Text

EA Report GPU44G Entrainment and Impingement Studies at the Oyster Creek Nuclear Generating Station, 1984-1985.
	ML072080210
Person / Time
Site:	Oyster Creek
Issue date:	07/31/1986
From:	; EA Engineering, Science, & Technology
To:	; GPU Nuclear Corp, Office of Nuclear Reactor Regulation
	Davis J NRR/DLR/REBB, 415-3835
References
	GPU44G
	Download: ML072080210 (202)
	v • d • e

EA Report GPU44G ENTRAINMENT AND IMPINGEMENT STUDIES AT OYSTER CREEK NUCLEAR GENERATING STATION 1984 - 1985 Prepared for GPU Nuclear Corporation Prepared by EA Engineering, Science, and Techn6logy, Inc.

Hunt Valley/Loveton Center 15 Loveton Circle Sparks, Maryland 21152

/

July 1986

CONTENTS Pare LIST OF TABLES LIST OF FIGURES EXECUTIVE

SUMMARY

1

1. INTRODUCTION 1-1

,,2N-METHODS

2. '.2-1 2.1 Impingement Composition, Abundance, and Initial Condition 2-1 2.1.1 Sampling Gear and Schedule 2-1 2.1.2 Sampling, Procedures 2-1 2.2 Impingement Latent Survival 2-2 2.2.1 Sampling Gear and Schedule 2-2 2.2.2 Sampling Procedures 2-3 2.3 Impingement Screen Collection? Efficiency 2-3 2.3.1 Sampling Gear and Schedule 2-3.

2.3.2 Sampling Procedures 2-4 2.4 Dilution Pump: Composition and Abundance of Entrainable-Sized Organisms 2-4 2.5 Dilution Pump: Composition, Abundance, and Initial Condition of Impingeable-Sized Organisms 2-4 2.5.1 Sampling Gear and Schedule 2-4 2.5.2 Sampling Procedures 2-5 2.6 Condenser Entrainment Mortality Studies 2-6 2.6.1 Sampling Gear 2-6 2.6.2 Sampling Procedures 7 2.7 Data Processing 2-8 2.7.1 Impingement Estimates 2-8 2.7.2 Impingement Initial Condition Determinations 2-9 2.7.3 Impingement Latent Mortality Determinations 2-10 2.7.4 Screenwash Efficiency Determinations 2-10 2.7.5 Dilution-Pump Abundance Estimates--

............ Entrainable-Sized Organisms 2-11 2.7.6 Dilution- Es imat-ip oition DeteOrganisms 2-1-2 2.7.7 Dilution-Pump Initial Condition Determination 2-13

CONTENTS (Cont.)

2.7.8 Ichthyoplankton Entrainment Mortality Estimates 2-13 2.7.9 Statistical Analysis of the Relationship Among Impingement Catches, Meteorological Phenomena, Water Quality Data, and Plant-Operational Characteristics 2-16

3. IMPINGEMENT COMPOSITION, ABUNDANCE, AND INITIAL CONDITION 3-1

.t . - 1 L'.

b ý 3.1 General Species Composition and Abundance 3-1 3.2 Discussion of Key Species 3-1 3.2.1 Atlantic Silverside 3-2 3.2.2 Bay Anchovy 3-3 3.2.3 Northern Pipefish 3-4 3.2.4 Blueback Herring 3-5 3.2.5 Winter Flounder 3-5 3.2.6 .Weakfish 3-6 3.2.7 Atlantic Menhaden 3-6 3.2.8 Bluefish 3-7 3.2.9 Summer Flounder 3-7 3.2.10 Northern Puffer 3-7 3.2.11 Sand Shrimp 3-8 3.2.12 Blue Crab 3-8 3.2.13 Other Key Species 3-10 3.3 Summary 3-10

4. POST-IMPINGEMENT LATENT EFFECTS 4-1 4.1 Introduction 4-1 4.2 Bay Anchovy 4-2 4.3 Atlantic Silverside 4-4 4.4 Sand Shrimp 4-6 4.5 Winter Flounder 4-8 4.6 Survival of Ristroph Screen Impingement 4-9 4.7 Summary 4-10

5. IMPINGEMENT-SCREEN COLLECTION EFFICIENCY 5-1 5.1 Time-of-Passage Studies 5-1 5.2 Overall Screen Efficiency 5-2 5.3 Efficiency of Isolated Screening System Components 5-2 5.4 Summary 5-4

6. DILUTION PUMP: ENTRAINABLE-SIZED ORGANISMS 6-1

CONTENTS (Contt.)

7. DILUTION. PUNP: IPINGEAELE-SIZED ORGA1ISMS 7-1 7.1 General Species Composition and Abundance 7-1 7.2 Discussion of Selected Species .7-2 7..'2.1 Sand: Shrimp 7-2 7.2.2 Blue Crab 7-2 7.2.3 Bay Anchovy 7"-3

... 7.2.4,,-,*At'lantic: Silverside ..

7.2...5. Other-.. Spece.s.- 7-4 7.3 Dilution Special Studies 7-5 7.3.1 Accuracy of Dilution Sampling Gear Volume Determination at OCNGS 7-6 7.3.2 Collection of Organisms Not Passed Through the Dilution Pumps at OCNGS- 7-8 7A3.3 Comparison of Size Selectivity of Dilution Sampling Gear to Impingement Sampling Gear at OCNGS 7-9 7.4 Summary 7-10

8. POST-ENTRAINMENT LATENT EFFECTS 8-1 8.1 Bay Anchovy Eggs 8-2 8.1.1 Initial Survival 8-2 8.1.2 Latent Survival 8-2 8.1.3 Total Survival 8-3 8.2 Bay Anchovy Larvae 8-4 8.2.1 Initial Survival 8-4 8.2.2 Latent Survival 8-5 8.3 Winter Flounder Larvae 8-5 8.3.1 Initial Survival 8-5 8.3.2 Latent Survival 8-6 8.3.3 Total Survival 8-7 8.4 Factors Affecting the Utility of Entrainment-Survival Data 8-7 8.4.1 Sorting-Error Considerations 8-7 8.4.2 Artificiality of Thermal Test Regime 8-8

I~ *v rr-77 77. 7

--ýx T1.7.7 771.

.7777-777 -777m777 .717

-~ '9' ,

!CONTENTS (Con=t.)

7' 8.5 tmpac.- of Condense~r Passage 8-9 8-9 8.6 Summary LITERATURE CITED APPENDIX A: LIST OF SCIENTIFIC AND COMMON NAMES OF ORGANISMS COLLECTED IN IMPINGEMENT AND ENTRAINMENT SAMPLES,

- *-,.,'%r*-.~*'~ -.~ -

OYSTEi CREkIZ NUCLEAA GENERATING STATION., 1984-1985

.1

ý,i .:i .iý7 .'i~. .......... ..

LIST OF TABLES Number,- Title 3-1 Total number, percent composition, and cumulative percent of finfish, other vertebrates, and macroinvertebrates impinged at OCNGS, November 1984 through November 1985.

3-2 Total weight, percent composition, and cumulative percent of finfish, other vertebrates, and macroinvertebrates impinged at'OCNGS, November 1984 through. November 1985.

3-3 Percent-of-catch for day and night collections of selected species from the OCNGS traveling screens, November 1984 through October 1985.

3-4 Weekly estimated numbers of selected species impinged on the OCNGS traveling screens, November 1984 through November 1985.

3-5 Weekly estimated weights of selected species impinged on the OCNGS traveling screens, November 1984 through November 1985.

3-6 Total estimated number and weight of taxa impinged at OCNGS, November 1984 through November 1985.

3-7 Day-night comparisons of initial conditions of selected species collected from the OCNGS traveling screens, November 1984 through November 1985.

3-8 Weekly mean water quality values, OCNGS, 1984-1985.

3-9 General linear model results for selected species impinged on the OCNGS traveling screens, November 1985.

3-10 Estimated annual impingement of selected species and all organisms combined by study year adjusted for differences in sampling effort.

4-1 Proportional survival of non-impinged control organisms by observation time and exposure temperature at OCNGS.

4-2 Thermal parameters associated with latent effects testing of bay anchovy at OCNGS conducted from March through December 1985.

4-3 Survival associated with latent effects testing of bay anchovy at OCNGS conducted from March through December 1985.

4-4 Mean fork length, standard deviation, and number of bay anchovy by condition at the termination of 96-hour post-i.- in . em-ent-_l-at ent- ef-f ec

-tes-te ts_--c ondu c-ted-.-a.tCNGS__from ... .............

March through December 1985.

LIST OF TABLES (Con°t.)

4-5 General linear model results and mean survival values for bay anchovy relative to various thermal values tested at OCNGS, March through December 1.985.

4-6 Thermal parameters associated with latent effects testing of Atlantic silverside at OCNGS conducted from February through December 1985.

4-7 Proportional survival of organisms collected from the impingement sampling pool by observation time and holding

.... ............. . ....- .. wvar t~r-- rntut r~a. .... . . . ___

4-8 Survival associated with latent effects testing of Atlantic silverside at OCNGS conducted from February through December 1995.

4-9 General linear model results and mean survival values for Atlantic silverside relative to various thermal values tested at OCNGS, February through December 1985.

4-10 Mean fork length, standard deviation, and number of Atlantic silverside by condition at the termination of 96-hour post-impingement latent effects tests conducted at OCNGS from February through December 1985.

4-11 Thermal parameters associated with latent effects testing of sand -shrimp at OCNGS conducted from January through December 1985.

4-12 Survival associated with latent effects testing of sand shrimp at OCNGS conducted from January through December 1985.

4-13 General linear model results and mean survival values for sand shrimp relative to various thermal values tested at OCNGS, January through December 1985.

4-14 Mean length, standard deviation, and number of sand shrimp by condition at the termination of 96-hour post-impingement latent effects tests conducted at OCNGS from January through December 1985.

4-15 Survival associated with latent effects testing of winter flounder at OCNGS conducted from January through December 1985.

... . 4 .emal--parameters stsng i.assoiatednwithlat~nt.ef of . .......

winter flounder at OCNGS conducted from January through, December 1985.

LIST OF TABLES (Cont.)

4-17 Mean fork length, standard deviation, and number of winter flounder by condition at the termination of 96-hour post-impingement latent effects tests conducted at OCNGS from January through December 1985.

4-18 General linear model-results and mean survival values for winter flounder relative to various thermal values tested at OCNGS, January through December 1985. .

4-19 Comparison of initial and latent impingement survival between conventional and Ristroph vertical traveling screens, OCNCS, 1975-1985.

4-20 Comparison of total impingement survival between conventional and Ristroph vertical traveling screens, OCNGS, 1975-1985.

5-1 Number recovered by minute after release of buoyant foam balls into the forebay of the OCNGS intake structure on 7-20 November 1984 using fast screen speed.

5-2 Number recovered by minute after release of preserved Atlantic silverside into the forebay of the OCNGS intake structure on 1-2 May 1985.

5-3 Results of overall screen efficiency studies using preserved Atlantic silverside, May and November 1985.

5-4 Percent of released and recovered Atlantic silverside by size class and screen speed used in OCNGS intake-screen efficiency studies of 1-2 May 1985.

5-5 Results of screen efficiency studies using preserved Atlantic silverside and different release points, 13-21 November 1985 and 3, January 1986.

6-1 Estimated number of selected ichthyoplankton passed through ',,

the condenser and dilution pumps at OCNGS from September 1975 through August 1981.

6-2 Estimated number of macrozooplankton passed through the condenser and dilution pumps at OCNGS from September 1975 through August 1981.

6-3 Estimated number of selected microzooplankton passed through the condenser and dilution pumps at OCNGS from September 1975

LIST OF TABLES (Co'ft.)

Number T 7-1 Total number collected, percent composition, and cumulative percent of finfish, other vertebrates,. and macr0invertebrates entrained. through the dilution pumps at 0CNGS, December. 1984 through December 1985.

7-2 Total weight collected, percent composition, and cumulative percent of finfish, other vertebrates, and macroinvertebrates entrained.. through the dilution pumps at O SDecember 1984 through December 1985.

.-. _ D.aynight...

. .comparisona.of number* QEf....jselec.ted orgsn.na. col-lected from the dilution pump discharge at OCNGS, December.

1984 through December 1985.

7-4 We-ekly estimgted numbers of selected species passed 'throUgh the dilution pump discharge at OCNGS, December 1984 through December 1985.

7-5 Weekly estimated weights of selected species passed through the dilution pump discharge at OCNGS, December 1984 through December 1985..

7-6 Total estimated number and weight of taxa entrained through the dilution pumps at OCNGS, December 1984 through December 1985.

7-7 Day-night comparisons of -initial conditions of selected species collected from the OCNGS dilution discharge, December 1984 through December 1985.

7-8 Comparison of standard and gear-mounted flowmeter readings under various dilution pump-operational modes.

7-9 Percent operation of various dilution pump configurations sampled at OCNGS, December 1984 through December 1985.

7-10 Number of:liveAtlantic,. silverside ..collec ted.by dilution.

sampling gear at OCNGS during special studies.

7-11 Number per 1,000 m3 of live Atlantic silverside collected at OCNGS used to determine depth distribution.

7-12 Number and percent by size class of sand shrimp collected by dilution sampler and impingement pool sampler at OCNGS, 18-28 March 1985.

.................. 7-1-3-- .. -..... Numb er---and---pe~rcent-by--si~z-e.-c.-ia se---of--sand-sh.-.imp-.co-llec~ted .... .......... =.......

by dilution sampler and impingement pool sampler at OCNGS, 18-28 March 1985.

LIST OF TABLES (Cont.)

Number il 8-1 Thermal factors and post-entrainment latent effects survival values for bay anchovy egg studies conducted at OCNGS, May through August 1985.

8-2 Results of linear regression analyses performed on various measures of survival of bay anchovy eggs subjected to entrainment at OCNGS, May through August 1985.

8-3, Thermal 'factors' and latent survival Values f orbay anchovy eggs collected at the intake and discharge of OCNGS, May through August 1985.

8-4 Results of linear regression analyses performed on latent survival of bay anchovy eggs subjected to entrainment at OCNGS, May through August 1985.

8-5 Thermal factors and initial survival values for bay anchovy larvae collected at the intake and discharge of OCNGS, May through August 1985.

8-6 Summary of number of bay anchovy larvae stocked, number surviving at each observation period, and weighted mean proportion surviving at each observation period for tests conducted at OCNGS, May through August 1985.

8-7 Summary of number of bay anchovy post-yolk-sac larvae stocked, number surviving at each observation period, and weighted mean proportion surviving at each observation period for tests comparing the efficacy of different holding containers for tests conducted at OCNCS, May through August 1985.

8-8 Thermal factors and initial survival values for winter flounder larvae collected at OCNGS, February through March 1985.

8-9 Number stocked and latent survival by observation hour of

.vinter-..flounder.la:vae collected. at OCNGS, February through . .

March 1985.

8-10 Thermal factors and latent survival values for winter flounder larvae collected at OCNGS, February through March 1985.

8-11 Results of linear regression analyses performed on latent sur-vival of winter flounder larvae subjected to entrainment at OCNGS, February through March 1985.

.. .8.......... ..........-.

....... 2 ........... Th.mal fac -tors--and- entrainment - ur -iva.L.-v-alues-for-v winter ............

flounder larvae collected at OCNGS, February through March 1985.

LIST OF TABLES (Cont.)

Titla 8-13 Results of linear regression analyses performed on total sur-vival of winter flounder larvae subjected to entrairment at OCNGS, February through March 1985.

8-14 Investigation of uncertainty associated with initial survival of winter flounder larvae at OCINS, February through March 1985.

,Investigation of uncertainty associated vith initial :survivel of bay anchovy larvae at OCNGS, May through August 1985.

8-16 Total estimated number of selected ichthyoplankton taxa entrained through the condenser-cooling system and estimated number killed at OCNGS, 1975-1981.

LIST OF FIGURES Number Title 1-1 Map of the middle portion of.Barnegat Bay.

2-1 Diagram of the intake and discharge of the circulating water system and the dilution pumps at the Oyster Creek Nuclear Generating Station.

2-2 Oyster Creek Nuclear Generating Station cooling water intake structure and fish sampling pool.

2-3 Side view of vertical traveling screens used at Oyster Creek Nuclear Generating Station.

2-4 Schematic diagram of the dilution-pump discharge sampling device.

2-5 Schematic diagram of the portable entrainment survival sampling device.

3-1 Estimated number of fish and macroinvertebrates impinged on the Oyster Creek Nuclear Generating Station traveling screens, November 1984 - October 1985.

3-2 Estimated annual impingement catches for total organisms and key and abundant organisms at Oyster Creek Nuclear Generating Station.

4-1 Relationship of total survival to collection temperatures for bay anchovy impinged at the Oyster Creek Nuclear Generating Station, January through December 1985.

4-2 Relationship of total survival to collection temperatures for Atlantic silversides impinged at the Oyster Creek Nuclear Generating Station, January through December 1985.

4-3 Relationship of total survival to collection temperatures for sand shrimp impinged at the Oyster Creek Nuclear Generating Station from January through December 1985.

4-4 Relationship of total survival to collection temperatures for winter flounder at the Oyster Creek Nuclear Generating Station from January through December 1985.

7-1 Sampling catch of fish and-macroinvertebrates entrained through the Oyster Creek Nuclear Generating Station dilution pumps, December 1984 - December 1985.

LIST, OF FIGURES (Cont.)

Rumbthe r il 7-2 Mean monthly weight-per-individual of blue crab from screen (pool) impingement -and dilution pump samples at OCNGS, November 1984 - December 1985.

7-3 Mean monthly weight-per-individual of bay anchovy from screen (pool) impingement and dilution pump samples at OCNGS, November 1984- December 1985.

7-4 Mean monthly weight-per-individual "of sand shrimp from screen (pool) impingement and dilution pump samples at OCNGS, November 1984- December 1985.

8-1 Proportion of bay anchovy eggs that hatchcollected from the intake and discharge of the Oyster Creek Nuclear Generating Stat-ion- --May- - -August-. -985... "-....

8-2 Proportion of bay anchovy eggs that survive entrainment at Oyster Creek Nuclear Generating Station as a function of discharge temperature.

8-3 Initial survival of bay anchovy larvae collected at the Oyster Creek Nuclear Generating Station intake and discharge as a function of collection temperatures.

8-4 Latent survival of bay anchovy larvae in open holding containers versus closed holding containers during holding experiments at the Oyster Creek Nuclear Generating Station, May - August 1985.

8-5 Initial entrainment survival of winter flounder larvae as a function of delta-T at the Oyster Creek Nuclear Generating Station for studies conducted from February - March 1985.

8-6 Latent entrainment survival of winter flounder larvae from low delta-T and high delta-T collections at the Oyster Creek Nuclear Generating Station from February - March 1985.

8-7 Proportion of winter flounder larvae that survive entrainment at Oyster Creek Nuclear Generating Station as a function of delta-T.

EXECUTIVE

SUMMARY

From November 1984 through December 1985, EA Engineering, Science, and Technology, Inc. performed several aquatic sampling programs in the cooling water intake and discharge canals of the Oyster Creek Nuclear Generating. Station. The programs were designed both to estimate the number of fish and other organisms passing through the cooling system, and to determine survival of selected species after passage through the system. Studies involved the three pathways through the cooling system that an organism may experience: (1) impingement on the traveling screens in the condenser intake and shunting through the screenwash

,::Ydischarge pipe into theedischarge canal; (2) passage (i.e., entrainment) through the traveling scr'e'ens and' -co'ndenser' tubes aind 2into"' the discharge-canal; and (3) passage through the dilution-pump system into the dis-

.. charge canal.

Several aspects of screen impingement were examined, including composi-tion, abundance, and initial condition (i.e., survival) of organisms; efficiency of the traveling screens in diverting organisms from the cooling water flow; and latent survival (96 hours0.00111 days 0.0267 hours 1.587302e-4 weeks 3.6528e-5 months after impingement) of selected fish and shellfish species. Weekly sampling of impinged organ-isms over a 12-month period produced 83 types of fish, shellfish, and other aquatic organisms. Sand shrimp accounted for 76 percent of the' catch. The second and third most abundant organisms--the grass shrimp and blue crab-when added to sand shrimp, composed nearly 94 percent of the annual impingement catch. The finfish species-Atlantic silverside, bay anchovy, and northern pipefish-were next in order of abundance, but none accounted for more than 2 percent of the total catch. The total estimated number and weight of all organisms impinged during the 12-month period were 22 million organisms weighing 208,000 lb. For all organisms combined, the estimated annual impingement for. 1984-1985 was the highest in 9 years of record, due primarily to the high impingement rates of sand shrimp in 1984-1985.

A series of experiments was conducted that involved the release of inanimate objects and preserved, marked fish in the condenser cooling water flow. Results showed about 90 percent of the test organisms were screened and removed from the condenser cooling water when the screens were in good operating condition.

Latent (96-hour) survival .was measured, for Atlantic silverside, bay anchovy, winter flounder, and sand shrimp. Organisms 'that had~ b . . .

impinged were captured and held in both heated and unheated water to determine potential delayed effects of impingement. Results for Atlantic silverside, winter flounder, and sand shrimp indicated that physical effects of impingement (i.e., from organism contact with screens, debris, wash sprays) were inconsequential and that survival of organisms held in heated water decreased only when heated discharge water temperatures exceeded certain limits. For Atlantic silverside and Sand shrimp, the critical temperatures were between 27 and 29 C (81-84 F). The critical temperaure-or---- ingei-e s....t tounder-hat higih sur-vival was measured at about 22 C (72 F) and no survival at 30 C-(86-F). .

1

'Resul ts for bay anchovy were variable and inconclusive, owing to the d ifficulty of holding this fragile species for observation. There was some indication that a discharge temperature of about 30 C was critical for bay anchovy. Thus; survival after impingement is dependent on the thermal regime in the discharge canal. Given that cooling of heated discharge water due to dilution was not incorporated into the testing regime, actual survival of organisms in the discharge canal may be higher than that inferred from test data.

An analogous program of latent survival testing was carried out for bay anchovy eggs and larvae and winter flcunder larvae entrained through the intake screens and condenser tubes and into the discharge canal. At discharge temperatures up to 27 C (81 F), survival of bay anchovy eggs esceeded-70 percent. A csdischarge temperatures increased' above that' .-

point, survival steadily decreased until zero survival was recorded at

....---...... -(-100-F)-.- Latentt -survival---tests-- for bay anchovy -lamvae-were unsuc-- .. .

cessful in that few survived 96 hours0.00111 days 0.0267 hours 1.587302e-4 weeks 3.6528e-5 months , regardless of whether they were held in ambient or heated water. Based on initial survival of bay anchovy larvae, measured so on after collection, a discharge water tem-perature of 35 C (95 F) appears to be 'critical; below this temperature,'

initial survival ranged between 50 and 100 percent, and essentially none survived above 35 C. Survival of winter flounder larvae was found to be closely related to delta-T, or the difference in water temperature between the discharge and intake. Statistical analyses revealed that survival was greater than 90 percent when delta-T was less than 4 C (7 F).. As delta-T increased from that point, survival decreased corres-pondingly until zero survival was predicted at a delta-T of 12 C (22 F).

Using these survival data in conjunction with plant-operating data and measured organism abundances for 6 years (August 1975 - September 1981),

the total number killed by passing through the condenser system was esti-mated. Because of year-to-year variation in natural water temperatures, delta-T, and plant shutdown periods, the proportion of bay anchovy eggs and winter flounder larvae killed was quite variable. The annual range for bay anchovy eggs was 13-83 percent, and 21-88 percent for winter flounder larvae. Problems with latent testing of bay anchovy larvae precluded meaningful projections of the number killed.

