marine Ecology Semi-Annual Report #23.

Results of the impingement monitoring and survival program for this reporting period are Ilj discussed in Section IllD. gl C. Station Operation History The daily average, reactor thermal power levels from January through June 1994 are shown in 51 '

Figure 2. As can be seen, PNPS was in a nomul operating stage for most of this reporting period.

I E. 1994 Environmental Programs I'

A planning schedule bar chart for 1994 environmental monitoring programs related to the operation of Pilgrim Station, showing task activities and milestones from December 1993 - June 1995, is included. Shrimp trawling, experimental lobster pot monitoring, and overflight fish spotting surveillance were terminated in 1994.

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M M M M M M M M M W W M M M M M M M M

[ 1933 1994 1995

!_NOV_t_DEC__JAN a_FEB_2_ MAR _._APR_1_MAY_ uJUN _ __JUL_n_ AUG1SEP, _OCT _ t NOV_ u DEC _ .JAN o FEB _t_ MAR._ _ APR _a _MAY_1 StN _ _ JJL _

ZONE 1.PATC

> 94 Monitoring Programs (NPDES) to EPA NRC DWPC PATC uff Committee) 0 Review results of 93 Programs FISHERIES (Sub-committee) f' Recommend for FISHERIES 95 Programs BENTHIC (Sub-committee) <f '

Recommend for BENTHIC 95 Progra s PATC (Full Committee)

Recommend for 95 monitoring (NPDES) programs q BECo meet with EPA DWPC (Potential)

' I BECO P rep ueDes 95 Moniiering Prog,ams " M" .

BECO approve 95 Monitoring Programs Submit 94 Programs to EPA NRC DWPC g Initiate 95 Monitoring Programs f PATC (Full Committee)

Review results of 94 Programs f i

PNPS 1994 ENVIRONMENTAL PROGRAMS (NPDES PERMIT #MA 0003557)

! 1993 -

1994 1995 LNOV i DEC_._JAN _.n FEB_uMAR_ ._APR _1_MAY __ uJUN q _ JUL_ _uAUG i SEP_ ._OCT _uNOV __uDEC .. ._ JAN _ _, . FEBa_ MAR _ _.. APR _ u M AY u JUN _ _JUL_'

Zone 2 - MARINE FISHERIES MONITORING Issue 94 P.O. to MDMF 01/03!94 ! 07/05/94 Winter flounder I cunner population studies 05/02/94 06/30/94 Underwater observation (Bi-weekly) _ _

l 07/01/94 09/15/94 Prep semi annual report (draft)

Submit draft report to BECO <f

! 09!15/9410/03/94 BECO review / comment on draft report y I 10/03/9410/10/94 Final report prep by MDMF lme Submit 94 se I-annual report to BECO 07/01/94 12/30/94 Winter ffounder / cunner population studies _ _

Underwater observation (Bi-weekly) _ _ _ _ . . . _ _ . _ ___ ._

Prep annual report (draft)

Submit draft report to BECO & Fish Subcom. O BECOlFish Subcom. review / comment on draft report

! 04/03/9504/10/95 i Final annual report prep. game Submit 94 annual report to BECO f PNPS 1994 ENVIRONMENTAL PROGRAMS (NPDES PERMIT #MA 0003557) se uma sua em uma um amm en as ums um um usa um uma aus aus aus au

M M M M M M M em W M m' W W W W W M- W j 1993 1994 1995

. LMOV i DEC_ _ JANu _ FEB_t _ MAR _._ APRa_MAY_t_JUN _ _ JUL_n. AUG._ t.SEP__..._ OCT _tNOV__t_ DEC_ _JANa_ FEB_2_ MAR _ _ APRu_M AY _1_ .JUN._ , _JUL ZONE 4 -IMPINGEMENT MONITORING

<[ issue 94 P.O. to MRI 01/03/94 ,

Biota sampling } 7._ -

~~--t 01/03/94 !

NPO record plant data f 02/15/94 0111W Contractor submit Biota data to DECO PS submit plant data to BECO _ _ _ _ _ . _ _ . . _ _ . _ _ - - - -

l l 03/01/94 ~ T~~ '

ECO prep. & distr. monthly reports _

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1 I 09/01/94 10/03/94 BECO prep 94 semi-annual report ._ _1.

02/01/95 04/03/95 BECO prep 94 annual report _

ZONE 5 - BENTHIC MONITORING issue 94 P.O.to SAIC 03/15/94 Qualitative transects sampling (1st) 0 Qualtative transects sampling (2nd) <

Prep draft semi-annual report Submit draft report to BECO Q BECO rvwico ent on draft report 10/03/9410/10/94 Final report prep. jame 10/11/94 Submit 94 semi-annual report to BECO l: ,

! 09/15/94 Qualitative transect sampling (3rd) o Qualitative transact sampling (4th) -

PNPS 1994 ENVIRONMENTAL PROGRAMS (NPDES PERMIT #MA 0003557)

l 1993 1994 1995 LNOV i DECul__JAN_nFEB_uMAR_ __APR , MAY i JUN_j_JUL_ u AUG a _SEP__OCT ,

NOV_t_DEC__JAN_1_ FEB_1_ MAR __ APR MAY_ u JUN_.._JUta prep draft annual report Submit draft report to BECO!B nthic Subcom. <f BECO/ Benthic Subcom. rvw/ comment on draft report 04/03/9504/10/95 Final report prep. jeen i

Submit 94 annual report to BECO <f ZONE 6 -ENTRAINMENT MONITORING i

Q lssue 94 P.O. to MRI 01/03/94 02/28/94 Plank, ton sampling by MRI (Bi-weekly) 03/01/94_ 03/31/94 plankton sampling by MRI(weekly) __g I 04/01/94 05/02/94 Sample processing & data analysis e

! 05/02/94

, Submit data analysis sheets to BECO Q Plankton sampling by MRI(weekly) 07/01/94 _ 08/01/94 Sample processing & data analysis I 08/02/94 Submit data analysis sheets to BECO Q

! 08/1S/94_ 09/15!94 MRI prep semi-annual draft Rvwicomment by BECO PNPs 1994 ENVIRONMENTAL. PROGRAMS (NPDES PERMIT #MA 0003557) ao ama um som amm aan an en se en an em um in an ami en sum ei

E E E E E E E O E S E E E E E E E E E j 1993 1994 1995-i_NOV i DEC JAN i FEB_t_ MAR _._ APR2_ MAY__1_JUM JUL_ u AUGa_SEP I OCT 4_NOV i DEC_ _JAN _nF EB_i_ MAR _. _, APR _t_MAY_uJUN_._JUL.

10/03/9410/10/94 MRI final report prep. p l Submit 94 semi-annual report to BECO l<f 0 09130/94 Plankton sampling by MRI(weekly) 7/01/94 .

3 Sample processing & data analysis Submit data analysis sheets to BE <

Plankton sampling by MRI (Bi-weekly) 01/h3/95 01/31/95 Sample processing & data analysis Submit data sheets to BECO I 02/01/95 03/15/95 MRIprep annualreport draft) e Rvwicomment by BECO l MRI final report prep.

04!11/95 Submit 94 annual report to BECO 0 ZONE 11 THERM Ak. DISCHARGE (DIVE & NETS lWIAINT.)

<f issue 94 P.O. to inner Tech 01/03/94

- . - - - - - - . Barrier nets maint. (weekly)

<[ Issue 94 P.O. to Motte/Hi! er l 09/30/94 Barrier nets repi. (If required) 03/01/94 _. --

PNPS 1994 ENVIRONMENTAL PROGRAMS (NPDES PERMIT #MA 0003557)

1993 1994 1995 NOV e DEC__JAN . FEBa_ MAR _ _APR i MAY JtM JUL i AUG.a _SEP OCT i MOV i DEC__ JAM _t_FEB_t_M AR_ _APR , MAY . JUN_..;JUL._

ZONE 12 -PIPORT MONITORING PROGRAMS NPDES permit semi-annual report prep.

Printing finalsemiannual report l BECO rvw/ comment!a proval of semi-annual report N Submit 94 semi-annual report to EPA /DWPC/NRC <

03/01/95 I 04/17195 NPDES annual report prep. -

Printing final annual report

! 04/20/9504/28/95 BECO rvwIcomment/ approval of annual report e Submit 94 an at report to EPA /DWPCINRC PNPS 1994 ENVIRONMENTAL PROGRAMS (NPDES PERMIT #MA 0003557) tus aus num amm uma un am as as e uma em um use sus aus em nas as

-_ _ __ __-____ w_m_ ___ -_ - _ _ . _ _ _ . _ _ . _ _ _ _ _ - . _ - - _ _ _ _ - . - - _ . _ _

I E

I I SEMI-ANNUAL REPORT ON MONITORING TO ASSESS IMPACT OF I PIIERIM NUCLEAR POWER STATION ON MARINE FISHERIES RESOURCES OF WESTERN CAPE COD BAY I

Project Report No. 57 (January -- June 1994)

I By I Robert P. Lawton, Brian C. Kelly, Vincent J. Malkoski, John H. Chisholm, Paul Nitschke, Bethany Starr and Erin Casey I

I I

I October 1, 1994 I Massachusetts Department of Fisheries, Wildlife, and Environmental Law Enforcement Division of Marine Fisheries 100 Cambridge Street ;

Boston, Massachusetts 02202 l I

II l

TABLE OF CONTENTS I

Section Page I

1. Executive Summary 1 II. Introduction 5 III. Methods and Preliminary Results 6

1. Groundfish, with Emphasis on Winter Flounder 6 Groundfish 7

Winter Flounder Stock Size I Juvenile Winter Flounder Survey 10 12 a) Beach Seine 12 b) Beam Trawl 15 c) Diver Transects 16

2. Underwater Finfish Observations 17

3. Sportfishing 19

4. Cunner Fopulation Studies 20

5. Smelt Restocking 21 IV. Acknowledgments 25 V. Literature Cited 26 I

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I 11 I i I

1 5

LIST OF TABLES Table 4

Pace

1. Trawl catch, percent composition, size range, 8 and CPUE (fish per 15 minute tow) of finfish captured by nearshore trawling within quadrats in the vicinity of Pilgrim Station, January through June 1994,

2. Trawl catch data for dominant demersal 8 E finfish in just Warren Cove, January E through June 1994. v

3. Young-of-the-year winter flounder collected 15 by haul seine at fixed stations in the Pilgrim study area, June 1994.

I I

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I I

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lii I

l t - - - - _ - - - -- - - - - _ - - - - _ _ - _ _ _

I LIST OF FIGURES Fiaure I Pace

1. Study area (dark shading) inside and outside 6 the estuary that was sampled by otter trawl for groundfish, with emphasis on winter flounder, 1994 (not drawn to scale).

2. Station locations for young-of-the-year 14 winter flounder beach seine survey within Plymouth, Kingston, Duxbury Bcy and along I the Plymouth shoreline in the environs of Pilgrim Nuclear Power Station, June 1994.

l 1 -

3. Location of underwater finfish observation 17 stations at PNPS, 1994 (not drawn to scale).

l 3 4. Finfish abundance as observed by divers 18 fg 1

in the area around the Pilgrim Station discharge canal, May and June, 1994.

I

4. Finfish distribution as noted by divers in 19 the area around the Pilgrim Station discharge canal, May and June, 1994.

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I

I I. EXECUTIVE

SUMMARY

Groundfish. With EmDhasis on Winter Flounder Groundfish Little skate (Rajacrinacca) was again the most abundant species in I the trawl catches. The species of interest (winter flounder -

r/curonectes americanus) comprised a higher . Centage of the total catch this year as compared to last year. Also, the catch per unit effort for this species in Warren Cove increased this year.

Windowpane (Scophthalmus aquosus) ranked third in this year's catch, E followed by yellowtail flounder (Pleuronectes ferry Atlantic cod (Gadus morhua) catches (young-of-the-year) declined this year.

I Winter Flounder Stock Size Random trawl tows (standardized as to di stance towed) were made inside Plymouth, Kingston, Duxbury Bay .A nd in the inshore sector of western Cape Cod Bay with the primary objective of estimating absolute abundance for the local winter flounder population. Two independent types of estimates of absolute population size are being employed; I one is derived from the recapture of marked fish and the other from the expansion of l

sampled catches per unit area to the total area occupied by flounder of the local population, referred to as density !

extrapolation (area-swept). The bottom trawl survey provided both source of flounder for tagging and recapture effort in the I. vpture-ret Jture program and catch per unit effort data for the I

l density extrapolation technique.

I I !

l su i 5!

i This spring we tagged (Petersen tag) 178 winter flounder ( >_

200 mm total length) in the study area. Last year 206 flounder were marked (fin-clipped). To date, we have obtained three recaptures - two from fish marked in 1993 and one tagged this year (recaptured after June). An estimate of population size will be generated later this year when all data have been collected via density extrapolation.

Juvenile Winter Flounder Survey a) Beach Seine I Juvenile winter flounder (young-of-the-year and yearlings) were surveyed to index year-class strength. Thirteen fixed stations were sampled by seine inside and outside Plymouth, Kingston, Duxbury Bay during June. Forty-six seine hauls were made; few juvenile flounder were captured. All but one were taken inside the estuary.

b) Beam Trawl Preliminary results using a beam trawl to inventory juvenile winter flounder in our study area indicate excessive variation in '

replicate tow catches at sampling sites. This lessens the value of these data for density calculations as an index of relative abundance.

c) Diver Transects SCUBA diving transects show promise for visually enumerating i

E i 1

young flounder on sand bottom but have limitamions when surveying eel grass beds.

Underwater Finfish Observations Three biweekly SCUBA surveys were made, occupying six fixed stations in and around the discharge canal from May to June 1994.

Four species of finfish were sighted, with striped bass (AIoronesaxatilis) comprising 88% of the total observed. Distributionally, 98% of all the fish were observed in'the " denuded" zone and 1% both in the

" stunted" and " control" areas.

I Soortfishina Creel data were again collected this spring on the shore sportfishing at the Pilgrim Station Shorefront area. From April 24 to June 30, twenty-six days were sampled for sportfishing activity during which 458 angler-trips were recorded. The catch totalled I- 276 fish: 84% were striped bass, 14% were pollock (Pollachius rirens) ,

and 2% bluefish (Pomatomus saltattir) . The large catch of bass this spring is indicative of the upswing in numbers of this species along the Atlantic coast. Sportfishing activity will be monitored I throughout the summer and fall.

Cunner Population Stujie_g We have studied the distribution and movement patterns of adult cunner (Tauregolahms adspenus) off Pilgrim Station and are now working to estimate population size and determine fecundity.

I l

Cunner are caught in baited fish traps, with selected fish being removed from the population for fecundity and aging analysis.

Otherwise, cunner 90 mm or larger in total length (TL) are marked with Floy T-bar anchor tags and released in the capture area. This June 1,338 cunner were captured, of which 273 were retained for fecundity and aging; 510 were tagged. As for recaptures, 64 tagged fish were taken. We currently are conducting a controlled retention study for the Floy T-bar anchor tag with small cunner I 9

(90-120 mm TL) held at the National Marine Fisheries Aquarium in Woods Hole, MA.

smelt Restocking I

This was the first year of a two-year restocking program of rainbow smelt (Osmems mordar) in the Jones River, a tributary to Plymouth, Kingston, Duxbury Bay. This endeavor is a remedial measure to compensate for the plant-induced mortality in December 1993 of about 5,200 smelt. The overall goal of this program is to '

increase the smelt run in the Jones River via augmenting instream reproduction and enhancing the quality of spawning habitat in the Jones River.

We stocked over 600,000 fertilized smelt eggs into the Jones ;

River and added transient artificial substrate, i.e., trays filled with sphagnum moss, to the spawning ground to optimize egg sets and ,

hatching success.

I I

I E

l I !

)

l II. INTRODUCTION Monitoring of the marine environment off Pilgrim Nuclear Power Station is conducted to assess impact of plant operation.

Ecological studies are conducted by the Power Plant Team of the Massachusetts Division of Marine Fisheries (MDMF) , focusing on j indicator finfish species in the off-site waters of western Cape Cod Bay. This work is funded by Boston Edison Company under Purchase Order No. 112004 in 1994.

In this progress report, sampling methodology and preliminary findings for January through June 1994 are discussed. Measurements, counts, percentages, and visual observations are used in the l analyses, t

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I I 4 I

1 1

1 III. HETHODS AND PRELIMINARY RESULTS

1. GROUNDFISH, WITH EMPHASIS ON WINTER FLOUND_EE l During the first six months of 1994, we completed 92 bottom trawl tows using the Wilcox trawl that was employed in our i

nearshore fixed station groundfish survey. Thirty-two percent of l the tows were made inside Plymouth, Kingston, Duxbury Bay (PKDB) ,

with the other sixty-eight percent located along the Plymouth l shoreline in the inshore sector of western Cape Cod Bay (Figure 1) . _i Almost half the trawls were randomly selected, and the unit of effort was standardized at a 400-m towing distance. The locations

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Figure 1. Study area (dark shading) inside and outside the estuary that was sampled by otter trawl for groundfish, with emphasis on winter lE

flounder, 1994. (not drawn to scale)

I E

of the remaining tows were haphazardly chosen, while the unit of effort was generally 15 minutes of bottom towing time. Both l efforts placed emphasis on towing in areas that appeared to have i i

concentrations of winter flounder. l l

Presently, our primary objective is to estimate absolute l

l abundance of the local winter flounder population; this information i l

l is needed to assess impact of larval entrainment at Pilgrim I l

Station. A secondary objective is to survey groundfish in the area and maintain catch records, including relative abundance, of numerically dominant species. Data from the random tows will be used in a density extrapolation technique to estimate winter flounder population size; whereas, haphazard tows (includes fixed sites) are used as indices of relative abundance for all dominant groundfish in the area. For the haphazard tows, sampling in Warren Cove was stressed because tow sites were approximate to the f location of the fixed station there last year. In turn, winter I flounder catches from all town were used as a source of tagging fish for our capture-recapture program.

Groundfish k I

A total of 690 finfish comprising 16 species was collected during 33 (15-minute) tows outside PKDB in the study area (Table 1). Five species: little skate (Raja crinacca) , winter flounder, l

(Pleuronectes arnericanus) , windowpano (Scophthairnus aquosus) , yellowtail flounder (Picuranccles femigincus) , and Atlantic cod (Gadusinorhua) , comprised 91.8% of this year's catch. CPUE (catch per 15 minute tow) for all species pooled in the sampling area averaged 20.9 fish per tow. CPUE also I '

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was calculated for the dominants.

Table 1. Trawl catch, percent composition, size range, and l CPUE (fish per 15 minute tow) of finfish captured by nearshore trawling in the vicinity of Pilgrim Station, January through June, 1994 l1 l

Species Total Percent Size Range CPUE Catch of Catch (cm)

Little skate 262 37.9 18 63 7.9 l Winter flounder 222 32.2 5-42 6.7 i Windowpane 98 14.2 7 34 3.0 Yellowtail flounder 34 4.9 9-36 1.0 Atlantic cod 18 2.6 2-6 0.5 other spp.' 56 8.6 l Total catch 690 Number of tows 33 Catch per tow 20.9

' Represent combined totals from 11 species of low catch.

Little skate ranked first in trawl catch. The catch composition for the first half of this year (37.9% of the total) was similar to last year's value (36.7%). However, the relative abundance of little skate is down from 19.2 in 1993 to 7.9 this year. Within Warren Cove, the catch rate declined from 23.8 to 6.4 (Table 2).

Table 2. Trawl catch data for dominant demersal finfish in just Warren Cove, January through June, 1994.

Species Total CPUE Sire Range Mean size Catch (cm) (cm)

Winter flounder 118 9.1 5 42 22 Little skate 83 6.4 21-58 43 Windowpane 45 3.5 22-34 27 Ocean pout 12 0.9 5-70 53 Atlantic cod 7 0.5 2-4 3 Yellowtail flounder 6 0.5 11-24 14 Atlantic silverside 3 0.2 8-11 9 Rock gunnel 3 0.2 7-10 Northern pipefish 1 0.1 18 Grubby 1 0.1 5 -

Red hake 1 0.1 9 Total catch 284 Nunber of tows 13 Catch per tow 21.9 I

E

I The primary species of interest, winter flounder, comprised 32% of the catch as compared to 14% in 1993. Winter flounder ranked first in groundfish catch in Warren Cove. CPUE was 9.1, as compared to 6.9 for last year. The overall winter flounder abundance index was 6.7, which is similar to last year's value of 7.7. The size range was from 52-425 mm, with a mean size of 218 mm.

Ranking third, windowpane comprised 14% of the total catch, essentially the same as last year's contribution of 13.9%.

However, the relative abundance of windowpane was 3.0 overall in the study area and 3.5 in Warren Cove, marked decreases from 1993 (7.3 and 10.0, respectively).

Yellowtail flounder ranked fourth overall at 5% of the catch.

The mean length of captured yellowtail flounder in Warren Cove was 14 cm (a yearling fish). There was essentially no change in the relative contribution of their catch for the first half of 1993 and 1994. In 1993, this species comprised 5.5% of the trawl catch.

Relative abundance was 0.5 in Warren Cove and 1.0 overall this year; whereas last year, catch rates were 1.3 and 2.9, respectively.

Ranked fifth at 2.6% of the total catch was Atlantic cod, far I less than last year's contribution of 18.5% of the catch. All cod captured again this year were young-of-the-year (mean length of 3 cm). CPUE was 0.5 fish per tow in both Warren Cove and throughout the study area.

In summary, percent composition of the catches of little l

I 1

su 5

skate, windowpane, and yellowtail flounder remained relatively the same as last year. There was essentially no change in the overall catch of winter flounder, but there was a sizeable decrease in the catch of Atlantic cod.

Winter Flounder Stock Size on a navigational chart and a topographical map, we gridded Plymouth, Kingston, Duxbury Bay, Warren Cove and the other inshore waters from Rocky Point to Manomet Point into 1000-m square quadrats. This quadrat size allowed the field team to position the selected location in the field using land ranges and compass bearings. Quadrats were numbered on a chart to allow stations to be randomly selected by a random numbers table for each day's sampling. Outside PKDB, the quadrats were drawn within the 9-m depth contour (MLW) to correspond with the depth range within the estuary. To address potential differences in flounder distribution as a result of variation in water depth, we initially endeavored to assign sampling stations within PKDB to either flats (shallow) or channels (deep), i.e., to stratify. However, there were an insufficient number of navigational buoys marking the deeper channels for us to sample this way. Instead, we recorded depth from the boat's fathometer at regular intervals and calculated an average depth for each tow.

During their reproductive season, there is the possibility that winter flounder move in and/or out of PKDB. There is known spawning inside and outside the estuary. Flounder may aggregate out in deeper water, moving in on flood tide at night to spawn in

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I the estuary's shallows. We divided the study area into two zones -

Inside (PKDB) and Outside (Warren Cove and the water area between Rocky and Manomet Points); catches can be compared between zones over time. On each sampling outing, tows were made' in eight randomly selected quadrats (four from each of the two zones).

Trawling was severely limited this winter by weather and ice conditions, with no field trips possible from January through March. A sample was collected as follows: At each station location, two "high flyer" buoys were deployed 400 m apart with the aid of an optical range finder. A trawl tow of a standard distance (effort) as opposed to time improves precision of relative abundance or density estimates. All tows were made from buoy to buoy; tow times were recorded (ranging from 4 to 11 minutes). We used the same Wilcox trawl net (9.8-m sweep, 7-m headrope, 10.2-cm wings, 13-cm cod-end mesh fitted with a 6.4-mm stretch mesh liner) employed during our trawl survey for groundfish which included I fixed stations from past years. Finfish of species other than winter flounder also were enumerated, measured to the nearest centimeter, and released. Winter flounder were measured to the nearest millimeter, examined externally for gender (the blind side of the caudal peduncle was palpated; males possess a rough patch -

prominent etenii - while females are smooth to the touch) and gonadal development. All winter flounder 2 200 mm total length were tagged and released with numbered Petersen tags for our capture - recapture study.

This spring during the spc.wning season, we tagged 178 winter I

O E'

flounder (25 inside and 153 outside PKDB). The fish ranged in length from 204 - 425 mm and included fish ages 2 to 8. Last year we marked (finclipped) 206 flounder (17 inside and 189 outside the estuary). To date there have been only three recaptures recorded -

fish marked and retaken outside PKDB. Tagging will be resumed this fall and will continue throughout the winter and spring of 1995.

In addition, an independent estimate of population size will be generated when all data have been collected for 1994 using an area-swept approach.

Juvenile Winter Flounder Survey We began to survey spawning success and resultant year-class strength of winter flounder this June. Sampling will continue through August inside and outside PKDB. The intent is to monitor relative abundance of young-of-the-year (YOY) winter flounder (recruits) by measuring their density (catch /m ) following peak 2

recruitment to the bottom after metamorphosis. Yearlings also are being monitored in our surveys. YOY abundance indices can be compared to larval entrainment at Pilgrim Station. This year we are evaluating several sampling techniques (seine, beam trawl, and SCUBA line transects) for effectiveness of providing reliable measures of relative abundance.

a) Beach Seine We began the seine survey in early June 1994. Behavioral ,

determinants were important in designing our quantitative sampling ,

program for juvenile winter flounder. Following metamorphosis the l

winter flounder settles and becomes demersal, being limited mainly l I;

a m,

I to shoal waters during the first year of life. YOY are basically sedentary and remain motionless on the bottom for long periods of time. There is no evidence of gregariousness or territoriality (Pearcy 1962). It is common knowledge with fisheries biologists working with juvenile winter flounder that initially a disturbed individual usually will cover itself with sediment, if possible, and remain motionless. This behavior predisposes flounder to be caught by bottom trawls and seines. Another strategy of flounder is to dart ahead of a seine alternating between short bursts of activity and resting on the bottom.

Juveniles were sampled at shore sites with a nylon beach seine (6.1-m length, 1.8-m depth, 4.8-mm mesh) that had a double lead-weighted footrope designed to capture demersal fish. Replicate (two or three) shore zone hauls were made perpendicular to shore at fixed stations inside PKDB and outside this estuary (13 sites; see Figure 2) that initially were selected haphazardly. Depending on station depth profiles, the hauling distance ranged from 6-33 m in length perpendicular to the shoreline. Collections were made during a period of 1 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> of flood tide. All fish were identified, counted, and up to 50 individuals of each species measured to the nearest millimeter. The catch index (density) for winter flounder is expressed as number /m 2, A total of 46 haul-seine collections was made in June.

Juvenile winter flounder were relatively uncommon in the catches this first month of the survey (Table 3). YOY were taken at only two of the sampling sites (Stations 7 and 13), while yearlings were

- 13 -

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Figure 2. Station locations for young-of-the-year winter flounder 'ucach seine survey within Plymouth, Kingston, Duxbury Bay and along l

the Plymouth shoreline in the environs of Pilgrim Nuclear Power 1 Station, June, 1994.

I 14 E a

I Table 3. Young-of-the-year winter flounder collected by haul seine at fixed stations in the Pilgrim study area, June 1994.

I Station !

Replicates

!! Ill Mean Number Mean Density (Ntsnber/m')

June 6 I 1 2

3 0

0 0

0 0*

0 0

0 I

4 0 0 -

0 0 5 0 0 -

0 0 6 0 0 -

0 0 7 0 0 -

0 0 June 22 8 0 0 -

0 0 9 0 0 -

0 0 I

10 0 0 -

0 0 11 0 0 -

0 0 12 0 0* -

0 0 13 0 2* -

0.7 0.006 June 73 J 1

2 - - - - -

3 - - - - -

4 0 0 -

0 0 5 0 0 -

0 0 6 - - - - -

7 0 1 0 0.3 0.002 June,14 2 0 0 -

0 0 3 0 0 0 0 0

A yearling flounder was also taken.

1 taken at three locations (Stations 2, 12, and 13). Biweekly sampling will continue through August, and then the seine program will be evaluated for its effectiveness.

b) Beam Trawl Common to the inshore flounder and shrinp fisheries in Europe is the beam trawl. The one ve employea was on loan from the Maine Department of Marine Resources. Gear specifications follow: The wooden' beam was 2 m long (corresponding to the width of the swath covered on the bottom) and had 0.5-m high beam heads.

I The net was I

i O 1 s'

a 3.5-m long funnel-shaped bag of 6.4-mm stretch mesh. The beam.

heads were constructed of 5-cm wide flat steel fitted with three l

" tickler" chains (1.3-cm chain width) attached to the base of the shoes (i.e., the bottom portion of the head) forward of the bag.

We fished this gear with a bridle attached to a single warp (towing line). The warp / depth ratios ranged from 3:1 to 10:1; we had to experiment with this. To standardize distance covered, tows were made between buoys deployed 200 m apart, with towing times of two to five minutes. To address sampling variability in catches at a site, we towed both sides of the course established by the buoys.

Replicate tows were made far enough away from each other to limit bias caused by disturbance of the bottom.

Preliminary sampling results using this technique reveal there is much variation in the catch of juvenile flounder between tows at a site; thus the value of these data for density calculations is limited. A critical factor seemed to be warp length and its effect on gear efficiency, in that a few meters too long or too short at a given station depth markedly affected the catch. We will continue to evaluate this gear through August.

c) Diver Transects The use of SCUBA diving transects to enumerate juvenile winter flounder was also explored. Unmeasured transect swims (divers were carried along by tidal currents) were conducted to locate concentrations of flounder - adults and juveniles. We also used ,

our T-shaped sampling tool and swam known areal transect lines, both to evaluate gear efficiency of the beam trawl and to visually al

I I Table 3. Young-of-the-year winter flounder collected by haut seine at fixed stations in the Pilgrim study area, June 1994.

I Station I Replicates Mean Number Mean Density (Number /m')

June 6 I 1 2

3 0

0 0

0 0*

0 0

0 I

4 0 0 -

0 0 5 0 0 -

0 0 6 0 0 -

0 0 7 0 0 -

0 0 I June 22 8

9 0

0 0

0 I

10 0 0 -

0 0 11 0 0 -

0 0 12 0 0* -

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A yearling flounder was also taken.

taken at three locations (Stations 2, 12, and 13). Biweekly sampling will continue through August, and then the seine program will be evaluated for its effectiveness.

I b) Beam Trawl Common to the inshore flounder and shrimp fisheries in Europe is the beam trawl. The one we employed was on loan from the Maine Department of Marine Resources. Gear specifications follow: The :

wooden beam was 2 m long (corresponding to the width of the swath i

covered on the bottom) and had 0.5-m high beam heads.

I The net was I

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a 3.5-m long funnel-shaped bag of 6.4-mm stretch mesh. The beam heads were constructed of 5-cm wide flat steel fitted with three

" tickler" chains (1.3-cm chain width) attached to the base of the shoes (i.e., the bottom portion of the head) forward of the bag.

We fished this gear with a bridle attached to a single warp (towing line). The warp / depth ratios ranged from 3:1 to 10:1; we had to experiment with this. To standardize distance covered, tows were made between buoys deployed 200 m apart, with towing times of two to five minutes. To address sampling variability in catches at a site, we towed both sides of the course established by the buoys.

Replicate tows were made far enough away from each other to limit bias caused by disturbance of the bottom.

Preliminary sampling results using this technique reveal there is much variation in the catch of juvenile flounder between tows at a site; thus the value of these data for density calculations is limited. A critical factor seemed to be warp length and its effect on gear efficiency, in that a few meters too long or too short at a given cLation depth markedly affected the catch. We will continue to evaluate this gear through August.

c) Diver Transects The use of SCUBA diving transects to enumerate juvenile winter flounder was also explored. Unmeasured transect swims (divers were carried along by tidal currents) were conducted to locate concentrations of flounder - adults and juveniles. We also used our T-shaped sampling tool and swam known areal transect lines, 1

)

both to evaluate gear efficiency of the beam trawl and to visually l 1

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J survey densities of juvenile flounder (YOY and yearlings). This l technique shows promise for enumerating juvenile flounder on known i areas of sand bottom, but is limited in eel grass beds. We will continue this effort through August and then evaluate all three sampling techniques for effectiveness of providing a reliable index of recruits (year-class strength).

2. UNDERWATER FINFISH OBSERVATIONS Three SCUBA surveys at biweekly intervals were made with six fixed stations sampled in and around the Pilgrim Station discharge I canal during May and June, 1994 (Figure 3).

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I finfish were sighted: cunner (Tautogolabms adspersus) , pollock (Pollachius virens) , tautog (Tautoga onitis) , and striped bass (Morone saratilis) . As for invertebrates, blue mussels (Mytilusedulis) and American lobster (Homarus americanus) were noted. Finfish Abundance All Stations A total of 211 fish was tallied in our observations Str Bass 88%_

which is up from 1993 when 133 ' 85 "*h

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fish were sighted. However, 5 "*h

"' l y"g _TautoO 10%

20 fish three fewer species were recorded this year. Striped

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bass comprised 88% of all fish l Figure 4. Finfish abundance es observed by sighted, tautog was second, divers in the area around the Pilgr*

Station discharge canal, May and I followed by cunner and pollock l u

l (designated as other in Figure 4). The number of cunner (4) observed at the sampling stations has continually declined over the last few years (32 in '93 and 90 in '92). Tautog (20) were somewhat more abundant than last year when only 3 individuals were noted. The lone pollock in the control area is the first of this species sighted by our divers since 1991.

Distributionally, 98% of the fish observed were located in the

" denuded" zone (Stations Di and D 2) , with 1% both in the " stunted" (Stations S 2 and S 2 ) and " control" (Stations C 3 and C2 ) areas (Figure 5). Fish were seen at all stations except S. 2 Cunner sightings occurred in all three zones. Wath the exception of pollock, all other fish were found in the denuded zone, primarily at Station D 2-Blue mussels occurred throughout the " denuded zone" by the end

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I of June. However, the large rinfish Distribullon All Species numbers of starfish which I

Percent Distribution usually accompany a new mussel 1 so -

set off Pilgrim Station were I

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j conspicuous by their absence.

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Two lobster were observed in the ,, .

" stunted zone" at the end of a __ _ _ __

stunted Denuded controi May, but none were recorded in o,,,,,,,,f,,"erzon.

l June. Figure 5. Finfish distribution as noted by I divers in the area around the Pilgrim Station discharge canal, May and June 1994.

3. SPORTFISHING Creel data were collected on shore-based sportfishing at Pilgrim Station Shorefront by seasonal public relations personnel of Boston Edison Company. Anglers are intercepted at an access point, and daily information on the sportfishery is recorded oli a standard survey form. Fishing effort (i.e., number of angler trips), catch by species, and fishing locations are important variables to characterize a recreational fishery.

From April through June, information was obtained from twenty- D six sampling days, beginning April 24th and ending June 30th. A total of 458 angler trips was made to the shorefront, and 276 fish I caught - 233 striped bass, 40 pollock and 3 bluefish. The catch rate averaged 0.6 fish per angler trip or 10.6 fish per day.

Fishing was centered in the thermal plume.

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4. CUNNER POPULATION STUDIES We formerly studied the movement patterns and distribution of '

adult cunner in the vicinity of Pilgrim Station via mark and recapture, with particular emphasis on their susceptibility to impact of the discharge current. We now are working towards estimating population numbers and survival. In addition, fecundity and age structure of cunner in the Pilgrim area are being examined as part of a larger effort to determine if entrainment of cunner eggs and larvae at Pilgrim Station is deleterious to the local population.

The Floy T-bar anchor tag is used in our marking study. It is ,

embedded in the dorsal musculature via a tagging gun. To procure cunner, baited traps are fished overnight, in that cunner forage most actively at dusk and dawn. All captures are measured, and selected fish are removed for laboratory analysis (fecundity and aging) based on sampling protocol. Otherwise, a numbered tag is placed in the dorsal musculature of all individuals 90 mm in total length or greater before being released. Most cunner apparently are mature by this size. We are conducting a multiple census of tagging and recovery. Recapture information is obtained using the same baited fish traps set overnight. This method allows for multiple recaptures.

This year, our efforts began in June, resulting in the capture of 1,338 cunner in the Pilgrim area, of which 273 were kept for fecundity and aging while 510 were tagged and released. Spatially, we caught 563 cunner seaward of the outer intake breakwater at E'

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I Pilgrim Station (110 were retained and 210 tagged). Within the Pilgrim Intake, 615 cunner were captured (149 were removed from the population and 181 tagged). At White Horse Beach, we caught 160 cunner (14 were kept and 119 marked). There have been 64 recaptures of tagged fish this year as of the end of June, with 55 from off the outer breakwater, 7 from the Intake, and 2 from White Horse.

In addition to the field work, we are conducting a controlled tag retention study for cunner, evaluating the Floy T-Bar anchor tag.' Since mid-May we have been holding 25 cunner (20 tagged and 5 controls) between 90 and 120 mm in total length in a flow-through seawater tank containing structure as refuge habitat at the National Marine Fisheries Service's Woods Hole Aquarium. Cunner are fed and observed twice a week, and a log is kept of food, water temper ature, and pertinent observations. Through the end of June, no tags were dropped, and all fish have survived. There are a number of factors that can contribute to tag loss, including water temperature, tag style and size, tag location, and fish behavior.

Tag loss should be accounted for in a mark and recapture experiment. This effort will run through August.

I 5. SMELT RESTOCKING We completed the first year's work of a two-year restocking program of rainbow smelt (Osmerus mordar) in the Jones River, a tributary to the nearby Plymouth, Kingston, Duxbury Bay estuary.

This endeavor is a remedial measure to compensate for an l

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impingement mortality of an estimated 5,200 smelt that occurred at l Pilgrim Station in December 1993. There is compelling evidence 1 that smelt frequenting the area of the power plant are from a local sea-run population originating from PKDB, where the Jones River has been the site of the major smelt-spawning ground. This population is presently depressed. The magnitude of the fish kill in December, under the present condition of low stock size, could seriously impact the local smelt population the next few years.

The overall goal of our stocking program is to enhance the depleted smelt rur. in the Jones River, i.e., to increase the numbers of adult smelt in the local population. The objectives to attain this goal of restoration are to augment instream reproduction in the Jones River and to enhance the quality of spawning habitat on the run. ;

To accomplish the first, during the spring (1994), we stocked over 600,000 smelt eggs (conservative estimate) into the Jones River. These zygotes came from two selected genetically isolated, wild, anadromous broodstocks - one spawning in the Weweantic River in Wareham and the other, Back River in Weymouth. Within the two source streams, a total of 121 egg collection trays [each tray was a 35.6 x 45.7 cm (14 x 18 inch) weighted wooden frame, enclosed with chicken wire, and filled with unprocessed sphagnum moss as substrate for egg deposition] was deployed to collect smelt eggs which were transplanted into the Jones River for hatchout. The resulting larvae that hatched were expected to imprint on the waters of PKDB, and as adults should home to this estuary and I

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ascend the Jones River and possibly other tributaries flowing into this system to spawn. l The culturing of smelt by transplanting their fertilized eggs has successfully been used by management agencies. This species was introduced into the Great Lakes by egg stockings. The Massachusetts Division of Fisheries and Wildlife has introduced smelt as forage into suitable freshwater bodies across the state, e.g., Quabbin Reservoir. The Division of Marine Fisheries transplanted smelt eggs, which were obtained from an established population in the Quabbin, into the Jones River in 1962 to bolster a then declining population in the Jones.

To achieve the second objective - that of spawning habitat enhancement - and to increase the efficacy of our stocking program, we employed artificial substrate with high surface area, i.e., egg trays filled with sphagnum moss. Transplanted eggs were placed in riffle (high flow) areas to optimize hatching success. In conjunction to using egg collection trays to move eggs from one river system to another, we placed additional trays in the Jones River to collect eggs spawned there, so as to improve instream egg survival and hatching success. The sphagnum moss in the trays collects higher egg densities than natural hard bottom (e.g. , sand, gravel, and cobble). The only competing surface for higher egg sets and survival is the natural aquatic vegetation (macroscopic river plants) which on the smelt spawning ground in the Jones River comprises only about one quarter of the sunstrate. From a study in the Parker River, Sutter (1980) found that smelt egg deposition was

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greater in areas of high flow and on river plants. The latter provide 3-dimensional surfaces which were found to have 12 to 15 times higher egg densities than found on 2-dimensional hard surfaces, such as cobble. Furthermore, the survival of eggs to hatching on vegetation was about 10% as compared to 1% on other surfaces (Sutter 1980).

Our removable egg trays in the Jones River increased the amount of plant material on the spawning bed. The sphagnum moss that filled the trays had spaces between the fibrous plant material giving depth and thus providing a 3-dimensional surface. The I fertilized smelt eggs that land on the trays attach to the moss surface and within the interstices, creating a micro-environment that offers protection, reducing egg ' turnover', i.e. , the loss of eggs as a result of detachment or predation, yet is well aerated. !

Water seeps through the porous moss surface delivering oxygen to Ii '

I the developing embryos and washes away metabolic wastes.

We will continue these efforts in the spring of 1995 and will strive to transplant over 1 million eggs into the Jones River. We ,

once again will add artificial spawning substrate to the spawning ground. In 1996 and 1997, we will make a concerted effort to monitor the spawning run in the spring for the abundance of returning adults.

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I l IV. ACKNOWLEDGMENTS The authors thank Win Sibley and Robert Ellenberger for collecting sportfish data at the Pilgrim Shorefront. A special thanks to Kim Trotto of the Division for word-processing sections of this report. We appreciate the guidance of Robert D. Anderson of Boston Edison Company, W. Leigh Bridges of the Division, and the Pilgrim Administrative-Technical Committee. Their input on study programs and comments on project reports have been helpful.

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I V. LITERATUKi._:'ITED Pearcy, W. G. !?62. The ecology of an estuarine population of !

winter i. , e der, Psuedopleuronectes americamts (Halbaum). l Bulletin of the Bingham Oceanographic Collection. 18:4-78. I Sutter, F. C. 1980. Reproductive biology of anadromous rainbow smelt, Osmems mordar, in the Ipswich Bay area, Massachusetts.

a M.S. Thesis, Univ. of Mass., Amherst. 49 pp.

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I I FINAL SEMI-ANNUAL REPORT Number 44 I

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

January-June 1994 I .

I to BOSTON EDISON COMPANY Licensing Division I Pilgrim Nuclear Power Station Plymouth, Massachusetts 02360 From SCIENCE APPLICATIONS INTERNATIONAL CORPORATION 89 Water Street Woods Ifole, MA 0254.2 I (508) 540-7882 I

I I October 1994 I

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I I TABLE OF CONTENTS EXECUTIVE

SUMMARY

............................................ I 1.0 INTR O D UCTI ON . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 2.0 M ETI IO DS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 j 1

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3.0 R ESULTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 !

3.1 APRIL 1994 TRANSECT SURVEY .............................. 5 3.2 JUNE 1994 TRANSECT SURVEY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 4.0 DIS C USSI ON . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 5.0 LITERATURE CITED . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 I

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El LIST OF FIGURES Figure 1. Imcation of Pilgrim Nuclear Power Station Discharge Canal . . . . . . . . . . . . 3 Hgure 2. Design of Qualitative Transect Survey .......................... 4 Figure 3. Denuded, Sparse, and Stuned Chondrus Areas Observed in April 1994 .... 6 Hgure 4. Denuded, Sparse, and Stunted Chondrus Areas Observed in June 1994 .... 8 I

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I EXECUTIVE

SUMMARY

This report presents results of qualitative surveys of benthic algae in the thermal effluent of the Pilgrim Nuclear Power Station (PNPS) that were completed in April and June 1994. These investigations represent the most recent phase of long-term efforts to monitor effects of the thermal effluent on the benthic algal communities within and just offshore of the PNPS discharge canal. Field survey techniques were identical to those used in previous investigations.

The qualitative transect studies performed to evaluate the Chondrus crispus community in the thermal plume area indicated that in April and June 1994 the condition of the denuded and total affected I areas was typical of that seen in years prior to 1994 when the power plant was in full or nearly full operation. The denuded area (1065 m2), in April, was well within the size range seen in earlier spring surveys taken when the plant was in operation (765 m2 in April 1986 to 1321 m2 in March 1991). In I June, the denuded zone had increased 13% to 1223 m2, again an area well within the size range seen in previous summer surveys. The dense population of newly settled mussels (Mytilus edults) seen during the June survey was extensive and similar to that seen in the June 1990 and June 1992 surveys. Aside from the areas of greatest mussel density, there was no difficulty in discerning the boundaries of the sparse and stunted Chondrus zones.

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1.0 INTRODUCTION

This report represents a continuation of long-term (20 yr) benthic studies at Pilgrim Nuclear Power Station (PNPS) that are intended to monitor the effects of the thermal effluent. The 1994 monitoring program is identical to that performed in 1992 and 1993 and is limited to qualitative SCUBA surveys of algal cover in the thermal plume of the effluent within and beyond the discharge canal (Figure 1). Surveys are conducted quarterly during April, June, September, and December. No assessment of the benthic fauna is currently being made. This Semi-Annual Report includes qualitative observations recorded in April and June 1994. Work was performed under Boston Edison Co. (BECo) Purchase Order 112005, in accordance with requirements of the PNPS NPDES Permit No. MA 0003557.

g 2.0 METIIODS The qualitative algal survey is performed by SCUBA divers in the same location and with the same techniques that have been used since the current monitoring program began, approximately 14 years ago. The effluent area is surveyed by two or three SCUBA-equipped biologists operating from a small boat. For the qualitative transect survey, SCUBA observations hre 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 center of this line and deployed along the central axis of the canal to a distance of 100 m offshore. Using a compass, divers extend a 30-m measuring line, 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 throu;5 the denuded and stunted Gondrus areas, until the algal cover looks normal.

l The terminology established by Taxon (1982) and followed in subsequent years uses the growth morphology of Gondrus crispus to distinguish between " denuded" and " stunted" zones. The denuded zone is the area in which Gondrus occurs 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 areas. In the stunted zone, Gondrus is found on the upper surfaces of the rocks but is noticeably inferior in height, density, and frond development cornpared 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 Gondrus plants that are very thinly distributed. The norrnal zone begins at the point where Gondrus 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 Gondrus growth. In addition to evaluating algal cover, the divers record 2

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Figure 2. Design of the Qualitative Transect Survey I l 4 5 m

I any unusual occurrences or events in the area, such as unusually strong storms, and note the location of any distinctive algal or faunal associations.

I 3.0 RESULTS Qualitative transect surveys of acute nearfield impact zones began in January 1980 and have been conducted quarterly since 1982. Two surveys were performed (April 8 and June 28) during the current reporting period, bringing the total number of surveys conducted since 1980 to 50. Results of surveys conducted from January 1980 to June 1983 were reviewed in Semi-Annual Report 22 to BECo (BECo, 1983). A summary of the surveys conducted between 1983 and 1992, including a review of the four surveys performed in 1992, was presented in Semi-Annual Report No. 41 (BECo,1993). Results of the 1993 surveys were presented in Semi-Annual Report No. 43 (BECo,1994) and dealled results of the I mapping surveys conducted in April and June 1994 are presented in the next two sections.

I 3.1 APRIL 1994 TRANSECT SURVEY The denuded and sparse Gondrus crispus areas mapped on April 8,1994, immediately offshore of the PNPS are shown in Figure 3. A large boulder that is nearly exposed at mean low water, and that is used as a landmark by both the SAIC and the Massachusetts Division of Marine Fisheries dive teams, is plotted in the figure. He denuded zone is essentially devoid of Gondrus, whereas the sparse zones have normal-looking Gondrus that is sparsely distributed.

In April 1994, rocks within the Omndrus denuded zone essentially were bare with only a very few algal plants attached. As has been often seen in past surveys, algal density and species diversity beyond the Gondrus denuded zone, were greater south of the central transect line than north. Total stunted area in April 1994 was 1,065 m2 and stunted and sparse areas encompassed another 228 m2 for ta total affected area of 1,293 m2, an area equal to the entire denuded zone in the April 1993 survey (BECo,1994). Sparse and stunted areas were intermixed in this survey and no attempt was made to map them separately. The locations and spatial patterns of the denuded and sparse / stunted areas are seen in Figure 3. The overall size of the denuded zone (1,065 m2) was smaller than in April of 1993 (1,239 m2).

The sparse and stunted areas in April 1994 (228 m2) were also less than in 1993 (351 m2). The size of the affected area in April 1993 was noted to be larger than in previous years, and the results for 1994 appear to represent a more typical situation (see BECo,1993).