Two studi-e were conducted to determine the proportion of organisms that pass through the cooling-water dilutieion pumps, rather than through the condenser cooling water flow. One study involved weekly monitoring for a 12-mouth period of the species composition, abundance, and initial sur-vival ofiimpL organisms passing ieabl'e-sized through the dilution pumps. -

-7.. These organisms are of a size thought likely to ,be *s*top ped by the travel-ing screens, had they entered the condenser cooling-water flow rather than the dilution-pump flow. The second study involved estimating the

,.'total nmbr ý'6f' eitrAinable-sized, organi-sms passing -through the dilution pumps., based on organism abundance data for 6 previous years. Organisms evaluated in this effort include the young life stages (eggs, larvae, juveniles) of important finfish, and key forms of zooplankton.

The 12-month sampling program at the dilution-pump discharge yielded 108 types of fish and other aquatic organisms. The top three species, in order of abundance, were sand shrimp, bay anchovy, and grass shrimp; 2

together, they composed nearly 90 percent of the total number. Blue crab and Atlantic silverside were next in abundance. No other organism accounted for more than one percent of the total number. The total esti-mated numberand weight of organisms passing through the dilution pumps in the 12-mqnth period was 100.6 million and 666,600 lb, respectively.

With few exceptions, survival (based on observation right after capture) was high for most species passing through the dilution pumps. Greater than 90 percent of sand shrimp, blue crab, Atlantic silverside, northern pipefish, and winter flounder survived passage. The lowest survival (42 percent) was recorded for the fragile bay anchovy. The bay anchovy excepted, passage through the dilution pumps appears to have little dele-terious effect on organisms.

Week t.d n "annual1"esitima tes",of ;--the `.number'-of, 'impingeable-sized, organisms,:,..

passing -through the dilution pumps were considerably higher than corres-ponding estimates of the number of organisms impinged on the traveling screens. The total annual dilution-passage estimate was 100.6 million, nearly five times the screen-impingement estimate. Were the amount of water passing through the dilution pumps versus the condenser pumps the only factor involved, the dilution estimate should have been no more than 33 million. Differences in sampling efficiency between the dilution and screen-impingement studies may have contributed to the differences in estimates. It was also conjectured that some unknown behavioral mech-anism causes more organisms to go through the dilution pumps.

Estimates of the annual number of small fish and other organisms (entrainable-sized) that passed through the dilution pumps varied greatly from year to year, depending on organism abundance and plant-operational conditions. Bay anchovy eggs were nearly always the. most abundant life stage of fish; the range of annual dilution passage of this form was 179 million in 1976-1977, to 13.5 billion in 1975-1976.

Mysid shrimp were the most abundant forms of macrozooplankton--over 72 billion were estimated to have passed through the dilution pumps.

in 1976-1977. The smaller microzooplankton, particularly copepods, were even more abundant. The highest annual estimate of the number of microzooplankters passing through the dilution pumps was approxi-mately 70 trillion during the 1975-1976 study year.

3

1. INTRODUCTION This report presents the results of studies of entrainment and impinge-ment abundance and associated mortality carried out at the Oyster Creek Nuclear Generating Station (OCNGS) from November 1984 through January 1986. The impingement abundance portion of the program is required by the U.S. Nuclear Regulatory Commission (NRC), as specified in the Oyster Creek Environmental Technical Specifications (OCETS). Entrainment and impingement mortality studies were mandated by the U.S. Environmental Protection Agency, New Jersey Department of Environmental Protection, and NRC. These latter studies were designed to supplement GPU Nuclear Corporation's 316(a) and (b) Demonstrations for the Oyster Creek Nuclear GenratingSain~JPL~98. . .

The generating station and surrounding area were described by Daniia

-et al. (1979), based on literature reviews and their own studies. The station is a 630-MWe net boiling water reactor located 3.2 km west of Barnegat Bay in Lacey Township, New Jersey (Figure 1-1). During station operation, condenser cooling water is withdrawn from Barnegat Bay via the lower part of the South Branch of Forked River and a dredged intake canal. Heated water is discharged into a dredged discharge canal which empties into lower Oyster Creek and Barnegat Bay. Barnegat Bay is a large, shallow, lagoon-type estuary bordered by barrier beaches.

A limited exchange of bay and ocean water occurs through Barnegat Inlet and the Manasquan Canal.

The overall objective of the study program is to provide information that will permit a more detailed assessment of the impact of the OCNHS cooling system on the biota of adjacent areas of Barnegat Bay. Although entrain-ment and impingement studies have been conducted at Oyster Creek since 1975, the actual effect of the impingement or condenser-passage experi-ence could only be approximated. In the present study, the use of new technologies for capturing and holding both impingeable- and entrainable-sized organisms permitted evaluation of latent mortality. Thus, data are now available for adjusting simple entrainment and impingement abundance' estimates to account for survival. In addition, a dilution-pump inves-tigation was conducted to fill a gap in terms of the actual number of organisms passing through the entire cooling system. Previous studies have concentrated on organisms in the condenser cooling water flow.

Because the flow through the dilution pumps can be nearly 60 percent of the total cooling water flow, many organisms have been unaccounted for in previous studies. The data provided- herein permit an accounting..of.*total ..

organisms traversing the cooling system.

Following this introductory chapter, Chapter 2 provides detailed descrip-tions of the gear and procedures used in each sampling program. Methods sections are arranged in the same order as the following chapters, except that the last methods section (2.7) provides data processing and analysis methods for all study programs. Results of the impingement abundance and initial condition study are provided in Chapter 3. Discussions cover

.species

.. composition, both weekly and annual abundance estimates, periods of occurrence,-nit-al c tiif-fimp inged--organisms-, -and -compari-sons-.

1-1

with previous years' impingement data. Chapter 4 describes the impinge-ment latent mortality program. Initial, latent, and total survival of three, finfish and one macroinvertebrate species -are 4iscussed and. related statistically to various thermal conditions. Comparison is made with previous latent mortality studies at Oyster Creek conducted by Ichthyo-logical Associates. The efficiency of R.istroph traveling screens is evaluated in Chapter 5; tag and release studies were used to assess this efficiency. Chapter .6 includes annual estimates of the number of key ichthyoplankton, macroinvertebrate, and microinvertebrate species entrained through the dilution pumps from 1975 to 1981. Corresponding condenser-entrainment estimates are provided for comparison. The passage of (screen) impingeable-sized organisms through the dilution pumps is

,.des cribed _in C,,hap~t e~r 7. .,.Species, compo sit ion,~ and,,weekly;_and-:ýannua1,es tir-mates of numbers and weight are provided in addition to an evaluation. of gear effectiveness. Chapter 8 contains the results of latent mortality studies--on-bay .-acbovy--eg-gs .- and--l-ai-,ae- *and-vi--te-r-l-ounder- awvae,-,T-he-. .

relationship of survival to various thermal conditions is investigated statistically. The resulting survival data were used to adjust previous annual condenser-entrainment -estimates for these forms to reflect the true imp-act of-co ndense r entra i nment.

1-2

Kilometers

0 0.5 1.0 Double Creek

j.iw Map-of-the-middle- portion -of-Barnegat -Bay...(adapted frog. T.hr 11;- eM..t.m

a. 1978.)

2 . METHODS 2.1. IMPINGEMENT COMPOSITION, ABUNDANCE, AND INITIAL CONDITION This aspect of the impingement monitoring program sought to determine the species composition and abundance of fin- and shellfish impinged on the modified traveling screens, and to fulfill monitoring obligations mandated by Section 2.1.1A of OCETS. Determination of initial condition (live, dead, or stunned/damaged) of impinged fin- and shellfish was an additional objective. Data collected by this program were used to cal-culate weekly and annual estimates of total impingement.

2.1.1 Sa*imling Gear and Schedule .

Samples were collected in the newly constructed concrete screenwash diversion pool located at the north end of the traveling screens (Figure

.2-1). This structure is an extension of the newly developed fish-return system and provides a means of collecting and holding, for abundance and initial condition determinations, fish and macroinvertebrates that have been impinged on the screens (Figure 2-2). The sampling pool is a rect-angular structure, 8 x 5.8 m, into which screenwash water is diverted by a trough system. The depth of water in the pool is maintained at about I m when full by a fixed overflow weir. The pool is drained at its lowest point through an 8-in. butterfly valve and pipe. This pool furnishes a Water cushion to reduce the sampling trauma associated with traditional impingement sampling and, hence, any confounding effects on initial condition.

Samples were collected from the water-filled pool in a 3.7 x 5.0 x 1.1-m net constructed from 6.4--- heavy-delta nylon mesh netting. Samples were 3 minutes in duration, collected over one 24-hour interval per week; at least four samples were taken during the 12-hour period after sunset and seven samples were taken during the remaining 12-hour period. One night sample was collected 2 hours2.314815e-5 days 5.555556e-4 hours 3.306878e-6 weeks 7.61e-7 months after sunset to provide data from the period of expected maximum abundance. All sampling for this study was conducted during either a continuous wash mode or during a quasi-continuous wash mode (less 'than a 30-minute screen hold, i.e., wash periods were inter-spersed with nonwashing periods of less than 30-minute duration). Inter-mittent wash modes were not used by plant operations during the period of study.

2.1.2 Sanmling Procedures Initial condition (i.e., life condition) was determined 30 minutes after organisms were collected. Determinations were based on Live-Swimming vigorously; no apparent orientation problems, behavior normal Damaged (stunned)--Struggling or swimming on side; apparent orientation problems, behavior abnormal,

....... ..... ~------*---or~eaio-f.-eertion-ons-orace.rtions.

2-1

. Dead-No vital life signs; no body or .opercular movement; no response to gentle probing Organisms from each species/life condition were counted and a total weight of that species/life condition was determined using either a top-loading dial scale or an Ohaus Dial-O-Gram balance. Unknown or questionable organisms were preserved for positive laboratory identification.

Water quality and plant-operational data were collected concurrently with biological sampling. Instrumentation used to obtain water quality information consisted of YSI DO and S-C-T meters, and Orion pH meters calibrated prior to,.the actual sampling. Water quality parameters meas-ured were diss~olved oxygen (DO), water temperature, salinity pH, and secchi depth.

2.2 IMPINGEMENT LATENT SURVIVAL The objectives of the impingement latent survival program were to analyze the likelihood of mortality of- impinged drganisma released int6 Oyster Creek after exposure to the traveling screens and the fish-return system, and to consider factors that might contribute to measured mortality.

Collected organisms were held and periodically observed for 96 hour0.00111 days 0.0267 hours 1.587302e-4 weeks 3.6528e-5 months sr; after this time it was assumed that the likelihood of any further OCNGS-caused mortality was minimal and that the affected organisms have suc-cessfully survived the entire impingement experience.

Factors considered by this program that may have potentially influenced survival include screenwash mode, time of year, size and weight of impinged organisms, water quality, thermal elevation, and obvious phys-ical injuries. Data obtained from this program were used, in conjunction with abundance determinations, to provide estimates of the effects of the entire impingement experience on selected species. The results will supplement the 316(a) and (b) Demonstrations for OCNGS, providing the basis of a realistic multi-year determination of the impact of plant operation on local fin- and shellfish populations.

2.2.1 SamolinZ Gear and Schedule Organisms used to determine impingement latent effects were collected at the end of the screenwash-water discharge pipe, downstream of the

., dilution pump discharge (Figure 2-1)., ... ollection, of_,test,.organismS.oWaS accomplished by using dip nets deployed from a floating platform con-structed with a submerged central bay and net. The use of the submerged bay was necessary in order to preclude possible extraneous sources of damage to the test organisms (e.g., dilution pump discharge turbulence) and to reduce the source of potential error associated with collection of non-impinged organisms that either have passed through the dilution pumps or reside in the discharge canal.

Impingement latent mortality tests were conducted during periods when

- *-arget -og-an,-sm-s--wn fl-ounder,. .-bay.-,anchovy- ... Atlai-ti-c--ai-ve r-a

-er- ide-,.............. ..

and sand shrimp--were abundant. Spot was the fifth target species, but was so scarce in impingement samples that it could not be tested. Each 2-2

test consisted of holding up to 200 organisms (depending on availabil-ity), split equally between ambient and condenser discharge waters, and observing condition at intervals over 96 hours0.00111 days 0.0267 hours 1.587302e-4 weeks 3.6528e-5 months . Organism loading, in the holding system was limited to no more than 5 g/L at temperatures of 20 C or less, or 2.5 g/L at temperatures above 20 C. Non-impinged test organ-isms vere also tested to provide insight into the efficacy of the holding system. In these latter tests, the necessity to minimize handling of organisms often resulted in unequal distribution of test organisms between ambient and heated holding tanks. Most testing occurred during winter, spring, and fall, coinciding with periods of peak abundance of target organisms. Most sampling was conducted after sunset during the period of expected maximum abundance, primarily during continuous screen-wash conditions because the screenvashýschedule was pfedominantly contin-uous throughout the sampling year.

2.2.2 Samiling Procedures Organisms were collected using dip nets deployed for short periods of time; once collected, they were segregated into species-specific holding containers. The organism condition was determined at the outset of the holding period and subsequently at 0.5, 1, 2, 3, 6, 12, 24, 36, 48, 72, and 96 hours0.00111 days 0.0267 hours 1.587302e-4 weeks 3.6528e-5 months . Fork lengths (FL) of all finfish and weights were measured either at death or test termination. Lengths of sand shrimp were mea-sured from the end of the telson to the end of the antenna scale. Qual-itative observations of appearance and behavior (e.g., abrasions, scale loss, erratic swimming) were noted for each specimen. Water temperature, DO, salinity, and pH were measured during each observation period.

2.3 1IMPINGEMENT SCREEN COLLECTION EFFICIENCY The objectives of this program were (1) to quantify the collection efficiency of the OCNGS traveling screens, and (2) to characterize the temporal aspects of the impingement process, i.e., the length of time organisms are exposed to the screening and return systems. Determination of the timing aspects of the impingement process for various screenwash modes and screen speeds provided the basis for establishing a valid sam-pling program which adequately samples both abundance and initial condi-tion of impinged organisms.

2.3.1 SamDling Gear and Schedule Sampling for the screen collection efficiency iout experiments was'carried using either the end of the screenwash discharge pipe or the impingement sampling pool described in Section 2.1.2. Several release points within the screening apparatus were used in order to determine where losses occur. Release points included upstream of the trash racks, downstream of the trash racks but upstream of the screen panel, in the water at the screen panel, above water in the screen panel trough, and in the low-pressure organism-removal sluice behind the screen housing. Recovery points included the sluice entrance to the sampling pool structure, the samp~ling-pool---col lect

...... nnetan*~th ~mp oo~itself (Figures 2-2 and 2-3).

2-3

Tag/release experiments were performed during continuous wash conditions on 1-2 May 1985, 13-21 November 1985, and 3 January 1986 using dead, pre-served Atlantic silverside (Menidia menidia that were fin-clipped for positive identification. Three releases were conducted using slightly buoyant foam balls during 7-20 November 1984.

2.3.2 Samnling Procedures Each experiment using preserved Atlantic silversides consisted of tagging up to 400 individuals and distributing them over the specific area to be tested during a screenwash. Size distribution (FL) of the released specimens was-determined prior to release for one of the experiments and recaptue wee compar~e&" toeemni tee was a bisin -heý resultsa attributable to organism length. Collections were conducted for 30 min-utes after release. Foam ball experiments were conducted for 15 minutes.

Sexperment was conducted to deter mine t-ime of passage through the system, then catch returns were recorded for each one-minute interval over the collection period; otherwise, only the total catch after 30 (or

15) minutes -was -recorded-.

2.4 DILUTION PUMP: COMPOSITION AND ABUNDANCE OF ENTRAINABLE-SIZED.

ORGANISMS-This program quantified the abundance of ichthyoplankton, macrozooplank-ton, and microzooplankton that have passed through the OCNGS dilution pumps for the period September 1975 - August 1981. The magnitude of dilution-pump entrainment has received little attention in past study efforts; this phase of study provided abundance estimates that were necessary in order to assess the impact of dilution-pump entrainment on local plankton populations. The approach employed to complete this phase of work used planktonic densities measured at the condenser cooling water system in conjunction with corresponding dilution pump volumes.

These data were accessed on GPU Nuclear's Reading, Pennsylvania, compu-ter. The organism-density data are in OCEAN data files and the dilution-pump volume data exist in the Plant Operating and Meteorological files.

Computational procedures are described in Section 2.7.5.

2.5 DILUTION PUMP: COMPOSITION, ABUNDANCE, AND INITIAL CONDITION OF IMPINGEABLE-SIZED ORGANISMS The species composition oand abundance of impingeable-sized fin- and shellfish that pass throUgh"t e 0[CNGS dilutionpumps were used to al-. . .

culate weekly estimates of total pump passage. Additionally, initial condition of these organisms was investigated.

2.5.1 Samnling Gear and Schedule Samples were collected at the easternmost dilution pump discharge port using a collar/net sampler, a live car, and a trough system equipped for flov-through s~h ndl d._nsholding

........................... w ngrw of

_*i collected organisms.tur~es ch and.-dav-it--a.tr~uc The

..-.......-entire sampling Tre -l~i.v~e gear car -was..- - -.

equipped with a diversion plate and reservoir that provides captured organisms with a refuge from pump discharge turbulance and minimized the stress of retrieval by providing a water pocket in which the collected 2-4

organisms reside until they were removed. This design reduced sample-collection stress that might otherwise have confounded initial condition de terminations.

Collections were made with the large net and live car system (Figure 2-4) suspended in the dilution discharge flow. The front of the net, through which organisms entered the device, consisted of a steel frame collar with a 1.2-m. square opening. Organisms then passed through a 3.5-m section of 8--mm square-mesh netting and entered the live car. The live car is a I x 1.3 x 1-m high structure made of 7-mm mesh netting over a steel frame.

Col*ections .. e- -- a**de' at -the surface and bo ttom ;--ini -random order,.for 30-minute periods; each pair of collections constituted a sample in order to account for the entire water column. Samples were collected five

. i. mes during the 12-hour period following sunset. and three times during the remaining 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months . This schedule was repeated three times a week for a total of 24 samples per week. One of the night samples was col-lected approximately 2 hours2.314815e-5 days 5.555556e-4 hours 3.306878e-6 weeks 7.61e-7 months after sunset to collect data from the period of expected maximum abundance.

The volume of water sampled varied as a function of pump operation; a flowmeter was deployed to measure mean water velocity through the col-lection collar. From mid-November 1984 through the end of the study in December 1985, water velocity in the sampled dilution port was measured once every 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months with a General Oceanics (GO) flowmeter that was suspended independently in the discharge at heights corresponding to the center of the collar when in sampling position. After late May 1985, a second GO flowmeter was mounted on the side of the collar and readings were -obtained of each deployment of the gear. Results of a special flow determination study revealed that differences in flow readings between the two meters for surface samples ranged from 1 to 18 percent for pump-operational modes which accounted for almost 95 percent of the pump modes sampled (Section 7.3). Bottom sample differences ranged from 2 to 10 percent. It was hypothesized that the apparent differences were due. to water current turbulence induced near the easternmost edge of the sampled dilution port. For purposes of abundance and density determinations, the standard daily flow measurements were used, possibly resulting in an overestimate of actual abundance in the dilution discharge.

2.52 S 1 in&

n Procedures

.................................................. .ro-c...

After deployment, the gear was retrieved -and organisms and debris were quickly removed from the reservoir using dip nets and placed into water-filled holding cars. These holding cars were then transferred to the flow-through holding system which used dilution discharge water as the holding medium. After transfer, most debris was removed from the holding cars so as not to affect organism survival adversely. After a sample was collected, sample processing; initial condition determinations, and water quality measurements were made as described in Section 2.1.2.

~. - .- ~. .~.~.-

- .~~- --- . ......

2-5

2.6 CONDENSER ENTRAINMENT MORTALITY STUDIES Studies were conducted to determine the .survival rates of selected organ-isms that are entrained through the OCNGS cooling system. An additional objective was to investigate the effects of several plant-operational and water-chemistry parameters on organism survival. Target species were blue crab (Callinectes uaidusi) zoeae and megalopae, bay anchovy (hnch.a mjtchili) eggs and larvae, and winter flounder (Pseudonleuronectes mi.) larvae. However, the virtual absence of blue crab zoeae and megalopae from intake waters- precluded survival testing for these forms.,

Of the many factors potentially affecting both initial and latent sur-

" ".... vival, 'two categories' were sp-c'fically6"by- a11inted for this program---

natural or background effects and sampling effects. These effects were accounted for by*collec at both the intake.,_priorto _ay.

plant interaction, and at the condenser discharge using identical gear employed in an identical fashion. Sample collection began 2 minutes later at the discharge than at the intake in order to sample the same portion-of water'with -each-gear-beaause- the-approximat time-of paSsa.e through OCNGS is 2 minutes (U.S. AEC 1974). After removing the effects of both natural and sampling mortality, actual entrainment mortality was calculated as outlined in Section 2.7.8. Assessment of plant-operational and water quality effects on survival was based on these calculated values. The last operation involved application of the survival data to entrainment abundance data for the period September 1975 - August 1981 to compute the annual number of organisms killed by entrainment.

2.6.1 Sameling Gear The collection gear used for this program of study was an EA-designed gear called the barrel sampler (Figure 2-5). This gear,' employing "larval table" technology, is constructed of two concentrically mounted cylindrical tanks. The inner cylinder is equipped with screened panels.

An inflow orifice is fixed to sample 0.9 m below the surface and is oriented into the flow. The other end of the sampling pipe is connected to an inlet port located near the bottom of the inner tank. An outlet line opens at the bottom of the sampler between the two tanks and is connected to a high'volume trash pump (610 gpm Homelite). To sample, the gear is submerged until the entire screened area of the inner tank is under water. Pump operation applies suction to the outlet line and sample water is drawn into the inner tank, out through the screened walls of the inner tank (331-,immesh)*, anthence out through e-outlet eth line to the trash pump. This design allows sampled water to enter the inner barrel and to exit through the screens while suspended particulate matter (e.g., fish eggs and larvae) in the-middle of the barrel are kept away from potential abrasion. After sampling, the gear is slowly drained and the sample is collected in a rigid codend. Use of this gear minimizes the potential for damage to collected organisms by minimizing the through-screen velocity, protects organisms 'from local environmental and gear-induced turbulence, and permits a relatively short sample-collection time. Water velocityro-uh _the filteri..ngmesh of the inner barrel is less than 1 cm/sec. This low velocity permits swimming larvae to avoid contact with the filtering mesh.

2-6

The holding system for collected target organisms employed a flow-through water system. which used condenser discharge water for thermally elevated test conditions and dilution-pump discharge water for ambient-water test conditions. Winter flounder larvae were held in screened flow-through containers; specimens from the intake station were held in ambient-water baths, and organisms collected from the condenser. discharge were held in thermally elevated conditions if OCNGS was producing power. Bay anchovy eggs and larvae were held in solid containers that were maintained in the flow-through water baths.

2.6.2 Samolina Procedures "Prior t sampling, barrelsamplers were deployedat.. -theý.easternmost.. . .

condenser discharge port and at the northernmost intake groin west of the recirculation/de-icing tunnel (this placement avoided collection

--of plant-passed larvae from the recirculation tunnel discharge at the intake). The samplers were lowered into position and the intake sample was begun 2 minutes prior to the start of the discharge sample, as described above in Section 2.6.1. Sample duration was generally 10 min-utes, but occasional samples of shorter duration were collected when organism or detrital abundance was extremely high, in order to facilitate rapid sorting procedures. After collection and sample washdown, the cod ends were transferred to a laboratory trailer; all sorted target organ-isms were categorized as live, dead, or stunned/damaged and the live and stunned/damaged specimens were carefully placed into either flow-through or solid holding containers in appropriate water baths. Initially dead specimens were preserved in 4 percent formalin. Observations of life condition were made 3, 6, 12, 24, 48, 72, and 96 (+/-2 hours for the 96-hour check) hours after collection. Larvae were fed either commercial fish-fry food or wild zooplankton at each observation period. Test organism conditions except for eggs, was based on the criteria outlined in Section 2.1.2. Egg condition was based on microscopic examination and eggs were judged to be live if they were clear and transparent, and continued to show development over the entire holding period (due to the short incubation time for bay anchovy eggs, all live eggs were those that successfully hatched prior to test termination). Eggs were judged to be dead if they were cloudy, opaque, had deposition of sedi-ments in or on the egg, had a ruptured chorion, or showed no development over the holding period.

To facilitate the sorting and handling of bay anchovy eggs and larvae, both veky difficult" forms -to see ýeven using microscopy,' neutral xred -z.dye .

solutions were introduced into the samples and holding containers. The use of this vital stain did not interfere with bay anchovy egg hatching and allowed an accurate accounting of egg numbers.

All dead specimens were preserved in 4 percent formalin, labeled, and held for subsequent identification. After initial sorting, all samples were preserved for later microscopic examination to determine both ini-tial egg viability and to determine the error that may have been attrib-utable to sorting effects (such as preferential sorting of live larvae because movement may catch the" s~ortýýer eyeY7 *.-- .~.........-

2-7

Water quality and plant-operational data were collected concurrently with the biological samples. Water temperature, DO, salinity, and pH were also measured throughout the 96-hour holding system in both the circulating water bath and representative holding containers. Addition-ally, total chlorine concentrations were determined -during the collection process to account for any biocidal effects. Instrumentation used to obtain water quality' information consisted of YSI DO and S-C-T meters, Orion pH meters, and a Fischer-Porter amperometric titrator; all instru-ments were calibrated prior to use except for the titrator (which cannot be calibrated).

2.7 DATA PROCESSING All field and laboratory data were recorded on standard data sheets and checked for accuracy. The data were then entered to computer-disk memory on a -Hewil-e-tt-Packard--983-OA"--coamput~er.- --Prtftout6 vrefteiWe-rteid an~d-'data' verified against the original data sheets. Using a telephone modem, all basic data files were transmitted to GPU Nuclear's Reading, Pennsylvania, computer.. This__Vas q. doneb .for-purp.oses ..of..permanent, ..secure.-storage of data, and also to utilize the SAS statistical package available on the Reading computer. Computational methodologies are outlined below for each study program.

2.7.1 Imroineement Estimates The impingement sampling program at OCNGS employed a multi-stage sampling design. In the first stage, sampling days were selected once a week with each week considered a sample event. In the second stage, the sample day was partitioned into two 12-hour periods roughly representing day and night. In a third stage, the 12-hour periods were subsampled in 3-minute subgroups to a maximum of seven samples per day or four samples per night.

Using data collected by this sampling design, impingement estimates were computed with the following formulas:

L 1 z N.Y. (Equation 2-1)

X 2.

i=l where I = estimated total number (or weight) of organisms impinged L = total number of strata (weeks) i - ordinal number of strat h N. number of days in the i stratum (7) ;

1

n. Y, Y. (Equation 2-2)

=average daily impingement for i th stratum 2-8

where

£th

n. = number of sample days in i stratum j = ordinal number for sample day 2 .

Yij K=I Yijk (Equation 2-3) th sample day of ith stratum

=estimated impingement for j where 2 = o nnumb er po.rf dieperiod k - ordinal number for diel period

[iik - ( I TBiiklYijk i (Equ*ation 2-4)

Y Tsijkl ) A

- estimated impingement of the Kth diel period of the jth sample day of the ith stratum where M = number of blocks within diel periods 1 = ordinal number for block TB ijkl = length of block (103 minutes for day, 180 minutes for night)

Tsijkl

='length of sample in minutes, collected in the ijklth block I - ideal number of samples in diel period A = actual number of samples in diel period 2.7.2 Impingement Initial Condition Determinations All organisms were categorized upon collection as either live, stunned, or dead (Section 2.1.2). These counts were summed by species,' by period, and summarized by period and by year. Final data was expressed as pro-portionswhich,_er.e generated using the following formulas:

Proportion live = (Equation 2-5)

(number live)

(number dead + number stunned + number live)

Proportion stunned = (Equation 2-6)'

(number stunned)

(number dead + number live + ub r stun ned ) - -- _ -_ ..................

2-9

Proportion dead = (Equation 2-7)

(number dead) -

(number live +'number dead + number stunned) 2.7.3 Imoingement Latent Mortality Determinations Samples collected at the end of the screenwash discharge pipe and, less frequently, in the OCNGS impingement pool were analyzed for initial con-dition (live, dead, and stunned) and then live and stunned organisms were held separately in either ambient or ambient plus delta-T water for 96 hours0.00111 days 0.0267 hours 1.587302e-4 weeks 3.6528e-5 months . The -number dead was. tabulated at 12 discrete intervals (0, 0.5.%

1, 2,3,s 6,s 12*, 24, 36, %`4C-:7`1 a~nd-9 hours) This ififormation .1was accumulated by sample event (generally a week) and the proportion live was calculated. Analysis of survival was. pqerfoormed on these values.

The following equations were used to determine survival:

Initial survival. (Equation 2-8)

(number live + number stunned (number live + number stunned + number dead) 96-Hour survival = (Equation 2-9) 11 (number stocked) - * (number dead @ interval j)/number stocked j-i Total survival (Equation 2-10) initial survival

96-hour survival GL models using these proportions were performed against the following variables:

I - ambient temperature 2 - delta-T 3 - high/low screenwash pressures 4 - number of screens operating 5 - maximum holding temperature 6- mean holding temperatiire ..

7 - tidal height Models were run by holding-water type (ambient or ambient + delta-T) and by species.

2.7.4 Screenwash Efficiency Determinations Data processing of screenwash efficiency data consisted of simple tabula-tions and calculation of percent efficiencies.

2-10

2.7.5 Dilution-Pump Abundance Estimates--Entrainable-Sized Organisms Ichthyoplankton, macrozooplankton, and microzooplankton data collected from 1975 through 1983 at the OCNGS condenser discharge were used to estimate annual dilution-pump entrainment during those years. The data were analyzed using a multi-stage sampling design. In the first stage, sampling days were selected once a week, each week being a sample event.

In the second stage, the sample day was partitioned into two 12-hour per-iods roughly representing day and night. In a third stage, the 12-hour periods were subsampled twice..

Microzooplankton data were only available for 1.5 years and other data were not collected with the same frequency in each study year. Balancing sampling effort was ccompli"shed by averaging in a weekly strati idd model.

Using data collected by this sampling design, dilution estimates were computed with the following formulas:

L Is Z i=l V.*Y.

1 (Equation 2-11) where I = estimated total number of organisms entrained L = total number of strata (weeks) i = ordinal number for strata V - total volume pumped through the dilution pumps in the ith stratum (in cubic meters)

~*~.Ln.

Y.J1m (Yij) (Equation 2-12)

Y.1 average daily capture per cubic meter for i stratum where

4. ,- .'

th n.1 number of sample days in i stratum

.1 = ordinal number for sample day Y.. = Kj (Y ijk)/ (Equation 2-13) 1 \=1 y

=

mean n.entrainment capture per cubic meter for j th sample

=._.m.ea i j -. d ay o f i t h s t r a t um . . .. .. . ... .. . .... . . ... . . . ... . . ...

2-11

where 2 - number of diel periods K - ordinal number for diel periods Y ijk (Tsijkl) (Equation 2-14)

Y - mean entrainment density of the Kth diel period of the j th ijk sample day of the ith stratum where.ý.,-

Y.. - total number of organisms captured in sample L of block. +K

.. 1Jk-- ----------

M = number of blocks within diel periods 1 - ordinal number for block T .k voluinmesampled (in cubic meters) in the ijkith block.

2.7.6 Dilutigo Estimates--Imningeable-Sized Organisms The dilution sampling program at OCNGS used a multi-stage sampling design. 'In the first stage, sampling days were selected once a week, each week being a sample event. In the second stage, the sample day was partitioned into two 12-hour periods roughly representing day and night. In a third stage, the 12-hour periods were subsampled in 30-minute units to a maximum of 16 samples per day or 32 samples per night.

Using data collected by this sampling design, dilution estimates were computed with the following formulas:

L

= zI V. Y. (Equation 2-15) i-li1 1 where I = estimated total number (or weight) of organisms captured L 'total number of strata(weeks) .

i = ordinal number for strata V. total volume pumped in the ith stratum (in cubic meters)

Y.

= Y (Equation 2-16)

.i ni n jl-2-12

where

n. -number of sample days in ith stratum

= ordinal number for sample day Y X Y=, (Equation 2-1.7) mean dilution capture per cubic meter for jth sample day of ith stratum where.

2 - number of diel periods k = ordinal number for diel period 3.jk ijk = (.1z Ti-1}

kl) m (Equation 2-18)

= mean dilution of the Kth diel period of the jth sample day of the :th Itratum where Yijkl total number of organisms captured in sample 1 of block k m - number of blocks within diel periods 1 = ordinal number for block T sijkl= volume sampled (in cubic meters) in the ijklth block 2.7.7 Dilution Pump Initial Condition Determination Calculation of initial condition of organisms captured in the dilution-pump discharge was performed in the same manner as that described in Section 2.7.2 for screen-impinged organisms.

.. 2.7.8 Ichthvoplankton Entrainment Mortality Estimates Dat'a analysis of entrainment survival information consisted of three phases. The first was calculation of initial and latent survival at each collection station (intake and discharge). The second phase used initial and latent survivals at each station to derive total entrainment survival values. The third step determined.which thermal factors affect total entrainment survival. The final step applies the derived relationships of total entrainment survival to the historical temperature database in conjunction with historical abundance values to estimate the number of t... w -ta "*-rsece tha.-.succumb -t-o entr anment--sesses . - ....... .-

2-13

Initial survival is computed as S(j) = (Lo + So)/(Lo + So + Do) (Equation 2-19) where Lo = number live at time of collection So - number stunned at time of -collection Do = number dead at time of collection The number live, stunned, and dead for larvae were the numbers counted d.during the, field .-sort procedures. .. Live and ,dead egg:valueswere, composed of the sum of field-sort categories and later laboratory-based micro-scopic sorts because initial egg condition could be determined after Latent survival is computed as S(1) = (L96 + S96)/(Ls'+ So) (Equation 2-20) where L96 = number alive after 96 hours0.00111 days 0.0267 hours 1.587302e-4 weeks 3.6528e-5 months S96 number stunned after 96 hours0.00111 days 0.0267 hours 1.587302e-4 weeks 3.6528e-5 months Lse number stocked live into test containers Ss number stocked stunned into test containers Total survival is computed as S(t) = S(i) x S(1) (Equation 2-21) for each collection station.

Entrainment survival values were estimated as the quotient of condenser discharge survival and intake survival.

SE. =. S. (Equation 2-22) where S. initial survival at the condenser discharge 1

SI= initial survival at the intake 2-14

D sIE -- sI/s I (Equation 2-23) where S D = latent survival at the condenser discharge 1

SS1= latent survival at the intake and E E E (Equation 2-24)

The relationship of these survival values to thermal parameters was then

.investiated to provide a mechanism that allows survival rates to be applied to historical abundance data. The thermal values used were Intake collection temperature,- mean ambient temperature measured during sample event Discharge collection temperature - mean condenser discharge temperature measured during sample event Mean discharge holding temperature - average discharge water temperature measured in the holding system, based on values measured at each observation Maximum exposure temperature - maximum temperature encountered in discharge holding system throughout the sample event Delta T -,.mean difference between intake and. discharge collection temperatures during a 'sample event Linear relationships were determined using a Hewlett-Packard installed, multiple regression program in conjunction with an HP-9830A computer.

Weekly abundance was derived by multiplying historical mean weekly densi-ties by the weekly volume that was pumped through the OCNGS cooling sys-tem. Annual estimates were based on the summation of weekly estimates for each target species.

Annual estimates of numbers of target species lost due to entrainment at OCNGS were determined by first selecting the "best fit" model that used thermal data that have historically been measured at OCNGS (intake and discharge temperatures and delta-T). Weekly mean thermal data were then computed using SAS. The appropriate thermal values were used in conjunc-tion with the survival model to compute the proportion of the target spe-cies expected to survive entrainment (sE). The proportions not surviving entrainment (1 - SE) were derived and tfose values were multiplied by the coincident estimated weekly abundances of the target species, and summed for each study year. --- --- ---

2-15

2.7.9 Statistical Analvsis of the Relationshi2 Among Imningement Catches. Meteorological Phenomena. Water Oualitv Data.

and Plant-Ooerational Charac ters tics The relationship of the various parameters to impingement catches was investigated statistically using the SAS-General Linear Model (GLM) multiple regression program.

In a preliminary analysis, correlation cofficients (r) were derived from regression analyses among various plant-operational and water quality variables. This was done to quantify the expected relationships among such variables as ambient water temperature and air temperature, ambient wa-ter-,temperaturpe anddissolved oxygen,,. and, heat. .rejecti~n and.deltaT..

In this manner, those variables that were cross-correlated with other variables were identified.

As a preliminary procedure using biological data, the coefficients of determination (r 2 ) were computed between impingement catch rates for abundant species and the various meteorological, wter .quality,, and_

plant-operational parameters for the entire 1984-1985 database. This was an attempt at early isolation of any very strong relationships.

However, all coefficients of determination (r2) were relatively low (Cg.0.20), suggesting no strong relationships among the variables.

The full GLM model then was run using number and weight impinged per hour for important and abundant organisms relative to certain plant-operational, physical/chemical, and meteorological parameters. The regressions were runi for each season because of the highly seasonal distribution of most organisms.

2-16.

Oischarg~ Canal Figurel 2-1 Diagram of the intake and discharge of the circulatingoWater system and the dil ution pumps at the Oyster Creek Nuclear Generating Station ect i samplingdiso for impingement abundance; B =post-impingement latent effects; C dilutlon dicarBe for impvigeable organisms D entrainmet latent effects.

Trash Racks Debris

- Removal Trough Intake Flow I

Figure 2-2. Oyster Creek Nuclear Generating Station cooling water intake structure and fish sampling pool.

Low Pressure Sluice

-High Pressure Sluice Water Surface FLOW :ý Oyster Creek Nuclear Generating Station.

~0.95-cm ;

Mesh Net

Live Car/Cod End i Flow 0.64-cm Mesh Not

Diversion Plate/Reservoir - Sampling Collar 1.19 by 1.06m 5.9 m j-Opening Figure 2-4. Schematic diagram of the dilution-pump discharge samplin device.2 9

Exit to Pump Tank Inner Tank with 331 -Am Mesh Screen

.I.. - ". 0 Collection Box Figure 2-5. Schematic diagram of the portable entrainment survival sampling device (Barrel sampler).

3. .IPINGEMENT COMPOSITION, ABUNDANCE, AND INITIAL CONDITION 3.1 GENERAL SPECIES COMPOSITION AND ABUNDANCE Weekly impingement collections from November 1984 through October 1985 yielded 83 taxa of fish, invertebrates, and amphibians. Of these taxa, 63 forms were finfish, 19 were invertebrates, and 1 was an amphibian.

Four species constituted 95 percent of the total annual numerical catch from the vertical traveling screens (Table 3-1). The total annual (sampling) catch of all species collected during the study period was 55,941 specimens; of this total catch, 2,743 were fish (4.9 percent),

S53 ,8 were invertebrates (95.1 percent), and 1 was an amphibian

(<0.1 percent)'. ,..

The total -eight of all specimens collected during the study period was 266.9 kg. Of this total, 42.2 kg (15.8 percent) was fish weight,"

224.7 kg (84.2 percent) invertebrate weight," and <0.1 kg (<0.1 percent) amphibian weight. Eighteen taxa accounted for more than 95 percent of the total weight of the annual catch (Table 3-2).

The seasonal distribution of estimated weekly numbers of organisms impinged is illustrated in Figure 3-1. The period of maximum numerical abundance was bimodal--the first peak ranged from mid-November to the end of January, followed by another that ranged from the end of February to the end of May. The first peak is composed chiefly of sand shrimp, whereas the second peak is a combination of organisms with sand shrimp and blue crabs the most abundant forms. Bay anchovies, Atlantic silver-sides, and northern pipefish are also abundant during the second peak,.

but they accounted for only 10 percent of the-catch. The peak weekly estimate of 3,447,783 individuals occurred during the third week of November.

The day-night distribution of organisms collected from the traveling screens is presented in Table 3-3. Most organisms were more abundant in night samples. The top four species, in numerical abundance, were predominantly collected at night: sand shrimp (92 percent of night catch), grass shrimp (80 percent), blue crab (80 percent),-and Atlantic silverside (64 percent). Bay anchovy exhibited the greatest difference in numbers caught during the day (6.4 percent) and night (93.6 percent).

Of abundant species, the bay anchovy and sand shrimp yielded the greatest

-.difference. in: weight between, day and night catches (95 and 90 percent, respectively)

3.2 DISCUSSION OF KEY SPECIES The U.S. Nuclear Regulatory Commission has defined 11 fish species and 2 invertebrate species as "Key Species" of finfish and shellfish (NRC 1978). The species so designated are: summer flounder, winter flounder, Atlantic menhaden, Atlantic silverside, bay anchovy, bluefish, weakfish, striped bass, northern pipefish, -northern puffer, northern kingfish,

.bue-crab-.ndsa .shrmp........ AlL-of.the.A.l.de.nd key .fish secies, except striped bass and northern kingfish, were collected from OCNGS.

screens during 1984-1985; both invertebrate species were collected.

3-1

The nine key fish species accounted for 63.2 percent of the fish col-lected (54 percent by weight) from the traveling screens. The two key invertebrate species accounted for 87.1 percent of the invertebrate catch by number and 82.9 percent of the catch by weight.

Each key species is discussed separately below. Abundance and periods of occurrence are first described for the November 1984 - October 1985 study period. For the more abundant species, the results of statistical analyses are presented that describe the relationships of impingement to plant-operating and meteorological phenomena. The 1984-1985 results are then compared to abundance data for the previous 9-year period and annual variation is discussed. In addition to the key species,' the blueback herring..is.,discussed*. * .,_

In these presentations, the use of the terms "collected" and "sampled" (and *Mirants)_ref azthose.sp imensActalytzinedinwenkly samples from the OCNGS screens. When referring to weekfy or annual pro-jected impingement catches, the terms "estimate" or "estimated" are used.

3.2.1 .Atlantic S'ivr.de -(M :iid 'meni&.a' Atlantic silverside was the most abundant fish species collected from the OCNGS screens; 824 specimens accounted for 30.1 percent of the total fish catch (1.5 percent of total organism catch) (Table 3-1). Atlantic silverside ranked 3rd in fish weight with 4.8 kg, accounting for 11.3 percent of the total fish catch (1.8 percent of total organism catch)

(Table 3-2). The period of maximum abundance ranged from mid-November through mid-April, with the peak estimate of weekly abundance occurring during the second week of November (82,200 individuals). The period of minimum estimated weekly abundance occurred during the warmer part of the year from mid-July through the end of October (Table 3-4). The peak weekly estimate of impinged weight was 371.2 kg which occurred during the second week of November (Table 3-5). No Atlantic silversides were impinged between the beginning of July and the end of October. The annual estimate of the numbers impinged for this species was 276,942 and the total estimated weight was 1,573.5 kg (Table 3-6). Sixty-four percent of the silversides were collected at night; the remaining 36 percent came from daytime collections (Table 3-3); Based on examination of Atlantic silversides 30 minutes after impingement (initial condition),

the experience was not very harmful. Ninety-one percent of impinged specimens exhibited no initial damage or stress, and there was little

.... difference between day and,,.night,1(:Table 3-7).e ater quality dataasso- .

ciated with impingement sampling are shown in Table 3-8.

Very little of the variation in number and weight of Atlantic silversides impinged was explained by the General Linear Model (GLM9 multiple regres-sion) analysis (Table 3-9). At most, 17 percent (r 2 ) of the variation in both number and weight was explained for the spring season. This small proportion of explained variation was most influenced by temperature and tidal height.

....................... A~tlan tic--ei-l--ve-ri-e. populati.ons ~ ae *f-luc~uated -g-reatly

-- vet-t *ps* .......................

-9_ ..

years (Figure 3-2; Table 3-10).iEstimated :.abunda0ne ra.d- .m:35051 in 1976-1977:to :týhe previous-:highý.!of 268,961 in 1980-1981. The estimate 3-2

of 276,943 impinged during this study established a new peak abundance for the species. As presented in past reports (EA 1981, 1982), the severity of the winter and the amount of time the plant remains opera-tional affect the number of Atlantic silversides that are impinged.

Although a year-round resident of Barnegat Bay, these fish are only vul-nerable to impingement during the colder months of late fall, winter, and spring. This may be due to movement of this species from the shoreline-shallows habitat into deeper water, increasing its vulnerability' to the screens. This would explain the high numbers impinged during fall and winter, but the large numbers taken during April and May (Table 3-4) may be due to the species' habit of forming large breeding schools at that time of year (Fay et al. 1983). The mild winter of 1984-1985, with a me an water,* teperature.of 4.71 C %may--have,,enhanced. winter survival:and contributed to the high abundance. Hoff and Westnan (1966) reported that Atlantic silverside cannot tolerate water temperatures below 1.0 C.

3.2.2 Bay Anchovr (Anchoa mitchilli)

The bay anchovy was the 2nd most abundant fish species collected from the screens-487 specimens constituted 17.8 percent of the total fish catch (0.9 percent of total screen catch) (Table 3-1). Bay anchovy ranked 6th in terms of -fish weight (3.7 percent of fish catch; 0.6 percent of total catch). Bay anchovy were collected from the end of March to the end of November; no anchovies were collected during January, February, and the first three weeks of March. Maximum estimated weekly abundance for this species was 100,941 specimens during mid-April. The period of minimum estimated weekly abundance occurred from January through March 1985.

The peak weekly estimated weight of 334.5 kg occurred in the third week of April. The annual estimate of number impinged for this species was 195,871; the total estimated weight was 629.6 kg. Night catches accounted for 94 percent of the annual anchovy catch by number; 95 per-cent of the total weight catch occurred at night (Table 3-3).

Bay anchovy fared less well after impingement compared to Atlantic sil-verside. Seventy-eight percent of anchovies were dead and an additional 8 percent were stunned or otherwise damaged. Mortality was greater at night (Table 3-7). The high mortality was attributed to the relatively fragile nature of this species.

Temperature and period (day or night) were the most influential variables affecting bay anchovy impingement (Table 3-9). However, only 2-16 per-cen*t df"V tevari*ation inorg weight" in-any s by the GLM model. Intuitively, temperature and day-night period are more influential than shown by the model. The naturally high variation in biological data may preclude identification of strong cause and effect relationships with this method.

Bay anchovy, always a major component of each annual estimated screen catch, dropped from a 1975-1976 maximum of 1.8 million individuals to a relatively low and stable annual catch of 77,000-155,000 during the

_foliowipngyears of 1977-1982 (Figure 3-2). The low catch of 1982-1983 (25,497 estimate iniviuiai-si)-c-a-4-explained-byt--he-fact..that--the-plant only operated for a 7-month period. No estimate was made for 3-3

the 1983-1984 study due to a plant outage.. .Thepisen ::s tudy -shows an inceas i iub of, tsa~o~ h 'siae amind nual1 total ws h'1ret ic19h Previous annual reports (EA 1981, 1982, 1983) discussed possible reasons for apparent declines in bay anchovy populations.. Possible contributing factors considered were predation on early life stages by ctenophores or Atlantic silverside, and the effects of entrainment of eggs and larvae through the OCNGS cooling system. These conjectures were not substan-tiated, however. Because there are no comparable data for other nearby estuaries during the period in question, it is not clear whether the apparent population fluctuations are limited to Barnegat Bay or whether

they* ar *syip a 3c o more wid on luc ti on.

3.2.3 Northern PiDefish (Svn=nathus fuscus)_

The 3rd most abundant fish species collected was northern pipefish with 297 specimens accounting for 10.8 percent of the total fish catch on the sc'reens-.(GO.,5.-percent-of --total, organism catc-h-) (Table- 1:) r----Northern pipefish accounted for 1.7 percent of the annual fish weight catch (0.3 percent of total organism weight); 0.7 kg were collected during the study year (Table 3-2). Species abundance was high between early. November 1984 and the end of January 1985 and again from mid-March to the third week in June; peak estimated weekly abundance occurred during the third week of November when 31,022 individuals were estimated to have been impinged on the screens (Table 3-4). Estimated weight distribution throughout the year for pipefish was similar to the numerical distribution, with the peak estimated catch of 73.4 kg occurring during the third week of November (Table 3-5). Annual estimated abundance for this species was 107,875 individuals; the total annual estimated weight was 254.6 kg (Table 3-6). Night catches for this species accounted for 77 percent of overall numerical catch and 77 percent of the weight (Table 3-3).