The divers were able to record other biological features in the area including the presence of ,

indicator algal species and obvious benthic animals Gracilaria, an alga indicative of warmer waters, was 5 1 I

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I widespread throughout the discharge area and was recorded from the 30 to the 80 m distance.

Cystocloniumpurpureum was common from the 30 to 60 m distances. He rockweed, Fucus, was evident at about the 60-70 m mark. The encrusting red alga, Corallina, was found beyond 50 m. Among the animals, snails of the genus Littorina littorea, were widespread and common throughout the study area, whereas, mussels were rare at this time of the year. The starfish Asterlasforbest, which are predators of mussels were present beyond the 60 m mark. However, the mussel Mytllus edulls was limited to only few isolated patches of very small specimens at about the 60 m mark. Swarms of amphipods were apparent among the algae and rocks. The ectoproct Membran/pora membranacea was evident on the I Chondrus plants at the 100+ meter line.

3.2 JUNE 1994 TRANSECT SURVEY I Results of the divers' survey for June 28,1994 are mapped in Figure 4. The boundary between the Chondrus denuded zone and regions with normal healthy Chondrus was easily seen, but obscured somewhat on the north side of the transect due to extensive populations of the mussel Mytilus edulls.

The denuded zone in June 1994 encompassed an area of 1,222 m2, an increase over April (1,065 m2), and the area might have been even larger were it not for the large mussel settlement on the north side that obscured the algal cover. The sparse and stunted Ozondrus areas encompassed a total of 119 m2, actually less than in April, but again probably obscured by the mussel population. The total impacted area for June was 1,342 m2, slightly more than the 1,293 m2 of April. The overall affected area far June 1994 (1,342 m2) was considerably less than that of a year ago, when the affected area for June 1993 included 2,058 m2 (1,055 m2 for the denuded zone and 1,003 m2 for the stunted and sparse areas).

According to the diving team, the head of the effluent canal was dominated by Gracilarla, Chaeromorpha purpureum, and Ulva lactea. Ulva appeared to be more common that in recent years.

De rockweed, Fucus as more common on the north side around the 60 m mark and northward by about 15 m, where numerous small plants had become established. Chondrus was most abundant from the 50 m station and seaward. The exotic alga Codium, was relatively rare, but was present the 60 m mark.

This alga is indicative of warmer waters and has been recorded from the vicinity of the Pilgrim discharge for several years.

With regard to the fauna, the dense settlement of mussels was apparent from the 40 m mark and seaward, especially on the north side. These bivalves were relatively large (5 to 15 cm) and completely covered the surfaces of rocks, any algal plants available, and various types of debris. Starfish densities (Asterlas) were also present in high densities, but appeared to be mostly juveniles. Only 3 fish were observed including two adult winter flounder and one adult tautog.

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, !, j! 2 4N!

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c ; l

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. . gg Submerged Jetty ti

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1 do ho lo o 10 20 30 NORTH METERS SOUTH Legend Denuded Area Sparse tunted Control Area I e m -

i . .. ..

g

~

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Figure 4. Denuded, Sparse, and Stunted Chondrus Areas Observed in June 1994.

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I i 4.0 DISCUSSION The configuration of the Omndrus crispus denuded zone that may extend as far as 100 m beyond the discharge canal is readily apparent to SCUBA divers and is easily mapped for the qualitative transect I survey. The stunted and sparse zones are somewhat less obvious but in April and June 1994 were easily delineated. in June 1994, a dense mussel mat, similar to that seen in June 1990,1992, and 1993 was seen. The timing of this mussel settlement following the April survey is now well documented. For April and June 1994, the size of the denuded and total affected zones were well within those seen in past years when the power plant was in full or nearly full operation. In fact, the total affected area of June 1994 was considerably less than in June of 1993.

I 5.0 LITERATURE CITED Boston Edison Co.1983. Marine Ecology Studies related to the operation of Pilpim Station. Semi-Annual Report No. 22. 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.

Taxon.1982. Benthic studies in the vicinity of Pilgrim Station. la Marine Ecology Studies Related to Operation of Pilgrim Station. Semi-Annual Report No.19.

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.E ICHTHYOPLANKTON ENTRAINMENT MONITORING AT PILGRIM NUCLEAR POWER STATION JANUARY - JUNE 1994 I

I Submitted to I Boston Edison Company Boston, Massachusetts I

by Marine Research, Inc.

Falmouth, Massachusetts E

October 1, 1994 E

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I TABLE OF CONTENTS SECTION PAGE I

SUMMARY

1 II INTRODUCTION 3 III METHODS AND MATERIALS Monitoring 4 Notification Procedures 6 Mesh Extrusion 9 Power Analysis 9 IV RESULTS Monitoring 14 Hesh Extrusion 20 Power Analysis 21 V LITERATURE CITED 34 I

APPENDIX A* Densities of fish eggs and larvae per 100 m8 of I water recorded in the PNPS discharge canal by species, date, and replicate, January-June 1994.

I APPENDIX B Mean monthly densities and range per 100 m8 of water for the dominant species of fish eggs and larvae entrained at PNPS, January-June 1975-1994.

Available upon request.

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LIST OF FIGURES FIGURE 1 Entrainment sampling station in PNPS discharge canal. 5 E

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5 LIST OF TABLES TABLE EAGE 1 PNPS ichthyoplankton entrainment notification I

levels for 1994 by species category and month. 12 5

See text for details. E Ichthyoplankton densities (number per 100 m8 of water) for each sampling occasion during months when notably high densities were recorded, January-June 1994. 24 3 Species of fish eggs (E) and larvae (L) I obtained in ichthyoplankton collections from the Pilgrim Nuclear Power Station g discharge canal, January-June 1994. 25 g 4 Fish egg and larval densities per 100 m8 of water for select taxa taken with 0.333 and 0.202 mesh netting on two dates in May 1994. 27 5 Statistical power (P) to detect increasing 3 trends in larval flounder annual abundance E ranging from r = 0.40 to 5.0 over n = 2, 3, 4, and 5 years (see text for details). Type 3 1 error probability was set to 0.05. 30 E 6 Statistical power (P) to detect decreasing trends in larval flounder annual abundance ranging from r = -0.10 to -1.0 over n = 2, 3, 4, and 5 years (see text for details).

Type 1 error probability was set to 0.05. 31 7 Statistical power (P) to detect increasing trends in larval flounder annual abundance ranging from r = 0.20 to 8.0 over n = 2, 3, 4, and 5 years (see text for details). Type 1 error probability was set to 0.10. 32 8 Statistical power (P) to detect decreasing trends in larval flounder annual abundance ranging from r = -0.10 to -1.0 over n = 2, 3, 4, and 5 years (see text for details).

Type 1 error probability was set to 0.10. 33 I

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I SECTION I

SUMMARY

I Entrainment sampling at PNPS during the first half of 1994 was completed twice per month during January and February, weekly in March, and three times per week from April-June. Additional sampling was completed to make a preliminary assessment of larval flounder extrusion through 0.333-mm mesh.

A total of 24 species of fish were represented in the January-June collections. The winter-early spring spawning period (January-April) consisted of low densities ($3 per 100 m8 of water) of winter flounder, American plaice, yellowtail flounder, Atlantic cod, and fourbeard rockling eggs along with sand lance, rock gunnel, and grubby larvae. Collections in May and June, which together with July encompass the late spring-summer season, were dominated by Atlantic mackerel and tautog/ cunner eggs; sand lance, radiated shanny, fourbeard rockling, and winter flounder larvae.

Comparison of January-June 1994 egg and larval densities with those recorded dating back to 1975 suggested that Atlantic cod I continue to contribute few eggs to the PNPS area. Both larval tautog and cunner were absent from the June collections, the first time this occurred dating back to 1975. Larval mackerel, while not absent, were uncommon in June. In contrast larval sand lance, Atlantic herring, sculpin, and radiated shanny were relatively abundant with all four species reaching " unusually high" densities E

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m 51 on several occasions each; additional sampling did not appear justified.

No lobster larvae were noted in the collections through the end of June.

Paired sample comparisons indicated that stage 2 winter flounder larvae were taken in significantly higher densities in finer 0.202-mm mesh (p <0.05) than in the 0.333-mm mesh used in the monitoring program. Smaller stage 1 larvae were not sufficiently I; abundant to provide an adequate comparison.

Statistical power tables are provided which summarize the ability of the current sampling plan to detect changes in the annual abundance of larval winter flounder. Generally, with a coefficient of variation of the mean of 0.27 under a sampling regime of three times per week, power was relatively high. l I

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I SECTION II INTRODUCTION I

This progress report briefly summarizes results of ichthyo-plankton entrainment sampling conducted at the Pilgrim Nuclear Power Station (PNPS) from January through June 1994 by Marine Research, Inc. (MRI) for Loston Edison Company (BECo) under Purchase Order No. 112010. Based on discussions held at a PNPS fisheries monitoring workshop in January which focused on potential power plant impacts to local winter flounder and cunner popula-tions, two additional tasks were addressed during this report period. One involved a preliminary determination of the extrusion of larval winter flounder through the 0.333-mm mesh used for entrainment sampling. The second consisted of a review of the statistical power associated with the entrainment sampling program; specifically what is the probability of detecting various differ-ences in annual mean larval flounder density. A more detailed )

annual report covering all 1994 data will be prepared following the July-December collection periods. Included in that report will be I mesh extrusion and power analyses for cunner eggs and larvae I

completed during the summer months.

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SECTION III METHODS AND MATERIALS I

Honitoring Entrainment sampling at PNPS has historically been completed twice per month during January and February, weekly during March through June. Following a PNPS fisheries monitoring review workshop in early 1994, the sampling regime was modified beginning !

= 1 April 1994. From January through March sampling was completed in l triplicate near low water during daylight hours following the regime established in past years. Beginning with the first week of April, to improve temporal coverage, single samples were taken three times per week. To minimize costs, sampling was linked to )

1 the impingement schedule so that collections were made Monday morning, Wednesday afternoon, and Friday night regardless of tide.

All sampling was completed with a 0.333-mm mesh, 60-cm diameter l plankton net streamed from rigging mounted approximately 30 meters from the headwall of the discharge canal (Figure 1) . Sampling time i i

varied from 8 to 35 minutes depending on tide, higher tide requiring a longer interval due to lower discharge stream veloci- I l 1

ties. 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. Exact filtration volumes were calculated using a General oceanics Model 2030R digital flowmeter mounted in the mouth of the net. Near I times of high water a 2030 R2 rotor was employed to improve sensitivity at low velocities.

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I l x CAPE' COD BAY I , ' i .i, I ij.)..;,

92 ""

DISCHARGE CANAL

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y BRIDGE, o

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40 f IN TAgg D \ c B A sin

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I O ICHTHYOPLANKTON PNPS UNIT 1 man

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STATION I i 100 METERS 8

I Figure 1. Entrainment sampling station in PNPS discharge canal.

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as 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) . Larval winter flounder (Pleuronectes americanus) were enumerated in four developmental stages as follows:

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

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

Stage 3 - from the end of stage 2 until the left eye migrates E past the midline of the head during transformation (3.5-8 mm TL). 5 Stage 4 - from the end of stage 3 onward (7.3-8.2 mm TL).

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 of the unusual occurrence. An offshore array of stations was established which could be used to determine whether circum- !

stances in the vicinity of Rocky Point, attributable to PNPS operation, were causing an abnormally large percentage of ichthyo-plankton populations there to be entrained or, alternatively, whether high entrainment levels simply were a reflection of unusually high population levels in Cape Cod Bay. The impact attributable to any large entrainment event would clearly be greater if ichthyoplankton densities were particularly high only -

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I close to the PNPS shoreline. In past years when ,high densities were identified, additional entrainment sampling was requested by regulatory personnel and the unusual density in most cases was found to be of short dt 4; ion (<2 days). With the change in 1994 to Monday, Wednesday, Friday sampling the temporal extent of any unusual density will be more clearly indicated.

Until 1994 "unusue11y 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 compari-sons 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) were examined and tested for normality following logarithmic transformation. Where data sets (for example, mackerel 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.2 In cases where data sets did not fit the lognormal distribution (generally months when a species was frequently but not always absent, i.e. , many zeros occurred), the mean and standard deviation l

' Normal distribution curve theory states that 2.5% of the measurements in l a normally distributed population exceed the mean plus 1.96 standard deviations

(- s, we rounded to 2 for simplicity), 2.5% lie below the mean minus 1.96 standard deviations. Stated another way 95% of the population lies within that range and 97.5% lies below the mean plus 1.96s. Likewise 0.5% of measurements I exceed the mean plus 2.58s, 99% lie within the range of the mean i 2.58s, 99.5%

lie above the mean + 2.58s.

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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 of each species.

The more critical criterion was applied to species of commercial, recreational, or biological interest, the less critical to the remaining species (i.e., relatively greater densities were .,

l necessary to trigger notification). Species of commercial, gI gI recreational, or biological interest include Atlantic menhaden, I Atlantic herring, Atlantic cod, tautog and cunner (the labrids),

sand lance, Atlantic mackerel, windowpane, American plaice, and winter flounder. Table 1 provides summary data for each species of egg and larva by month within these two categories showing the 1994 notification level.

A scan of Table 1 will indicate that, in cases where the long-tern mean amounts to 1 or 2 eggs or larvae per 100 m8, the critical level is 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. I 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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Mesh Extrusion To potentially improve enumeration of larval winter flounder i in PNPS entrainment samples, preliminary sampling was conducted in 1994 to see if young larvae are extruded through the standard j 0.333-mm mesh netting. On two occasions, May 4 and May 9, collections were made in triplicate with both 0.333 and 0.202-mm mesh nets. These dates were selected based on previous samples and historical data to correspond to the likely period of occurrence of small, early-stage flounder. All samples were taken at low water when velocity and potential extrusion would be greatest, each collection ten minutes in duration. Nets were alternately attached to the rigging until six samples had been taken. Methodology followed that described for the routine sampling.

As in past years, larval winter flounder were staged using the criteria described above.

Power Analysis An examination of statistical power was completed in order to determine the ability to detect differences in annual abundance for samples of larval flounder taken in the PNPS discharge stream.

I The ability to detect population trends over time is based on five parameters: the rate of change in population size (r); the number of samples (n); a measure of precision in measuring abundance - the coefficient of variation (CV); a measure of the probability of making Type 1 errors (a); and the probability of making Type 2 errors (B) . A Type 1 error occurs when a statistical test results in rejection of the null hypothesis when it is in fact 9

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true. This is commonly p = 0.05, the level reported with most statistical tests, and represents the probability that an observed difference could occur by chance alone. A Type 2 error occurs when a test results in failure to reject the null hypothesis when it is in fact false; i.e., when a real difference in the data sets is not correctly identified. Type 2 errors may typically occur when sample sizes are small and/or variability within samples is high.

Power is defined as one minus the Type 2 error probability (1-8). ,

Gerrodette (1987) provides equations relating the above parameters; j given any four, the fifth can be derived. Selection of the appropriate equation involves two decisions - whether the popula-tion change is expected to be linear or exponential and how population abundance and CV are related. Equations are provided for three common relationships between CV and abundance (A) - CV proportional to /A, CV proportional to 1//A, and CV constant with respect to A. Ten years were selected from the PNPS data base to determine the necessary approach. During each of the ten years one or both circulating seawater pumps was in operation during the larval flounder ceason. Coefficient of variation of the mean (CV

= S.E./mean) was calculated within each year using the mean larval I{'

flounder density (per 100 m8 of water) over three replicates from each date on which larval flounder occurred. The relationship between CV and annual mean abundance (=A), /A and 1//A, was ;

examined using correlation and linear regression analysis. Power was calculated for increasing trends ranging from r = 0.10 to 5.0 10 E'

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and decreasing trends ranging from r = -0.10 to -5.0. Trends over j 1

2, 3, 4, and 5 years were considered.

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Table 1. PNPS ichthyoplankton entrainment notification levels for 1994 by specios category and month. l E

See text for details.

Densities per Long-term Mean + Mean +

100 m8 of water: Mean* 2 std.dev. 2.58 std.dev.

January LARVAE Atlantic herring ** 0.2 1 Sculpin Rock gunnel 0.8 E 1.4 5 Sand lance ** 5 11 February LARVAE Atlantic herring ** 0.1 0.8 Sculpin 2 65 Rock gunnel 3 99 Sand lance ** 5 10 March EGGS ,

l American plaice ** 2 3 LARVAE {

Atlantic herring ** l 0.8 1.2 !

Sculpin 17 608 l Seasnails 0.6 1 Rock gunnel 10.7 723 Sand lance ** 7 130 l Winter flounder ** 0.4 0.7 ADril EGGS American plaice ** 3 32 LARVAE ,

Atlantic herring ** 0.6 0.8 Sculpin 15 391 Seasnails 6 10 Radiated shanny 3 6 Rock gunnel 4 142 Sand lance ** 13 425 3

Winter flounder ** 7 12 E

=

EGGS Labrids** 36 3514 I

Mackerel ** 10 1803 Windowpane ** 9 147 American plaice ** 2 15 I

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I Table 1 (continued).

Densit'7 per Long-term Mean + Mean +

100 m8 '

3er: Mean* 2 std.dev. 2.58 std.dev.

BD1 LARVAE I Atlantic herring Fourbeard rockling Sculpin 0.7 2

3 1.1 5

4 Radiated shanny I Sand lance

Winter flot'nder**

7 14 9

23 123 236 I J2I1R EGGS Atlantic menhaden ** 4 6 Searobins 3 4 Labrids** 1237 17243 Mackerel ** 61 3442 Windowpane **

I American plaice **

LARVAE 27 1

261 2

Fourbeard rockling 9 634 I Cunner **

Radiated shanny Mackerel ** 63 6

1 265 109 15 I Winter flounder ** 2 20

Geometric or Delta Mean.

I ** Species of commercial, recre:tional, or biological interest for which more critical notification level will be used.

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== l El SECTION IV RESULTS Monitoring Population densities per 100 m8 of water for euch species listed by date, station, and replicate are presented for January-June 1994 in Appendix A (available upon request). The occurrence of eggs and larvae of each species by month appears in Table 2.

Ichthyoplankton entrained during January through April generally represent winter-early spring spawning fishes. The number of species represented in the discharge collections was two in January, nine in February, sixteen in Harr'., and fourteen in April. Fish eggs are typically uncommon during the winter-early spring period since species spawning in the FNPS area during that time employ a reproductive strategy utilizing demersal, adhesive eggs not generally subject to entrainment. Eggs were in fact absent from the January and February collections. March sampling, occurring more frequently, produced egge of five species each in small numbers, winter flounder, American plaice (Hionoclossoides platessoides), yellowtail flounder (Pleuronectes ferrucingng),

Atlantic cod (Gadng morhua), and fourbeard rockling (Enchelvoous cimbrius). Winter flounder were tsken on each of the four sampling dates actounting for 49% of total with an overall monthly mean density cf 1.3 per 100 m8 The remair.ing four species showed monthly mean densities below 0.5 per 100 m8 Overall egg densities increased very little in april with the same species being taken as 14 E

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in March. Amarican plaice were most numerous with a monthly mean density of 2.7 per 100 m8 accounting for 48% of the total. Winter flounder accounted for an additional 25% of the eggs with a monthly mean of 1.4 per 100 m8 The remaining three species were each taken at densities below 0.5 per 100 m8 Since they are demersal and adhesive, winter flounder eggs are not typically entrained at PNPS. Their numbers in PNPS samples are therefore not considered representative of numbers in the surround-ing area. Those that were taken were probably dislodged from the bottom by currents and perhaps other fish and large invertebrates.

Typical for the winter-early spring period, numbers of larvae increased steadily with time. Numbers of species amounted to two in January, nine in February, twelve in March, and ten in April.

Sand lance (Ammodvtes sp.), rock gunnel (Pholis aunnellus), and grubby (Myoxocechalus aenaeus) contributed most to the larval total. Sand lance contributed 80% to the seasonal total with mean densities of 2 in January, 21 in February, 197 in March, and 544 per 100 m8 in April. Rock gunnel accounted for an additional 12%

of the seasonal total with mean densities of 0.3, 4, 97, and 14 in January, February, darch, and April, respectively. Larval grubby did not appear until February but still contributed 4% to the seasonal total with monthly mean densities of 1,17, und 24 per 100 m8, respectively.

May and June collections (along with July) encompass the late spring-summer ichthyoplankton season. Spawning activity, particu-larly among species with pelagic eggs, increases with expanding day l 15 I

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length and rising water temperature. A total of 14 species were represented in May,13 were represented in June. Atlantic mackerel (Scomber scombrus) clearly dominated numerically among eggs in May (83% of total), ranking second in June (21%) with monthly mean densities of 477 and 348, respectively. Tautog/ cunner eggs (Tautoaa pnitis/Tautocolabrus adsoersus) exchanged with mackerel, ranking second in May (10% of total), first in June (74%) with respective monthly mean densities of 55 and 1228 per 100 m8 !

um Larval collections continued to be dominated by sand lance in May followed by radiated shanny (Ulvaria subbifurcata), fourbeard rockling, and winter flounder in June. In May sand lance contrib-uted 58% of the larval total with a monthly mean density of 98 per 100 m8 of water; their numbers declined to less than 1 per 100 m8 in June. Radiated shanny accounted for an additional 6% of the May total 34% of the June total, with respective monthly mean densities of 10 and 13 per 100 m8 Fourbeard rockling appeared only in June when a monthly mean density of 6 per ' 00 m8 accounted for 15% of !

l the month's total. Lastly larval winter flounder represented 13% j of the May total with a meau density of 29 per 100 m8 and 15% of i the June total with a mean of 6 per 100 m8 Il;1 Appendix B lists mean monthly densities for each of the j numerical dominants collected over the January-June period dating back to 1975. Generally low values obtained for both eggs and )

larvae during April-June of 1984 and 1987 were shaded because low through-plant water volumes during those months probably affected densities of ichthyoplankton (MRI 1994). Shaded values were ,

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I omitted from the following discussion. Because densities of each ichthyoplankton species rise from and fall to zero over the course of each respective season, inter-year comparisons are most conveniently made within monthly periods. A general review of the data through the first six months of 1994 suggests the following:

1. Atlantic cod eggs were typically collected in low numbers (<5 per 100 2 8 of water) at PNPS during winter months from 1975-1987. From 1988 onward they have rarely been collected during January and February; none were found either month in 1993 or 1994. This appears consistent with a genera.'. stock decline throughout the region (NOAA 1993).

2. After two years in which May densities were except.ionally low, fourbeard rockling eggs (combined with the Enchelyoous-Uronhvcis-Peorilus group which they dominate) were entrained in more typical numbers in 1994. Numbers remained low however, the 1994 monthly mean of 22.7 ranking ahead of only six other years. Densities exceeding 60 per 100 m8 were recorded in six previous years.

3. Larval sand lance were abundant throughout their period of occurrence in 1994. Mean monthly densities for February (21),

March (197), April (544), and May (98 per 100 m8) each ranked first or second over the 1975-1994 period.

4. Atlantic herring (Clucea harenaus) were numerous in the March and April collections. The March 1994 mean of 2 per 100 m8 exceeded all previous March values except 1981 (2.4) and 1983 i

(4.3), and April 1994's density (6 per 100 m8) exceeded all l 17 I I J

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l previous values for that month. High larval herring densities 4 are consistent with recent stock increases following reduc- .

tions in foreign fishing pressure (Smith and Sherman 1993, 1

Sherman 1994).

5. Larval winter flounder were absent from the April collections for the first time although both 1992 and 1993 densities averaged well below 1 larva per 100 m8 at that time. Their I absence in April 1994 may have resulted from a delay in I,,,

spawning or development caused by cold winter temperatures g (January air temperature 6.4*F below average, February 3.4*F ll '

below, March 0.4*F below) rather than poor overall production since May densities were relatively high. With a mean density of 29 larval flounder per 100 m8, May 1994's value exceeded every other May but two (30 in 1982, 38 in 1978). mJ l

6. Larval sculpin (Myoxoceohalus spp.) were notably abundant in l!

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May (12 per 100 m8) exceeding the previous high May value of 6 taken in 1979 by a factor of two. In 1994 as in previous May periods grubby contributed the overwhelming majority of sculpin larvae.