This hardy species exhibited 91 percent initial survival of impingement (Table 3-7). ".

The results of the GLM analysis indicated that temperature (fall) and number of screens plus day-night period (spring) influenced the number and/or weight of northern pipefish impinged (Table 3-9). The highest coefficients of determination (r 2 ) for any species was recorded for the spring season. The model, in particular screens and day-night period, explained one-fourth of the variation in catches. The number of screens

'4ý.!;" I operating would have an v e on catches and the day-n-ight' period influence is documented in Table 3-3, where over three-fourths of the number impinged were recorded at night..

The annual estimated catch on the OCNGS traveling screens ranged from a low of 'about 11,000 individuals in 197.6-4,9,77. to a maximum of almost 93,000 in 1980-1981 (Figure 3-2). The aef.rth'a** "ipf i.sh;ring the -study .,year e.ded the prev.ou, , .. ivid.

fl ~ u ons 3-4,

The 1984-1985 catch continued to reflect a bimodal distribution, with one peak occurring during the period of rapidly falling water temperatures in November and December, and another peak occurring in the spring from March through May. The pipefish in Barnegat Bay probably behave simi-larly to those found in Chesapeake Bay, overwintering in the deeper Bay waters and found along the shoreline during the remaining period of the year (Hildebrand and Schroeder 1928). Hildebrand and Schroeder also state that most inshore migration occurs from late March into early April and most offshore migration occurs in November. It is reasonable to assume that similar seasonal movements take place in Barnegat Bay. This would explain the peak impingement catches in fall and spring-they occur when pipefish are moving to (fall) or from (spring) the deeper waters of 4`-- "Barnegat, -Bay.

3.2.4 Blueback Herrina (Alosa aestivalis)

Blueback herring ranked 6th in abundance in impingement catches. A total of 152 specimens accounted for 5.5 percent of the total fish catch (0.3 percent of total organism catch) (Table 3-1). Blueback herring accounted for 11.8 percent of the annual fish weight catch (1.9 percent of total organism weight); 5.0 kg were collected during the study year. Species occurrence was greatest between late December and the third week of April; peak estimated abundance occurred during the third week of Decem-ber when 12,817 individuals were estimated to have been impinged on the screens. The peak weekly estimated weight of 304.5 kg occurred during the third week of April. Annual estimated abundance for this species was 52,191 individuals; the.total annual estimated weight was 1,650.9 kg (Table 3-6). Night catches accounted for 66 percent of the overall numerical catch and 56 percent of the weight. Initial survival of blue-back herring after impingement was 70 percent during the day and less than 50 percent at night. Based on the GLM model, the number of screens running appeared to have a slight influence on impingement catches (Table 3-9).

The estimated-number of blueback herring impinged during the 1984-1985 study year. was the 2nd highest in 10 years (Figure 3-2; Table 3-10). -

According to EA (1981) the impinged fish are young of the year that typically use Barnegat Bay as a nursery ground. Thus, variation in annual impingement abundance may reflect simple year class strength.

The relatively high annual estimate for 1984-1985 may be related to a peak catch in the spring of 1985 (Table 3-4). This contrasts with the as e1smentof-EA-(981,)- -that, sugges~tedf 0alling*,,tempera..ur t schooling and migration of the young herring from the bay to the ocean.

The unusual spring peak in 1985 (in addition to the previous late fall/

winter peak) may have been composed of fish that overwintered in the bay because of relatively mild water temperatures.

3.2.5 Winter Flounder (Pseudopleuronectes americanus)

A total of 53 specimens of winter flounder accounted for 1.9 percent of the total fish catch (0.1 percent of total organism catch) (Table 3-1).

Although t8" -i-n-*i- rical -'-nd-al-e *,--he-rel-atively--great--r-size- attai ned .... ......... .........

by this species resulted in its ranking first in fish weight; 12.1 kg composed 27.3 percent of the total fish catch (4.5 percent of total

" 3-5

organism catch by weight) (Table 3-2). The period of maximum estimated weekly abundance extended from early November through April (Tables 3-4 and 3-5). The peak occurred in the second week, of January when 4,157 individuals (1,125.2 kg) were estimated to have been impinged. Only one winter flounder was collected between the third week of April and the middle of October 1985. Total estimated impingement for this species was 18,210 individuals weighing 4,116.3 kg (Table 3-6). Night collections accounted for 62 percent of the total numerical catch for this species; 60 percent of the weight collected was accounted for by night collections (Table 3-3). The winter flounder proved to be relatively hardy; initial survival after impingement exceeded 90 percent (Table 3-7). No signif-icant correlation was found between number or weight impinged

...... " *and plant-

'operttng or -enviio~nmen'tal vk iablesb /(T~ ble 3r-9)*-o-o- . -

Th~e'ri-aiiing-effect~~~~~~

abwipze QY4 th t CG.Teldco arnegat Bay collec -

tions and entrainment abundance data for winter flounder since September 1981 precludes relating impingement to fluctuations in Bay populations.

3.2.6 Weakfish (Cvnoscion revalis)

Weakfish was the 13th most abundant fish species collected from the OCNGS screens with 32 specimens accounting for 1.2 percent of the annual fish catch (0.06 percent of total organism catch) (Table 3-1). Weakfish accounted for 1.6 percent of the total fish weight collected (0.3 percent of total organism catch) and was the 14th highest contributor to fish biomass (Table 3-2). This species was abundant from November 1984 to the first week of December, and then from the first week of August to the third week of October 1985. No weakfish were impinged from the second week of December to the first week of August (Table 3-4). Maximum weekly estimated weight occurred during the second week of October when 94.8 kg of weakfish was impinged (Table 3-5). Annual estimated abundance for this species was 11,084 individuals; the estimated annual weight was 244.7 kg (Table 3-6). Night catches accounted for 76 percent of the numerical catch and 81 percent of the catch by weight (Table 3-3).

Based on examination of relatively few fish, initial survival ranged from 64 percent during the day to 71 percent at night (Table 3-7).

but the relationship was not strong. Less than 10 percent of the vari-ation was explained by the GLM model.

The~~~ yery etbof .iaeý11 .ý000waih a 0ý5os p0rett grek .a~r!th-asn the last 'r~r~c a't.h 9218 ~be30 Figure 3-2). Typically, those impinged on the OCNGS screensware young of the year that migrate into the Bay in early summer as larvae. Their rapid growth makes them vulnerable to impingement by midsummer and they con-tinue to occur in screen collections until late fall when they migrate from-te *ay. t~uctuations in impingement may reflect year lass strength.

3-6

3.2.7 Atlantic Menhaden (Brevoortia tvrannus)

The 14 specimens of Atlantic menhaden collected from the OCNGS traveling screens accounted for 0.5 percent of the total fish caught (0.03 percent of total organism catch) (Table 3-1) and 2.5 percent-of the total fish weight collected. The total weight for the study year was 1.0 kg (0.4 percent of total organism catch) (Table 3-2). The period-of maximum estimated abundance ranged from the third. week of November 1984 to the first week of January 1985. The annual estimated impingement abundance of menhaden was 4,654 individuals weighing 3".6 kg (Table 3-6).

The estimated .numbersof Atlanic imenhaden, have changed little in the past seven year s.(igut-. 3-2; Tableg 3-10).Based on previous studies, the annual numbers impinged at `Oysterý Creek appepar related- to, abund-ance,*:-:*+*,.=*:_.*...+

of the species in Barnegat Bay. For example, Kurtz (1978) related the relatively high impingement of menhaden in 1976-1977 to a large 1976 year

....class present i -th-e bay., The. -ow and- similar ..impingement leve-lsma. ... . .

indicate a lack of highly successful spawnings over the last seven years.

3.2.8 Bluefish (Pomatomus saltatrix)

The 14 bluefish captured accounted for 0.5 percent of the total fish caught (0.03 percent of total organism catch) and 0.1 percent of total fish weight (0.06 kg). The peak estimated weekly abundance (1,260 fish) occurred during the third week of June, after which the catch began to decline. Peak estimated weekly weight occurred during the middle of July 1985 (10.1 kg). Annual estimated abundance of bluefish was 4,938 indi-viduals weighing 23.0 kg. Nine 'of 14 specimens were collected at night.

Bluefish, like Veakfish, use Barnegat Bay as a nursery area. They enter the Bay as juveniles in early summer and peak in impingement collections by midsummer. In 1984-1985, the annual impingement estimate was 4,938 specimens, up slightly from the previous study year's total .(Figure 3-2).

It would ,appear ,that ,bluefish population fluctuation is caused by unknown environmental factors andthat the number impinged is directly related to the population in Barnegat Bay.

3.2.9 - Summer Flounder (Paralichthys dentatus)

Summer flounder ranked 22nd and 7th, respectively, in terms of numbers and weight in the samples (Tables 3-1 and 3-2). Consistently low catches

... wererecorded from,,the second week in August to the end of October; most catches contained only a single fishi. Only t!wo other 66.vec ions---

occurred during the rest of the year-one during the third week of November and the other during the first of July. The period of peak estimated summer flounder abundance occurred during the first week of July, whereas the maximum estimated weight (158.3 kg) occurred during the first week of November. The latter catch was made up of mostly larger fish. The annual estimated impingement abundance for this spe-cies was 3,437 individuals weighing 511.6 kg (Table 3-6).

- Smr~rd~,ieuost of the%-other key: sEcis ncreased. in abun-dance ~

dyýnqI~ ~ ..*!`t~~

tu iyea r e* *` n-e~n e* *n r*-d ..........

dance during. the ov'stu year19 .4-1985. ehave inc ++

by 32 percent over the last yearly estimate, in 1'982-1.983. They have 3-7

varied in numerical ranking between 15th and 30th, and even the increase in number has had little effect on its ranking. As presented in earlier EA reports, the muddy substrate of the western shore of Barnegat Bay is not the preferred habitat of this species. Therefore, the screen catches do not reflect the abundance of summer flounder found at the eastern shore of Barnegat Bay or nearshore coastal areas.

3.2.10 Northern Puffer (Sohoeroides maculatus)

A total of three northern puffer were collected from the OCNGS travel-ing screens during the study year. This amounted to 0.1 percent of the annual total fish collected and 0.01 percent of total organisms caught

.I-(Table`3I). The total weightfthisspecies collected from- the- screens was 0.5 kg, which accounted for 1.1 percent of the total fish weight collected (0.2 percent of total organism weight collected) (Table 3-2).

The e Wtfel--& a---- 98--ind-i 1d--s---a weighing -5.

(Table 3-6).,

Just under...1,000. northern. puffer were estimated -.to...have-.been impinged-during 1984-1985. This annual impingement rate is similar to most other years, except September 1977 - August 1978 and September 1980 - August 1981. The large catches during those periods were attributed to larger numbers .,of.young...of the year in the Bay (Metzger ,1979; EA 1982) ..-

imiz~m1~ab~nace, 'isq generally -a ref ldction. f fld.budue

-- t-he

Aa Wd.pas

..impingement r..ut.s suges.t .c:-o-intinu-ed liow populatiop:.ilone-leivs AtBay. . . . . . . ....

3.2.11 Sand Shrimp (Cranizon sentemsninosa)

Sand shrimp was the most numerous organism collected. A total of 42,691 specimens was collected during the study period, which accounted for 80.2 percent of the total invertebrate catch (76.3 percent of total organism catch) (Table 3-1). A total of 50 kg of sand shrimp was collected but accounted for only 22.3 percent of the total invertebrate catch weight (18.7 percent of total organism catch) because of the small size this species attains (Table 3-2). The period of maximum abundance ranged from November through mid-July. The greatest estimated weekly abundance was 3,046,463 specimens weighing 3,673.0 kg, which occurred during the third week of November. Estimated annual abundance for sand shrimp was 17,090,788 specimens weighing: 19,71-9.6 kg (Table 3-6). The night catches accounted for 92 percent of the total numerical catch and 90 percent of should be less affected by impingement and this was corroborated by the 85 percent initial survival rate (Table 3-7).

Several variables proved significant in explaining small portions of the variation in catches of sand shrimp (Table 3-9). Temperature, number of screens operating, and day-night period are obvious as possible influ-ences. Salinity is less clear since it doesn't change much seasonally (Table 3-8). The influence of temperature and day-night period, particu-

.. ..yon.mp~ng.ement of shrimp.isprobably ssand muchmore important than indicated by the GLM model rsults.

3-8

-The m io "band- sht-im eiap4tohvbenipinged in 1984-1985 (Figure 3-2; Table 3-10) is the hihghestestma"inlO years. The reason for the high number is unknown, but it is probably a function of higher numbers of sand shrimp in Barnegat Bay. As with many other species, the annual variation in impingement catches of sand shrimp (Figure 3-2) appears to be related to natural population fluctuations within Barnegat Bay.

3.2.12 Blue Crab (Callinectes sanidus)

Blue crab ranked 3rd in numerical abundance on the OCNGS traveling screens. ' A total of 3,626 specimens accounted for 6.8 percent of the total invertebrate catch (6.5 percent of total organism catch). With

. ..egarde *owei'ht,*his peciesaccountied forthe'majority, of boththe ...

invertebrate. catch (60.7 percent) and total organism catch (51.2 per-cent); 136.5 kg were collected during the study year.: Blue crabs alraed 1n--large-numbers "throughout -the-warmer--part--of---the-study -. ..

period with the peak estimated weekly abundance occurring during mid-April (212,122 individuals); maximum estimated weight of blue crabs impinged in a week was 6,595.5 kg during the third week of July. The period of minimum abundance extended from mid-November through mid-March.

The estimated annual catch was 1,333,894 specimens weighing 46,891 kg.

Night catches accounted for 80 percent of the total number of blue crabs and 70 percent of total weight (Table 3-3). Ninety percent of blue crabs were recorded as live during initial condition observations (Table 3-7).

In a similar fashion to all other species, the GLM multiple regression model explained very little (18 percent maximum) of the variation in numbers and weight of crabs impinged (Table 3-9). Temperature and day-night period were most consistently significant in the model. The influence of temperature was not unexpected, given the fall and spring movements of crabs to and from deeper water as temperatures change.

The influence of period is documented in Table 3-3; 80 percent of the blue crabs were impinged at night.

The number 4ofU b1ue crab impinged; in 1.984-1985 was the 3rd highest in 10 years- {Figire 3-2;:TabTle310). Annual variation in impingement appears. related.to population dynamics in Barnegat Bay, as discussed below.

In previous annual reports, EA (1981, 1982) identified an inverse rela-tionship between the average size of crabs impinged and the total esti-mated* umber impinged in agivefi year. Itwste,-dthiweite blue crabs in the vicinity of OCNGS were larger and thus less vulnerable to impingement, fewer were impinged. This relationship was consistent for the first. 8 years of record and is further substantiated by data from the present study year.

3-9

Estimated Mean Weight Number Per Crab Impinged Year (g) (Z lO 1975-1976 9.1 5.63 1976-1977 47.0 0.23 1977-1978 18.0 1.17 1978-1979 52.8 0.31 1979-1980 64.7 0.28 1980-1981 21.2 1.83 1981-1982 58.8 0.25 1983-1984 Plant down, no samples collected 1984-1985 35.2 0.60 The reasons for the inverse relationship between mean weight and catch are unclear because there are no comparable data for Barnegat Bay for 1981-1985. Higher impingement of crabs in some years (e.g., 1975-1976, 1980-1981) may be a result of both greater vulnerability of the smaller crabs and larger year classes. Conversely, low impingement may be influ-enced by fewer numbers in the bay, as well as lesser vulnerability of the larger crabs.

3.2.13 Other Key Svecies The northern kingfish and striped bass occur only rarely in the vicinity of OCNGS (Metzger 1979). During 1984-1985, no northern kingfish or striped bass were collected from OCNGS screens. The scarcity of these species continues, as indicated by 1984-1985 impingement results.

Boyle (1978a,b) reviewed the status of northern kingfish and striped bass populations in Barnegat Bay and nearby coastal waters. The rarity of striped bass in Barnegat Bay is not unusual. Although seasonal migra-tions take place off the coast of New Jersey, the entrance and use of the bay by striped bass has historically been incidental. The decline in numbers of northern kingfish in the bay appears to be related to a general population decline in New Jersey coastal waters that began in the 1960s.

3.3

SUMMARY

Weekly impingement collections from November 1984 through October 1985 yielded 55,941 specimens (267 kg)-distributed among 83 taxa of fish, invertebrates, and amphibians. Four species-the sand shrimp, grass shrimp, blue crab, and Atlantic silverside-contributed 95 percent of the catch. Although organisms were impinged during every week of the study year, the majority were impinged between November 1984 and May 1985. During this period, two major peaks occurred, one in November and December and one in April. Most species showed a greater vulnerability to imýpingement at night. For the most abundant species," the proportion impinged at night ranged fromn61.7 for winter lounder to 93.6. or bay anchovy*

3-10

Among the key species, as. designated by NRC, sand shrimp and blue crab were most abundant, together accounting for ,nearly 83 percent of the impingement catch. Fish were far less abundant than invertebrtes.

The three most abundant were the key species--Atlantic silverside, bay anchovy, and northern pipefish--together composing less than three percent of the overall catch." Other key species and their respective percent contributing to the impingement samples were: winter flounder (0.09), weakfish (0.06), Atlantic menhaden (0.03), bluefish (0.03), sum-mer flounder (0.02), and northern puffer (0.01). The striped bass and northern kingfish were also designated as key species, but neither was collected during the study.

Difeece n ~fehistorypten-mn~th.audn-~e species_,..,

influenced the temporal distribution of impingement catches.. Sand shrimp are most abundant from late fall through early summer, at which time they

.-.- mi*gr-a-t-e-. off-shor e-toG-cooler waters... - inshore..-abundance,-. and_ thus _imp.inge- .

ment, of blue crabs is highest from spring through early fall. Young of the year of bluefish and weakfish, both of which use Barnegat Bay as a nursery area, are impinged in summer and fall, respectively. The bay anchovy is most vulnerable in the warmer seasons, April into October, whereas Atlantic silverside are impinged primarily during November through April. Northern pipefish exhibited two peaks in impingement, one in fall and one in the spring. Winter flounder occurred in impinge-ment catches from November into April.

A large percentage of most species survive the impingement experience.

Based on initial condition observations made 30 minutes after collection, nearly or greater than 90 percent survival was exhibited by blue crab, sand shrimp, winter flounder, northern pipefish, and Atlantic silverside.

Experience suggests that members of the herring and anchovy families are relatively fragile fish, and this was confirmed in the initial condition evaluation. Less than 50 percent survival was recorded for bay anchovy and Atlantic menhaden. Slightly more than one-half of the blueback her-ring were recorded as live. These values do not take into account the latent effects of impingement, which is the subject of Chapter' 4.

Based on application of the General Linear (multiple regression) model, several plant-operational and/or environmental variables were shown to be significant in influencing impingement rates. Temperature and day-night period were significant for most species. The reasons for this were discussed in the foregoing. Number of screens operating, tidal height,

'and'sainity

. ... w~ere sigifcant much less frequentlyt.'- ..... '-'-.j.-...

Anestimated, 22.million. org omnss were. impinged...-from.Noember 1984 thro.gh . Thi

' . a.. nearly.. ide t.... pevi* a igannual estimateof 11.5 .mil lion in 1975-1976ý Thi'Ls veraLI. increase was pri-marily the reosult o thf et number of saud..hrimp mpinged (17.1 mil lion) ;.,_ith-is-estimate xeddtepeiu ig o . million in 1980-1981 by two.-and!.one-half times. Most of the key and/or abundant species increased in estimated ..annual abundance during 1984-1985, com-

.p.d...... ... ..... ....... s.td.e........ ror of 9 1...... northern pipefish and Atlantic silverside, the 1984-1985 estimates of 148;06o -id277,0 - . .

respectively, were the highest in the 10-year record.

3-11

The reasons for the increases in impingement in the past study year, particularly that for sand shrimp, are not readily apparent from the present moonitoriig.. database. In al'gei1eaLit.pesha t,:.aB:discussed uvieai tcia 0aper .11e1 afgmt"a .fc~n isa'n jccirrn bf al~~~~~~~~~d~f aim abidneQ u"t~gt3y ~nthis basis ainumber of species, particularly sand shrimp, were mt~ving toward, or were at, high points in their population cycles during 1984-1985. The impact of impingement at OCNGS can be quantified in -terms of ...number. of organisms killed...(Chapter 4, Chapter 8). However, the .6i1at g"10-year dataa-se.

pieulati-n: Fe, 1..a~ '.h 0P-.tr1

,uened r b pacion Oraitin g eg'th I "

ciesat CNGSappars b i -influenced by ,population levels1in 'arnegat 3-12

3,447,783 2,515,456 t 2 oo- 4.

190-180-

170" 160-150-140-130-120-

. 110-x

,- 100-E: go-

80-70" 60-50-40-30-20-10-NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP OCT Figure 3-1. Estimated number of fish and macroinvertebrates impinged on the Oyster Creek Nuclear Generating Station traveling screens, November 1984 - October 1b85.

17.1 Million x

SedShrimp E

Blue Crab U

'U C.) 0

'U S

U U)

'U-C C

a' U

22-a.'

U, w 21.9 Million a'

16 14-12- -- All Organisms Combined 4,

2-I I [ T I F]

[ II I I I F-in I T I

1984-1975- 1976- 1977- 1978- 1979- 1980- 1981- 1982- 1983-1976 1977 1978 1979 1980 1981 .1982 1983 1984 1985

Plant Outage Study Year

. fii3-b2. niiiiand gan impingementcatas Nortota organismsaion, k nd abundant organisms at Oyster Creek Nuclear Generating Station.

-. -~Weakfish Z~~ 2 7F

r-m Northern Puffer I

2-j Atlantic Menhaden a-1 4

12 )Bluebacic Herring I I I I 1975- 1976- 1977- 1978- 1979- 1980- 1981- 1982- 1984- 1983-1976 1977 1978 1979 1980 1981 1982 1983 1985 1984 Plant Outage Study Year Figure 3-2. (Cont.).

161 Winter Rounder 4-I i l I I r-~F1

m A

E U 24.

U C-,

Atlantic Silverside U

S Is, U

C C Im I HE

w SW Anchovy 12-a a.

4-I1979-m--n, r-n.--Ir- 19.

m--

1979-- 1960- 1981- 1982- 1983- 1984-1975- 1976- 1977- 1978- .;1982 * "1983-,i:ý.i.ýý-19847t,..,,-ý- *o1985- t, ,',*'.,,".'.-'-I

_-- *197 6 , .4 97 ,7

- 197M " 1979, 1980 . 19811 Plant Outage Study Year Figure 3-2. (Cont.).

Summer Flounder i

.0 2'

E 16 , Bluefish

-12' C 4 HF 7 HmFm 'H 10-8*

a E

6' 4

2.'

Hm Northern Pipefish i HH ]

1975-- 1976- 1977- 1978- 1979- 1980- 1981- 1982- 1983- 19854-1982 1983 1984 1985 1976 1977 1978 1977 1980 1981 Plant Outage Study Year, Figure 3-2. (Cont.)