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7. Both larval tautog and cunner were absent from the June collections, the first time this has occurred dating back to 1975. In previous years June values have ranged from 0.3 to 13 per 100 m* for tautog and 0.5 to 232 per 100 m8 for cunner.

8. Radiated shanny larvae were notably abundant in June, the monthly mean density of 13 exceeding all previous values.

Prior to 1994 the June high was 5 per 100 m8 (1976).

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9. Larval mackerel were uncommon in June (4 per 100 m8) tying with 1976, the previous low year. Average densities reached as high as 318 per 100 m' in 1981.

Ichthyoplankton densities reaching' unusually high levels during the first half of 1994 occurred on a number of occasions involving larval sand lance, Atlantic herring, sculpin, and radiated shanny plus Atlantic menhaden (Brevoortia tyrannus) eggs and larvae (Table 3) . In the case of sand lance, Atlantic herring, sculpin, and radiated shanny, high densities occurred over an extended period of time, suggesting that larval production was strong perhaps facilitated and/or prolonged by the uncommonly cold winter. In the case of menhaden high densities occurred only briefly, suggesting a high density patch entered the area of influence of the plant. No additional sampling was requested for sand lance, sculpin, and shanny because these species have no commercial or recreational value and the sampling regime offered good temporal coverage. In the case of herring, larval densities were high relative to past years but they were still typically low

(<10 per 100 m8 of water) and populations are reportedly increasing I (see above); additional sampling did not appear warranted. Lastly, high menhaden densities were short-lived, so no extra sampling was deemed necessary.

No lobster larvae (Homarus americanus) were encountered through the end of June, a total of five having been taken through the month of June in previous years.

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I Hesh Extrusion Mesh extrusion data for larval flounder appear in Table 4.

Chance probability levels for paired sample t-tests are included.

Since six pairs is a minimal number, the 90% probability level was considered significant rather than the conventional 95%. Paired sample tests indicated that stage 2 larvae were taken in signifi-cantly higher densities in the finer 0.202-mm mesh (p<0.05) . Stage 1 larvae were found in only half the replicates so the t-tests lack statistical power in that case. Combining numbers of stage 1 and 2 larvae resulted in a significant value (p<0.08) . For both stages combined the ratio 0.202:0.333 was 1.6:1. Interestingly larger stage 3 larvae appeared to be more abundant in the 0.333-mm mesh net (p<0.10). Due to the relatively high velocity during the sampling intervals, close proximity of the net to the headwall, and probability of high larval mortality, we believe gear avoidance is I unlikely. The observed difference may be a sampling artifact due to the minimal number of pairs.

Among other taxa abundant at the time mackerel eggs were significantly more abundant (p<0.04) in the finer mesh (ratio =

1.4:1) as were tautog/ cunner eggs (p<0.06, ratio = 2.2:1). These results indicate how flexible eggs must be since they range from 0.98-1.37 and 0.78-1.15 mm in diameter, respectively (Colton and Marak 1969), considerably larger than the mesh. Larval grubby, seasnail (Liparis spp. ) , radiated shanny, rock gunnel, and sand lance were all collected in similar numbers in both nets, not surprising considering all are robust larval species.

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I These data indicate that small fish eggs and larvae are extruded through 0.333-mm mesh netting at flow rates experienced in I the PNPS discharge stream. This is consistent with studies conducted at Millstone Station in Connecticut (NUSCO 1987). If future studies at PNPS require that all larval flounder (or other small species) be fully retained by the sampling gear, then 0.202-mm mesh should be used until Stage 1 and 2 individuals are no longer taken. Once Stage 3 predominates, a switch to 0.333 can be made to reduce sorting time. Under the current monitoring regime 0.333 mesh is undersampling small larvae. This error would attain its highest value during years when spawning occurs in control areas nearer PNPS than Plymouth Harbor-Kingston, Duxbury Bay, younger larvae being subject to entrainment in those cases. When calculating adult equivalents, a mesh extrusion factor has been applied to Stage 1 and 2 larval counts.

Power Analysig Tables 5 and 6 present power values for increasing and decreasing trends, respectively. Based on the ten-year data set, the CV approximately proportional to abundance model was employed.

Type 1 error was initially set to 5% following convention. To produce power estimates a single CV value was required as input to the model. The median value over the ten years examined was 0.40.

This value was relatively high due to the natural within-season variation in larval densities (ranging from zero at the beginning i and end of the spawning season to peak densities as high as 108 per 100 m 8 between) and the weekly sampling interval which resulted in i 21

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only 9 to 15 data points per year. The revised sampling plan l initiated in 1994 essentially tripled the number of sampling dates l

by reducing replication. (Since replicates are not independent l

5 random samples, they do not contribute to sample size = n.) CV over the 1994 season was 0.27, the value used for Tables 5 and 6.

As an example, in Table 5 for power = P20.90, n = 5, r = 0.80, the shaded cell indicates that there is a 90% or greater but less than 95% probability of detecting an 80%-per-year increase in abundance if it occurs each year for five years. Similarly there is an 80-85% probability of detecting the same increase if it occurs for four years. Note that an 80%-per-year increase over five years amounts to a net change (R) of r (n - 1) or 3.2 over the five-year period (Gerrodette 1987), not a large change for larval fish populations. A comparison of Tables 5 and 6 confirms that a decreasing linear trend (r<0) is markedly easier to detect, i.e.,

power is greater, than an increasing linear trend (Gerrodette 1987); for example, with r = 3 years, power = 90% for an increasing trend of 2.6 compared with a decreasing trend of only 0.45.

Tables 7 and 8 summarize identical data as above but with alpha relaxed somewhat to 10%. For n = 5, r = 0.80 power improves I from 91.0 to 95.2%.

In general, power for larval flounder is relatively high with the revised three day-per-week sampling regime. Since flounder do not typically reach very high densities in PNPS samples (high = 83 per 100 m8 in 1994) and they occur over a fairly long period of I time (mid-April to nid-June in 1994), the coefficient of variation l 22 5 _

E

I is relatively low and can be expected to remain so in coming seasons. To reduce CV further would require additional sampling events at obviously greater expense.

I I

I n

g

==

5 1 1

Table 2. Species of fish eggs (E) and larvae (L) obtained in ichthyoplankton collections from the Pilgrim Nuclear Power Station discharge canal, 4 January-June, 1994. ,

l Species Feb Jan Mar Apr May June g;

m 1

Atlantic menhaden Brevoortia tyrannus E I Atlantic herring Clucea harenaus L L L L Fourboard rockling Enchelyopas cimbrius E E E E/L Atlantic cod Gadus morhua E/L E/L E/L E/L Atlantic tomcod Microcadus tomcod L Pollock Pollachius virens L '

Sea raven Hemitrioterus americanus L Grubby Mvoxocephalus genaeus L L L L Longhorn sculpin H. octodecenseinosus L L L L Shorthorn sculpin M. scorolus L L L Sacanail Liparis atlanticus L L L Gulf snailfish L. coheni L L Wrasses Labridae E Snakeblenny Lumnenus lumoretaeformig L L Radiated shanny Ulvaria agbbifurcata L L Rock gunnel Pholis aunnellus L L L L L Wrymouth Cryotacanthodes maculatus L L Sand lance Ammodytes sp. L L L L L L Atlantic mackerel Scomber scombrus E E E/L Fourspot flounder Paralichthys oblonaus L Windowpane Sconhthalmus aquosus E E An3rican plaice Hionoalossoides olatessoides E E E/L E/LE/L u Winter flounder Pleuronectes americanus E E E/L L Ysllowtail flounder E. ferrugin.qua E E E E/L I

I 24 g

a

i I

Table 3. Ichthyoplankton densities (number per 100 m8) for each sampling occasion during months when notably high densities were recorded, January-June 1994.

Sand lance Atlantic herring I Feb. 7 21 28 22.0+

27.1+

11.2+

Mar. 9 15 22 0

1.9+

2.5+-

l 30 3.0+

Previous high: 95.8 (1985)

_I-Notice level: 10 Previous high: 9.1 (1983)

Notice level: 1.2 Mar. 9 3.2 15 235.0+ Apr. 4 0 22 28.9 6 7.0+

30 507.0+ 8 10.5+

11 2.6+

Previous high: 504 (1982) 13 0.8 Notice level: 130 15 6.2+

I Apr. 4 6

67.3 226.8 18 20 22 6.0+

5.8+

13.8+

I 8 11 13 70.5 85.0 372.8 25 27 29 0

6.7+

8.3+

15 147.5 I 18 20 123.5 283.0 Previous high:

Notice level: 0.8 3.6 (1983) 22 2590.6+

I 25 27 29 338.9 816.1+

1406.2+

May 2 4

6 5.0+

1.0 2.0+

I Previous high: 1037 Notice level: 425 (1978) 9 11 13 2.2+

0 3.3+

16 0 May 2 157.8+ 18 1.4+

4 152.0+ 20 0 6 366.7+ 23 0 -

9 130.8+ 25 0 I- 11 25.9+ 27 0 13 43.5+ 30 0 16 I 18 20 32.4+

18.6 72.0+

Previous high:

Notice level: 1.1 10.5 (1975) 23 1.9 I 25 27 30 149.6+

22.0 2.6 Previous high: 368 (1978)

HQtice level: 23 25 I

I Table 3 (continued).

l Atlantic menhadBD Radiated shanny I EGGS LARVAE '

June 1 0 0 June 1 12.6 3 2.4 0 3 29,0+

6 1.0 0 6 0 g; 8 0 0 8 13.6 g; 10 0 0 10 41.5+ l 13 0 1.6 13 1.6 !

15 2.6 0 15 1.7 i 17 0 2.1 17 17.5+

20 0 0 20 22.3+

22 23.0+ 0 22 35.3+ lj 24 19.1+ 0 24 9.6 27 115.9+ 26.6+ 27 0 l 29 6.8+ 1.0 29 2.9 m l Previous high: 74.2 (1980)(E) Previous high: 14.8 E1 '

496 (1981) (L) (1976)

Notice level: 6 10 Notice level: 15 Sculpin May 2 18.2+

4 37.0+ g i 6 19.6+

9 20.9+

E'j 11 6.0+ '

13 27.1+

16 3.6 ;

18 0 20 6.8+ E' 23 0 5 l 25 1.9 27 0 30 0 Previous high: 35.2 (1978)

Notice level: 4

+ Unusually high density.

I I

26 E

m

I I Table 4. Fish egg and larval densities per 100 m8 of water for select taxa taken with 0.333 and 0.202 mesh nettino on two dates in May 1994.

I LARVAE Winter Date 1

Reolicate 1

0.333 0

Mesh 0.202 0

o* ,

0 I flounder 2 0 Stage 1 3 0 0.7 2 1 1.1 4.8 I 2 3

1.9 4.5 2.0 0

Hean 1.3 1.3 0 .96 S.E. 0.7 0.8 Flounder 1 1 7.8 5.8 I Stage 2 2 3

8.1 10.5 10.5 20.6 I 2 1 2

3 11.0 6.6 11.6 18.4 19.5 19.5 Hean 9.3 15.7 0.mi S.E. 0.8 2.5 Flounder 1 1 7.8 5.8 Stages 1 & 2 2 8.1 10.5 3 10.5 21.3 2 1 12.1 23.2 2 8.5 21.5 3 16.1 19.5 Hean 10.5 17.0 0 .03 S.E. 1.3 2.9 Flounder 1 1 2.0 2.3 Stage 3 2 0.8 0.8 3 2.1 0.7 2 1 8.8 8.7 ,

I 2 3

15.1 10.7 4.9 3.9 Mean 6.7 3.6 0.2 S.E. 2.4 1.2 Flounder 1 1 9.8 8.1 I total 2 3

8.9 12.6 11.3 22.0

Probability level from paired sample t-tests on log-I tranFformed densities.

27

se .

El Table 4 (continued).

Mesh I LARVAE Date Reclicate 0.333 0.202 D* l Flounder 2 1 20.9 31.9 )

total 2 23.6 26.4 3 26.8 23.4 Hean 17.1 20.5 0 .23 S.E. 3.1 3.7 EGGS Mackerel 1 1 8.8 13.8 2 5.7 7.5 3 5.3 8.8 _

2 1 7.7 6.8 2 2.8 3.9 3 2.7 6.8 Mean 5.5 7.9 0.04 S.E. 1.0 1.3 Tautog/ 1 1 2.9 16.1 3 cunner 2 3.2 9.0 3 3 5.3 4.4 2 1 1.1 3.9 ,

2 4.7 4.9 3 1.8 2.9 Mean 3.2 6.9 0.06 S.E. 0.7 2.0 American 1 1 6.8 21.9 plaice 2 23.5 19.5 3 30.6 21.4 2 1 5.5 2.9 2 0.9 1.0 3 4.5 3.9 Mean 12.0 11.8 0.97 S.E. 4.9 4.1 Grubby 1 1 36.1 41.4 2 30.0 37.5 3 30.6 28.0 28 5

in

I Table 4 (continued).

Mesh LARVAE Date Reolicate 0.333 0.202 o*

I Grubby 2 1 2

3 20.9 18.8 21.4 12.6 24.4 19.5 Mean 26.3 27.2 0 .93 S.E. 2.8 4.4 I Seasnail 1 1 2

3 2.9 2.4 5.3 0

1.5 4.4 2 1 12.1 6.8 2 6.6 8.8 3 8.0 10.7 Mean 6.2 5.4 0.27 S.E. 1.5 1.7 Radiated 1 1 3.9 3.5 shanny 2 5.7 2.3 3 5.3 2.2 2 1 3.3 1.0 2 1.9 3.9 I 3 0.9 1.0 Mean 3.5 2.3 0.26 S.E. 0.8 0.5 Rock gunnel 1 1 5.9 6.9 I 2 3

8.9 8.4 10.5 0.7 2 1 0 1.9 2 0.01 2.0 3 0 0 I Mean S.E.

3.9 1.8 3.7 1.7 0.78 I Sand lance 1 2

3 1

146.0 123.4 152.0 161.5 125.3 169.1 2 1 130.8 95.9 ;

2 116.8 187.5 )

3 114.4 92.8 Mean 130.6 138.7 0 .80 J S.E. 6.3 16.3 29 I

r i ' ![i [ i i t[; [ <l , l

! ll\ l I ll B . _

0 o 0

5 0

t W_ _

4 _

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4 0

=

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4 5 m0 o

0 4

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r0 gt o

m 0 n 2 i t ge 4

0 ns a

rs W

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ny 0

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_ 4 0 0 t _

A p= S5 -

n = _

_ 34523452345234523452345 - r, _

o .

Vrr 5 5 0 5 0 0 0 Ce

. 9 9 8 8 7 5 l: 1 e 0

P

=

0 P

=

0 P

=

0

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=

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=

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a m_

o _

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oy rt fi l

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.m 0-0 a) rl ei s

_. 7 d a

. 7 0 nt 2 d

- ue -

_. e.

od n5 l 0 e6 f r

= r0 o T-V g lf a

- C n i6 0 vt rx ae s0

- S a-e l t

_ P r5 c5 ne i e

_ N s

_ e.. P r

e0 D-0 d

s(

ns :

)5 er

_ f o r (0

ra t e e-

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- s g5 g .

e n4 i n5 ,

- s y

a0 h -

sd an C0 ea

_m l

a f o4 r

c ,

n 0 e4 A t e-a5 d

t3 r

e R3 c e ,

0 t2 w la-u 0 e .

_ o n3 d =

7 P n 0 on

_. A- t .

_. e. 5 2

) e P v

( o r

0-

_ 0 2

r0 e

w1 5

_ 0-o0 p .

o0 :

_ 5 1

l t a o c0t

_ m. 0 0

1 5

0 0

i1 t

s0 e i - s t

a= s t

e 0-n234 34 34 34 3452345 Ap

=

= ,r

~o t

S rw a

Vrr .

5 0 5 0 0 0 Ce 6 9 9 8 8 7 5 l: 1 e e d pe

. 0 0 0 0 0 0 l

. = = = = = = b

> > > > > > oy a P P P P P P MT T

-. e U

e t' ; .ji ;i! i ,

Power Analyses for PNPS CV=0.27 5

Annual Rate of Change (r)- Increasing Trend n 0.20 0.25 0 30 0 35 0 40 0 45 0.50 0.60 0.70 0.80 0.90 1.00 1.10 1.20 1.30 1.40 1.50 1.60 1.70 1.80 2.00 3.00 4 00 5 00 8.00

, P>=0.95 3 l 4 ?

5 l

2 l P>=0.90 3 4

t 5

2 i P>=0.85 3 4

5 2

P>=0.80 3 4

5 2

P>=0.70 3 U 5 2

P>=0.50 3 4

5 Modet CV -=A Type 1 error, p=0.10 l

Table 7. Statistical power (P) to detect increasing trends in larval flounder annual abundance ranging from 0.20 to 8.0 over n =_2, 3, 4, and 5 years'(see text for details). Type 1 error probability was set to 0.10.

r

{

r l !

l EE W M O- M M M M M .M 'M M W M M EE

t ' : ,I ,

r " > l ; i! I i. '

0 m oy e 0 1

rt fi gi l

5 9 nb i a 0 gb e 0 9

no ar rp 0 er

- co m nr e 5 8

0-ar d e n

u1 b

0 aep e 8 0- l y aT u

5 n 7 n .

0- a) e 0 rl ei d a s

7 7 0 nt ue 2 d od e 0

=

n5 e6 r0 l

f r o

l f T-s V g a

vt i C n i6 0 rx ae m S s0 a- l t P e r5 ne i e c5 N s e P r

D-e0

- 0 d

s(

ns er o )5r ra f (0 t e y

e-e s e

g5 n4 i g

n5 s

y a0 h -

sd an s C ea

. u l a f 0 r c ,

m n o 4 0 d e4 A t e-a5 t3 s r c u e R3 e ,

s w l

a-u 0 0 t2 e

~d o n3

=

. P n on A-0 t r

a 5 2

)

P v

( o e

0

- r0

. n 0 e

w1 0 e 2 0

o1 p

- o0 l t 5 a o 1 c0t

.e i1 0- t .t s0 e 0 0 i - s 1 t su 1

0 a= s '

0- = t a Ap S rw s 34 34 345 = ,r n234 34 34

- o .

Vr r 8 a 5 0 5 0 0 0 Ce m 9 9 8 8 7 5 :

l 1 e u 0 0 0 0 0 e l d pe 0 b

= = = =

> > > > > > o y a P P P P P P MT T jiIlI llIl l ' ,l j i j ii lj

um E

SECTION V LITERATURE CITED E

Box, G.E.P., W.G. Hunter, and J.. Hunter. 1975. Statistics for 3 Experimenters. John Wiley & Sons, New York. 3l l Colton, J.B.,Jr. and R.R. Marak. 1969. Guide for identifying the j common planktonic fish eggs and larvae of Continental Shelf ,

waters, Cape Sable to Block Island. MBL Laboratory Reference No. 69-9. September 15, 1969. I Gerrodette, T. 1987. A power analysis for detecting trends. --

1 Ecology 68(5):1364-1372. !

MRI (Marine Research, Inc.). 1988. Ichthyoplankton Entrainment Monitoring at Pilgrim Nuclear Power Station January-December 1987. III.C.1. In Marine Ecology Studies Related to Opera- <

tion of Pilgrim Station. Semi-annual Report No. 31. Boston Edison Company.

. 1994. Ichthyoplankton Entrainment Monitoring at Pilgrim E Nuclear Power Station January-December 1993. III.C.1. ID E Marine Ecology Studies Related to Operation of Pilgrim Station. Semi-annual Report No. 43. Boston Edison Company. g NOAA (National Oceanic and Atmospheric Administration). 1993.

Status of Fishery Resources off the Northeastern United States for 1993. NOAA Technical Memorandum NMFS-F/NEC-101. 140p.

NUSCO (Northeast Utilities Service Company). 1987. Winter flounder studies. p60-61 ID: Monitoring the marine environ- 3 ment of Long Island Sound at Millstone Nuclear Power Station. E Summary of studies prior to Unit 3 operation.

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

Sherman, K. 1994. The changing ecosystem. Maritimes 37(1):36.

Smith, W.G. and K. Sherman. 1993. Georges Bank herring continue recovery, sand lance continue decline. p2 ID Research g Highlights. Northeast Fisheries Science Center. March-April 1993.

5' I ;

34 I!

5 m l 1

I

I I

I I APPENDIX A*. Densities of fish eggs and larvae per 100 m8 of water recorded in the PNPS discharge cana).

by species, date, and replicate, January-June 1994.

I

Available upon request.

I I

I

I Appendix B. Mean monthly densities and range per 100 m8 of water for the dominant species of fish eggs and larvae entrained at PNPS, January-June 1975-1994.

Some standardization of data sets was required to adjust for changes in the sampling program which have occurred over the years:

1. Only 0.333-mm mesh net data we're used in those cases (1975) when field sampling was carried out using both 0.333 and 0.505 mesh nets.

2. When, as in 1976 and 1977, 24-hour sampling series were conducted, the samples taken nearest the time of daylight low tide were selected for comparison since this conforms to the routine specification for the time of entrainment sampling used in all subsequent years.

3. For the same reason only daylight low tide data were used when, in 1975, samples were also taken at high tide and/or at night.

4. Cod and pollock egg densities were summed to make up the category " gadidae" since these eggs were not distinguished prior to 1976. In January, February and December when witch flounder do not spawn, all three egg stages are included in this category. During the remaining months early-stage eggs are included with the gadidae-Glvotocechalus group.

5. Beginning in April when the Enchelvoous-Urophycis-Peorilus grouping became necessary, the listing for Enchelvoous cimbrius includes only late-stage eggs, the two early stages being included with the grouped eggs.

6. Since the Brosme-Scomber grouping was not considered necessary after 1983, grouped eggs were added to .S_. scombrus eggs in the table for 1975-1983 (H. brosme eggs having always been rare).

1 l .

O E

i

7. Sculpin larvae were identified to species beginning in 1979 following Khan (1971).** They are shown by species beginning '

with that year as well as added together (Myoxocephalus spp.)

for comparison with prior years.

8.

Similar results are shown for seasnail larvae which were not speciated prior to 1981.

9. Although samples were in fact taken once in April 1976 and once in March and August 1977, comparisons with other years when sampling was weekly are not valid and consequently do not appear in the table. Data collected in 1974 was not included because samples were not collected at low tide in all cases.

10. When extra sampling series were required under the contingency sampling regime, results were included in calculating monthly B E.

Icean densities.

11. Shaded columns for certain months in 1984 and 1987 delineate periods when 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 1993).***

Table format: Mean I

Range Khan, N.Y . 1971. Comparative morphology and ecology of the pelagic larvae of nine cottidae (Pisces) on the northwest Atlantic and St. Lawrence drainage. Ph.D. thesis, University of ottowa.

'"MRI (Marine Research, Inc. ) 1993. Ichthyoplankton entrainment monitoring at Pilgrim Nuclear Power Station January-December 1992, Volume 2 (Impact Perspective). ID: Marine Ecology Studies Related to Operation of Pilgrim Station. Semi-annual Report No. 41. Boston Edison Company.

2 E

i.

I I EQQ1 knuary J.977). 19% + 1977 + j.911 1919 1980 jl 1932 1983 j9ff 19,8J Brevoortia tyrannue 0 0 0 0 0 0 0 0 0 Enchelvoous-Urophyc+ - Penrilve - - Enchelvoous cimheius** 01 0 0 0 0-0.6 0 0 0 0 0 f UroPhYels opp. 0 0 0 0 0 0 0 0 0 Gadidae-Olvotocenhalus - t L - . . . Oadidas* QJ, 01 O O (2 9.) Q.9 0 00.7 05 (0J.) QA) 0 0.3-6 1-9 01 0-2 0-2 91d.y2 marhua - JO 0-0,7 ll 0-5

                                                                                                   ),,9        M          JO          0         Q.f         0 0.3-6          1-9        0-1        02         0-2 L        Pollechius .vig.ns                    -

0 0_! 0

                                                                                     .                          0          0          0 0-0.4                                                         0          0 h        Pnonorus app.                        0 0            0            0           0           0         0           0         0 Labridso-Pfeuro, em                   0 i                                                                         0           0            0

. 0 0 0 0 0 Labridae 0 I 0 0 0 0 0 0 i 0 0 h ge.m&3g 0 0 0 0 0 0 0 0 0 Persfichthys-Scoohthsimus 0 0 0 0 0 0 0 0 0 Hinnectoinnida 0

       &enoide,                                                        0           0            0           pl          0         0          0 0-0.4                                        0 Total J

O OJ U 01 0-0.7 M M JO 0 05 0.3-6 19 0.,,3 0

Represents Q. rnorhu_a_ and f. ytrens eggs in ali stages. 0-1 02

   " Represents au three egg stages, January through April.
    + No sampling.

3

I. h e.n Ecos E E N E E O O O O O O O O O PrfYo9me III!LD321

                                                                          '        ~

Enchelvoove-Urophycit- - Ef.EIDA! O O O O O O O O Enchelvoous g,imh.I!g1** O 0 0 0 0 0 0 0 0 0 UrophYCil spp.

                                                         *         ~
                                   -          -                                                                                        ~

Gadidae-Givotocechslus 0 0 0 0 Oadidae* g g 0 0 0.6-2 0-1 0 U g 0.6-2 M 0-1 0 0 g 0 0 0 0 0 0 0 0 0 0 Po11ech.ive XLrgsg 0 0 0 0 0 0 0 0 0 0 Prionotus sPP-0 0 0 0 0 0 0 0 0 Labridae-Pleuronectes 0 0 0 0 0 0 0 0 0 Labridae 0 0 0 0 0 0 0 0 0 Scomber ecombrus 0 0 0 0 0 0 0 0 0 Perslichthys-Scoobthalmus 0 0 0 0 0 0 0 0 tilocoeloissoides 0 clatessoides M 0 M 0 0 M 0 Total M O2 0-2 0.6-2 01 0-1 0-2 Tkepresents 2. morbus and E. virens eggs in ou stages.

 " Represents all three egg stages, January through April I

I I

I I hmisry E9.pj g 1976 + 1977+ 3 g jf8Q R jf9M jf9J8,3_ jf84 E81 Brevoortie tyrannus 0 0 0 0 0 0 0 0 0 Enchelvoous-Urophysit - - - - - - - - - Peorilus Enchelvoeus timbrius" M 0 0 0 0 0 0 0 0 0-0.6 Urwtytis app. 0 0 0 0 0 0 0 0 0 I Oadidu-Olvotxeohelus - - - - - - - . - Oadidac* J O C) (M) 1 99 ) O @ 0 11) 0 0-1 0-0.7 05 0.36 1-9 0-1 0-2 0-2 Osdue rnorbus - J O M M M M 0 J O 0 0-0.7 0-5 0.3-6 1-9 0-1 0-2 0-2 Pollachius virens 0 O1 0 0 0 0 0 0 0-0.4 Prionotus spp. 0 0 0 0 0 0 0 0 0 e Labridae-Elevurss.es.te.t

                   -                  0                             0       0      0     0     0     0       0   0 Labridae                         0                             0       0      0     0     0     0       0  0 Scomber scombs                   0                             0       0      0     0     0     0       0  0 Paralichthys-Scochthalmus I

0 0 0 0 0 0 0 0 0 Hionocloissoides 0 0 0 0 M 0 0 0 0 I platessnides 0-0.4 I Total 91 0-1

  ' Represents 9. morhua and t, virens eggs in all pages.

02 0-0.7 M 0-5 M 0.3-6 M l9 0.5 0-1 0 0.4 0-2 0 I *+ NoRepresents sampling. all three egg stages, January through April. I 3 I I

11021 2

   -                               -          -           -   -    m2    -  -  -    -

Drmema ImnDat 0 0 0 0 0 0 0 0 0 Encheiropue-Urophyvie- - - - - - - - - - Preri!ve Enchelvoous timbrius** 0 0 0 0 0 0 0 0 0 Urophycts gp. 0 0 0 0 0 0 0 0 0 (.,4idse-Glyetoceehalus - - - - - - - - - I Cadidae* (9_s) (M) O C (9,1) 0 0 0 0 0.62 0-1 0-2 Gedus morhus 9,,1 Q,,1 0 0 22 0 0 0 0 0.6-2 0-1 0-2 Potlachius v_irrn 0 0 0 0 0 0 0 0 0 EtpgL,ugapp. i 0 0 0 0 0 0 0 0 0 Labridae-E]eurorieetes 0 0 0 0 0 0 0 0 0 Labridae 0 0 0 0 0 0 0 0 0 Senmber ecombrus 0 0 0 0 0 0 0 0 0 Perstichthve-Sconhthalmus 0 0 0 0 0 0 0 0 0 Hienortoissoides 0 0 0 0 0 0 0 0 0 platessoides Total 0,2 p1 0 Q_t _ 92 0 0 Q,,2 0 0.6-2 0-1 0-1 0-2 0-2

 *kepresents 2. rnorhua and f. virens eggs in ail stages.

- Represents all three egg stages, January through April.

I 4 I

l FebruerY I f;QQj 19,]j, 1076 + 1977 + B g H8Q 1981 g g82 g g ' Davo9 die Imnas 0 0 0 0 0 0 0 0 0 Enchelvoove-Unmhycis- - . . . . . . . . Pernlue

I Enchelvonus simbrivn" 0 0 0 0 0 0 0 0 0 I Urophyris opp. 0 0 0 0 0 0 0 0 0 l Gadidae-01votocer.helus . . . . . . . . . ) l Gedidae* (M) (g) g g Q9 (DJ (g) (g) g 04 0-5 0-3 0.4-3 0-2 0-0.6 0-1 0-3 0-3 I 9th.I moitm - U 0-4 M 0-3 0.4-3 M M 42 y 0-0.6 y 01 13 0-3 g 0-3 Polischive rirtat - g9 0 0 I 0 0 0 0 0 0-5 Pnenceve opp. 0 0 0 0 0 0 0 0 0 I labridae-Pleuronectes 0 0 0 0 0 0 0 0 0 Labridae 0 0 0 0 0 0 0 0 0 Scomber scombni, 0 0 0 0 0 0 0 0 0 Parstichthve-jsccpigty,;p 0 0 0 0 0 0 0 0 0

      }Jirrectoimijn                          0                                                                               M                                        M                                                               M riatessnides                                                                                                        0-0.8 0      0        M    Q4                                          0 0-0.5                                                           0-0.6                                                                                0-1  0-2 I    M                                   1.9 0-3 M

05 IJlt 0-3 U

0. 8-3 M

0-13 91 0-0.6 26 0.5-2 29 0-4 O 0-3 I *+* Represents Reptroents No sampling. Q.January all three egg stages, rnorbus through Aprit. and f. wrna eggs in all stagen. J 5 l 1 l l 1

O l February Drevmme tyrennus 0 0 0 0 0 0 0 0 0 Enchelynput-UnTh ytip- - - - - . - - - - EDIllut Dxhelvoous strnbrius" 0 0 0 0 0 0 0 0 0 UrophYrie spp. 0 0 0 0 0 0 0 0 0 I Gadidas-G!votocephalus - - - - - - - - Gadidae * (Q,4,) (0J 0 0 0 0 (0)2) 0 0 01 0-1 0-1 fady.g mo%e U M 0 0 0 0 M 0 0 01 0-1 0-1 Pollachips virens 0 0 0 0 0 0 0 0 0 Prionotus spp. 0 0 0 0 0 0 0 0 0 Labridae-Pleuronectes 0 0 0 0 0 0 0 0 0 Labridae 0 0 0 0 0 0 0 0 0

   $ comber g,qmbrus                 0           0          0   0    0  0    0    0  0 Paralichthys-Sconhthalmus         0           0          0   0    0  0    0    0  0 Hincorloinwides                   0           0        O,,1

_ 0 0 0 0 0 0 r!a.tessoides 0-1 Total U Oj. _ U U 0 0 M M 0 0-1 0- 1 01 0-1 0-1 0-1 =

 ' Represents Q. morhus and E. virens eggs in all siegen.

Represents all there egg stages, January through Apnl. 6 I 5

I i I LQgj g 1976 + 1977 + + 1978 1979 8 J9.82 19,818 1982 1.9,8} 8 g g Brevtertie fyrsnnus 0 0 0 0 0 0 0 0 0 1 Enchelvoous-Urophycis- . . . . . . . . . ! l Enchelvoous cimbrius" 0 0 0 0 0 0 0 0 0 UrwhYCis spp. 0 0 0 0 0 0 0 0 0 I Gadidae-Olvetxeobalus M 0-2 M 0-3 M 0-32 M 0-2 0 0 M 0-3 M 02 0 I cadidae* M 0-3 u 01 o0-1 o 0-1 u0-9 u 0-2 u 0.6-24 u 0-11 o 0-2 I Gedus m2 dan - M 0-1 M 01 M 0-1 M 0-9 M 0-2 M 0.6-24 2.1 0-11 M 0-2 Pollachius virens . 0 0 0 0 0 0 0 0 Prionneus app. 0 0 0 0 0 0 0 0 0 I labridae-Pleuronectes 0 0 0 0 0 0 0 0 0 Labridae 0 0 0 0 0 0 0 0 0

     }cenig scombrus                   0                             0       0     0      0     0      0       0    0 Paralichthys-Sconhthalmus         O                                     0     0 C                    0     0      0       0    0  l Hinnorloissoides                 M                             M       M     M      M      0    M       M     02 oletessoides                   0-1                           0-4     07   0-1    0-14        0.5-17   0-22  0-1 l

I Total M 0.8-41 u 0-5 in 0.4-35 u 0-12 u 0.5 20 u 0-9

                                                                                                     .tu 2-50 M

0.7-30 u 0-9

  ' Represents late-stage 9. morhus and f virens eggs.                                                                 I
 ** Represents all three egg stages, January through Apnl.
  + No sampling.
 + +One sampling period only.

7 I I l

O E Mitih , EQ9.1 L9M 1 181 1983 1989 1290 1921 1922 J292 L991 Brevwnie imnnus 0 0 0 0 0 0 0 0 0 Enchelvoous-Urophyvis- - - - - - - - - - P.IPd1R Enchelvoous cimbrius" 0 0 M 0 0 0 0 0 M 0-1 0-3 UrwhYCis spp. 0 0 0 0 0 0 0 0 0 Gadidae-O!vntacephalve 0 9.J, M M 0 J O 0 0 M 0-2 02 01 0-1 0-2 Gadidae * (0.4) (0 f) (M) j) (0 0 (Q.2) 0 g 0 02 0-2 0-1 01 0-1 0-2 Gedus morhua M 0_f

                                               ,           M     M       0    M      0   p_1    0 0-2        0-2         0-1   0- l         0-1        0-2       5 Pollachm virens                    0           0           0    0      0     0    0     0     0 ErigggLug opp.                     0           0           0    0      0     0    0     0     0 Labridae-Pleumnectes               0           0           0    0      0     0    0     0     0 Labridae                           0           0           0    0      0     0    0     0    0 Scomber ocombnis                   0           0          0     0      0     0    0     0    0 Peralichthve-Scoobthalmus          0           0          0     0      0     0    0     0    0     l Hipportoincide:                                          j platesmides 0           0         O      0      0   M     M     9.1  M      j 0-1               02    0-1   01   02     ;

Total 48 9 94 04 0 J gl Q.1 O i9 L2 0-34 1 219 0-81 0-2 03 0-3 0 56 0-8 '

*Reprcsents late-stage Q. mortua and f. virem. eggs.

- Represents all three egg stages. January through April.

Il 8 l s

i i I ggg} Actil 1971 7 1976 + M 197,[ M 1989 1961 19$1 1981 PjMy mams I Brevoonia (Yrannus 0 0 0 0 0 0 0 0 m 1 g(3j $j[R C l '. s

x. c.

0 I Enchelvoous-Urophyvie - - - - - - - ff! 4l@ ETEDlV.I f$ 'id$

D % :r$

Enchelvmus ennhius" M Q,j 0,J G Q1 0 QJ 9.fi h3f N: Id ?59.s?..[.. 1,9 ;;J I 0-10 0-1 0-1 0-2 0-4 0-2 0-2 ...:.$ 04} l 0-6 w ir -.., ,. . Urophycis spp. O Q,1 0 0 0 0 0 0 g ?;:9j . 0 0-0.8 . N[b .f.4j Gadidae-01votoceche]yqj U QJ U U LQ 0 0 QJ j,:(g ' O 0-5 0-2 2-14 0.8-12 0-7 0-3 ;

                                                                                                               'R.;         O. -3. 5. .

I

                                                                                                                     ,e         .,:.

Gadidae

U (OJ) Q,4.) (U) (L1) (Q,d) (Q,1) (9,.4_) , $ (LQ)$ $ (Lg) 0-6 0-3 0.6-14 03 0-4 0-3 0-3 0-2 A 0 5 T: 0-4 y.j. y

[ :.: ..... $: Gedus rnothva - Q,J 1.3 LQ L1 0.1 Q1 Q,3 iLQEsl L1 0,3 0.6. I 4 0-3 0-4 0-3 0-3 0-2 ((jj0 gl 2w $y? 0-4 9 = . ,. ,

                                                                                                                        .> < .;l:{

Pollnhive zittna - 0 0 9,,0.J 0 0 0 0 0-0.6

                                                                                                               @plotiu)s       " l*U 0-0.7 Q6 L:                     '

y:;. Pdonotus spp. 0 0 0 0 0 0 0 0 [M , O I Labridae-Pleuronectes 4,,_1 2,J 1U U 0 0 0 0 sf p un k

                                                                                                               %* [0]

W

                                                                                                                        ?...,

a 2$ O 0-! 8 0-7 0 26 0-28 ^ O

                                                                                                                        ..: m labridae                             0                    QJ     9.J       M        0    0     0      0     h1!(0)g              ^

o 0-0.9 0-3 0-1 M <. u I Scomber gepmbrus 0 0 0 0 0 0 0 0 In _ . .., d [W.((0y 69 0 k!3 .., . Parslichthys-Seonhthalmus 0.J 0 0 0 0 0 0 0 0

                                                                                                               % '20)                     ,

0-0.7 j h .r.1.. Hipporloissoides M 4 M M M Lp QJ LQ [7 Qi)

U p,Latessoides 0-41 09 0.8 79 0-49 l-18 0-5 0-1 0-6 0-12 QL5-11$

hll ^ ! I

Total 2M l 84 191 1-18 01 8 114 IU 4-546 2M 0-29 IU 0 77 M

0-42 M mlLQ,UW.. . . Q 0.7-19 IS. 7:, 5.16 %. ~ IM 0-25 I *+*Representa late-stage Q mothus and t. virens eggs. Represents all three egg stages, January through April. 0ne sampling period only. 9 I

M g 1,9J8p 1987+ g g j]99 19919 g M g I Bffvp9rtie tyrannus 0 0 0 0 0 0 0 0 hehelYgpug Urophytts - - - - - - - PernIvo Enchelvoous Cm)hrius" M M 09 44 M M QJ QJ 0-14 0-10 0-6 0 28 0-16 0-7 0-1 0-3 Urophytis 9p. 0 0 0 0 0 0 0 0 Gadidae-Givotocechalug 0 gl pl I

9_1 O J O 0 0 01 0-1 0-1 0-2 Gadidac' O (M) (0_i) (0_1) (M) (U) (0J) (0J 0-3 07 0-3 0-1 0-5 0-3 0-2 02 9Juf23 innrhun p_2 M g_q QJ M M gj M 03 0-7 0-3 0- 1 05 03 0-2 0-2 Potischius y,ggn: g 0 0 0 0 0 0 0 0 Prionntvo app. 0 0 0 0 0 0 0 0 labridae-Pfeuronecies 0 0 g,y 0 0 0 0 0 I 0-10 ' Labridae 0 0 0 0 0 0 0 0 l Scomber scombrvs 0 0 0 0 0 0 0 0 Paestichthys-Sconhthalmus 93 0 0 0 0 M 0 0 0-2 0-13 5 1 Hinnorinissnides ofstessoides JO U M M M M J 7 M l 0-1 0-14 09 0-7 0-16 0-77 2-16 0-9 Total 2.1 0-21 14J 3-29 1,,2 0-27 s.,2 10 2 M 2,J M l-28 2 51 0-90 2-16 0-21

Represents late-stage 9,. morhua and t. virens eggs.

i

 ** Represents all three egg stages, January through April.                                                   '
  + Pumps down - no sampling.

10

I EOOS MH 1171 1221 1922 192! 1222 1212 121l 19J2 1282 p'll2K 3<w y 1911 I Brevoonis tyrannus 0 0 0 0 0 M 0-1 0 0 0 p %.s h'j0( g g,g - 0 Enchelvooue-Urophycis-Pwrilus U 0-30 L3.J 0-72 1U 5 22 2! 2-125 2J 0.6-34 M 4-14 2E 1 19 M l-8 M 3 18 h[ E[0-413g 0 98 hk 14 i..,.. Enche!voous cirnbriue 2j.2 22 I 14 9 10J M 1L2 lil M 11] [QfMj ' 2J I 6-70 0-91 0-32 0 37 0-15 1 0-73 0-55 02 0-59 041-[, 1 22 g$p r O . . .. prwbycis orp. 0 0 QJ 0 0 0 9J 0 M M07,' 9.2 0-3 0-1 0-05 3 0-9 I Oedidae-GIvetocechslus L2 0-2 2.), 0-6 2J 0-11 34 0-14 14 0-5 2J 0-6 U 0-2 Q4 02 4.Q 0-18 G p:. bio-81

gy --

                                                                                                                        ' ,- .z Q:MyE Lg 0-3 W:n    . . , ~ ,

Gadidae

L1 (L,5.)

0-4 (M) (9J) (L!) (L2) (0J) (gl) (0j) fy(M)? (2,1) 0-3 0-3 0-61 0-5 0-4 03 0-0.8 0-3 M S4n, 0-2 g p

                                                                                                                      -           o, I                                                                                   M lj Q.th1 rnorbus                 -

0-4 12 0-3 SJ 0-61 L1 0-5 0-4 9J 0-3 91 00.8 QQ ! fM QJ 0-3 0-2 Q.0 51 Pollachius virens (..-

                                    .         0         0        0          0                0 0               0      0    [15Oj                  0 I    Prionotus spp,               QJ2          0         0        0          0       0        0      0       0 N

F.!7 y# qx w

                                                                                                                         >jm Q,J.

0-0.5 ){ 20h ' g'j x 0-1 Labridae-Pleuronectes 145 8 12 9 232J 184) 4 14919 3024 0 2d 917.8 22J py f,.j { 14f4,j 2 1248 5 23 3 1240 3 11809 6-9475 5-9331 2-94 4-248 0-4622 0-209 l-30-40 O. s v .. , . . : + Labridae gj 86 0-2 0 0 20j j4 119 0 23 M 9.2 sjdp 26 0 55 0-169 0-19 0-431 0-23 0.5-15 0-1 [Q sij 0-5 0?( 16 3 pw.4 . ,. m { comber scornbryf' 2j LQ 4,,6.9 16,.! !2.2 231.6 4,72 160.9 0-8 a 116 4 PM @_. 1485.5 0-11 0 104 0-308 0.2- 57-621 0-195 2-705 0-424 jS441 5-355 g , 20871 I Perniichthve-SconMhalmus 12J 62 12j 0-64 0-19 2 32 2.04 0-169 2LQ 0-76 24,9 7-67 212 0-64 LL2 2,j dm hf' 2LQ 0-43 0-27 y';0 23M 3-85 Hipportoissoidej 2.9 2.1 f9 IL2 lj pu a < 9.J 14 2 L2 2J gym [< IJ I riniessoides 0- 9 09 0-16 0 79 0-11 0 51 0.5-16 0-7 0.5-9 R 96 ' O7 ki' [4j h > $$ I Total 1965 24.,2 396 3 2017 8 [%n fdj ?. 1920 3480.0 151 6 25L9 185.9 4051.5 l 12 1366 35-126 31 1324 13-12428 45- I- 29- 40-425 10-524 {191233-g 38- ) 9925 10314 368 21505 l

  '8%$,nts late-stage Q. morbus and f. vnens eggs.

I ** Includes Bmsme-Scomber, 1975 1983. I 11 I ' I i

LO O au [Qgg 3 . jf,g] - 1983 1989 1990 1991 199,4 1992 1992 Envoortia tyrannus 0 OII O g.1 0 g.6 0 0 0 0-1 0-4 Enchelvoous-Urophycis-M L g. 22.1 147 6 10 4 0 j.0_1 O g g f.Edhi 3-189 l-66 j 0-131 2-894 4 271 1186 0-5 2-14 0 24 Enchelvoous cimbrius 2M JMi 2M 2,0,,2 13 8 33 4 M ll 16_d 0-52 0-57.( ; 1 91 0-95 2-27 4-132 0-29 0-5 0-103 Urophytis spp. QJ 7. DJ, ' , 0 il 0 0 0 0 0 0-1 ;011 0-12 Gadideo-ClYDtocephalus M 2Q Q,] 09 0.7 L2 9.4 0 0 0-5 0-13 .- 02 0-4 0-3 0-17 0-4 Gadidae * (21) - (p,d) ' (0 004) (2.4) (0,,2) (11) (1.,1) 0 (01) (p g) 0-2 0-3 J 0-1 0-2 0-3 0-4 0-7 0-1 0-3 " Ondus mortius 02 -M 0 004 04 07 I3 il QJ Q,1 0-2 'D 3 01 0-2 0-3 0-4 0-7 0-1 0-3 Pollechius virens 0 '0- 0 0 0 0 0 0 0

                                                   <.,A Prionntus spp.                    0        :Q(             0        0            0        0      0,J

_ 0 0 0-l ' 0-1 Labridae Pleuronectes j,4 0 2,M 108 8 1289 8 91,2 3018 100.5 660 6 jj.d 2 225 10 141 3-424 0-!!376 1-426 11214 0423 2 2311 0-302 Labridae 2,4,1 M. M 1.1 M 19,,9 14 1,1 0 0 13 0-5 -. 0-23 0-19 0-16 0-88 0-21 0-17 Scomber-scombrus 116_J },{J 1723.7 5941 1477 1 537 9 g8,4 4144 6 476.5 30-236 0125 0-11981 0-22910 1-11023 1 1781 0 231 38-9358 = 0 4451 Paratichthys-Sconhthalmus 17J M 24j g g g g g g 2 92 0-28 . 0-392 0-132 0-92 3-35 0-58 1-248 Hipporloissnides . M, . 0_1 02 lj 17 2J 21 1.,8 J6 olstessoides 0-2 04 0- 1 0-14 0-4 0-6 0-25 0-8 0-27 Total 275 8 . 11 M 19891 7492 0 1666.5 967.5 215 8 49121 12M 75-513 21 407 17 12625 32-35350 22-18593 30-3108 20-513 56-11861 3-4791

Represents late-stage Q. morhua and P. virem egp.
- Includes Brosme-Scomber, 1975 1983.

1 12 Il

=4

l I I Ecos lE!! 1221 122n e e a e a a eM vj,.y. m I h - 1 Brevoortie tyrannus QJ 0-2 9,2 0-1 J O 0-3 L2 0-9 O2 _ 19,1 L9 L1 Q1 hj.,,.., f,2il Lg l 0-2 0 83 0-10 0-11 0-4 0-8 [y o<51j W .. . :. I Enchelvoous lJrophycie-Pernius 2M IL2 21 4 2).J l!_0 14,1 9,,L2

                                                                                                                           ,                             !J      29J l1:12Jj - IM 16-55    2-25      0-96    0308        17-98       2-26                              4-634                         0-19                                      3 50 6-160 : f t-44 7 Enchelvorus simbrius                  21,1 ti..