TABLE 3-1 TOTAL NUMBER, PERCENT COMPOSITION, AND CUMULATIVE PERCENT OF FINFISH, OTHER VERTEBRATES, AND MACROINVERTEB RATES INPT*YcGED AT OCNCS.- NOVEMBER I 9R1& THROUGHI "NOVEMBER 1 qR IMPINGED AT OCNGS NOVEMBER 19A4 THROUGH NOVEMBER 19RS Cumulative Species Name Number M

-- Sand shrimp 42,691 76.31 76.31 Grass shrimp 6,092 10.89 87.20 Blue crab 3,626 6.48 93.69 Atlantic silverside 824 1.47 95.16 Bay anchovy 487 0.87 96.03

.N6rtherhipipefish ""297" 0 .53 .. 96.56 Lady crab 271 0.48 97.05 Naked goby 195 0.35 97.39 Ribbon worm .167 0.30 97.69 Fourspine stickleback 153 0.27 97.97 Blueback herring 152 0.27 98.24 Brown -shrimp . 152" o .27 Class Scyphozoa (jellyfish) 84 '0.15 98.66 Threespine stickleback 70 0.13 98.78 Winter flounder 53 0.09 98.88 Smallmouth flounder 52 0.09 98.97 Lesser blue crab 47 0.08 99.06 Mumnichog 44 0.08 99.13 American eel 34 0.06 99.20 Oyster toadfish 33 0.06 99.25 Weakfish 32 0.06 99.31 31 0.06 99.37 Striped searobin Windowpane 31 0.06 99.42 Striped cusk-eel 30 0.05 99.48 26 0.05 99.52 Spider crab Rock crab 21 0.04 99.56 Lined seahorse 18 0.03 99.59 Goby family 16 0.03 99.62 Atlantic menhaden 14 0.03 99.65 Bluefish 14 0.03 99.67 Hogchoker 11 0.02 99.69 Summer flounder 10 0.02 99.71 10 0.02 99.73 Alewife Sheepshead minnow 9 0.02 99.74

-0.01 99.76 Spotted hake 8 0.01 99.77 Horseshoe crab 7 0.01 99-.78 Spot Gray snapper 7 0.01 99.80 Inland silverside 6 0.01 99.81 Crevalle jack 6 0.01 99.82 6 0.01 99.83 Striped mullet Menidia (silverside) sp. 5 0.01 99.84 5 0.01 99.85 Butterfish an d fish .. ..........

................... ........ 5 . .0.01 99.86 American sand lance 5 0.01 99.86

TABLE 3-1 (Conit.')

Cumulative Species Name Atlantic needlefisýh 5 0.01 99.87 Black sea bass 4 0.01 99.88 Striped blenny 4 0.01 99.89 Grubby 4 0.01 99.89 Lookdown 4 0.01 99.90 Planehead filefish ..4 0.01 99.91

'Tuog 3 -0._01.- -99.91 Hermit crab 3 0.01 99.92 Northern puffer 0.01 99.92 Strpi-d--burrf ish ... 3 .--99,.93--.-

Silver perch 33 0.01 99.94 Halfbeak 2 0.01 99.94 Conger eel 2 0.00 99.94 Scup 2 0.00 99.95 Cunner 2 0.00 99.95 Sea cucumber 0.00 99.96 Many-ribbed hydromEedusa 2 0.00 99*96 Portunus irbbs (c.rab) 2 0.00 99.96 Northern stargazer 2 0.00 99.97 Spotfin butterflyfi .sh 1 0.00 99.97 1

Herring family ) 1 0.00 99*97 Herring (Alosa sp.) 1 0.00 99.97 Anchovy ..family 1 0.00 99.97 Red hake 0.00 99.97 1

Squid 0.00 99.98 1

Banded sunfish 0.00 99.98 1

Brief squid 1 0.00 99.98 Green crab 1 0.00 99.98 Silverside family 1 0.00 99.98 Fowler's toad 1 0.00 99.99 Rock crab 1 0.00 99.99 Striped anchovy 0.00 99.99 Inshore lizardfish 0.00 99.99 Scrawled cowfish 1 0.00 99.99 Ladyfish 0.00 99.-99 Nothe rn' .sennet 0.00 100.00 Seaboard goby 0.00 100.00 I

Northern searobin 0.00 100.00

-Fish fragments . 0.00 100.00 Organic material 0.00 100.00

TABLE 3-2 TOTAL WEIGHT (g), PERCENT COMPOSITION, AND CUMULATIVE PERCENT OF FINFISH, OTHER VERTEBRATES, AND MACRO-INVERTEBRATES IMPINGED AT OCNGS, NOVEMBER 1984 THROU3GH NOVEMBER 1 985 THROUGH NOVEMBER 191M Cumulative Species Name - Weisht Percent Organic material. 2,336,795 0.00 0.00 Blue crab 136,542 51.15 51.15 Sand shrimp 49,964 18.72 69.87 Class Scyphozoa (jellyfish) 13,972 .5.23 75.10

.Winter flounder 12,082.. 14-.53' Horseshoe crab 7,090 2.66 82..29 Blueback herring 4,962 1.86 .84.14 Atlantic silver-de 4,773.- .-79 85. 93 Grass shrimp 4,557 1.71 87.64 Spider crab 3,458 1.30 88.94

.2,158 -90.01--

Brown -shrimp 1.02 Lady crab 2,723 91.03 Rock crab 2,226 0.83 91.86 Oyster toadfish 1,964 0.74 92.60 American eel 1,644 0.62 93.21 Bay anchovy 1,554 0.58 93.79 Summer flounder 1,436 0.54 94.33 Alewife 1,326 0.50 94.83 Striped cusk-eel 1,277 0.48 95.31 Striped burrfish 1,268 0.48 95.78 Atlantic menhaden 1,045 0.39 96.17 Ribbon worm 1,035 0.39 96.56 Striped searobin 898 0.34 96.90 Windowpane 803 0.30 97.20 Weakfish 721 0.27 97.47 Northern pipefish 704 0.26 97.73 Northern puffer 503 0.19 97.92 Northern searobin 488 0.18 98.10 Black sea bass 449 0.17 98.27 Hogchoker 443 0.17 98.44 Smallmouth flounder 423 0.16 98.60 Spot 378 0.14 98.74 Spotted hake 306 0.11 98.85 Striped-mullet.. . ...... 2*81 " 98;96"-

Scup 272 0.10 99.06 Atlantic needlefish 229 0.09 99.15 Planehead filefish 214 0.08 99.23 Threespine stickleback 195 0.07 99.30 Mummichog 190 0.07 99.37 Lesser blue crab 168 0.06 99.43 Fourspine stickleback 162 0.06 99.49 Note: Organic material not included in percent calculations.

TABLE 3-2 (Cont.)

Cumulative Species Name Naked goby 156 0.06 99.55 Ladyfish 128 0.05 99.60 Butterfish 114 0.04 99.64 Conger eel 100. 0.04 99.68 Lookdown 77 0.03 99.71 Lined

seahorsee 76 0.03 99.74

-- ,99.77..

Tautog -99.79 Grubby 62 0.02 62 0.02 99.81 Inshore lizardfish luef ish 60 0.02 99.83 Gray snapper 51 0.02 99'.85 51 0.02 99.87 Northern stargazer Many-ribbed hydromedusa 41 0.02 99.89 Green crab 33 0.01 99.90 Northern sennet 32 0.01 99.91 Banded killifish 25 0.01 99.92-Hal fbeak 25 0.01 99.93 American sand lance 21 0.01 99.94 Silver perch 21 0.01 99.95 Sea cucumber 19 0.01 99.95 Sheepshead minnow 17 0.01 99.96 Goby family 12 0.01 99.97 Fish fragments 12 0.00 99*97 Portunus gjbbesi (crab) 10 0.00 99.97 Banded sunfish 8 0.00 99.98 Crevalle jack 7 0.00 99.98 Striped blenny 6 0.00 99.98 Cunner 6 0.00 99.98 Hermit crab 6 0.00 99.99 Scrawled cowfish 6 0.00 ) 99.99 Menidia (silverside) sp. 5 0.00 99.99 Spotfin butterflyfish 5 0.00 99.99 Brief squid 5 0.00 99.99 Red hake 4 0.00 -100.00 Inland, silvers ide.. 4 0.00 100.00 Herring family 0.00 10.0-.

Herring (&12u sp.) 1 0.00 100.00 1 0.00 100.00 Anchovy family 1 Squid 0.00 100.00 1 0.00 -100.00 Silverside family 1 Fowler's toad 0.00 100.00 1 0.00 100.00 Rock crab 1 0.00 100.00 Striped anchovy 1 0.00 Seaboard goby 100.00

.~.-~-...-~....~...~.....-..~......~.

TABLE 3-3 PERCENT-OF-CATCH FOR DAY AND NIGHT COLLECTIONS OF SELECTED SPECIES FROM THE OCNGS TRAVELING SCREENS, NOVEMBER 1984 MPROUGH OC.TQRVR I QRS By .Aumber .By Weivht Spec ies DayI Niaht Sand shrimp 8.1 91.9 10.0 90.0 Grass shrimp 20.0 80.0 16.3 83.7 Blue crab 19.5 80.5 29.9 70.1 Lady ;ra.b,6.5 84.5 11.6 88.4 93.6`ý

5.3 94..7 Bay anchovy 84.2 Striped searobin 12.8 87.2 15.8 Oyster toadfish 13.5 86.5 31.9 68.1

... ... 80 -;6.... ........ 1-9.5-

.... ..... . 8..

0.-5 SmalImouth flounder 22.2 77.8 16.7 83.3 Northern pipefish 23.0 77.0 23.3 76.7 Weakfish 23.9 76.1 19.0 81 .o Naked goby 24.8 75.2 27.0 73.0 Blueback herring 34.1 65.9 43.9 56.4 Atlantic silverside 36.2 63.8 39.6 60.4 Winter flounder *38.3 61.7 40.0 60.0

.1 1, tw 1 1. ýý I ý 1 ý , I .................-.

~ N

TABLE 3-4 WEEKLY ESTIMATED NUMBERS OF SELECTED SPECIES IMPINGED ON THE O NGS TRAVELING

_______----- NOVEMBER 1984 TRC.I.H NOVEMBER 1985 SCREENS, Blusback Atlantic 8ay Atlantic Northern Northern Wattier Mnhaden Ef.fLLah BLuWeih vapkfiah Northern yourspine Sand Crass 0imfish Blue 12 NOV 64 420 0 1,920 82.200 4.081 0 1.080 0 19 NOV 84 0 1.500 0 420 1.981 989.135 0 13,921 31 022 0 240 138.861 7.861 1.256.949 26 HOV 64 0 0 0 .- 0 0 420 840 0 8.701 30239 0 0 0 3.046,463 302,965 420 3.447.783:

0 0 1,862 1.280.041 0 82,137 0 3 DEC 84 280 1.113 1 .402 0 1.32o703 1.621 0 420 0 2.772 10 DEC 64 0 0 840 2,941 2.662 280 0 664.508 0 0 0 0 0 133.083 1,120 826.461.

17 DEC 84 1.120 0 0 5.041 659,399 0 0 0 0 71.991 0 751,.37 24 DIC 84 12.817 481 0 7.158 0 700 0 1.261 1.090,346 1 .920 0 0 0 42.025 7.705 1.156.185 31 DEC 64 0 280 1,120 560 0 0 236 0 1.310 1.066,947 319,176 0 0 0 840 1.421.497 0 0 -0 399.748 18,458 34,724 7 JAN 1.62) 462..432 65 420 0 0 0 0 0 0 0 28D 0 14 JAN 85 3,869 617 0 0 1.857 382.418 28,752 0 2,0833 2.008 0 0 0 420.870 21 JAN 85 0 0 481 0 4.157 0 3.082 537,326 54.495 1.080 0 0 0 1.3581 0 618.360 28 JAN 65 0 0 901 0 0 0 15.008 537,821 176.182 0 10 0 0 840 2.522 756,504 00 420 325,889 51.498 1 ,080 381.700 4 FEr 85 841 0 0 555 0 11 FEB 85 280 0 0 0 277 0 445 0 0 1,143 0 0 "0 44.802 4.056 0 50.811 00 0 0 0 0 25 1FE 65 28D 0 14.429 0 0 0 41 309 3,866 0 46.761 0 0 0 0 0 189.706 0 336 0 5.376 0 0 0 0 8,263 216,879.

0 0 745 0 79.132 12.835 2,100 108,087 4 hIAR85 6,224 0 15.881 0 0 0 0 3.702 0 1.948 4.764 0 0 1 .962 0 280,637 18.458 280 359,636 3.708 17.090 0 0 0 0 0 1.261 18i Hu 65 0 35,731 0 173.780 16,673. 26.301 247.056 8.256 0 0 0 0 0 660 25 MAR 85 2.081 410 553 -8.782 0 2866683 22,933 0 367,075 3.492 0 0 0 277 0 1.680 157,987 55.073 93,251 335.036 1 APR 65 2.5831 0 0 240 42,2.92 4.681 0 0 0 0 0 1 .321 8 23143 p 0 145,142 44,469 31.085 280,692 APR 65 0 4,622 17,658 11.944 0 0 240 0 0 0 19.260 188,407 93,916 56,469 364,003 15 APR 85 0 0 2.396 5.992 2.401 0 0 415 0 238,165 0 0 83.206 40,270 379.433 1

22 APR 85 11.061 0 100,941 1.1122 lt'463 0 0 3.640 0 0 0 0 0 *0

1.971.627 368,176 212.122 2.515,456 29 APR 85 0 1 0 1 .500- 1,321 0 0 1,436,663 0 1,314.292 84,265 30.164 6 0 0 0 0 MAT 65 0 840 420 901 -0 0 0 '420 0 0 0 107,342 12,843 12.724 141.971 13 MAV 85 2,775 420 0 0 0 0 0 0 86 239 48.319 8.361 149,666 2o H&A $5 0 1.318 1,379 420 0 0 0 0 r.00 0 '."0 280 7065965 67.3593 57,516 27 MAO 05 0 700 420 0 0 0 0 0 18.485 0 "420

42,008 15.691 87.249 0 0 0 3 JUN 05 0 1,141 0 0 0 0 0 0 .0 14,700 11,282 13.002 43,415 10-JvN 65 0 410 420 0 0 01 0 420 0 420 9,361 20.230 17 JUN 65 1.260 0 1,260 0 .- 0 0, 45,495 0 0 0 0 00 4.860 15.241 102.4531 142.176 24 JUN 85 840 420 0 0 240 16.144 '41,648 88,897 1584272 Note, Toteal colun jicludes a11 organism not listed separately.

7

TABLE 3-=4 (Cont.)

Bluaback Atlantic Say Atlantic Northern Summer vinter Northern!

Northern Fouropina Band Ifg~ n Anhuh Fone Flumnder Puffer Grano Crag. blue line I JUL 85 0 0 1.510 0 672 336 0 a 616 "0 0 I '0 3.810 6,048 64.501 87.351 8 JUL 85 0 o 0 336 0 0 0 0 0 0 0 0 1.500 0 0 952 47,383 51 i584 Of 0 240 0 0 0 0 0 t280 85 JUL 85 I 25JU. 14.943 9,602 152.471 190.819 0I 0 420 .0 0 420 0 o 0 0 0 1.920 I JUL85 ýo 0 420 49.217 65.480 01 0 0 0 0 0 0 0 0 901 42.928 47.530

+0 0 5 AVG 85 O0 0 420 0 so 0 1.741 0 0 0 0 . 280 -0 1.080 24,787

.2 AUG 85

.9 01 420 700 0 0 0 700 0 420 0 o 0 0 AUJGas 36.125 0i 0 2:821 ,o 0 0 1,!40 0 420 0 .0 +0 0 AUG 85 0 1 260 0 420 420 0 O -0 0 0 12.906 25,569 O 0 20.284 0 0 9.543 "10 0 2 SEP 85 01 420 1.500 0 420 0 0 0 0 0 0 0 6.662 13.862 9 SEP as O1 0 1.260 0 0 1,260 "0 00 0 0 0 ,+o 0 0 3,481 A6 SEP 85 3 SEP 85 0O o

0.

0 0 48,136 0 `0o

0o 0 0

0 481 0 0 0

4 240 0

0 0

0o

-o0 -0

-0 0 *0 3,001 6.9242 0 240 4,263 76,079 10 SEP 85 0 0 8.640 0 0 o 420 0 481 0* 0 /0 0 0 2,161 17.642 "

7 0CT85 0o 240 1.920 240 420 721 0 o0 C 0 840. 9.903.

4 OCT 85 01 0 280: 0 420 0 0 0 0 0 0 +0 0 0 699 8,275 11 OCT85 o0i 0 561 '0 0 0 1,680 0 0 0 561i 0 2.296 24*908. ..

toOCT 85-0 0 0 0 0 0 0 -0 00 0 0 840 0 8410 2,1526 4 Nov85 a0 0 1,261 0 +2,380 0 0 0 420 280 0o 0 561 26.695.

TABLE 3-5 WEEKLY ESTIMATED WEIGHTS (kg) OF SELECTED SPECIES IMPINGED ON THE OCNGS TRAVELING SCREENS, HfVI.MRP12 t* 1 QAR TRR1IrII.1 N(MMRUU I QR~q Olueback Atlantic Bay Atlantj*c Northrn lorthern Summer Vinter 111yerfd northern Yourspine $and grass ploof4.h 0uall. Blue 2 1l09 84 0.84 0.00 8.28 371.23 12.90. 0.00 23.94 0.00 AM1O084 0.00 26.28 0.00 0.00 150.36 0.00 3.6 937.93 6 15O9 84 63.16 73.39 0.00 6.73 0.00 100.33 14.U6 5,132.90 0.00 0.00 0.00 '86.10 121.80 0.00 10.38 3.673.01 0.00 6.34 0.00 0.00 0.00 0.00 314.49 0.42 15.37149 0.00 0.00 2.28 1,841.13 46.96 0.00 7,600.36 I3 DEC 84 0.00 7.01 3.63 11.22 3.08 0.00 9.66 0.00 0 DEC 84 0.00 0.00 3.36 0.00 140.19 0.00 2.51 762.51 0.020 0.00 13.58 4.34 0.00 0.00 0.00 99.25 1.96 49 o.40.2 "

7 DEC 84 0.00 5.46 0 .00 0.00 0.00 0.00 0.00 6.4 755.73 44.32 4 DEC 84 0.00 0.00 0.00 438.93 0.00 6.00 134.12 8,.392.14 75.24 6.73 0.00 43.09 4.68 0.00 1.68 1.012.30 26.90 It97.8 1 DEC 84 0.00 0.00 0.00 0.00 62.17 0.00 144.96 4.48 2.80 0.00 1.54 1,237.89 254.802 0.84 0.00 0.00 0.00 0.00 0.00 0.00 14,640.82 0.00 394.11 10.35 106.39 7,066.72 7 JAN585 13.02 0.00 0.00 8.i6 0.00 0:00 0.00 0.00 0,00 42.06 0.00 4 JAN 83 192.48 0.62 0.00 1.44 355.68 17.93 0.00 11.91 2.90 0.00 0.00 0.00 1.125.18 0.00 21,440.62 I JAN 85 0 .O0 0.00 0.00 3.50 589.77 33.95 8 JANl as 0.00 0.48 2.34 0.00 0.00 0.00 .360.73 0.00 4.149.25 0.00 0.00 0.00 12.97 572.27 105.71 8311* 85 0.00 0.00 7.14 0.00 0.00 0.00 1.38 16,513.57 0.00 22.68 0.00 0.42 391.11 183.55 3.08 2,0720.7 w 34.49 0.00 0.00 5.27 0.28 0.00 0.00 0.00 0.00 4.71 0.00 0.00 49.28 0.00 4.92 46.48 2.93 0.00 .325.40 8I 11t 85 13.74 0.00 0. 00 0.00 0:00 0.00 0:00 0.00 0.00 0.00 0.00 aSII* 0.00 72.42 0.00 44.67 2.79 0.00 -1393 "

0.00 0.00 0,00 0.00 0.00 0.005. 0.00

583 8n5 1.01 0.00 0.00 34.02 233.95 4.76 0.00 721.04 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.15 85.29 8.14. 5.88 596.61 4 116 85 248.864 0.00 0.00 102.33 0.00 0.00 0.00 0.00 0.00 703.86 0.00 2.23 329.12 I Al aS5 239.02 0.00 0.00 10.94 0.28 9 .019,15 8 MMI 85 106.46 4.62 0.00 0.00 0.00 0.00 0.00 0.00 1.-26 144.83 0.00 0.00 232.45 9.67 81.26 2,911.31 261.04 17.07 0.00 0.00 0.00 0.00 0.00 0.00 0.66

,3 HA083 147.94 100305 1.94 0.00 356.12 13.35 0.00 3.206.67 23.90 18.69 0.00 0.00 0.00 19.41 0.00 1.68 196.74 31.44 452.54 2,011.73 -

I APIE85 129.30 0.00 0.09 245.63 30.88 0.00 0.00 0.00 0.00 0.00 3."8 188.10 19.92 8 APE 85 56.16 0.00 117.36 29.21 0:000 0.00 177.88 "6,3.16 0.00 0.00 48.07 0.00 1.68 236.41 45.67

.5 ApE 85 0.00 0.00 43.72 5.34 0.00 0.00 918.12 -6,103.69 12 APR 85 0.00 0.00 45.28 0.00 0.00 317.71 3.190 14.013.94 304.53 0.00 s34.46 7.01 30.53 0.00 0.00 3.901.53 19 AiL 85 0.00 0.00 0.00 725.86 0.00 0.00 2,615.3$ 83.08 4,372.54 0.00 0.00 5.76 0.00 4.08 17,291.50 0.00 0.00 0.00 0.00 0.00 1,405.82 36.49 0.00 0.00 1,82.7.36 7.479.2.7 6 KAY85 0.00 0.00 3.36 3. 36 4.02 0.00 0.00 0.00

.3 No 85 0.00 0.00 0.00 0o.4 105.43 8.40 1,185.34 4,775.66 0.00 0.00 7.78 *0.00 1.26 0.00 0.00 0.00 0.00 0.00 0.00 80.39 30.72 246.95 5,417.29.

!0 MAY 85 0.00 0.00 2.40 4.62 2.10 0.42 0.00 0.00 0.00 0.00 0.00 0.00 601.58 54.59 1,475.36 13,85.38

.7 MAY85 0.00 0.00 1.98 0.00 1.26 0.28 0.00 -

0.00 0.00 55.02 0.42 34.17 14.42 1,24o.30 .11,026;64 0.00 3 JonI 85 0.00 0.00 0.00 0.00 0.00 1.38 0.00 0.00 0.00 0.00 0.00 01.00 12.60 8.52 926.19 14.922.13 10 JUN 85 0.00 0.00 0.00 0.00 0.84 0.42 0.00 0.00 0.00 0.00 0 00 I7 jug 85 0.00 0.00 0.42 6.84 1,642.99 56,124.92 0.00 3.36 0.42 0.00 2.94 0.00 0.00 0.00 0.00 0.00 0.00 34 3318 85 0.o00 0,00 3.42 8.88 3,480.72 64.587416 0.o0 0.00 1.68 0.00 0.84 0.00 44.46 0.00 0.00 12.AA 33.99 2,252.24 29.,.635.03 laot: Total co1%sn iuc udaaL all otganhs. not listed sepa-ratly.

TABLE 1-5 (Cnnt.),

Bluebaci Atlantic may Atlantic' Northern Northern Summer Uister " Northarl Youriping 4huefish Veakfish Flounde [lounder Stickleback Uid .

Shrine. Grass Btu*

O.00.

1 JUL 85 0.00 3.97 0.00 3.02 1.01 0.00 0,00. 0.00 0.00 0.00 11.26 0.00 0.00 .0.00 2.66 8 JUL 85 0.00i 0.67 0.00 0.00 4.37 3.641.86 39J141.03 0.00 4.26 0.00 0.00 0.00 0.00 0.00 0.00 0.28 15 JUL 85 0.00 0.00 1.44 0.62 1.399.63 4.0.86.05 0.00 0.00 0.00 0.00 0.00 12.78 22 JUL 85 0.00, 0.00 1.26 0.00 0.00 10.08 0.00 0.00 8.76 6 jss.51 414.194.26 0.00 0.00 0.00,; 0.00 0,42 1.50 29 JUL 85 0:.0o0 .00 0.00 0.00 0.00 0.00 0.00 2,555.35 28.38).99 O0.o0i .0.00 0.00 0.00. 0.00 0.00 0.90

0.00 2.705.14 IS.651.51 5 AUG 85 0.00 1.26 0.00 0.00 0.00 5.16 o.oq 0.00 0.00 0.00.; 00. 0.00 0.66 1.975.03 12 ABC 85 0.00 121.38 1.54 0.00 0.84 0.00 4.90 8,42.01 0.00 30.66 0.00; 0.00 0.00 0.00 0.00 2J806.45 49.2.681 19 AUG 85 0.O. 0.00 6.00 0.00 0.00 0.00 10.68 49.14 0.00:

0.00 0.00 '0.00 0.00 0.00 1.181.89 .40.912.44 26 AUG 85 0.00 3.36 0.00 0.00 0.00 6.30 58.8O 0.00 0.00 0.0: 0.00 0.00 0.00 703.89 22.412.919 2 SEP 85 '0.00 0.00 4.62 4.26 9.00 0.00 0.00 4.62 O.A0 0.00 0.00 0.00 ýQ.00 0.00 0.00 389.47 5,050.30 9 SEP 85 0.00 0.00 3.36 0.00 0.00 0.00 28.98 16 SEP 85 0.00 .0.00 0.00 0.00 0.00 0.00 :o10.00

.oo 0.00 B.00. 110.70 11.385.61.

23 SDP 85 0.00d 0.00 0.00 150.35 0.00 0.00 0.00 0.00 0.00 0.00 o.0.oo 0.00

+o.oo 0.00 0.00 243.30 43.1425.86 0.00 0.00 7.45 0.00 32.69 0.00* 0.00 1 0.00 0.00 0.24 30 SEP 85 496.17. 38.020.90 0.00 25.92 O.00 0.00 0.00 15.12 0.00 84.60 0.00 0.00 0 0.00 0.00 182.05 10.932.74 7 OCT 85 0.00 14.66 4.44 *0.00 2.88 26.44 5.04 0.00 0.00 0.00 0.00 :0.00 0.00 0.00 117.18 14 OCt a5 0.013 34,763.56 0.00 1.12 0.00 0.84 0.00 0.00 0.00 0.00 0.00i 0.00 0.00 0.00 0.00 62.85 5,307.23 21 OCT 85 O.Od 0.00 1.40 0.00 0.00 0.00 94.75 0.00 0.00 0.00 104.30 0.00 0.00 0.00 264.66 2.526.41i 428NO 85 o.od 0.00 0.00 ,0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.0 0.00 0.00 60.90 198.37

4. 1601 85 O.0ý ..0O.00 0.00 .0.00 0.00 4.62 6.16 0.00 0.00 158.34 60.56 0.00 0.84 0.00 2.808 1.093.49

TABLE 3-6 TOTAL ESTIMATED NUMBER AND WEIGHT OF TAXA IMPINGED AT OCNGS, NOVEMBER 1984 THROUGH NOVEMBER 1985 Weight Snecies Number Sand shrimp 17,090,788 19,719.6 Grass shrimp 2,262,2 98 1,729.3 Blue crab 1,333,894 46,890.9 Atlantic silverside 276,942 1,573.5

.Bay anchovy ,195,871 629.6 Northern pipefish 107,875 '254.6 Lady crab 102,7.50 1,046.3.

Naked goby 70,841 56.1 Ribbon worm 65,090 Brown shrimp 57,513 1,082.5 Fourspine stickleback 53,011 57.2 Blueback herring. 52,191 1,650.9 Class Scyphozoa (jellyfish) 27,174 4,867.2 Threespine stickleback 25,004 69.8 Smallmouth flounder 19,156 161.8 Lesser blue crab 18,219 66.5 Winter flounder 18,210 4,116.3 Mummichog 15,342 69.5 American eel 12,581 603.2 Oyster toadfish 12,574 660.3 Windowpane 12,216 241.4 Striped cusk-eel 11,925 498.5 Striped searobin 11,539 319.4 Weakfish 11,084 244.7 Spider crab 8,122 1,087.6 Rock crab 7,912 817.5 Lined seahorse 5,872 24.7 Goby family 5,409 4.2 Bluefish 4,938 23.0 Atlantic menhaden 4,654 346.6 Hogchoker 4,329 185.2 Alewife 3,544 449.4 Summer flounder 3,437 511.6 3,170 6.0 Spotted hake 3,0 385.6 Gray snapper 2,940 21.4 Horseshoe crab 2,535 2,235.9 Spot 2,382 108.5 Inland silverside 2,286 1.5 Striped mullet 2,212 102.0 Crevalle jack 2,212 2.5 But terfish 1,960 47.3 American sand lance 1,920 8.5

......... Atlani.c neetieish e ... 1,877 89.8 Black sea bass 1,680 Lookdown 1,680 32.3

TABLE 3-6 (Cont.)

Weight S~ec jes (kg)

Grubby 1 ,646 24.6 Banded killifish 11601 7.6 Planehead filefish 1,500 75.9 Mfenidia (silverside) sp. 1,421 1.4 Striped blenny 1,401 2.1 Silver perch 1,260 88.2

,+:...1,080' * ...9;I TJmLE (C0-t,

~Y4s -- ,'~

Hal fbeak Hermit crab 1 .073 2.0 Northern puffer 981 .159.3 au to g .-.. . ... ....

ST . .

Striped burrfish 857 367.0 Many-ribbed hydromedusa 756 16.1 Cunner 689 1.8 Conger eel 660 33.0 Sea cucumber 660 5.8 Pornus gibbesi (crab) 660 3.5 Scup 656 80.1 Spotfin butterflyfish 420 2.1 Herring family .420 0.4 Red hake .420 1.7 Squid 420 0.4 Banded sunfish 420 3.4 Brief squid 420 2.1 Green crab 420 13.9 Silverside family 420 0.4 Striped anchovy 420 0.4 Inshore lizardfish 420 26.0 Scrawled cowfish 420 2.5 Ladyfish 280 35 9 Anchovy family 240 0.2 Fouler's toad 240 0.2 Rock crab 240 0.2 Herring (Alosa sp.) 236 0.2

'/.

TABLE 3-7 DAY-NIGHT COMPARISONS OF INITIAL CONDITIONS OF SELECTED SPECIES COLLECTED FROM THE OCNGS TRAVELING SCREENS. NOVEMBER 1984 THROUGH NOVEMBER 1985.

Day Night Siec ies -

Bluebaik herring 2 70 70 20 10 82 46 24 Atlantic menhaden 30 8 25 13 62 6 Bay anchovy 17. 67 16

-51 31 10 59 436 12 Atlantic silverside -8 80 403 93 3 4 421 89 4 Northein pipefish 100 95 0 5 197 89 0 11 Bluefish 5 80 0 20 9 44 0 56 WeakfiSh 11 64 0 36 21 71 19 10 Summeri flounder 4 100 0 0 6 100 Winter' flounder 0 0 26 96 0 4 27 89 4 Sand shrimp 7 5,347 94 1 5 37,220 84 0 16 Blue crab 992 92 6 2 2,633 89 11 0 Note: Slight discrepancies between combined day-night totals in this table and totals in Table 3-1. are due to computer rounding error.

TABLE 3-8 WEEKLY MEAN WATER OUALITY VALUES. OCNGS. 19 -1985 Dissolved Temperature Oxygen Secchi Salinity Depth

. ai - .(C) ,-(mg/L) ,, (22 -..

pay -LahiZ M iay i

13 NOV 84 10.3 9.4 8.0 7.9 20 23.0 23.2 7.8 7.8 126.0 NOV 84 4.3 4.8 10.0 9.5 27 N0O, 23.8 24.6 7.9 8.1 131.3 84 5.2 6.4 11.8 12.3 22.1 22.5 :8.0 8.1 139.4 4 DEt 84 6.9 6.4 9.6 9.6 25.1 24.8 8.2 8.2 118.8 10 DEC 84 5.7 6.0 8.0 8.0 22.8 18 22.6 8.1 8.2 137.0 DE6 84 8.5 8.9 9.8 9.7 25.1 25.3 18.1 8.1 167.5 26 DEC 84 6.0 5A9 9.9 9.9 24.3 24.3 8.1 8.1 120.3 2 JAN 85 9.2 8.0 9.4 9.5 24.9 24.5 :8.0 8.0 131.3 7 JAN 85 2.2 2.3 11.6 11.6 23.3 23.1 8.0 8.0 106.8 15 JAN 85 1.5 1.0 ND 10.4 ND 25.5 8.1 108.8 22 JAN 85 1.7 1.6 12.3 12.4 24.0 24.7 i8.0 8.0 89.2 29 JAN 85 2.7 2.7 11.3 11.3 25.3 24.9 8.1 8.1 172.8 5 FEB 85 1.7 1.9 11.6 11.8 22.6 23.4 8.o0 8.0 171.4 12 FEB 85 1.0 0.6 11.5 11.4 24.4 25.0 :8.1 8.3 122.1 19 FEB 85 3.6 4.6 11.9 11.2 22.7 23.4 :8.3 8.3 130.9 26 FEB 85 8.1 8.1 9.9 10.2 23.1 23.6 18.3 8.4 143.8 8 MAý 85 7.3 6.6 11 .0 11.0 25.6 25.9 ;8.2 12 8.3 83.3 MAt 85 9.5 9.9 9.4 8.8 25.4 25.4 -8.3 19 MAR _8.2 8.2 .89.6 85 7.0 7.1 10.4 10.1 26.2 26.2 8.2 26 MA 97.9 85 9.7 8.6 10.5 9.9 24.8 25.1 '8.2 8.2 111.4 1 APi 85 10.4 9.9 9.4 9.4 24.9 25.1 :8.1 8.1 94.8' 8 APi 85 9.8 9.0 9.1 9.0 25.8 26.1 /8.1 8.1 94.4 15 API 85 13.8 13.7 9.2 8.7 25.6 25.8 ý,8.2 8.1 105.4 23 APA 85 15.1 15.4 8.0 7.8 25.0 24.6 8.0 8.0 115.9 29 APRt 85 16.7 17.9 7.8 7.2 25.1 25.4 -7.9 8.0 80.1 6 MAY 85 17.7 16.9 8.4 8.0 24.6 24.,7 +8.1 8.1 104.0 13 MAY 85 22.4 22.1 7.1 6.7 24.3 24.4 8.1 8.1 79.9 Note: ND = no data

______TABLE 3-8. (Cont.)

Dissolved Temperature Secchi Oxygen Salinity Depth (c) (ag/L) . (RIg)

h-Da.te!_ - l--p .- .(cvi)

UDay iL -yHzb 20 HAYI 85 21.4 21.2 7.5 7.2 23.6 23.3 '8.0 7.9 74.2 28 MAY, 85 22.6 22.0 7.3 7.0 3 23.9 23.7 8.0 8.0 73.3 JUN 85 22.3 22.2 7.4 6.9 8.0 23.9 23.8 7.8 100.6 10 JaU 85 23.7 23.5 7.8 7.5 26.2 26.1 8.1 83.3 17 JUIý 85 22.6 21.9 7.5 7.0 25.8 25.9 ,8.2 8.2 68.5 24 JUN 85 22.4 22.2 7.9 7.2 25.3 25.2 .8.1 8.1 51.9 1 JUL 85 23.0 23.0 7.8 6.7 24.2 3 M1185 24.7 8.2 8.1 52.2 26.3 25.9 7.3 6.5 25.4 25.4 !8.2 15 JR85 8.1 56.9 27.2 26.8 7.4 6.7 26.0 26.4 8.1 22 JUi 85 "8.1 47.7 26.2 26.1 7.0 6.6 27.3 27.5 *8.1 8.2 51.2 29 JU1.85 25.5 25.7 7.3 6.5 25.8 24.7 8.0 8.0 48.4 5 AUG 85 27.1 27.3 6.9 6.0 26.8 27.3 8.2 8.2 52.1 12 AUd 85 28.4 28.9 6.3 5.5 27.4 27.2 :8.1 8.2 54.9 19 AU6 85 24.7 24.6 6.4 5.9 26.8 26.5 .8.0 8.1 59.6 26 AUq 85 26.4 26.1 7.1 6.7 25.7 25.7 8.2 8.2 54.6 2 SE 85 26.0 .25.8 7.1 6.6 26.2 25.9 8,1 8.1 54.8 9 SE* 85 24.8 25.3 6.4 5.9 27.4 27.5 8.1 8.1 63.3 16 SE* 85 21.2 21.6 7.3 7.2 27.1 27.5 8.2 8.2 67.9 23 SET 85 22.0 22.4 6.6 6.5 26.4 26.7 ::8.2 8.2 67.5 30 SEP 85 21.4 22.1 6.6 6.4 24.9 25.4 .8.0 8.0 67 .l 7 OCT 85 19.0 19.6 7.8 7.6 24.5 24.0 8.1 8.1 69.2 14 OCT 85 18.8 19.8 6.9 6.9 25.6 25.9 *8,1 8.1 8.1 75.0 22 OCT 85 14.8 15.2 7.6 7.3 24.6 24.4 8.1 52.0 29 OCT 85 13.5 14.4 7.8 8.0 24.9 25.3 8.0 8.2 59.0 5 NOV 85 13.0 12.5 8.3 8.5 25.2 25.7 ,7.9 7.9 47.0 20 N0* 85 13.3 A 13.6 8.1 8.6 25.4 25.6 ,8.2 8.2 49.2 25 NOV 85 9.1 9.5 9.6 9.6 24.5 24.7 -8.1 8.1 60.6 4 DEC 85 5.5 6.5 10.4 10.2 21.8 22.1 7.9 7.9 50.8

¶ABLE 3-9 GENERAL LINEAR MODEL RESULTS FOR SELECTED SPECIES IMPINGED ON OCNGS' TRAVELING SCREENS, iI - NOVEMBER 1985 Continuou Discrete Variablei Variab.lea.

Specijes jeasn r 1 2 Bay anehovy (number) Fall 0.07 85 Pe riod riod Winter 0.08 191 Temperature Pe K Spring 0.02 96 riod Summer 0.11 172 Pe riod Bay anchovy (weight) Fall 0.06 85 Pe riod Winter 0.10 191 Temperature Pe Spring 0.02 96 nrod Summer 0.16 173 Pe Atlantic silveruide Fall 0.00 67 nrod (number) Winter 0.02 194 Pe Spring 0.17 95 Temperature Tidal Heiight Atlantic silverside Fall 0.00 67-(weikht) Spring 0.17 95 Temperature Northern pipefish (number) Fall 0.06 85 Temperature .

Winter 0.01 194 94 Sc:reens Period Spring 0.25 Summer 0.03 173 Northern pipefish (weight),. Fall 0.04 85 Winter 0.01 193 Spring 0.22 95 8 :reens Period Weakfi'h (number) 'Winter 0.01 194 Summer 0.04 173 Pieriod Weakfiph (weight) Summer 0.06 173 P eriod Note: in

number.of specimens; period u day or night; screens = number of screens operating; Ir 2 - coefficient of determination; Variables under Column 1 are more in luential than those under Column -2. Variables listed under any column were significaht at'p j 0.05.

TABLE 3-9 (Cont.)

J Continuous -' Discrete Variables. .Variab~les-I Sgeciess Sa_--

2 n ; 2 _ l ~2-

Winte? flounder (number) Winter 0.004 194 Spring 0.03 96 Winter flounder (weight) Spring 0.03 96 BluebAck herring (number) Spring 0.07 96 Screens Blueb~ck herring (weight), Spring 0.10 96 Screens Atlantic menhaden (number) Summer 0.02 173 Atlandc menhaden (weight) Summer 0.02 173 Summer flounder (weight) Summer 0.04 171 Period Blue crab (number) Fall 0.08 85 Period Winter 0.16 191 Temperature Spring 0.18- 94 Temperature Screens Period Summer 0.13 173 Period Blue crab (weight) Fall 0.13 84 Temperature Period Winter 0.08 192 Temperature Spring 0.06 96 Tidal height Summer 0.04 173 Period Sand ihrimp (number) Fall 0.09 82 Period Winter 0.03 194 Spring 0.01 96 Summer 0.13 172 Salinity Period Sand shrimp (weight) Fall 0.09 82 Winter 0.02 194 Period Spring 0.05 95 Temperature Screens Summer 0.13 172 Salinity Period

TABLE 3-10 ESTIMATED ANNUAL IMPINGEME1T OF SELECTED SPECIES AND ALL ORGANI 1S COMIBINED BY STUDY YEAR ADJUSTED FOR DIFFERENCES IN SAMPLING EFFORT(a)

SEP 1975 - SEP 1976 - SEP 1977 - SBP 1978- SEP 1979 -

Smecieg Name __ *AUG 17 M 1977 AUG-1978 AUG 1979 S89 1980- SEP 1981 - SEP 1982 - NOV 1984 -

AUG 1980 -AUG 198i AUG I1i82 Blueback herring 28,120 27,496 42,279 103,498 35,D34 29,923 18,181 Atlantic menhaden

17,788 94,960 26,122 52,190 54,460 9,388 3,427 12,005 9,157 Bay anchovy 1,811,550 147,202 6,334 4,654 155,858 146,531 85,611 76,994 147,110 Atlantic silvereLde

61,272 25,497 195,867 35,051 86,687 196,164 153,912 268,961 45,i622 Northern pipefish 36.066 11,220 117,889 276,943 21,881 53,700 29,822 92,602 42P808 Bluefish 14,086 28.479 107,87.5 3,935 3,661 9,658 2,392 9,154 Weakfish 11,790 3,278 3,639 4.937 27,297 20,839 5,272 46,186 37,401 Northern kingfish 16 18,936 6,390 11,083 105 23 20 342 117 1-2 1 Summer flounder 4,266 2,380 28 0 1,881 1,308 6,440 8,228 1,012 2,602 Winter flounder 8,908 18,618 27,600 3,437 148,442 16,122 48,511 25,767 37,619 Northern puffer 3,313 1.516 18,205 50,414 272 420 17,179 1436 Sand shrimp -3,342,143 600,278 655 981

5 ,627 ,253 3.793,355 4,818,977 3,365,975 6C,821,222 1,602,897 4,955,771 Blue crab .230,691 17,090,788

.1*,167,289 310,873 277,727 1:,831 ,654 248*,73 44,248 1,333.894 Other species 519,542 280,647 521,660 877,982 235,526 11,039,660 805,i727 424.541 2.866,715 Total 11,486,113 1,481,396 6,043,508 6,682,085 4,258,936 I1,293,611 I 2.970;425 5,679,814 21.967,567 J

(a) Night samples only 4ere collected for the period from Septmber 1977 through Nay 1979.

4. POST-IIPINGENENT LATENT EFFECTS 401 INTRODUCTION Three measures of impingement survival were used in the course of this study-initial, latent, and total. Initial survival (measured immedi-ately upon collection) is defined as the proportion of live and stunned specimens of a species that are collected during sampling relative to the total number (including dead) of that species collected. Values obtained by this approach ranged from 1.0 (complete survival) to 0.0 (complete mortality). Latent survival is defined as the number of specimens that survive the 96-hour test period (.live and stunned combined) relative to the number of specimens tested. As with initial survival, latent sur-vival- values ranged -from 0:.0 :*to 1.0. .Total-,survival*-is-,the,.product -of, initial and latent survival.

SThe- ine-lusion. of stunned individual.&. with -live.. individuals in. analyses.

was based on the rationale that they may recover during the 96-hour hold-ing period. It was assumed that 96 hours0.00111 days 0.0267 hours 1.587302e-4 weeks 3.6528e-5 months is sufficient time to allow mortal effects of impingement to manifest themselves. Sprague (1969) indicated that acute effects of pollutants are usually evident within.

96 hours0.00111 days 0.0267 hours 1.587302e-4 weeks 3.6528e-5 months .

Test organisms were maintained in the holding system described in Section 2.2. The possibility that the holding system may have exerted a mortal effect upon test organisms was investigated by collecting non-impinged (control) organisms and subjecting them to the holding system for 96 hours0.00111 days 0.0267 hours 1.587302e-4 weeks 3.6528e-5 months . Latent survival of control organisms was uniformly high in ambi-ent water, Therefore, it was not necessary to correct latent survival results for holding-system effects.

Test organisms were primarily collected at the screenwash discharge pipe located just downstream of the eastermost dilution pump discharge port (Figure 2-1). By testing at the very end of the screenwash and- return system, all possible stresses in the system were incorporated into the survival results. Additional test collections were made using the impingement sampling pool described in Section 2.1.1. These data were compared to the former to elucidate any additional mortality specific to the return sluiceway and discharge pipe.

Throughout this chapter, results are presented in terms of best- and worst-case scenarios. The best case is based on data for organisms held for 96-hours in ambient (intake) water.- The screenwash 4discharge -.empt-ies--

into the dilution pump discharge area. This ambient water, and presum-ably any previously impinged organisms, remains distinct from the.heated condenser cooling water (Figure 2-1) for some distance down the discharge canal before mixing occurs.- The potential exists for previously impinged organisms to remain in the ambient water, or to acclimate gradually and enter the mixed plume at a point where moderately elevated temperatures would not be detrimental--thus, the best case. The worst-case analysis is based on total survival data for organisms held for 96 hours0.00111 days 0.0267 hours 1.587302e-4 weeks 3.6528e-5 months in heated water directly from the condenser discharge. This scenario reflects the rather unreaist ic assumption tifatan organism, upon discharge from the ............................

4-1

screenwash pipe, immediately swims east into the condenser (heated) dis-charge and stays there for 96 hours0.00111 days 0.0267 hours 1.587302e-4 weeks 3.6528e-5 months . Reality probably exists between the best- and worst-case situations.

Regression analysis was used to assess the effects of several parameters in organism survival. The parameters considered'included: ambient and discharge temperatures encountered during collection, salinity measured during collection, temperature encountered during the 96-hour test period, and the number of screens operating at the time of collection.

Additionally, the effect of organism size was investigated by visual comparison of the mean size and standard deviation of organisms that had died throughout the 96-hour test period to the mean size and standard

- v -,orani-msoon s a u.,t the. :e . -, . - .- .%........

The results for each species are presented below. Under each species h~ git - d ~ -a

d-d b d-i -h -£ t own--eq enc * .. ............ . .......................

1. Control tests

2. Survival of organisms collected from the-impingement sampling pool, as opposed to those collected at the end of the screenwash discharge pipe

3. Initial survival, screenwash discharge terminus

4. Latent survival, screenwash discharge terminus

5. Total survival, screenvash discharge terminus

6. Statistical results, if any, and discussion In the discussion of results, emphasis is placed on total survival rela-tive to collection temperature because it facilitates direct comparison between best- and worst-case scenarios. The "collection temperature" is recorded at the end of the screenwash discharge pipe and is essentially equivalent to the "ambient hold" temperature.

Following the species accounts are sections on a comparison of impinge-ment survival for conventional traveling screens at Oyster Creek, with survival after impingement on the relatively new Ristroph screens, and a summary section.

4.2 BAY ANCHOVY Adult bay anchovy were dip-netted at the dilution pump discharge as con-trol test organisms. Of the 445 specimens collected, 227 were held in intake water and 218 were held in condenser discharge water to determine the effect of the holding system on this species. Survival of control bay anchovy held in ambient water was 0.978 at 96 hours0.00111 days 0.0267 hours 1.587302e-4 weeks 3.6528e-5 months (Table 4-1).

The average holding temperature during, this test was 23.3 C (Table 4-2).

The survival of bay anchovy held in condenser discharge water was 0.005

.- at -96hours,; however, -very'*low.-su'vival--(0.014) occurred ...af-ter.-36.-.-hours-(Table 4-1). The average holding temperature encountered during the first 36 hours4.166667e-4 days 0.01 hours 5.952381e-5 weeks 1.3698e-5 months of testing was 33.0 C. The results of the ambient tests 4-2

confirmed that the holding system was appropriate for testing this spe-cies. Survival test results were not confounded by any holding-system effects.

Bay anchovy were not collected from the impingement sampling pool in sufficient numbers to conduct survival tests at that location.