20.2 l-76 ljlJ 14,2 21,2 4,9.J 1EJ M li.Q , [lli , Lg l I 9-90 5 114 0 33 2-65 2-51 7-38 0-23 0-39 L c 0-12 g 0-19 J OrophYris Bpp. [2 9.2 i,2 i,2 10,,] 2.2 M Lj, L2 Pl }j ..% L1 0-6 02 0 15 0-l 4 0-27 4-5 0-56 0-6 0-6 {T}t Mj 0-9 I l 9

                                                                                                                                                                         . . . . . .                    l Gadidae-Glyptocephaba         L1       2J        23      U            L1         QJ                                  2.2                         O_1       Q,3    [fLj{                    M     l 0-4      0-6      0-! 7    0-7          0-5      0-16                                  0-9                         0-3       0-2        ?0141                0-3 f

I Gadidae

2.[

0-3 (ll) 0-4 (1,2) 0-27 (2.2) 0-7 (0,,,4,) 0-2 (92) 0-25 (2,1) 0-22 (gl) 0-1 (gl) 0-5 h(M)f 37003; {s (91) 0-1 i j j Osdue morhua - lj 11 2.2 04 02 L2 QJ QJ NMh:{ gj i j 0-4 0-27 0-7 02 0 25 0-22 0-1 0-5 0-1 I E g 0. 3,0 '", k : c '> Pottschlus virens - 0 0 0 0 0 0 0 0 t h J 01 0 i:' i

                                                                                                                                                                        $ 1'. . . . m Prionotus opp.                  0       0                03                      IO                                 Lg 2.2                  0i                                                                         0,,,}

M $:lf M[ M 0-3 0-2 0-2 0-4 0-7 ;e 04t I 0-2 0-5 0-15 ( :s - ' Labridae-Pleuronectes 2432 0 699 0 5739 1 1317.7 809- 147- 289- 24-5217 8 1080-631 0 248-3497.7 1607.8 6978 7 .. dl 639 9 184- 276 57- p 4 L 47.; 52 I 5501 2258 19708 3876 10505 1266 12537 4588 17918 1126 y a: 5983 :. Labridae 137.I 214 13 4 29.g 216 3 101 6 199 0 1}L2 189.7 .[LQ f 94.9 0-294 7-249 26 0-262 50-774 13 191 82 75-238 14 650 %:. M f 12-241 1181 1492 E~~ u Scomber ecombrus" 126 3 1,9 11,9 I51 8 y . .:. ^ IL9 40,,J l55 9 1),1,2 144.I p;E:))M f( IQ9.,J l 4-746 0.8 19 6-199 0 360 4-41 0-100 3 1083 0-663 5-202 Q:;.. 1-88; 3-349 y lI ) 1 hrelichthv3-Scophthalmus 1[,2 2 78 1,7,,,2 0 73 2LQ 3 129 4,,LH 0-132 6,L2 20-141 22j 14-26 gQ 0-501 2M 5-83

45. 2 (( 2,} i-(

2-76 ,7031; ^ 4),9 2-95 U . . . .m i Hinnertoiswides pistessoides g_2 0g 2] M 93 10,,g (( 0 QJ [j #1 0 01 0-5 0-14 0-4 0-1 0-42 0-5 0-3 WD 1::j ff d fi 4 Total 2819 8 f,16_2 6301 5 1934 7 930.5 4158.4 7

                                                                      }620 2                                                                        19741    7614.9 f 15F13                    936.7 819-    342-      609-     228-      1401-       414-                               407                           420-       309 5718    2393      19425   5917 FC 93.i:{3 79 l                                                                        11522       1652                             22226                           4912    18628                              1798
                                                                                                                                                                           $60741 I

l g 3Repmenta late-stage 9. nELa and L. vuvn, eggi.

   ** Includes Brosme-Senmher. 1975 1983.

i l 13 { l

ma l

    -                               -             -       -         -          -         -                                                       -          -         -     I Brtvoortia tyrannus              21           J O       ILg      22,,9                 Lg                                                                 L,2 l                                                                                QJ                                                                QJ                   1M l                                      0-9          0-4     0-56     9-36        0-3       0-4                                                     0-6       0-18     0-116 l

Enchelvoous-Urophveis-l 4.1.9 IQ.2 )92 10.1 211 LQ !1 2ql 12,J Terilus 0 204 0-80 2137 15-52 2-114 1 15 0-25 0-1 0-1 I Enchelvoous cirnbrius 7.41 Ill flQ 14 9 19 1 M 24 IL2 11.Q l l223 3-52 4 196 11-93 0-66 0-8 0-41 0-75 0 77 i Urophytte app. M 1.8 fQ L1 2M Q_8 8 Q.1 Q1 0 I 0-19 0 24 0-10 12-51 0-32 0-2 03 0-1 Gadidae-Clvotocerbatus L9 QJ ll 9.2 L2 gl Q-2 Q.1 Q4 0-4 0-4 0-5 0-2 0-3 01 0-3 0-4 0-3 Gaddac* (Ql) (Q [) (9.1) 0 (21) 0 (0J) (2.1) (1.1) 0-1 05 02 0-2 0-2 0-4 07 Gadus rnorhus gl Q1 03 0 0.5 0 Ql QJ L1 0-1 00 0-2 C2 0-2 0-4 0-7 Pollachius virens 0 0 0 0 0 0 0 0 0 Pnonotus spp- 12 77 Q 22 1.9 9.2 2.1 92 0 0 I l l-9 0225 0-20 0-9 0-2 0-8 0-2 g l Labridae-Pleuroneegt 1826 0 5166 2 1100 8 3801.7 987 6 456.5 779.0 1199 4 18111 332-6515 177 14223 238-3907 968 9011 205-1973 357 570 115-2470 14-17042 13-13968 l l Labridae sLt i10 7 163 8 778 9 g 6 1501 161.7 1 13. 1 18.1 0-119 2-359 67-338 239 1516 0-287 2-361 0-1105 3-1039 0-229 geomb,,e2 scombrus" 276 7 122 6 2220 3 1012 0 2080 7 473.4 494 0 347 6 120 1 l 0-990 12-411 27 6243 11-4440 1 8742 11078 0-22#s 0-691 3-1406 i Perslichthys-Scophthalmus 2M 1L2 4.0 1}_7,J 212 2L} 20 ] 18a 1 211 7-42 9-119 3-97 29-251 2-75 4 57 4-115 22-178 0-127 am l Hipportoinnides l O L1 91 0 14 0 0 L1 gl platesonides 0-13 0-2 0-8 0-5 0-9 I Toul 2326 7 5589 8 3654 5 5867 2 3229 9 l 126.6 1482 6 32441 1651.7 499-6712 313-14910 474-7879 1330 10308 333-10774 364-2113 202-4572 510 17220 121 15125

  *Representa late-stage 9. morhus and 1. virens eggs.
 ** Includes Ilrosme Scomber, 1975 1983.

W l

                                                                    ,4 I

I l - l k l

I I ,L.AR VA E innuarv 1221 1976 1977! 192,1 L922 1919 j Clucca harenev_s M 19)(1 1932 12 0 19?! lill 3 0 0 0-0.6 0 9J 9J M 0 0 0-0.5 00.6 0-3 Enchelvoou_s fjmberiuj 0 0 0 0 0 0 0 0 0 3 Myoxocenhelus spp. M M 04 O (QJ) 0 (2,,J) Q,8) I 0-1 0-1 0-0.6 0-1 O (M) M.esnarve 0.5 12 00.8 0-4 91 92 0 0- 1 0-0.6 91 0 0 0-0.6 91 _ M. octodecemeninosut - 0-1 0 91 0 0-0.5 QJ M Q1 M 0-0.6 0.5-12 M E.2gjuj - 0-0.8 0-4 0 0 0 0 0 0 0 I M spp. 0 0 0 0 0 0 (gj) 0 (gl) L. edonticus 00.5 04.5 0 0 0 0 0 0 L. Lobs,g[ - 0 0 0 Ql 0 QJ 0-0.5 1.R9.!223 2Dili! 0 0-0.5 0 0 0 0 0 0 0 0 Teutocolsbrus .edsperous 0 0 0 0 0 0 0 0 0 1!!vma rubbifesta 0 0 0 0 0 0 0 0 0 fh21it Funmiluj ! g,,2 0-3 11 1,9 gl g,1 ! 29 0-5 9.J 2J 9,1 0-1 0-0. 4 gj 0-0.6 05.5 Ammw3vtes sp. 0-1 00.6 M L3 0 18 O ji.t M 0-4 0 11 DJ QJ 0 0-38 0-5 01 01 S4

          $cornher scombrus                0                                                                                                                         0-111 0               0               0           0             0             0            0            0 Ple.ironectes arnericanus         0 0               0               0 I

0 0 0 0 0

         ~                               9.

0-25

                                                                   >4              m              m             a            m              m
     ' tio sanWing.

3 13 0 12 0-39 0-5 02 4-14 o e 03 0 113 I 15 I

                                                                                                                                                                                  -   E

I _ L E January 1921 P22 P.21 1223 12.83 128.2 1222 LARVAE 1182 12!.2 gl 9.1 0 0 0 gj 0_1 M LQ 0-2 0-1 01 fdMPtt herenzus 0-3 0-1 0-0.6 0 0 0 0 0 0 0 0 0 Enchelynpus cimbrius 0 (0,)) (0.3) 0 0 O (0.1) (2.3) 0-2 Myoxocechelus spp. (0.s) 0-1 C' 02 0-1 0-1 0 0 OJ 0 gl 0 0 M. senaeus 0 QJ 0-1 0-1 0-1 gl 0 0 OJ Ql M 0 Q1 Q_2 0-1 0-1 0-1 M. octodecemscinosus 01 0- 1 0-2 0 0 0 0 0 0 Q2 0 0 M. peorpius 0-1 O O (02) 0 O O O O O 0-2 W Lign.til spp. 0-1 0 OJ 0 0 0 0 0 0 0 02 L. ettanticus 0 0 0 0 0 0 QJ 0 OJ 0-1 L. f.2h.tal 0- 1 0 0 0 0 0 0 0 0 0 Tevtorn 9.lstjs 0 0 0 0 0 0 0 0 Tautorotebrvs edspenus 0 0 0 0 0 0 0 0 0 0 Mb:Eng subbifartsta J gl Lj, gl gj OJ O_2 M p.J, O 43 41 Do]il runnellus 41 41 41 45 41 43 41 0,J 0,_l 0 il 2.3 0 0 0 Amrnodytes sp. L2 ,01 0-1 0-!! 0-6 0-3 0 0 0 I 0 0 0 0 0 0 Scomber ecombrus 0 0 0 0 0 0 0 0 0 Pleumntgg,t americanus

                                                                                                                                     },1         O_,_f        2J          L2 Lj.          L2           L2                        9.2                            J O

0-2 0-15 0-6 Total 02 0-1 0-1 17 0 11 0-5 16 I N

1 I January LARYAE 1921 1976* 1977* j925 9 s g 9 1982 19g j9g 9 g j,9g gj M Cluts.t herenrus 0 0 0 gj M 0 0 -I 0-0.6 0-0.5 0-0.6 0-3 I Enchelvopus cirnbiius 0 0 0 0 0 0 0 0 0 Myoxocechslus spp. M 9,3 (9,1) (01) 0 (ql) Q1) (gj) g 0-6 0-1 0-1 0-0.6 0-1 0.5 12 04.8 0-4 M. senaeus - - Q.5 gj 0 gj 0 0 gj 0-1 04.6 0-0.6 0-1 M. octWecemmoinosus - - O gl 0 gj M gj M 0-0.5 0-0.6 0.5-12 04.8 0-4 M. Morrive - - 0 0 0 0 0 0 0 I Licult opp. 0 0 0 0 0 0 (0J) 0-0.5 0 (gl) 04.5 L. etlanticus - - 0 0 0 0 0 0 L. cobeni - - 0 0 0 gj 0 gl 0-0.5 0-0.5 Teutora 2 Lit.it 0 0 0 0 0 0 0 0 0 .l g inutorolsbrus adspernv, 0 0 0 0 0 0 0 0 0

     ]J1vant subbifumata       0                  0        0     0     0       0     0    0      0 I                             J                 f,J M runnellu,              O                          J.,9   gj    gl           2,j   9,J 0-3 QJ                J O

2-9 0-5 0-1 0-0.4 0-0.6 0-5.5 0-1 0-0.6 AmmMytes sp. O U M jl,[ M J O QJ 0 4,M 0-18 0-4 0-11 0-38 0-5 0-1 01 0 111 Scomber scombs 0 0 0 0 0 0 0 0 0 I Pleuronectes emericanus 0 0 0 0 0 0 0 0 0 Tota! 94 74 Il J 7,9 M j,J U gj g 0-25 3 13 0-12 0-39 0-5 02 4-14 03 0-113

  Two sangeng.

I 15 1 1 I l

m E nnuary LAFVAE M 1932 M M L999 J991 M M M91 fjP.2 n barenrue M LQ 0 0 gj gj gl gf( 0 0-0.6 03 0-1 0-2 01 0-1 Enchelvoous cimbrius 0 0 0 0 0 0 0 0 0 Myoxoceobatus spp. (g_i) (Q)1) (0 4) 0 0 (gj) (02) (0J) 0 0-2 0-1 0-1 0-1 01 0-2 M. eenseus 0 gl gj 0 0 0 0 g.). 0 0-1 0-1 0-1 M. octodecemsninosus 96 gj gj 0 0 QJ gl gl 0 - 0-2 01 0-1 0-1 0-1 0-1 M. E9EiV.g 0 0 0 0 0 gj 0 0 0 0-1 Lics. rig spp. 0 (gl) 0 0 0 0 0 (gl) 0 0-1 0-2 5 L. ettenticus 0 0 0 0 0 0 0 0 QJ 0-2 L. Ephtni 0 0,,_1 0 0 0 0 gj 0 0 0-1 0-1 Tauton 2nitig 0 0 0 0 0 0 0 0 0 Teutorolabrus adspersus 0 0 0 0 0 0 0 0 0 Ulveria subbifurtsta 0 0 0 0 0 0 0 0 0 Eh9.lig rumitus L1 g_1 g,1 gj 0,_1 2J 2,,1 O9 _ 0J 0-3 01 01 0-1 0-1 0-5 0-1 0-3 01 Ammodytes sp. M 0 0 0 M gl 0 fj LA 03 0-1 0-1 0-11 06 Scomber ecombrus 0 0 0 0 0 0 0 0 0 Pleuronectes americanus 0 0 0 0 0 0 0 0 0 I Total L9 Lg g6 dl 0-11 0-5 93 96 L4 M M 0-2 0- 1 0-1 l-7 0-2 0-15 0-6 16 I imi

I February LARVAE 1921 1976* 1977' Jjd! 19_727 8 1.9.89 98 J.981 19!81 1982 1214 9 1981 I h herenrus M 0-0.5 JO 0-2 0 0 0 0 9.J 0-2 91 0-1

9. 4 0-0.9 I Enchelvoous cirnbrius 0 0 0 0 0 0 0 0 0 Myoxoccohalus spp. U 2.2 (6J) (L2) G (0,y @ Q (14_2) 0-7 0-1 0-26 0-5 0-4 0-0.6 0.53 03 0-44 n u n u u u =

0 26 0-5 0-0.5 0-0.6 0-3 0-2 0-24

 .I  ,

bj. octodecemminosus - - 0 J O L1 0 M 9.3 Lg 0-0.6 0-4 0-0.6 0-1 0-3 M. scomius - - 0 0 0 0 0 0 f_2 0-20 I Liparis spp. 0 0 0 0 (0,_D 0-0.5 0 (gl) 0-0.9 0 (01) 0-1 L. etlanticus - . . - - 0 0 0 0 L. soheni - - - - - 0 9.2 0 9_1 0-0.9 0-1 Teutore p.ni@ 0 0 0 0 0 0 0 0 0 I Teutocolabrus adsnersus 0 0 0 0 0 0 0 0 0 I h subbifurtsta 0 0 0 0 JO 0-0.4 0 0 0 0 I Pholis runnellus M 0-14 L2 0-3 2.2 0 10 Q,,g 0-2 2d 0-5 QJ 0-3 LQ 0.6-2 10J 0 21 2.4.2 0-51 Ammodytes sp. Il M

                                                   )!      lll             19J     L2      2d     LQ    21d 08               0.6-24    4 21    0.4-8   3-16    0-9   0.5-1.4  0-3  0-132 Scomber scombrus          0                  0        0       0       0      0       0      0      0 I    Pleumnectes emericanus    0                  0        0       0       0      0       0      0      0 Total                   10J                         29 !     12            21 11.9                     lit             11    12_8  212 0-17              0.5-29    4-58   0.7 10   3-24   0-12    2-11   0-26  0-223
    'No samphng.

17 I :

1 sun l E. Februarv

LAlu'AS 1211 1112 128J L912 L922 L921 L922 L991 1221 Clucia hannrus 2.1 QJ 0 0 0 QJ QJ Id QJ l 41 41 41 43 04 41 I{1 l Enchelvoous cimbrius 0 0 0 0 0 0 0 0 0 l l Myoxocechslus spp. (1,1) (RJ) (4LO) QS) Q9.j) (90J) Q.!) (6J) QJ) 02 9-16 1 93 0-5 0-1 10-53 05 0-14 0-7 I a.. - . u u u u u u u u u 0-2 5 10 0-17 0-2 01 6 15 01 0 10 0-4 M. oc todecemsninosos gj 9J 9J, 0 0 9J pj QJ gj 1 0-2 0-1 0-1 0-1 0-1 01 0-4 i l M. pcorpius O L4 L3J Lt 0 2J0 2J g g4 0-7 l 75 0-3 2 44 0-5 0-4 0-2 Linejig opp. 0 0 (L2) 0 (gl) (gl) (0 I) 0 12) 41 43 41 41 41 g l L. missisy. 0 0 0 0 0 0 0 0 0 l 2 1 L. s2bsmi 0 0 L2 0 93 9_1 93 0 DJ 0-1 0-3 01 0- 1 0-1 gi Isutegg ggLtig 0 0 0 0 0 0 0 0 0 ei ' Toutorolabryg edenersu 0 0 0 0 0 0 0 0 0 Ulveria subbifurcate 0 0 0 0 0 0 0 0 0 4 Eb2!il runnelius 1! 42 L9 LLf! L2 dsl 2.1 u 2I 3 14 4-6 0 16 4 37 0-5 39-59 0-4 0-9 0-16 Ammodytes sp. J O 0 J O 0 L), j O 1L2 1M 2Lg 0-0.6 0-2 05 0-1 0-25 0-38 5-31 Scomber scombrus 0 0 0 0 0 0 0 0 0 Pleuronectes emericanus 0 0 0 0 0 0 0 0 0 1_, u 5-16 m 17-21 m 3 109 m 5-45 u 0-Il m 51 104 m 1-38 m 0-66 m 5 55 I 18 I

I I L&BXAE L921 1976+ 1977" 1978 1929 1989 1981 1982 19,12 3 10818 I GEced arenen b 08 0-2 0 04 01 QJ 0-2 M 0-8 Q3 0-2 12 1-10 J O 0-5 M 0-4 I Enchelvoous timb.f.,a 0 0 0 0 0 3 0 0 0 Myoxocephalus spp. e.L4 21.8 (12.1) (6u) QL2) Q23) 6 (.62) Q23,) qu) 17 137 11-65 1-35 0-182 5-91 0-67 0 17 0-228 0-61 M. senseu: - - 12.2 (19 2M 1L,1 gj 26J 212 1 35 0-177 4-86 4-64 0-17 0156 0-58 M. octodece msninosus - - 0 Lg LZ L2 gl 0 QJ 0-3 0-5 0-1 0-1 0-2 M. ecorpius . - 0 L2 J O L2 0 IL2 L2 05 0-1 0-4 0.7 72 0-3 I LIPJLtil 8PP+ 9.1 0-1 0 94 0-4 2,9 0 18 (QJ) 0-2 (9J) 0-1 (L9) 08 (QJ4.,) 0-0.8 (QJ) 0-2 M I 9.B L. etlanticus - - - 0 0 g_01 0-0.5 0-8 04.7 L rd.1al - - - - 91 91 9A Q&4 91 0-2 01 0-2 0-0.8 0-2 Tsutoes cnili,s 0 0 0 0 0 0 0 0 0 Teutorolabrus adspersus 0 0 0 0 0 0 0 0 0 Ulverie subbifuresta 0 0 0 0 QJ 0 0 g_02 0 0-0.5 04.6 I D.pjig etmnellus 24,,,,9 26-47 1,1,_2 0.7 28 92 l-34 22J 0-81 22 ] 1-62 1!J 18 34 gj 3-25 108.9 0-482 4L2 0-96 Ammndytes sp. 29J IL1 21Q 13,,,9 2L4 190.0 12 Lg 10j 11 60 0.7 22 9-228 l-157 10-78 0-613 0-29 0-3 0 47 Scomber scopibrys 0 0 0 0 0 0 0 0 0 I Pleuroneette americenus 0 0 9.,0] 0 0-0.5 QJ 0-0.7 DJ 0-5 23 0-12 La pl 04.9 pl 0-7 0-3 Total ,'2L2 55.7 76 8 ilu 99d 240.6 28J 148.7 12j 6t, 736 26-96 11 293 3-385 43-169 31-174 1-83 0-172 2-179 I No sampling.

 **'One sampling period only.

19 I

I) p-LJ LARVAE 1211 1932 1211 1932

                                                  .       1229   1291      J.2.0. 2               1222   1224 I

gap.n berenrus O2 _ 0 C QJ 0 0_2

                                                                  .            L2                  J O       ll 0-1          0-l 8    0-1              0-3          0-6                 0-4     1-6 EnchelYODUs simbrius        0     0       0       0        0       0                0              0       0 Myoxocmhalus spp.       (11,b)  (4.1) (lid 6)  (s.0. 6) (12 2)  (4Lg)    (19J)                   g      (2M) 8-218   0-10  32 356   0-183      2 22  14-87       l 91                 0-259    l-53 M.eenatue                19 0     12    102 9   }.4 2     2J     }9.3         12                  44,1   1Q 5-213   0-10   12-347   0-65      28    13 85     0-22                   0 222   0-43 M. octodecemminnsus       1,Q    0]

_ QJ J,_1 0 0 L1 QJ 27 0-3 01 0-2 06 0-6 0-2 0-12 M. sorriu, u 92 1].J 24.! 96 Le 12_g sa L.6 0-12 0-1 0-26 0-119 0-20 0-4 0-68 0 39 0-9 Id21df app. (QJ) (0J) (gj) (0_]) (gl) (01) 0 (Lg) (0.l) 0-5 0-1 0-1 0-4 01 01 0-5 0-1 E L. atlanticus gj 0 gl gl 0 J 0-4 0-1 0-1 O 0 0 gl g 0-1 0-1 E L. g.ebeDi g4 gl Q4 J 0 gj gj 0 Lg gl 0-2 0-1 0-2 0-4 0-1 0-1 05 0-1 Teutore d 0 0 0 0 0 0 0 0 0 Tautorolabrus edmersus 0 0 0 0 0 0 0 0 0 Utveria subbi6mata gj 0 0 0 0 0 0 QJ 0 02 0-1 fb91].g runne!!us f.14 M llL! jLg L2 19J 19 ] L1 2-159 0-11 4-375 0-126 0-8 2-48 0-91 0 38 22 3 18-197 l g Am.modyte'sp. 92 O1 14 U _ _ 2. 8 L1 4.LQ IL9 196.5 0-30 01 0-9 0-1 l 0-4 1-19 l111 0-74 2-577 Scomber ecombrvs 0 0 0 0 0 0 0 0 0 Pleuronectes emericanus M 0 0 0 0 gl 0 0 0 0-7 0-1 Total 1365 Lg 237 8 128 4 j.7_1 gl2 8]7J ILg 223 a2 14-346 l-19 19-736 2-286 4-30 21 127 5-277 0-393 22-801 I 2e I E

62I!! LARVAE jf]71 1976' 19272 1975 M 19Jg j9]u 9 M j 91),gjy@!s m adj 98), 8 s - I Clupea harenru, M 0 12 J O 0-! QJ 0-2 0,_,q 0-3 J O 01 0 M 0.4-5 M 0-9 U p

                                                                                                               >    <.: c H ;i~ '

{0? ' gl 0-0.9

                                                                                                               ,:  c.,.     . :. . .:

I Enchelvoous cimbrius 0 0 0 0 0 0 0 W gy.;9 yf j 0-0.5 tidec,; 0 b??N ..x, s.q Myoxoccohalva spp. M ).gl 21 ] (gy) Q,g) gz (J,.6,,.).) (L6 4.) (19J) { I M. nnnus 3-12 14-57 0-57 l 32 16J 0-59 ji 4 2 53 18,1 0-347 88.2 0-24 7.0 M[(JJJd 0415M 18442 Ml,7*a 3;I

                                                                                                              ; 7Q;-} Mijf 12,LQ l (12M) l-32       0-59      2 53    0 344    0-24      g'

!; 0,qli I8-442 '

I M. octodecemminosus - - - 0 0 93 0-2 QJ 01 0

                                                                                                              $N ji (Oy '-
                                                                                                                       '[.<..

fj# y 0 I M, ocorrms - - - 0 0 gl 0-1 gj 0-3 0 jy 6: ec h %ld gl

                                                                                                                                  's 0-0.8 I

c.. u. . M r Licensopp. 16J U M M (9,,.9) (g y.) Q,M) j (0j , (M) 0-11 0-72 0-7 0-8 0-29 0-3 0-4 1 69 t'-- 1 26 L. etlanticus 0

                                                                                                                            - ., ;          M Q ,9 I

jj,2 0-3 1-69

                                                                                                               .f {,$0["%

pi;. 0-26 Q@ L setani - - - - - 0 9,2 0 E0i 93 I

,~

0-4 ;

                                                                                                                                     ,      0-2 4     '4:...;
                                                                                                                   ,-;I              /

Tsutnes onitis 0 0 0 0 0 0 0 0 0 (0$ I Tautorolabrus admersu 0 0 0 0 0 0 0 0 W( '

                                                                                                           $(0)                              0 f                      A I   pjvfgig subbifurcata      M 0-19 M

0-19 gj 0-2 QJ 01 M 0-6 QJ 0-2 gl 0-2 M I4E0f 0-11 w.