Initial survival at the screenwash terminus was determined for 2,081 adult and subadult bay anchovy; results are summarized by sample event in Table 4-3. Excluding initial survival values when less than 20 speci-mens were collected, the calculated mean initial survival of bay anchovy was 0.83 (SD = 0.16) for the combined ambient and discharge data.

Latent survival (after 96hour) was' calculated separately' for bay anchovy specimens held in ambient water and condenser discharge water.

Excludingsamp.le event tests with less than 20 test specimens, mean latent survival for bay anchovy held' in ambi-entwater was 0.42 (SD 0.33) and ranged from 0.03 to 0.91 (Table 4-3). - Latent survival of bay anchovy held in condenser discharge water ranged from 0 to 0.7; the mean latent survival of bay anchovy was 0.11 (SD = 0.20).

Total survival ofbay anchovy under the best-case (i.e., ambient) scenario ranged from 0.01 to 0.84 for tests with 20 or more specimens tested; mean total survival was 0.37 (SD - 0.32). Worst-case scenario results ranged from 0 to 0.66; the mean total survival of bay anchovy, considering. only tests with 20 or more specimens, was 0.10 (SD - 0.19).

Visual inspection of length data (Table 4-4) revealed no difference between live and dead test specimens. Thus, survival was not related to the size of fish tested.

The high variability in survival for this species prompted the use of regression analyses to determine if significant trends exist within the data set. Review of the total survival data set (considering only tests with 20 or more specimens) reveals that critical temperatures exist that could confound attempts to describe results in a linear fashion (Figure 4-1). Low total survival of bay anchovy held in ambient conditions occurs at collection temperatures of 14 C and below, and again at col-lection temperatures of 22 C and above. Relatively high total survivals (ambient hold) are recorded from 16 to 25 C. Low total survival of bay anchovy held in condenser discharge water occurs throughout the tempera-tures encountered. PeakPsurival (discharge held) occurred when collec-tion temperatures were 22.6 C. The variation within tl.7his data set s a reflection of the fragile nature of this species and points to other, unmeasured factors that influence its survival (e.g., effects of collec-.

tion, handling, stocking).

General linear model results employing the entire data set are summarized for specific collection temperature ranges in Table 4-5 for bay anchovy.

Bay anchovy total survival is variable and is not easily described by linear modeling techniques. It is clear that total survival is greater

.... n.-amb ient--wa terco-nditions-than.-in-c i............ densex-dis-h*r.eonditions . When -

collection temperatures exceed 23.5 C or mean holding temperature exceeds 30 C, discharge-held bay anchovy exhibit no survival. The correlation 4-3

of collection temperature and initial survival at temperatures above 23.5 C was :highly significant (Table 4-5). These values compare well with information tabulated by Terpin et al. (1977) who reported critical temperatures of 27-33 C resulting in total mortality.

In spite of the inconsistent results in total survival of ambient-held fish, there were five sampling events (weeks) in which best-case ambient total survival exceeded 50 percent when more than 20 specimens were tested (Table 4-3). Total survival reached as high as 84 percent (Event 15). This gives some indication that, under the right conditions, sub-stantial numbers of previously impinged bay anchovy may survive if they remain in the dilution water stream within the discharge canal and pos-

~ ibly,ac climate,-slowly to ~the mixed dilution-and discharge.,.plumes .(in, best case). Except for one sampling event (21), -total survival orf fish'.

held in discharge water was very low (worst case). Thus,' at least for

--even ie~igareai.cl i abets rvi-Ma1 , _pojeet~iGUt--f---

~. _

true survival depends on the thermal characteristics of the discharge canal and bay anchovy response to unknown temperature gradients. The presnt dta prmitonlythe co~nclusion that the potential exists for some unknown level of survival of impinged bay anchovy.

4.3 ATLANTIC SILVERSIDE Adult Atlantic silverside were collected at the condenser discharge false bays by dip net for control testing of the holding system. A total of 175 specimens was collected--ll8 were held in ambient water and 57 were held in condenser discharge water. Survival over the 96-hour holding period was essentially 1.0 for both ambient and condenser-discharge water; thus, no correction for mortality attributable to the holding system was necessary (Table 4-1). The mean ambient water temperature was 6.3 C and the mean condenser discharge water temperature was 10.1 C (Table 4-6). Unlike the control test results for bay anchovy, the hold-ing temperature encountered during these tests is not an important factor affecting survival of unimpinged Atlantic silverside.

One hundred and thirty-one Atlantic silversides were collected from the impingement sampling pool-118 were held in ambient water and 13 were held in condenser discharge water. The mean ambient holding temperature during the 96-hour holding period was 8.3 C; the mean discharge tempera-ture was 17.9 C (Table 4-6). Latent survival was about equal for both water temperature regimes--0.89 in ambient, 0.846 in'discharge (Table 4-) !These,,reut eesmlar.toq tho~se from tests~of fish.,col~lected, under similar conditions at the end of the screenwash discharge pipe as discussed below.

A total of 3,388 adult and subadult Atlantic silversides was collected at the screenwash terminus and inspected for initial survival. Initial survival of this species ranged from 0.849 to 1.0 (Table 4-8); mean ini-tial survival was 0.96 (SD - 0.04) over all tests, ambient and discharge combined. The values of initial survival were high and very stable over all collection temperatures which ranged from 0.9 to 25.1 C (Table 4-6).

4-4

I Lat it.survival was calculated separately for Atlantic silverside held in ambient water and condenser discharge waters (Table 4!48). Excluding.'

tesft with less, than 20 specimens,; ambient latent survival ranged from 0.51 to 0.99; mean latent survival was 0.86 (SD - 0.14), .Discharge latent survival ranged from 0 to 0.975 over all tests; exclusion of tests when less than 20 specimens were collected yielded a mean discharge latent survival of 0.91 (SD = 0.06).

Excluding tests with low numbers of organisms (<20), mean ambient total survival was 0.82 (SD - 0.15) and ranged from 0.46 to 0.97. Total, survi-val of Atlantic silverside* held in condenser discharge water ranged from 0 to 0.97 for all tests; mean total survival (Z20 test organisms) was

" " 0 ' 84 (SD-' 0.0.08)'. 2....

The majority of tests that were conducted with less than 20 specimens

. . ...occur.red.during.._peak, disc.hanrge, temperature conditions (Tables 4-7 and 4-8). The low abundance encountered was probably a result of this spe-cies' preference for shallow warm waters and avoidance of deeper channels that could lead into the Forked River intake. There was a marked differ-ence in total survival between Atlantic silverside held in ambient water and those held in discharge water during this warm period. Figure 4-2 illustrates the relationship of total survival relative to collection temperature and presents the data for each holding water system sepa-rately. Minimum and maximum privotal temperatures become evident: at temperatures of 6 C or lower, a linear relationship is observable for ambient-held specimens. At temperatures above 6 C, a high and relatively-stable total survival is detectable; the same high and relatively stable survival of this species held in discharge water is apparent to 17.5 C, above which an abrupt reduction of survival occurs. Since the normal operating delta-T of OCNGS is 10 C, it appears as though a discharge temperature of 27.5 C for Atlantic silverside acclimated to 17.5 C is lethal.

The data set was partitioned by the above stated thermal values and the General Linear Model (GIM) was employed. Results are summarized in Table 4-9 and reveal the following:

Best Case Temperature <6C: Total survival - -0.164 + 0.182 x collection temperature

. . Tempe rature' >6 CTtlsr~viam IV9.

Worst Case Temperature <_7.5 C: Total survival = 0.861 Temperature >17.5 C: Total survival = 0.16 Because of the steep, linear distribution of ambient hold (best case) data below 6 C (Figure 4-2), total survival is best described by the aovee-q-- tien." Fo r---the imte- .uvia

...mn

.tr .alus..er.mor...

descriptive. The above values appear to characterize adequately post-impingement latent survival of Atlantic silverside at OCNGS for the two 4-5

hypothetical thermal regimes tested and compare well with data presented by lail et al. (1982), which suggested a critical thermal maximum of 30.5-33.8 C. It should be noted,' however, that the.vast majority of Atlantic silversides impinged occur at ambient temperatures less than 17.5 C. During 1984-1985, less than one percent of Atlantic silversides impinged occurred at temperatures above 17.5 C (Chapter 3).

There was no observed difference between the mean lengths of live speci-mens and dead specimens of Atlantic silverside tested during this study (Table 4-10). Survival results were not confounded by the size of fish tested.

Two hundred and one sand shrimp were collected from. the mouth of Cedar Cre-ek-by--bea4ch--sei-ieý----eent-r-ol--teoi-ng--ef-thee -hoting-st-em................ .---

stocked in ambient water and 100 were stocked in condenser discharge water. Control survival of this species held in ambient water was 0.960 at 96 hours0.00111 days 0.0267 hours 1.587302e-4 weeks 3.6528e-5 months ; conrtrolvsurival of this species held in condenser discharge water was .0.83 at 96 hours0.00111 days 0.0267 hours 1.587302e-4 weeks 3.6528e-5 months (Table 4-1). However, survival in the heated water system was comparable to survival in the ambient water system through 72 hours8.333333e-4 days 0.02 hours 1.190476e-4 weeks 2.7396e-5 months , and that reduction in survival to 0.830 is primarily due to lost (unaccounted for) specimens which could have escaped or been eaten (living sand shrimp were on occasion observed to cannibalize. dead sand shrimp). The very high survival in ambient holding conditions pre-cluded the necessity vf correcting the post-impingement survival data for holding-system effects.

Two hundred thirteen 'sand shrimp were collected from the impingement sampling pool-113 were held in ambient water conditions and 100 were held in condenser discharge water conditions. Survival was about equal in both thermal regimes--0.894 in ambient and 0.91 in discharge (Table 4-7).. The mean ambient holding temperature was 8.4 C over the 96-hour holding period; mean discharge temperature was 17.9 C (Table 4-11).

These survival results were similar to those derived from tests of sand shrimp collected under similar thermal conditions at the screenwash dis-charge pipe (discussed below).

A total of 6,845 sand shrimp was collected and inspected for initial condition. Initial condition for this species ranged from 0.94 to 1.0; mean initial condition was 0.99 (SD m 0.016) for all tests (Table 4-12).

temperatures from 0.8 to 25.5 C (Table 4-12).

Latent survival values were calculated separately for sand shrimp held in ambient and condenser discharge waters. Latent survival ranged from 0.88 to 1.0 in ambient water tests (mean = 0.97, SD = 0.02). Discharge latent survival ranged from 0 to 0.98 (mean = 0.52, SD = 0.47) (Table 4-12). Mean ambient-holding water temperature ranged from 1.0 to 24.4 C; mean discharge holding water temperature ranged from 12.3 to 33.2 C (Table 4-Il).

4-6

Total survival of sand shrimp held in ambient water ranged from 0.88 to 0.99; mean survival was 0.96 (SD - 0.03) for all tests (Table 4-12).

Total survival of discharge-held specimens ranged from 0 to 0.98 (mean -. 0.50, SD = 0.46).

Figure 4-3 reveals that sand shrimp total survival in ambient water appears to be unaffected by the impingement process. Sand shrimp that were subjected to 96-hour exposure in discharge water of less than 12 C displayed survivals equivalent to those held in ambient water (i.e.,

unaffected). Mortalities were apparent at collection temperatures of 12 C and above for specimens held in discharge -water. Total survival was low (0.1 and less) at mean collection temperatures of 16.9 C and "aboive,` which, correspond ýto mean.,holding,-,t emperatur es .of,ýý,2-.8;; C-.and..,above~o.-.

One intermediate total survival value of 0.58 was measured during a col-lection temperature of 12.0 C and associated with a mean holding temper-

..... a-tureof 22-.9- C. Mortalities during this ...teat were observed . at the final (96-hour) check. This mortality coincided with a rise in discharge hold-ing temperature to 26.8 C. This value appears reasonable when compared to the temperature effects noted for 28.8 C.

The data set was partitioned into three temperature categories based on the above thermal considerations and the GLM was applied. Results are summarized in Table 4-13; the following values have been extracted to describe sand shrimp total survival relative to collection temperature.

Best Case All (test) temperatures: Total survival = 0.956 Worst Case Temperature <12 C: Total survival = 0.945 Temperature 212 C: Total survival - 0.074 Mean holding and maximum temperature encountered during the 96-hour test period appear to be important factors affecting sand shrimp survival in discharge water when ambient temperatures reach 12 C and above.

Visual inspection of length data (Table 4-14) indicated no prominent differences between lengths of live and dead test specimens. Therefore, To evaluate potential impact, the ecology of the sand shrimp must be integrated with the survival data., Many sand shrimp emigrate from Barnegat Bay into the ocean during the warmer part of the year; those remaining appear to avoid shallower,' warmer water (Moore 1978). Thus, impingement is minimal during this period. During the 1984-1985 study year (Chapter 3), only 6 percent of the sand shrimp impinged occurred at temperatures above 16 C. Consequently, the. high mortality associated with temperatures above 16 C would have had a negligible effect with

.. e- I -number inp nged -during.......... .ota.l 4-7

4.5 WINTER FLOUNDER Because of the relatively low numbers of winter flounder collected,*

neither holding-system control nor impingement-pool location testing was possible.

A total of 699 adult and juvenile winter flounder was collected from the screenwash terminus and observed for initial survival. Initial survival ranged from 0.94 to 1.0 (Table 4-15). The mean initial survival of this species wap 0.99 (SD - 0.01) for all tests.

Latent survival was calculated separately for winter flounder held in ambient -'and ,condenser*.-dischargexwatere ... Ambient..-.latent survival.ranged,.. ,

from..0 to 1 .0; the zero value was a single test based on one specimen.

Except for this single test; latent survival in ambient water ranged f Vý-95---o-1 -- Considering only- the -six--wampii-ng-events--invo-kvi-g..

20 or more test specimens,* mean latent survival was 0.99 (SD - 0.02).

Condenser discharge latent survival also ranged from 0 to 1 (Table 4-15);

mean survival (220 specimens) was 0.97 (SD - 0.06)Y. Thermal conditions in the holding system are described in Table 4-16.

Total survival of winter flounder held in ambient water ranged from 0 to 1.0; mean total survival was 0.97 (SD - 0.03) for all ambient water tests involving more than 20 specimens. Winter flounder held in condenser dis-charge water showed a total survival range from 0 to 1.0; the mean (Ž20 specimens) was 0.96 (SD - 0.06).

Figure 4-4 illustrates the relationship of total survival values to collection temperatures for winter flounder held in both ambient water and condenser discharge water. For specimens held in ambient water, a relatively stable total survival rate is evident throughout collection temperature ranges of 1.3-26.8 C (Figure 4-4, Table 4-16). Winter flounder held in condenser discharge water displayed relatively high survival in collection temperatures up to 11.9 C. One exception was an occurrence of lower survival (0.85) which, at a collection temperature of 3.8 C, was not caused by thermal factors. A total of 84 winter flounder was tested in this particular event and most of the specimens that exhib-ited mortality were large adults greater than 250 mm FL that were stunned and near death at collection. Because few specimens were available when collection temperatures ranged from 12 to 20 C, none were tested in dis-charge water. Those few specimens held in discharge water when collec-1.1-1°Iti oR-temperature*"rose-*above *20 *Cýshowed`*a.-reduced-..s urtviva.L-.*rat e. 'ýonlýy*:i:.....*,* ,.*:*

one organism was tested when the collection temperature was 20.1 C (Table 4-15, Event 13). A total of five winter flounder held in discharge water died when the collection temperature was 26.8 C.

With one notable exception, there was no difference between the mean size of live and dead winter flounder at the end of 96 hours0.00111 days 0.0267 hours 1.587302e-4 weeks 3.6528e-5 months . The unusual point occurred during Event 47 as mentioned above; mean size of survivors (Table 4-17) at the end of the test was 122.5 mm FL (SD = 33.6) compared to the mean size of dead specimens, which was 301.6 mm FL (SD - 71.5).

........ This-situation-occur ed--only-once-and.exlanation is-proffer-ed-.---..

4-8

Table 4-18 lists the results-of the regression analyses; the following values have been extracted to describe winter flounder survival at OCNGS relative to collection temperature.

Best Case All (test) temperatures: Total survival 0.929 Worst Case Temperature _111.9 C: Total survival = 0.976 The worst-case results may be put in perspective using the abundance and temperature data tabulated in Chapter 3. Seventy-five percent of the annual estimated number of winter flounder were impinged when collection (ambient), temperatures were less than 11.9 C. Survival of these fish would have -been nearly 100 percent. No winter flounder were impinged at collection temperatures above 20.1 C. Based on the 1984-1985 study year, at least 75 percent, and perhaps more,' of the winter flounder were pro-jected *to have survived.

4.6 SURVIVAL OF RISTROPH SCREEN IMPINGEMENT During 1983-1984, the then existing vertical traveling screens in the intake of the Oyster Creek Nuclear Generating Station were replaced with Ristroph screens. The latter offer three improvements over conventional screens to minimize damage to impinged organisms:

1. They are designed to operate continuously, thus preventing extended periods of contact of organisms with the screen face.

2. Each screen panel (Figure 2-3) has a trough that holds sufficient water to keep organisms from suffocating and drying when they are lifted above the water surface.

3. Organisms are removed from the screens with low-pressure water sprays.

~~ 'To'd"etermine wehr'h ue'f survival of impinged organisms, the 1985 survival data are compared-herein to corresponding data for the conventional screens. The latter data were gathered by Ichthyological Associates (IA) at Oyster Creek prior to 1979. In the IA studies, test organisms were collected at points in the screenwash sluiceways, rather than at the end of the screenwash discharge pipes, as in EA studies. The final survival observations were made at 48 hours5.555556e-4 days 0.0133 hours 7.936508e-5 weeks 1.8264e-5 months in the IA studies, rather than 96 hours0.00111 days 0.0267 hours 1.587302e-4 weeks 3.6528e-5 months .

4-9

Tables 4-19 and 4-20 contain the IA and EA survival data, calculated as mean survival.. Survival repults for organisms held in heated discharge water are presented for completeness, but -they are not appropriate for comparing the effects of the two types of .screens. Thermal effects can mask effects due to the screens alone. Survival in ambient water permits evaluation of screen effects.

Both initial and latent survival (ambient) of bay anchovy from the Ristroph screens were higher than conventional screen survival (Table 4-19). This resulted in a three-fold increase (0.06 - 0.19) in total survival with the Ristroph screens (Table 4-20). In contrast,* total ambient survival of Atlantic silverside; winter flounder, and sand shrimp was essentially the same for the Ristroph and conventional bcreen ."b- Totalbt survlval o these species was very high, - regardless of. screen type. The slight decrease in total survival of winter floun-der with Ristroph screens is not considered to be---a4ncr.&atimate. .

due to lte extremely small sample size tested for conventional screens.

Based on the above results,' the Ristroph screens appear to have increased survival where it was most critical--for fragilespecies such as bay anchovy. As discussed in Section 4.2, the chances of bay anchovy suc-cessfully negotiating the thermal gradients in the discharge canal to re-enter Barnegat Bay are unknown, but increased ambient survival due to the Ristroph screens increases the potential for survival and successful passage through the discharge canal.

4.7

SUMMARY

Total survival varied among target species and thermal conditions encountered after passage through the screenwash system. Survival of Atlantic silverside, winter flounder, and sand shrimp was high (>85 percent) in ambient-holding conditions (best case). Survival of these species was also high in heated (worst case) holding conditions, up to certain threshold temperatures. These threshold (ambient) temperatures, above which survival sharply decreased, were 17.5 C for Atlantic silver-side, 12 C for sand shrimp, and between 12 and 20 C for winter flounder.

Bay anchovy fared less well in. survival tests. In heated waters (worst case), many tests resulted in zero survival, and only one test resulted in more than 30 percent total survival. Best-case (ambient) survival was variables Below 16 C and above 25 C, very poor survival was recorded.

The reason for the erratic results of the ambient tests is unknown.

'...... ...... ee thiat s*xabent tets yielded total survivals from 56 to 84 percent suggests the potential for survival of many bay anchovy under best-case conditions. That is, after impingement, fish may stay' in the cooler (ambient) dilution discharge or slowly acclimate to the mixed dilution and condenser discharge plumes.

To assess the potential impact of impingement mortality, the ambient tem-perature ranges (and corresponding time periods) over which the highest mortality occurred were compared to the periods of occurrence of test species. Based on. impingement abundance .dataco.le,_ed.*dring.984. .. .

4-10

the majority of Atlantic silverside, winter flounder,i and sand shrimp occurred when worst-case total survival was quite high, nearly or over 90 pelrcent. Thus, for these important species, impingement mortality is projected to be minimal on an annual basis.

For Atlantic silverside and sand shrimp, survival tests were conducted on specimens collected in the impingement sampling pool-, as well as from the end of the screenwash discharge pipe. Survival results were the same for both sampling locations. At least for these two species,; the screenwash sluiceway downstream of the sampling pool and the underground discharge pipe do not exert additional stress on impinged specimens.

. The. recently installed Ristroph traveling screens appear to have

increased survival of impinged bay and ovy..u conventional screens at Oyster Creek yielded a-mean total :survival ..of 0.06 in ambient holding conditions. The corresponding value for bay

. - . anchovy impinged on the Ristroph screens in 1985 was 0..19. This three-fold increase represents a substantial benefit to the notably fragile bay anchovy. For Atlantic silverside, winter flounder, and sand shrimp, survival was similar between Ristroph and conventional screens.

4-11

I 4

1.00

Ambient Held

.90- N Discharge Held ib0 S

.80-S

.70-U S

.60-0

.50-9 I-0

.40-

.30-

40

.20- 0 6 0 0

2 .

.10- U Un~

I ILML v W i ....

i i

F - 7 I 3 3F 6 9 12 15 18 21 24 30 33 lemperature IQ, Figure 4-1. Relationship of total survival to collection temperatures for bay anchovy impinged at the Oyster Creek Nuclear Generating Station, January through December 1985.

0 0 S

0 0 Ambient Held E Discharge Held UO 0 liu* 0 0

S

.0 U a

U 00 2 a 0

w

.70- U

.60" S

.50" 0

0 0 ; t'.

U 30I I 33 3 6 9 15 18 27 Temperature (C)

Figure 4-2. Relationship of total survival to collection temperatures for Atlantic silversides impinged at the Oyster Creek Nuclear Generating Station, January through December 1985.

r 1.001 0 0 Ue U 0 4 Ambient Held S

%~ aX 0 0 0% I Discharge Held

.90- U.

U. *0

.80-

.70-

.60-0 U) .50-

'U 4..

0 I-

.40-

.30-t

.20-

.10-M 0 0 MW I ' I , Ii l 013 30 33 3 6 9 12 15 18 21 24 27 Temperature (C)

Figure';4-3. Relationship of total survival to collection temperatures for sand shrimp rmpinged at the Oyster Creek Nuclear Generating Station from January through December 1985."

1.00- LOcfr on 0u 4M

0 0 0 S S ill

ES 0

Ambient Held 0 0 Discharge Held

.90- 9 U

.80-

.70-

.60 -

'U C/)

4-. .50-0 1-

.40-2

.30-

.20-

.10-I l~ ~

3 6 9 12 15 18 21 24 .27 30 33 Temperature (C)

!Figure 4-4. Relationship of total survival to collection temperatures for winter flounder at the Oyster Creek Nuclear Generating Station from January through Docembei 1985.