                                                                                                                       ,g .y" M

0-21 W n I lhelis runnellus M 0-8 M 0-19 j,j 0-5 y 0 13 gj 0-1 y 0-14 32 3 0-75

                                                                                                    ),3 0-21 f:j[My 2M
                                                                                                           ~10-111
                                                                                                          @ JRi%

0-77 Ammadytes sp. M 26,6 JJ!L8 9.3 1gj 13J M 19,j ' ? 0 s " 21,.4 I Scomber scombrus 0.8 18 0 6-85 0 6-1252 0 26 196 0 0-171 0 7 66 0 2 261 0 0-58 0 1 1-89 0

                                                                                                                        ,0 I

15 Pleumnectes emericanus y M }.M M M M 16 0',l M 0.8-10 08 2.& f' 0-21 0-127 2-24 0-3 0-36 0 13 r' s 0-11 I s l' Toul 2?97 103.1 458.2 120J 3.6 S t.6J 6 185 4 },Q ',Qt 189.5 14-43 55 154 21 1324 57-238 8 266 29 142 4-732 3-135 5 0 17 ' 54-524

 'One samphng penud only.

g 2,

s. E ! LARVAE 98 19.81 1987* E E J_9jQ R E M9),, E I ' O. Eta hertrigus Q,3 O M gl 9.,,9 L1 9.J Lg 42 43 42 42 41 45 41 4 14 Enchelvoous cimbrius 0 Ql 0 0 QJ 0 0 0 ' 0-1 0-1 Myoxocephalus spp. G2,6_) Q2J) QL),) (43_0) (26 8) Q3J) (jll) Q6J) l l 295 3-1Il 6-73 2-72 4 23 4-37 0-27 4-96 , l M.senaeus 2L,9 18_9 6 2.6.4 M 2 J,,2_8 jf.) j,L1 24_g l 1 292 3-111 6 71 2-71 4-23 4-32 0-27 3-90 gj E

i M. octodecemsninosu JO 0 0 J 0-4 JO O gl 0 M l 0-1 0-I 0-2 0-3 M. news M gl 05 _ 9.1 91 L2 0 M Il 0-2 0-2 0-2 0-3 0-2 0-9 O-5 Licerig app. Ql) QL4) (M) Q,6_) G,2) (22) 0 0 0-27 0-99 0-33 1-8 0-14 0-2 35 L. silanticus 89 J.22 U U L2 92 0 0 0-27 0-99 0-33 1-8 0-14 02 L fittui 92 gl 0 M 0 0 0 0 0-1 0-1 0-1 4 Teutor* P.D.it.i!! 0 0 0 0 0 0 0 0 Tautocolabrus edmersus 0 0 0 0 0 0 0 l' l Ulvaria subbifurcete 08 2.2 08 04 08 L1 M 0 0 l 0-3 02 0-3 0-26 0 10 fbpglig runne!!us j_4 M j.L,j, J,2_), L2 }ll ll j d,, Q 0 27 0-8 0-44 0-41 0-20 0-130 0-8 1-35 W i Ammndytes sp. 31 1 Ll_Q 21 89 7 38 0 13,J

                                                                              ,    2,9,,1  544.0         ;

0-156 0 64 0-14 4-344 1-71 12 163 1-65 67-2591

Scomber scombrus 0 0 0 0 0 0 0 0 i Pleumnectes emericanus O LO_2 0-33 L.9 2 17 L1 0 20 L), 06 Lt 0-10 02 0-2 9,2 0-1 0 I! ] 1 Total 139 4 f.82 13,.1 14.6_g 18_1 E 421 iM I: 1 12-358 9-307 6-120 30 366 8 Il5 54-180 2 102 95-2693 rpomp, ,,,,. ,o ,,mpuo,, a I! M m

I I LARVAE Mn 1921 122Q L.22 19]s 1222 198_0,

                                                                             ,       12,8.1   L982     198)3 ' 3%

yswe 193} I f,1un harenrus 2.2 0-24 0 0 pj 01 g.,92 0-0.5 0 0 gj. 0-1 g,g, 0-0.5

                                                                                                                         ......7 gj-; gd?gi t'ie 1Mt
                                                                                                                           .,4 0

Enchelynoun cimbrius g z ., . M I 2,9 40

                                                                                                                  .,x..

2,Q 4.5 14 Lg 93 QJ p[{03 ; j d 0 10 0-13 01 0-19 0-19 5-11 0-3 0-0.6 0-1 tp 0-6 gy li,n is : Myotoceobalus spp. 12 L2 9! 2.2 (M) ( 20 1 ) (0,2) (L1) (61) *lj(M)] Ql) I 0-il 02 0-9 0-37 0-17 03 0-1 0-10 0-15 $0-10j 0-11 lW'.1., . < M.senaeus - - - - M 9,,} Q,2 M 6] , M 0-17 0-3 0-10 g$[010sf. 0-11 h.'kd. l 0-1 0-25 M. ociodecemminosus - EY . . +.

0 0 gioj ".

0 0 0 O (t I M. peorpius - - - - 0 0 0 0 0 19 y eOs 8 0 (j,M) $9 I Liparis spp. 2,,2 0-30 J2,,Q 6 31

                                           }{9 0-112 2],,9 1 92 20,,2 6-40 22,,}

16-45 (1gl) 2-69 QJ) 0-12 0.5-37 d(M)h,(jjil) b._)

                                                                                                                       ?011F                   0-30 L. etlanticus                -      -      -

I j)Li ,. .,f M, .3:) L5 a2 L6,j, 2,2 2-69 0-12 0-30 0.5-37 fi 0 11% ' t

                                                                                                               . . 3 L. toheni M

0 0 0

                                                                                                               @" 10l1 I                                                                                               0-2                                          -
                                                                                                                /                      <

Teutore onitis 0 0 0 0 0

                                                                                                                          -s             n 2.1      2.9                    0       0      y 10ll; f 9.3 0-1     0-39                                   W                               0-1 i::             .-s v:;+:::

pt '. ' Teutorolebrus admersus 0 0 0 0 Q.2 L2 gg 0 0 k:

3. :; 0P' />* 0 0-2 08 0-0.2 E '"

I tyvpna MNfurents 65 4 10-235 7.3 l-24 12 0-20 f.) ! 11 141 M 0-23 1Q,2 5 21 M 4-27 4Q 0 16 k . . . .. 9 3 j,9J [' Q23 2-73 M W. . .. 0 75

                                                                                                                                       ': 1 Li 6 I D.211 runnenus Ammodvies sp, 92 00.5 0      0       23 0-4 9_05 0-1 0           0       9.1 0-2 9m2 0-0.6
                                                                                                              . Y. : U p- 0-4f -
                                                                                                              $$ .....;.d 0-0.6        '

1 i.Q 2.1 2.,2 22.2 20.1 28 L1 212 g,j Qlffp gj I Secmber rombrus 0-22 gl 0-8 0 0-7 0 0265 2.t 0-88 s.,1 29 28 0-4 p.9 0 29 pl 0.5-17 b 057:3 0

                                                                                                             ; :.g. -

I 201d 91 03 0-0.4 0-27 I 0-29 0-12 0.5-5 0-1 L *T.! 0-6 ' t >, l Pleuronectes emeriesnus j),9 2,3 2Lg hh s... M l 2-36 2 18 Ifj 1!. 4 29J ILI 292 1}J > -{ff <i 1L1 - 4 29 0129 13-40 11-75 0-98 1-49 0.5-7 1027Fi 0-27 1 I Total 299,k 28 283 22.2 15 76 ILS 24-185 22L2 33 660 104 1 66 210 104 4 59-167 62.9, 12-234 if,J 8-182 iW' t-pc- ' . . < 12 3 pjjjQ 9-192 :(0-64lF 13J 8-79 l I 1 l 23

I , 1

sen E un g LARYAE 19Et L93.Z 1931 M 1229 1221 1222 1921 1214 f, hen harenrus 01 .OL 9.0! 92 0 9.2 )_Q 2_2 L2 0-1 0-1 0-2 0-10 0-2 0-8 0-5 as

                             < ..                                                                           l Enchelynove. tirnbrius   M   -
                                    / M ..        M      lj         0    2.1      0    9.2       0          ;

0-27 'i 0 3 i 0 31 0-17 0-6 0-2

                             ?::: .

Myoxncerhalus spp. (pl) 9' l(M)) (L9) @ (il) (0 9) Q,j) (0,,g) (1L)) 0-2 .D 1 0 10 0- 1 I 0-20 0-6 0-11 0-2 0-36 M. senaeus 91 PJ 2_Q 2J il 92 L1 9g IL2 0-2 01 -. < 0-10 0-11 0-20 0-6 0 11 0-2 0-36 M. octodecemeinosus 0 10. 0 0 0 0 9,,2 0 - 91 0-2 0-1 j M. ecorpius O LOL 0 0 0 0 0 0 0 Licuia spp. G_1) (LEL (2! D U1.D G (L2) G 2> (6 33 (L ,9.) 0-6 0101'- 1146 0-59 l 17 1-8 0-15 1-24 0-75 l L etlantieus L2 .1M w 20 n.1 U M L9 U L4.2 0-6 0-101 ' l 146 0-59 l 17 l8 0-15 0-24 0-75 L. s.ds.p.i 0 .0 0 0 0 0 0 9J 0 0-2 Teutm 2nitij 0 0. 0 0 0 0 0 0 9.1 01 Tautorolebrus adspersus 9,,2 -O' 0 9,1 0 9J 0 0 0 0-1 0-1 0-4 Ulvaria subbifunsts M M.. L} 20,2 2M M M ILg y 1 16 0-5 0-15 1 88 0-63 1 58 0-51 0 124 0-41 j j'hn!!g runneliue 9J 0. 9_9 97 pl j o 93 92 L2 i 0-1 03 0-5 0-3 0-1 0-4 0-1 0-6 ! Ammodytes sp. L2 -QJ' M 4,,9 2L$ 9.,! 21J 17] 97.8 0-5 0-l' 0 14 0-17 2-47 0-4 0-386 2-71 2 367 ; i Scomber scombrus 9J 0 i

                                ': 9J -                 9J        !L1   p.,k     0    9,,4       0          {

0-1 0-1 0-4 0-1 0-43 0-2 f 11euronectes ameriens 14 1M. 2,Le 7J IL2 M 15,8, ILi L8,,s l 2-13 0 52.. . 0-105 0 30 0-47 0-46 0-83 4-30 2-83 Total 21.1 215 gle },4,,,2 17,2 L6J 142.s 20j 167.5 15-41 0-158 10-291 20-108 26-125 23-105 11-446 17 158 31 396 I 2. 3 5 W

I I h02 tARVAE pp.aq 1921 19,21 L922 1921 1922 1919 E 1912 12!! yliff 1' 119 1 I Clupes herenzu, 0 0 0 0 0 0 0 0 0 4 .. g 707 TA j.} s "M M 4 232 0-1 n yj 01j I Enchelvorus cimbrius f.q,1 2!8.2 128 8 10.2 2_f J,4,J 26,J 0-137 D-46 84-248 0145 9,,2 ILi 20 1-15 4-102 0-149 0-5 0-47 ( 0-1.i , 3-73 4 Myoxoceobalus spp. 0 0 0 0 0 (2,9) 0 0 0 E 9,a- . ;01

O 0-7 W I ?g.s c ' e M. etnseve 0 Qg 50f '

0 0 0 - 0 47 sj I

                                                                                                       %%?g gy-jf. 4%

M. octodecemminosus - - 0 0 0 0 0 M&' :: 0

                                                                                                            + %.W       ,m.9_.

I .: ' M. semiv, M .g. 0 0 0 0 jj ijl05 fj 0 0 I k.lPtIi! sPP. 2I 0-7 9.2 0-50 9.2 0-28 11.9 2-65 L2 0-4 9.] 0 21 QJ 0-13 (0.1) 0-4 (LQ) y 0-8 ! 0-13 4

e. .z.

11s 0-3 L. stlanticus - M gfd?: I M O,j _ LQ 0-13 0-4 0-8 f; 013 6 0-3 L. gob,gs - - hsf. .: > 0 0 0 g [0j{ ' 's O {$ ; Tsutors 20 hit 9. 7 9.d 1.2 f_2 M 2A 12 1 L9 91 ; 0 14 L2 01 0-5 0 27 0-37 0-ll 0-20 0 162 0-27 0-2 0-41 Teutorolabrus admersus 112 2,.h 11.] 10 2!! 2L4 22.L2 J 6 12.,1 (07. fQ_I 0-39 0. I 3 0 750 0 107 4 78 0-83 0-l639 0-26 0.5-46 s 0-208 I Ulveria subbifureste Q.1 0-2 i_1 0-28 0 O 0 12 L2 0-3 2.,Q 0 12 J O 0-3 L4, 0-5 Q,9, 0-5 khlI', . 2_( 410.

                                                                                                      ,      .              #

l5 9

I D10lif runnellus 0 0 0 9,2 0-2 0 0 0 0 0 @Nh pgg_gy ; j+ s u v ^ 0 Amm<xf vtes sp. O 0 Q1 fr2 Q_2 0-2 9,,1 0-1 0 9.1 0-0.6 0 QJ k..Mjc; O 04.6 g;94? m. Scomber scombrus 29 9 D 14,,9 lLj 99 211 318.1 1!_g 20,3 ij{h:( !jj 0 149 I 0 15 0-55 0-126 0-37 0-809 0-3662 0-81 0-354 s. :0 It , 0-376 g,. c Pleuronectes emerkanus f,,j, Q 11,,9 0,,] WC , 0.5 15 0-47 j,,,,) L! 2,,,{ Qd "} My ., 2,] 0-16 0-54 0 39 3 19 0-8 0-17 0-2 10:2403 0-7 I Total 117 9 14 260

                                !L1 8139 9

2.92.1 125-641 176 7 51-343 12.1 27 154 liL! 49-377 710.7 5 5423

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f.hrn harenzv, O 0 0 0 0 0 0 91 0 0-2 Enchelvoeus cimbrius 2M Q. L3 23 29j g gg gg g 2 74 0-33 0-4 3-137 0-120 0-4 0-382 3 22 0-18 Myoxoccohntus spp. 0 l- 0 :. 0 0 (0.J) 0 0 0 0 s 02 M.eensey, 0 (0l 0 0 J O 0 0 0 0 0-2 M. octodecemsninosus 0 : 0~ 0 0 0 0 0 0 0 M. peorpius 0 ;0. 0 0 0 0 0 0 0 Upad, app. Q,6) ~ (M)l (6J) G I) (M) 0-11 0 13 1-32 (.L4_) 0-7 0-13 0-14 0 8.8.) 0-60 (4 f) 0-19 l W L. silenticus M - M ,- f._9 L3 L2 M 0 9J M 0-I l 0-13 1 32 0-7 0-13 0-14 0-60 0-19 L. Egb!.Dj 0 .0. 0 0 0 0 0 0 0 Tsutors onitis L1 05 M- gj 10.2 U Lg Lt L2 0 I 0-12 0-2 0-35 0-10 0-4 0-10 0-7 Teutorolabrus edsnersus 3.0,3 . gj - Lp 20_2 2.2 112 L2 2.1 0 0-157 0 0-5 4-196 0-30 0-37 0-6 0-3 Utvade subbifuresta Li M' L} [g 2J Lg M M J23 0-6 0-2 0-12 0 13 0-9 0-4 0-10 0-14 (M2 M runne!1us 0 0$ 0 0 0 0 0 0 0 Ammodytes sp. 0 0 J

                                    ' O ..            O       g_t       0     0     M     g.s 0-2     0-2                  0-26   05 Scombre peombrus         113 2    ' M-         Lg    137.2     Le     199.7  j.Lg   JL1    M 0-393         6-2     0-52  0-434     0-23    0-422  0-48   0-43  0-32 Pleumnectes smedesnus     M           M       g_t     9.,2     0,,1
                                                              ,       LH     gj     2J    fj 0-6      , . D-4     0-4    02       0-2     0-5    0-3   0-27  0-11 Total                    198 6    - J.M . 19 6   274 3    e6.9    222J  2Lt     M     219 17-663       U-61'    5 09  57-771    6-198   0-478 0-472  19-122 11-66 I

26 I E 3

I I I IMPINGEMENT OF ORGANISMS AT PILGRIM NUCLEAR POWER STATION (January - June 1994) I I I Prepared by / Robert D. Anderson Principal Marine Biologist I I ' I ! I Licensing Division l Boston Edison Company I l I l I I

I I I E u.,~., I n i. . , I I I c_ ,, I h commonly impinged species l I I I , I l I I i

l TABLE OF CONTENTS I i Snlien lille Eage l 1

SUMMARY

l 2 INTRODUCTION 2 g 3 METHODS AND MATER.lALS 5 4 RESULTS AND DISCUSSION 7 4.1 Fishes 7 4.2 Invertebrates 7 4.3 Fish Survival 11 5 CONCLUSIONS 13 6 LITERATURE CITED 14 I I ; I I I u

O E LIST OF FIGURES I Figure page 1 Location of Pilgrim Nuclear Power Station 3 2 Cross-Section ofIntake Structure of Pilgrim 4 Nuclear Power Station I I E I; l . 1 I l d

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LIST OF TABLES I Lbk Eale I 1 Monthly Impingement for All Fishes Collected From 8 I Pilgrim Station Intake Screens, January-June 1994 2 Species, Number, Total Length (mm), Weight (gms) 9 and Percentage for All Fishes Collected From Pilgrim Station impingement Sampling, January-June 1994 3 Monthly Impingement for All Invertebrates Collected 10 From Pilgrim Stat.on Intake Screens, January-June 1994 4 Survival Summary for the Fishes Collected During 12 Pilgrim Station Impingement Sampling, January-June 1994. Initial Survival Numbers are Shown Under Static (8-Hour) and Continuous Wash Cycles I I I . IV I

SECTION 1

SUMMARY

Fish impingement averaged 3.34 fish / hour during the period January-June 1994. Atlantic silverside (Menidia menidia), rainbow smelt (Osmerus Emd;g) and winter flounder I (Ple_uiopleuronectes americanus) accounted for 877c of the fishes collected. Initial impingement survival for all fishes from static screen wash collections was approximately 717c and from continuous screen washes 847c. The collection rate (no./hr.) for all invertebrates captured from January-June 1994 was 2.39+. Jellyfish, sevenspine bay shrimp (Crangon septemspinosa) and American lobster (Homarus americanus) accounted for 797c+ of the invertebrates impinged. Mixed species of algae collected on intake screens amounted to 2,268 pounds. The relatively high fish impingement rates from January-June 1993 (2.58), and 1994 (3.34), reflect circulating water pumps operating regularly during these entire periods, and high numbers of silversides impinged in early spring of each year. The invertebrate impingement was not as reflective of increased intake flow. The Pilgrim Nuclear Power Station capacity factor was 857c from January - June 1994. I , 1

su SECTION 2 INTRODUCTION Pilgrim Nuclear Power Station (lat. 4156' N, long. 70 34' W) is located on the northwestern I shore of Cape Cod Bay (Figure 1) with a licensed capacity of 655 MWe. The unit has two 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 travelling water screens of 3/8 inch wire mesh (Figure 2). There are two travelling 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. DWPC) for Pilgrim Nuclear Power Station, Unit 1. The report describes impingement of organisnu and survival of fishes carried onto the vertical travelling water screens at Unit 1. It presents analysis of ttn. relationships among impingement, environmental factors, and plant operational variables. , This report is based on data collected from screen wash samples during January-June 1994. l 1 l l I g; 51

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cs9' Figure 1. Location of Pilgrim fluclear Power Station.

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Figure 2: Cross-section of intake structure of Pilgrim Nuclear Power Station. I I 4-E

SECTION 3 METHODS AND MATERIALS Three screen washings each week were performed from January-June 1994 to provide data for evaluating the magnitude of marine biota impingement. The total weekly collection time was 24 hours (three separate 8-hour periods: moming, afternoon and night). Two collections represented dark period sampling and one represented light period sampling. At the beginning of each collection period, all four travelling screens were washed. Eight hours later, the screens were again washed (minimum of 30 minutes each) and all orpnisms 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 on a weekly basis. Water nozzles directed at the screens washed impinged organisms and debria into a sluiceway that flowed into a trap. The original trap is made of galvanized screen (3/8-inch mesh) attached to a removable steel frame and it collects impinged biota, in the screenhouse, shortly after being washed off the screens. A second trap was designed and used for sampling consisting of a section of half 18" corrugated metal pipe with 3/16-inch nylon, delta mesh netting attached. Impinged biota sampled by this trap were collected at the end of a 300' sluiceway. Initial fish survival was determined for static (8-hour) and continuous screenwash cycles. Variables recorded for organisms were total numbers, and individual total lengths (mm) and 1 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 l collection for a species was less than 20, all were measured and weighed. Field work was conducted by Marine Research, Inc. I I

O 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 collections. 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. All common and scientific names in this ieport follow the American Fisheries Society (1988,1989,1991a and 1991b). m Il I l Ii , I; I! I Il I I

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SECTION 4 RESULTS AND DISCUSSION 4.1 Eisites I In 361 collection hours,1,204 fishes of twenty-six species (Table 1) were collected from Pilgrim I Nuclear Power Station intake screens during January - June 1994. The collection rate was 3.34 fish / hour. Atlantic silverside (Menidia jnesidia) was the most abundant species accounting for 74.7% of all fishes collected (Table 2). Rainbow smelt (Osmerus mordax) and winter flounder (Pseudapkuronectes u mnericanus) accounted for 7.6 and 4.5% of the total number of fishes collected. Atlantic silverside were impinged in highest numbers during April. These were primarily adult fish that averaged 104 mm total length. Winter flounder were mostly impinged in April, also, rainbow smelt during January. The January-June 1994 fish impingement rate increased from the same period in 1989-1993, when rates varied from 0.52 (1990) to 2.58 (1993). Rates increased the past six years compared to the 1988 rate (0.30) and this is possibly attributable to greater circulating water pump operating capacity from 1989-1994 and higher silverside impingement numbers,in general. I 4.2. Invertebrates I In 361 collection hours,864+ invertebrates of 17 species (Table 3) were collected from Pilgrim Station intake screens between January-June 1994. The collection rate was 2.39+ invertebrates / hour. Jellyfish were collected in undetermined numbers. Sevenspine bay shrimp (Crangon septemspinosa) and American lobster (Homarus americanus) accounted for 71.1% and 8.0%, respectively, of the total number of invertebrates enumerated. Horseshoe crabs (Limulus pelypicinus) were fourth in abundance and were impinged predominantly in June. I I Table 1. Monthly Impingement For All Fishes Collected From Pilgrim Station Intake Screens, January-June 1994 I E Species Jan Feb. March April May June Total Atlantic silverside Rainbow smelt Winter flounder 17 73 6 18 15 1 82 6 744 34 3 38 1 899 92 Il 5 2 54 g ; Grubby 7 6 5 20 Threespine stickleback 3 3 12 2 52 g! 13 19 Radiated shanny 2 1 6 3 12 I Northern pipefish 5 5 10 Blueback herring 4 3 2 9 Rock. gunnel 4 1 2 7 Cunner 2 1 3 6 Northern searobin Atlantic tomcod 2 1 2 6 6 5 El 5 Windowpane 1 1 3 5 Lumpfish g 2 Alewife 1 1 3 4 3 gl ' Atlantic cod 2 1 3 Butternsh 3 3 i Silver hake 3 3 Atlantic herring 2 2 Blackspotted stickleback l 1 2 Little skate 1 1 2 Tautog 2 2 Pollock 1 I Red hake 1 1 Sand lance sp. I 1 Scup 1 1 TOTALS 114 40 104 840 83 23 1,204 I Collection Time (hrs.) 59 55 31 79 83 54 361 Collection Rate (#/hr.) 1.93 0.73 3.35 10.63 1.00 0.43 3.34 I

                                                   -8 I

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I I I Table 2. Species, Number, Total Length (mm), Weight (gms) and Percentage For All Fishes Collected From Pilgrim Station impingement Sampling, January- December 1994 I Length Mean Weight Mean Percent of Species Number Range Length Range Weight Total Fish Atlantic silverside 899 70-149 104 2-16 5 74.7 Rainbow smelt 92 71-219 127 2-73 14 7.6 Winter flounder 54 49-272 75 1-170 8 4.5 Grubby 52 45-95 65 1-18 4 4.3 Threespine stickleback 19 36-69 61 1-3 3 1.6 Radiated shanny 12 75-137 93 3-23 9 1.0 Northern pipefish 10 132-188 160 1-2 2 0.8 Blueback herring 9 57-88 77 1-3 3 0.7 I Rock gunnel Cunner Northern searobin 7 6 6 51-165 102-157 153-230 131 140 211 5-15 14-67 29-103 9 47 80 0.6 0.5 0.5 I Atlantic tomcod Windowpane Lumpfish 5 5 4 52-161 40-286 31-80 110 175 56 1-23 1-22 14 10 0.4

                                                                                                  ').4 0.3 Alewife                            3        93-147       115          4-20         10            0.2 I Atlantic cod Butterfish Silver hake 3

3 3 50-60 71-104 72-107 55 89 88 1-2 4-12 2-7 8 4 1 0.2 0.2 0.2 Atlantic herring 2 45-55 50 0.3-1 1 0.2 Blackspotted stickleback 2 40 40 1-3 2 0.2 Little skate 2 321-395 358 - - 0.2 Tautog 43-75 59 l-6 4 I 2 0.2 Pollock 1 60 60 2 2 0.1 Red hake 1 63 63 1 1 0.1 Sand lance sp. 1 82 82 4 4 0.1 Scup 1 205 205 112 112 0.1

~_

I I I me E I Table 3. Monthly Impingement For All Invertebrates Collected From Pilgrim Station intake Screens, January-June 1994 Species Jan. Feb. March April May June Totals Jellyfish *

Sevenspine bay shrimp 54 142 40 304 73 1 614 American lobster 1 2 55 11 69 Nereis sp. 14 17 28 1 60 Longfin squid 23 23 46 l Rock crab 5 2 4 4 4 3 22 Common starfish 2 1 4 4 2 Horseshoe crab 13 E Green crab 3 3 10 13 3 1 1 3 8 Green sea urchin 4 1 5 Orbiniidae 2 1 3 Gjyuntsp. 2 2 Mysidacea 1 1 2 Nemertea 2 Soft shell clam 2 E 2 2 E Arctic lyre crab i 1 Caridea l 1 Isopoda 1 1 TOTALS 79 167 79 322 163 54+ 864+

Collection Time (hrs.)66 59 55 31 79 83 54 361 Collection Rate (#/hr.)0.80 1.34 3.04 2.55 4.08 1.96 1.00+ 2.39+

Undetennined numbers I

I I I E E

I Ctenophores were impinged only during the month of June. The collections of sevenspine bay shrimp occurred primarily in April, and lobsters in May. In 1989 from January - June, blue mussels and mussel predators dominated impingement, possibly due to the lack of effective macrofouling controls that year. Sixty-nine specimens of the commercially important American lobster were captured which is higher than 1992 and 1993, and considerably more than other previous years; for example,16 and 21 were recorded for the same time frame in 1990 and 1991, respectively. Approximately 2,268 pounds of mixed algae species were recorded during impingement sampling, or 6.3 pounds / hour. Li.ke the January-June, 1989 - 1994 fish impingement rates, the algal impingement rate for these years was notably higher than recorded for the same period in 1988. I 4.3 Fish Survival Fish survival data collected while impingement monitoring are shown in Table 4. Static screen was collections provided high numbers of fishes and revealed relatively high impingement survival rates for some species, especially Atlantic silversides. Continuous screen wash collections had higher survival rates, although so few fishes were sampled that they are not a good indicator of continuous wash survival. I I I I I I

am E Table 4. Survival Summary for the Fishes Collected During Pilgrim Station Impingement Sampling, January-June 1994. Initial Survival Numbers Are Shown Under Static (8-Hour) and Continuous Wash Cycles Nuntber Collertni Number Survivine ~ l Static Cont. (Initial) Intal Length (mm) l Species W9shes Washes Static Cont. Mean Range l Atlantic silverside 876 23 617 20 104 70-149 Rainbow smelt 88 4 48 2 127 71-219 Winter flounder 50 4 47 4 75 49-272 Grubby 49 3 41 3 65 45-95 Threespine stickleback 18 1 16 1 61 36-69 Radiated shanny 12 0 12 - 93 75-137 Northern pipefish 9 Blueback herring 9 0 1 6 1 160 132-188 3 Rock gunnel 7 0 6 7 77 57-88 5 131 51-165 Cunner 6 0 4 - 140 102-157 Northern searobin Atlantic tomcod Windowpane 6 5 4 0 0 1 6 3 4 1 211 110 175 153-230 52-161 40-286 l Lumpfish 4 0 2 - 56 31-80 Alewife 3 0 0 - 115 93-147 Atlantic cod 3 0 0 - 55 50-60 Butterfish 3 0 0 - 89 71-104 Silver hake 3 0 0 - 88 72-107 Atlantic herring i 1 0 0 50 45-55 Blackspotted stickleback 2 0 1 - 40 40 l Little skate 2 0 2 - 358 321-395 l Tautog 2 0 2 - 59 43-75 Pollock 1 0 0 - 60 60 Red hake 1 0 0 63 Sand lance sp. 63 E 1 0 0 82 Scup 1 0 82 E 1 - 205 205 All Species: I Number 1,166 38 825 32 ('7c Surviving) (70.8) (84.2) 1 I 1 a L

SECTION 5 CONCLUSIONS

1. The average Pilgrim impingement rate for the period January-June 1994 was 3.34 fish / hour.

The collection rate was notably lower in 1988, than in 1989 - 1994, possibly due to more I i circulating water pump capacity during the latter years. I 2. Twenty-six species of fish were recorded in 361 impingement collection hours.

3. The major species collected and their relative percentages of the total collections were Atlantic silverside,74.7%; rainbow smelt,7.6%; and winter flounder,4.5%.

I 4. The hourly collection rate for invertebrates was 2.39+ with jellyfish (undetermined numbers), sevenspine bay shrimp (71.1%) and American lobster (8.0%) dominating the catch. Sixty-nine American lobsters were caught. Impingement rates for invertebrates were higher and algae lower for this period in 1988 (minimum circulating water pumps operating) then in 1989 - 1994. I 5. Impinged fish survival was high overall during static screen washes because of relatively high Atlantic silverside survival. I I I I I I -'3-I

man l SECTION 6 LITERATURFmCITED l American Fisheries Society. 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.

1989. Common and scientific names of aquatic invertebrates from the United States and Canada: decapod crustaceans. Spec. Pub. No.17:77 pp. I 1988. Common and scientific names of aquatic invertebrates from the United States and I Canada; mollusks. Spec. Pub. No.16: 277 pp. I I 1 1 I' I! I !

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                                                                      /88   a/      o  /-eet had/o/4    [zddac/uzac/li #ff8f        727-3i93 MEMORANDUM TO:           Members of the Administrative-Technical Committee, I                         FROM:

Pilgrim Power Plant Investigations and selected panel members John Chisholm, Recording Secretary, Massachusetts Division of Marine Fisheries

SUBJECT:

Minutes from the 81st meeting of the A-T Committee DATE: June 21, 1994 This meeting of the A-T committee was called to order by chairman Gerald Szal at 10:08 A.M. at the MA DEP Technical Assistance & Training Center in Millbury. I. Minutes of the 80th meetino I Gerald Szal wondered if the mid-cycle outage planned for April, as stated in the minutes, had occurred. Bob Anderson stated that the outage did not occur and was rescheduled for October 1994. Future mid-cycle outages will be scheduled for April. I Griswold moved to accept the minutes; Lee Bridges second. were accepted unanimously. Carolyn They II. Pilcrim Station 1993-1994 operational review Bob Anderson informed the committee that the plant operated I at an average capacity of 74% for 1993. For January through May, 1994 the average capacity was 84%. The mid-cycle outage, previously mentioned, will start October 1st and will last 30 days. The next refueling outage is scheduled for April-May 1995, during which time the shroud around the reactor will be inspected. According to Bob, the "Mescalero" indians in New Mexico have expressed an interest in storing spent fuel rods from nuclear power plants. Spent fuel rods at Pilgrim now are stored on sight. The committee was briefed on the recent striped bass I incident. Apparently a couple dozen small bass entered the discharge canal through a hole in the barrier net. Fisheries was notified and sent divers to observe the fish. The Marine 1 hole was repaired and as of this meeting most of the fish appear to I j have escaped. Perhaps the thermal backwash, which occurred on June , 1 1 ! I i I l 1

am E 19, prompted the fish to exit through the open cod end of the barrier net. This sparked a discussion on the effectiveness of barrier nets. Bob Lawton recommended this issue be pursued for Pilgrim and Brayton Point concerning barrier nets and fish. It was agreed that the Fisheries Subcommittee should address this subject. Bob Anderson reported that the dredging of the intake embayment will involve two phases. Phase one is planned for E April /May 1995 and covers the area adjacent to the intake 5 wall. Phase two is currently planned for either '96 or '97,_during a scheduled plant outage, and will cover the area in the vicinity a of the boat ramp. For phase one, 25,000 cubic yards will be removed, while phase two is roughly twice the size of phase one. I Boston Edison desires to dredge during an outage to prevent the intake of sediment. Marine Fisheries is concerned with the effects dredging will have on winter flounder in the intake - embayment and would like to avoid dredging during the spawning period. It was suggested that the dredging take place in the fall, and reference was made to the plant outage of this October. 3 Bob E Anderson explained that the October outage was an exception and all future outages are scheduled for April /May. As for this year, there is not enough time to be ready to dredge by October. 3 III. 1993 imoincoment/overflicht monitorina results Bob Anderson reported that 1993 was the last year of overflights. The money spent on overflights is now going towards funding the University of Massachusetts graduate student for the a next two years. Schools of Atlantic herring and menhaden were spotted in the vicinity of the plant during 1993 overflights. g However, the numbers of fish were down from previous years. As for impingement, the rate for 1993 was approaching 3 fish / hour, slightly up from the usual rate of 2 fish / hour. The top five species impinged in decreasing order of abundance were smelt, Atlantic silverside, winter flounder, alewife and grubby. From g December 15-28 5 to 6 thousand smelt were impinged. Over this 3 period there were two significant coastal storms. Not since 1978 has there been such a large smelt impingement; however there was no storm activity during the '78 incident. For mitigation, Boston Edison funded a two year Marine Fisheries program for $7,500 to stock smelt in the Jones River. It is believed that impinged smelt were from this local population. IV. 1993 Marine fish monitoring results Bob Lawton began by providing an overview of Marine Fisheries smelt stocking efforts. The overall goal is to augment instream , reproduction of smelt in the Jones River. This will be achieved by l enhancing the quality of spawning habitat and introducing smelt eggs taken from other rivers. Enhancement of spawning habitat is ; being done in two phases: 1. by providing artificial substrate, l 1.e., sphagnum moss in egg collection trays and 2. the Jones River Watershed Association has adopted the river and is working on El g l I l u

stormwater remediation. Transplanting of smelt eggs has long been used by wildlife agencies and is how smelt got into the Great Lakes. Also, in 1962 the Division of Marine Fisheries successfully I moved eggs from the Quabbin Reservoir into the Jones River. eggs are collected on trays of sphagnum moss. The It is known that plant material collects 12-15 times higher egg densities and has 10 times greater survivorship than hard bottom, which is why sphagnum I moss was used to collect the eggs. Riffle areas are also known to increase hatching success. In the spring of 1994, 121 egg trays were used to collect smelt eggs from spawning areas in the I Weweantic River in Wareham and the Back River in Weymouth. Estimates of eggs moved are between 600,000 to 1 million. Next, Bob provided the results of the research lobster study I which ended in 1993. This study looked at the effects of heat and current on lobster distribution in the area of the discharge canal. Nine fixed stations were established in a gradient across the discharge. Five lobster traps were set in a trawl at each station. I Traps were fished from June through September in over 56 sampling trips. A total of 6500 lobsters was captured. There were no consistent spacial patterns, but there were some interesting I findings. The outer stations had significantly higher legal catch rates in September. Also, there was a significant difference in legal catch rates going from North to South for July. This shows I a distinct depth and geographical gradient effect. suggests that the plume effect on the bottom is very small. This study Bob began discussing the results of the winter flounder population study by acknowledging that flounder stocks were in I trouble throughout the state. Then he presented Mike Scherer's estimate of 8.2 million flounder larvae entrained in 1993. an adult equivalent model this equates to 5,000 age three (mature) Using I fish. To bound the adult population of flounder in the area, Bob wants to work with Eric Adams on circulation patterns to ascertain where the larvae can come from. Marine Fisheries is using a mark and recapture technique to estimate population size. In 1993 they I tagged 200 fish and this year tagged 200+ fish to date. However, they have only two recaptures. Bob reported that they have also begun a young-of-the-year study of winter flounder using beach I seine and beam trawl surveys. study. The last topic presented was the cunner mark and recapture He reported to the committee that because of the I territoriality of this species it is hard to obtain a random sample and there will be biases. To address the issue of how to relate entrainment to adult equivalency, Marine Fisheries is collaborating with a graduate student from the University of Massachusetts to provide information on cunner fecundity. Bob informed the committee that the graduate student is striving to collect 10 female cunner per every Smm interval of size and that he had j I already begun collecting samples. The graduate student will also be working on settlement and recruitment of cunner with the Division's assistance. l l I 3 I I I l l

ml E' V. 1993 benthic monitorina results l The benthic monitoring results were provided by Jim Blake. He g reported that once each quarter of the year, divers run a 100 meter transect line out from the discharge and make observations of the g algae, particularly Chondrus criscus, to 30 meters on either side of the transect line at 10 meter intervals. The data is transposed i onto maps for the benthic report. The divers found that C. criscus is denuded from the rocks closest to the discharge along the transect line. Lateral to the denuded zone are various conditions 3 of stunted plants or a condition of sparseness. There is normal growth outside these boundaries. Jim found that there were 5' seasonal differences. In the spring, the denuded zone 'is relatively narrow out to 90 meters. In the summer, the effect is the denuded zone becomes considerably wider. Jim feels that the current and the heat of the discharge affects the denuded zone. The current produces a scouring effect. 3 The combined surface area of the denuded, stunted, and sparse E zones in December was 1522.5 square meters and extended out to 100 meters. The denuded zone this past winter was the largest recorded. Divers felt that fronds of algae were unusually covered a with a bryozoan never seen in such abundance before. This bryozoan g' is probably an exotic. It may be shading the surface of the algae and limiting light reaching the photosynthetic cells. So far this spring, the divers only have found the bryozoan on c. criseus at l, u ! the 100 meter mark, and it is not as prevalent as in December. Bob Anderson asked about mussel sets. Jim reported they were g l not extensive, but they usually recruit following the spring warm E up. VI. 1993 entrainment monitorina results Mike Scherer presented MRI's entrainment data results. They sampled twice a month from October '92-February '93 and weekly from g March-September '93 using triplicates. Mike breaks the year down g into three seasons. The dominant species for these seasons are as follows: 1-winter /early spring: plaice / cod eggs; sand lance, rock gunnel and grubby larvae. 2-late spring /early summer: tautog, cunner, and mackerel eggs, radiated shanny, sand lance, winter flounder, seasnail, and mackerel larvae. 3-late summer /early fall: menhaden, cunner, and rockling 4 l eggs and larvae. g l Mike then compared his data with local stock estimates in gj commercial fisheries and reported some of his findings. Cod stocks ! are down which was reflected in low cod egg collection. Four-beard I rockling, though of no commercial value, show a downward trend. Mackerel stocks are doing well and mackerel egg densities support this. Gerald Szal pointed out that there were 8 more species of E.t fish represented in entrainment (egg / larvae) catches than Marine 5 l l 4 I: El El

Fisheries catches, and wanted to know why. Mike replied that this was no surprise. Species like the snake blenny and radiated shanny are not succeptable to trawls, and some species spawn offshore. I Other interesting findings reported by Mike include the following: sand lance is probably down, but the larva season was really protracted, and they were caught through June and July for I the first time. Winter flounder appeared later in the collections, probably due to the colder winter. Tautog were not seen in July, but were in June, August, September and October. Lobster larva number 12 was caught in July '93. Mike also presented the new I sampling schedule for 1994. The best allocation of sampling is three times a week taking one sample each time. Sampling will take place from April through August on Monday morning, Wednesday I afternoon, and Friday at 11:30 pm. Addressing the contingency sampling plan, Mike stated that the notification level may be unrealistic, and he wants to know what he should do. It was agreed that this topic should be discussed by the Fisheries Sub-I committee. If Mike is to supply the committee with variances for monthly means on past data sets, he indicated he will need someone to do computer work, possibly a summer student. VIII. Review of 1993 and update of 1994 benthic monitorina (Taken out of sequence) Jack Parr, who spoke for Don Miller, reported the Benthic Subcommittee recommends that qualitative transect surveys continu'e. The mapping of the benthic thermal plume will have to wait until I the discharge jetties are repaired. If the repairs are done in July the study will take place from August 15 - October 1. If not, the study will be postponed until next year. VII. 1994 Marine Fish and Benthic sub-committees-membershio and schedules Carolyn Griswold will chair the fisheries sub-committee which will meet Tuesday July 26, in Narragansett at 10:00 am. Topics will include barrier nets and notification levels. IX. Other business Bob Lawton reported that Marine Fisheries will be putting out thermistors in the future in the study area. X. Adiournment i The 81st meeting of the Pilgrim A-T Committee adjourned at ! 1:52 pm. ) I I . E

f~l E I A-T Committee Meeting Attendance l! June 21, 1994 Gerald Szal, Chairman Mass. DEP, Grafton Robert Lawton Mass. DMF, Sandwich Mike Scherer MRI, Falmouth Jack Paar EPA, Lexington Bob Anderson BECo, Plymouth Carolyn Griswold NMFS, Narragansett Ted Landry U.S. EPA, Boston i William Eng U.S. EPA, Boston Jim Blake SAIC - Woods Hole Leigh Bridges Mass. DMF, Boston Rick Zeroka MCZM Bob Maietta Mass. DEQE John Chisholm Mass. DMF, Sandwich (recording secretary) ! I E I I I e I ; E

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                                                    /8 $6 6aA PHILIP G. COATES                         a/Zt'd/R   ,      AAM M 88888 I

DIRECTOR MEMORANDUM I 888-1155 TO: Members of the Administrative-Technical Committee, Pilgrim Power Plant Investigations and selected panel members FROM: John Chisholm, Recording Secretary, Massachusetts Division of Marine Fisheries

SUBJECT:

Minutes from the meeting of the A-T Committee to review workshop recommendations and the recent smelt impingement at Pilgrim DATE: February 17,1994 I This meeting of the A-T committee was called to order by c. .irman Gerald Szal at I 10:08 A.M.

1. PNPS Smelt Imoinnement Bob Anderson presented the facts of the recent smelt impingement. Over the period I of December 15-28,1993 there were two spikes of impingement, Dec,15-18 and 21-22.

Approximately 5,100 smcit were impinged over this period. The average impinged smelt had a mean total length of 116 mm and mean weight of 9 grams. A possible explanation for the impingement was incredibly high winds and stormy seas causing the fish to seek shelter in the intake. With another spike of larger smelt impinged on Dec.31, the expanded total for the entire month of December was ap' proximately 7,000 smelt. I Recommendations for remedial action were presented by Bob Lawton. Two possible actions were suggested: (1) the plant pays a fine, or (2) the plant funds the Division of Marine Fisheries to augment the local smelt population. The latter would be done by collecting smelt eggs from selected Massachusetts rivers and transporting them to the Jones River in Kingston, MA. The Jones River is the principle source of smelt recruitment in the I Pilgrim area. The cost of the two year project would be 57,500. The money would pay for materials, the labor to construct egg trays,and personnel services for restocking efforts. A motion supporting this recommendation pa:. sed unanimously. I I I I

su 5

11. PNPS Fisheries Workshoo Review The overall consensus was that the fisheries workshop held on January 14,1994 was productive. Mike Scherer addressed the recommendation that MRI should alter entrainment sampling methods. Current sampling involves performing triplicate sets during the same day. Workshop panelists suggested that these samples be distributed over a week, i.e., one collection per day on three separate days. It was recommended that at least one of the samples be collected at night, especially during the cunner spawning season. Mike agreed that it could be done, but with an increase in cost because of added travel time. It g

was finally agreed to accept a sampling schedule that would minimize a cost increase, g Entrainment samples willbe collected on Mondays, Wednesdays and Fridaysin conjunction with the regularly scheduled impingement monitoring. This willreduce travel time and also will distribute sampling to include one day, one af ternoon, and one night collection. .. Preliminary sampling with a smaller mesh net was also discussed. This protocol was endorsed unanimously. Bob Lawton addressed the panel's recommendations pertaining to the Division of Marine Fisheries research. Conceptually there were no recommended changes in the Division's study. Tagging of winter flounder and cunner were acknowledged to be good approaches for estimating absolute population size. However, suggestions had been made on tag 8i ng techniques, such as freczc branding and genetic tagging. These methods were investigated and found to be impractical for the Marine Fisheries study. The tags at Pilgrim are Peterson disk tag for flounder and the t-bar tag for cunner. As to number of fish to be tagged, Jay Hestbeck at UMass, Amherst is willing to work with the Marine Fisheries staff to address this and other questions related to study validity. In accordance with the panel's recommendation, Bob Lawton investigated water circulation in Cape Cod Bay. He contacted Eric Adams, who had previously worked on this issue in the Pilgrim area. Mr. Adams will be sought as a consultant. The role of the UMass graduate student was also discussed. The information he is expected to provide on cunner includes: age specific fecundity, maturity schedule, age composition, and sex ratio. There is also some work to be done on settlement and recruitment with the aid of a UMass post-doctoral candidate. Both Mike Scherer and Bob Lawton addressed the formulation of null hypotheses and g power analyses for respective programs. Wherever appropriate, power analyses will be 3 conducted and will be reported at the next meeting of the committee in June 1994. The meeting was adjourned at 2:15 p.m. I E I

I A-T Committee Meeting Attendance February 14, 1994 Gerald Szal, Chairman Mass. DEP, Grafton Robert Lawton Mass. DMF, Sandwich Mike Scherer MRI, Falmouth Jack Paar EPA, Lexington Bob Anderson BECo, Plymouth Carolyn Griswold NMFS, Narragansett Nick Prodany U.S. EPA, Boston Ted Landry U.S. EPA, Boston William Eng U.S. EPA, Boston Brian Kelly Mass. DMF, Sandwich John Chisholm Mass. DMF, Sandwich (recording secretary) , I I I I I I I I I I}}

BECO-94-109, Marine Ecology Studies Related to Operation of Pilgrim Station Semi-Annual Rept Number 44,Jan-June 1994

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BECO-94-109, Marine Ecology Studies Related to Operation of Pilgrim Station Semi-Annual Rept Number 44,Jan-June 1994

Text

Dear Sirs:

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SUMMARY

SUMMARY

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1.0 INTRODUCTION

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