TABLE 4-1 PROPORTIONAL SURVIVAL OF NON-IMPINGED CONTROL ORGANISMS

~V nuCeDUAITAJIM

&M Q An flW VVVDACTTRP TVMIADPDATI1Q AT APMVWQ Observation SBay Anchow v Atlantic Silverside Sand Shrimp AMbj=n DiseA~age A&hipnt Discarage a~bjn Dic-arb~ge 0.5 1.0 0.752 1.0 1.0 1.0 1.00 1 1.0 0.729 1.0 1.0 1.0 1.00 2 1.0 0.583 1.0 1.0 0.991 1.00 3 1 .0 0.472 1.0 1.0 0.991 1 .00 6 1.0 0.27.5 1.0 1.0 0.991 0.980 12 1.0 0.188 1.0 1.0 0.991 0.980 p 424 1"."o S0 . 9-80':":

ý -,:"J , , " ý .,."1. -I" ",

1.0 36 0.996 0.014 1.0 0.970 0.980

____ 48 .... ..._ ._9 _9.6_

0.009 1.0 1.0 .0.980 72 0.982 0.009 1.0 19.0 0.960 0.970 96 0.978 0.005 1 .0 0.982 0.960 0.830 Error(-a) 0.009 0.005 0.008 0.0 0.010 0.150 Number 227 218 118 57 101 100 (a) Error - Number unaccounted for divided by the number stocked.

TABLE 4-2 STHERMAL PARMETERS ASSOCIATEDUWITH LATENT EFFECTS TESTING

-OF*BAY AN~CHOVY AT OCNGS CONDUCTWD FROM MARCH THROUJGH DECEMBER- 1985 Ambient-Tem Derature (C)- Discharge Temperature (C)

Test Mean Max. Mean Max.

Number Hold Hold2 Collection Hold Hold Control 23.3 23.3 24.7 32.4 33.7 36.2 Event ý6 4 MAR 6.0 6.6 8.9 8.9 11.4 18.3 Event 8, -18MAR, .9.6 10 2, 12.5 17.3 15.0 Event 10 1 APR 10.7 Event 11 8 APR' 11.5 10.5 11.5 11.4 16.4 22.5 Event 12 15 APR 12.0 13.5 17.3 12.0 22.8 27.1 Event 13 22 APR 20.1 17.4 20.0 20.1 29-.7 30.3 Event 14 29 APR 16.7 17.4 22.6 16.9 28.5 33.7 Event 15 6 MAY 17.5 18.0 22.6 17.5 28.0 31.1 Event 16 13 MAY 24.7 23.3 24.9 24.6 32.6 33.0 Event 17 20 MAY 23.1 22.3 23.3 23.2 30.3 32.0 Event 18 28 MAY 23.6 22.6 24.4 23.4 32.4 34.2 Event 19 3 JUN. 25.1 24.4 25.8 24.9 32.4 33.9 Event 20 10 JUN 23.5 23.5 24.8 23.5 29.1 32.9 Event 21 17 JUN 22.5 22.5 23.9 22.6 25.7 33.9 Event 22 24 JUN 25.5 23.5 26.2 25.5 28.9 .35.1 Event 23 1 JUL 22.4 23.5 26.2 22.9 33.8 36.2 Event 24 9 JUL 26.4 33.9 36.1.

Event 25 15 JUL 31.1 38.6 38.6 Event 28 5 AUG 27.1 27.2 27

9 27.0 35.2 35.9 Event 29 12 AUG 30.0 28.2 28.8 30.0 38.0 38.7 Event 30 19 AUG 26.3 25.2' 26.3 26.1 35.0 36.0 Event 31 26 AUG 27.9 25.6 28.1 29.0 37.4 37.6 Event 33 9 SEP 28.1 26.1 28.3 28.1 38.0 38.0 Event 34 16 SEP 20.9 31.1 31.1 Event 35 23 SEP 22.3 22.1 23.1 23.0 22.3 32.8 32.9 Event 36 30 SEP 23.2 23.1 23.1 34.0 34.0 Event 37 7 OCT 18.5 18.8 21.1 1.8.5 28.5 31.1 Event 39 21 OCT 15.3 15.6 17.5 Event 41 4 NOV 12-.5 12.9 13.2 Event 42 11 NOV 13.5 13.5 14.2 Event 43 ,18, NOV... 12.6 _13.2 15.3, 12.6-. 16.,7. 18.9 Event 44 25 NOV 9.2 .10.3 11.4 9.2 17.8 Event 45 2 DEC 10.8 7.8 10.5 11.0 15.8 18.0 Event 46 9 DEC 5.4 6.0 7.5 Note: - i No data collected.

TABLE 4-3 SURVIVAL ASSOCIATED WITH LATENT EFFECTS TESTING OF BAY 'ANCHOVY AT OCNGS CONDUCTED FROM MARCH THROUGH DECEMBER 1 4R'i Test Ambient Conditions DischaýrgeConditions Number Initial Latet Total N Initial Latent Total N Control 1.00 0.'98 0.98 227 1 .00 0.005 0.005 218 Event 6 4 MAR 1.00 0 0 1 0.50 2 0 0 Event 8 18 MAR 1 .00 0 0 1 Event 10 I APR 0.67 0- 0 3 Event 11 8 APR 0.85 .0.24 0.20 20 0.63 .0 0 16 Event 12 15 APR 0.50 0 0 4 0.80 0 0 10 Event 13 22 APR *-* 0.81 0.31 0.25 151 0.94 0 0 16 Event 14 29 APR 0.93 0.89 0.83 29 0.98 0 40 Event 15 6 MAY 0.96 0.87 0.84 148 0.98 0.27 0.27 129 Event 16 13 MAY 0.89 0.54 0.48 100 0.90 0 0 180 Event 17 20 MAY 0.74 0.32 0.24 42 0.87 0.05 0.04 45 Event 18 28 MAY 0.93 0.60 0.56 16 0.82 0 0 28 Event 19 3 JUN 0.42 0 0 12 0.79 0 24 Event 20 10 JUN 0.98 0.68 0.66 86 0.98 0.13 0.13 86 Event 21 17 JUN 0.92 0.25 0.23 13 0.93 '0.70 0.66 29 Event 22 24 JUN 0.56 0.20 0.11 37 0.68 0 0 40 Event 23 1 JUL 0.91 0.91 0.83 127 0.93 0.01 0.01 129 Event 24 9 JUL 0.50 0 0 2 Event 25 15 JUL 0 0 0 1 Event 28 5 AUG 0.85 0.03 0.02 46 0.93 0 14

' 0 Event 29 12 AUG 0.0 0.0 0.0 1 0 0 0 3 Event 30 19 AUG 0.75 0 0 6 0.50 0 0 10 Event 31 26 AUG 0.50 0 0 2 0 0 0 2 Event 33 9 SEP 1 .00 0 0 1 0 0 0 1 Event 34 16 SEP 0 0 0 1 Event 35 23 SEP 0.40 0.03 0.01 247 0.49 0 0 157 Event 36 30 SEP 0.83 6 0.44 9 Event 37 7 OCT 1.00 0.42 0.42 12 1.00 0.20 0.20 12 (a) Calculated for events "When 20 or more organisms were tested. Control data not ic luded.

TABLE 4-3 . (Cont.)

Test Ambient -Conditions i -ischairwge -Conditions

.Number 1 inirtiiJ Latet Toal Initial, Tota -N Event 39 21 OCT 0.80 0.25 0.20 5 Event 41i 4 NOV 1.00 0.47 0.47 34.

Event 4* 11 NOV 0.76 0.15 0.11 82 Event 431 18 NOV 0.69 0.26 0.18 220 0.79 0.17 0.13 143 Event 44 25 NOV 0.88 0 0.88 0:.1 2 0 17 0.10 48 Event 45 2 DEC 1.00 5 0.55 0.0 0.0 11 Event 46, 9 DEC "1.00 0 0 2 Mean (arithmetic) survival(a) o.81 0.42 0.37 0.85 0.11 0.10 Standard deviation(a) 0.17 0.33 0.32 0.14 0.20 0.19 r.5

£,.

TABLE 4-4 MEAN FORK LENGTH ((mm), STANDARD DEVIATION, AND NUMBER OF BAY ANCHOVY BY CONDITION AT THE TERMINATION OF 96-HOUR{

POST-IMPINGEMENT LATENT EFFECTS TESTS CONDUCTED AT OCNGS P*ROM :MARCH THROUGCH DECEMBER 1 985 FROM-MARCH THROUGH DECEXBER 1995 I,

Sample Live Stunned Dead Event Mean SD Nunbe 'Man ' SD Number ka SD Nu~mber Control 65.6 7.6 120 64.5 8.0 111 6.3 Control 60.5 6.1 100 58.5 102 6

78.0 0.0 I

78.9 .4 64"

'1 7,

4 11 82.3 5.1 4 .32 79.5 7.1 14 12 13 77.1 78 ~36 74.6 6.4 127 14 70.0-' 6.4 24 68.3 8.8. 45 15 64.4 7.3 144 64.7 1L0.0 114 66.1. 9.5 122 16 64.4 8.7 43 11.4 9 59.5 1L2.1 73 17 57.9 18 66.8 6.9 .9 56.6 1.4.2 33 19 57.5 1.3.2 34 20 56.3 1.8 62 54.5 9.0 105 21 58.9 5.7 20 68.0 1.2.7 20 22 69.0. 6.1 3 65.6 6.9 70:

23 65.7 10.1 3 69.0 8.6 36 24 63.5 2.1 2 25 69.5 7.8 17 28 75.0 I 46.3 .1.4.8 57 29 .65.8 5.3 4 30 62.8 1 4.3 17 31 74.0 7.1 4 66.5 2.1 2 33 34 72.0 1 36 79.1 4.9 7 78.0 7.1 2 72.0 3.9 5 8.7 6 69.4 12.4 17 37 62.3 39 75.0 1 72.0 8.4 4 42 68.6 6.3 10 71.1 7.0 68 43 77.2 7.7 35 74.3 7.1 13 75.2 5.8 294 44 83.0 4.2 2 78.1 5.7 57 1 76.8 9.2e,', 6 78.2 8.8 10 77,ý.7 5.0 46

F.

TABLE 4-5 GENERAL LINEAR MODEL RESULTS (coefficients of determinatioi - r 2 ).AND MEAN SURVIVAL VALUES FOR BAY ANCHOVY RELATIVE TO VARIOUS THERMAL VALUES IESTED AT OCNGS, MARCH THROUGHl DEC*4RMRBR I QR" Ambient Hleld iDisiagegjgjjHeld ______

116.7 C 116.7 C 123.5C0 Thermal Conditions UiLia Latent Total.L Initial Latent TotAl. Initial LI~aLen !ga Initial Latent Ia"t Collection 2 temperature r 0.086 0.533(8) 0.486(a) 0.261(8) 0.331(a) 0.330(a) <0.001 0.067 0.0374 0.7 41I(b) 0 0 2

Mean holding r 0.181 0.492(a) 0.452(8) 0.190 0.209 0.200 <0.001 0.007 0.01L 0.603(b) 0 0 2

Maximum holding r 0.227 0.444(a) 0.414(a) 0.140 0.116 0.109 0.012 0.056 0.065'. 0.831(b) 0 0 2 0 0 Delta T r 0.008 0.006 0.003 0.429(b) 0.151 0.152 0.001 0.074 0.064;. 0.011 0.001 0 0 Mean survival 0.840 0.204 0.181 0.751 0.338 0.308 0.763 0.097 0.090 (a) Significant at p -=0.05.

(b) Significant at p = 0.01.

TABLE 4-6 "THERMAL PARANETERS ASSOCIATED WITH LATENT EFFECTS TESTING OF ATLANTIC SILVERSIDE AT OCVGS CONDUCTED FROM FEBRUARY THROUGH DECEMBER 1tQfK Ambient,(C) Discharýe (c)

Test Mean 4ax.t Mean Max.

Number- Date Collection Hold Hold Collection HolId Hold 6.3 7.8 9.1 10.1 12.5 17.3 Control Pool 7.4 8.3 13.2 15.9 17.9 24.2

.... -:Event,2-- -4 FEB; 1.7 -r Event 3 11 FEB 0.9 1.0 2.0.

Event 4 19 FEB 3.8 3.6 7.3

-Event-5---- . 25F- ...--.... 4-...... .....-- 8 2--..... 8 8..*

6.0 6.7 8.8 8.9 11.3 18.3 Event 6 4 MAR 9.8 11.6 12.2 19.2 21.7 Event 7 11 MAR 12.2 7.3 8.7 10.2 2..4 !7.3 Event 8 18.AR 6.6 8.2 13.2 7.5 18.0 24.2 Event 9 25 MAR 7.9 10.7 14.9 11.0 18.0 21.2 Event 10 1 APR 10.5 10.6 11.5 11.5 16.4 21.9 Event 11 8APR 11.5 13.5 17.3 12.0 22.8 27.1 Event 12 15 APR 12.0 17.4 20.0 20.1 29.7 30.3 Event:13 22 APR 20.1 18.0 22.6 17.5 27.7 31.1 Event 15 6 MAY 17.5 24.4 25.8 24.9 32.4 34.0 Event 19 3 JUN 25.1 23.7 24.9 23.4 29.9 33.1 Event 20 10 JUN 23.3

-- 24.8 34.6 35.2 Event 23 1 JUL Event 38 14 OCT 19.0 19.2 19.2 Event 39 21 OCT 14.9 15.7 17.8 Event 41 4 NOV 12.3 12.7 13.2 Event 42 11 NOV 13.5 13.5 14.2 12.8 16.2 11.9 16.4 21.0 Event 43 18 NOV 11.9 10.1 11.2 9.2 17.8 20.4 Event 44 25 NOV 9.2 7.9 10.5 11.0 15.8 18.0 Event 45 2 DEC 11.0 5.5 14.9 15.8 Event 46 9 DEC 5.5 6.1 7.7 3.2 4.2 4.0 5.4 9.4 Event 47 16 DEC 3.9

.' +.....-- '" ++ -° "'

'.L ;* ""

2 2 TABLE 4-7 *DI PRO ORTIONA U RIVA OF ORtAIS C: T. fROM TME. IWEMENT SAMPLINGPOL YOSRAINTN

.+. . .

AND :HOLDINGý WATER .TEMPEItATERE.

Observation Atlantic Silverside- . :-'San~d ShriMI ".

Time' (hrs) 0.5 1.0 1.0 1A. 1 .0 1.0 0.923 1 .0 1.0 1.0 0.923 1.0 1 .0

.. 3 0.991 0

923 1.0 1.0 0.9.8 0.923 1.0 1.0 12 ':*0.*991

..24 0.95ý8, -0 -0,990-

0. 941 0.923 04982 0.990 36 0 ..932 0.923 0.965 0'.990

.0-,915 0 . 923 .0.965 . 0.990.

72, 0.907 0. 846 0.956 0.;:950 96 0 .890 0.846 0.894 0.910 Error(a) 0.0 0.0 0.062 0.040 Number 118 13 113 100 (a) Error = Number unaccounted for divided by the number stocked.

TABLE 4-8 SURVIVAL ASSOCIATED WITH LATENT EFFECTS TESTING OF ATLANTIC SILVERSIDE AT OCNGS CONDUCTED FROM FEBRUARY THROUGH DECEMBER 1985 Test Ambient i Dischare ,,

Number Initial Latet Tal N Initial Ltn N-Control 1 .00 1.00 1.00 118 1.00 0.98 0.98 57 Pool 1.00 0.89 0.89 118 1.00 0.85 0.85 13 Event 2 4 FEB 1.00 0.00 0.00, 3 Event 3 11 FEB 1 .00 0.13 0.13 16 Event 4 17 FEB 0.91 0.51 0.46 257 Event 5 25 FEB 0.93 0.95 0.88 210 Event 6 4 MAR 0.96 0.92 0.89 26 0.85 0.86 0.73 33 Event 7 11 MAR 0.93 0.92 0.85 388 0.98 0.98 0.95 82 Event 8 18 MAR 0.97 0.92 0.89 177 0.98 0.98 0.96 112 Event 9 25 MAR 1.00 o.95 0.95 23 Event 10 I APR

0.99 0.97 0.96 112 1.00 0.94 0.94 62 Event 11 8 APR 0.98 0.99 0.97 106 0.99 0.94 0 *94 107 Event 12 15 APR 1 .00 0.84 0.84 19 0.99 0.84 0.82 74 Event 13 22 APR 1.00 0.77 0.77 30 1.00 0.00 0.00 5 Event 15 6 MAY 1.00 0.93 0.93 14 1.00 0.69 0.69 13 Event 19 3 JUN 1.00 1.00 1.00 2 0.94 0.07 0.06 16 10 JUN 1.00 1.00 1.00 1 1.00 0.00 0.00 4 Event 20 1 23 1 JUL 1.00 0.00 0.00 Event Event 38 14 OCT 1.00 1 .00 1.00 1.00 1.00 1 Event 39 21 OCT 1.00 1.00 1.00 5 Event 41 1 4 NOV 1.00

(-a) CalcuOlated for events when 20 or more organisms were tested. Control and po*0l data not included.

TABLE 4-8 (Cont.)

Test Number Ambient Date Initial L Discharge Total N Initial Latent N Event 42 11 NOV 0.99 0.95 0.94 106 ..

Event 43 18 NOV ..

0.90 0.76 0.68 78 Event 44 25 NOV 0.93 0.82 0.76 0.97 0.94 0.91 89 Event 45 178 0.98 0.89 2 DEC 0.91 0.89 0.87 190 Event 46 0.81 133 0.94 9 DEC 0.99 0.93 0.85 0.90 155 Event 47 0.92 75 0.97 16 DEC 0.97 0.60 0.97 0.94 62 0.58 35 0.97 Mean (arithmetic) 0.97 0.95 75 survival(a) 0.96 0.86 0.82 0.97 0.91 0.89 Standard deviation(a) 0.03 0.14 0.15 0.04 0.06 0.08

TABLE 4-9 GENERAL LINEAR 1ODEL RESULTS (coefficients of determination r 2 ):AND MEAN SURVIVAL VALUES FOR ATLANTIC SILVERSIDE RELATIVE TO VARIOUS THERMAL VALUES iTESTED AT OCNGS, FEBRUARY TMROGH DECEMBER 1985

.. bient Held - Dirnchbrye Held

!C <c c -17.5Cý Ž:17.5 C

~hertnal condition. Initial Jateng-L Totnal finiialL .atentL InMl Tutaila. b.atenLt ...XtmiL Iinitial Laltent DS 6ollection temperature r 2 0.160 0.938(s) 0.929(8) 0.207 0.005 0.044 0.099 0.465(b) 0.203- 0.218 0.218 0.218 2

Mean holding r 0.100 0.933(A) 0.929(a) 0.296(b) 0.013 0.077 0.092 0.434(b$ O.1961 0.048 0.048 0.048 2

Maximum holding r 0.364 0.820(b) 0.792(b) 0.277(b) 0.001 0.025 0.016 0.503(a) 0.317(b) 0.070 0.070 0.070 beilta T r2 I 0.570 0.342(b) 0.309 0.177 0.087 0.160 0.030 0.247 1 0.133 0.717 0.717 0:717 kean survival 0.971 0.515 0.496 0.975 0.923 0.896 0.959- 0.898 0.8616 0.984 0.017 0.016 (a) Significant at p - 0.'01.

(b) significant at p - 0.05.,

+*+ '+3

a -~' ~ a..

TABLE 4-10 MEAN FOIRK LEN~GTH(in) STANDAR~D DEVIATION(,' AND .NUMBER OF ATLANTIC. SILVERS-ID.E BY CONDITION AT THE TEP.MtNAITION OF 96-RC.UR POST-11 .PINGMIENT LATENT EFFECTS TESTS CONDUCTED AT OCNGS FROM FER1UARY THROUGcH 'flECEMB ER 1 9RS Sample Live- - Stunned Dead

-SD Nimber Mia SD er He an SD Nmp Event- Mean--

1 105.5 31.8 2 2 101,.7 4.0 3 3 92.5 12.0 2 88.6 10.2 13 4' '97.40 ,10.,4- 1~l39- W88.8 -7.1 ,8. 94.8 11.4, ,97, 9.9 182 98.3 ....9.5 23 5' 102 .0 6 102.7 14.5 47 101.5 9.3 11 7 101.6 7.9 469 104.5 8.5 4 100.3 7.4 59 8 101.6 9.4 438 98.2 5.9 20 9 103.7 8.5 133 99.0 8.6 20 10 99.2 9.0 165 101.2 11.3 11 11 98.9 7.6 202 100.6 9.4 10 12 102.1 7.8 77 102.8 6.3 15 13 95.2 11.1 19 103.9 10.9 14 15 96.6 7.6 18 98.8 7.5 1.5 18 104.0. 1 98.4 9.9 13 19 96.0 11.1 3 20 92.0 1 98.3 3.3 4 23 69.0 1 38 92.0 39 100.0 1 42 93.9 7.8 100 85.8 7.4 6 43 97.6 8.2 121 96.7 1.5 96.5 7.0 44 44 98.1 7.0 318 3 96.7 7.8 43 45 98.3 8.6 234 101.7 7.6 3 96.2 6.8 45 46 95.9 9.6 128 95.8 7.0 9 12.6 10 93.0 5.9 10 47 101.0 10.6 51 99.6 1' a '.

TABLE 4-11 THERMAL PARAMETERS ASSOCIATED WITH LATENT EFFECTS TESTING OF SAND SHRIMP AT OCNGS CONDUCTED FROM JANUARY THRCOJGH DECEM-ER I QRS Ambient (C) Discharge (C)

Test Mean Max. Mean Max.

Collection Hold Hl k12 Hold Control ND 10.6 14.4 ND 19.0 22.0 Pool 7.4 8.4 13.9 7.4 17.9 24.2

'Event 1 2-8JAN1-Event2 4FEB 1 .7 1.2 1.9 Event 3 11 FEB 0.8 1.0 2.1

..3 -9 .......

Event-4 .... 19--FEBB -..

Event*5 25 FEB 8.5 8.4 8.9 Event 6 4 MAR 6.0 6.7 8.8 Event 7 11 MAR 12.2 ,..9-7.

11.3 7.0 7.1 7.0 12.3 16.9 Event 8 18 MAR .2 Event 9 25 MAR 7.5 8.5 13.8 7.5 18.0 24.2 Event 10 1 APR 11.0 10.8 14.5 11 .0 18.5 21.7

.Event 11 8 APR 11.5 10.5 11.5 11.2 16.4 23.1 Event 12 15 APR 12.0 13.5 17.3 12.0 22.9 26.8 Event 13 22 APR 20.1 17.5 20.0 20.1 29.6 30.3 Event 14 29 APR 16.9 17.5 21.9 16.9 29.3 33.0 Event 15 6 MAY 17.5 18.1 23.0 17.5 28.3 31.2 Event 16 13 MAY 25.0 23.3 25.2 25.0 33.2 33.2 Event 17 20 MAY 23.2 22.3 23.3 23.2 31.3 32.0 Event 18 28 MAY 23.6 22.6 24.4 23.4 .32.4 34.2 Event 19 3 JUN 25.1 24.4 25.8 25.1 32.2 33.9 Event 22 24 JUN 25.5 23.5 26.2 25.2 28.8 35.0 Event 43 18 NOV 11.9 13.7 16.3 11.9 16.5 21.0 Event 44 25 NOV 9.2 10.3 11 .2 9.2 17.6 20.0 Event 45 2 DEC 11.3 8.2 10.5 11.3 15.8 18.4 Event 46 9 DEC 5.6 6.4 8.1 5.6 15.0 16.6 Note: ND = No data.

TABLE 4-12 SURVIVAL ASSOCIATED WITH LATENT EFFECTS TESTING OF. SAND SHRIMP AT OCNGS CONDUCTED FROM JANUARY THROUGH DECEMBER 1985.

Test I Ambient ýDischargfe Numb e Initial Latent Tot Initial Laen :Discharee*Total Control 1.00 0.96 0.96 101 1.00 0.83 0.83 100 Pool 1.00 0.89 0.89 113 1.00 O.91 0.91 100 Event 1 28 JAN 0.99 0.98 0.98 355 Event 2 4 FEB 0.99 1.00 0.99 433 Event

11 FEB 0.99 0.99 0.98 342 Event 4 19 FEB 0.99 1.00 0.99 103 Event 5 25 FEB 0-.95 0.96 0.92 61 Event 6 4 MAR 1.00 0.98 0.98 226 Event 11 MAR 0.98 0.96 0.94 194 Event 8 18 MAR 0.99 0.98 0.97 98 0 .94 b.92 0.88 121 Event 25 MAR 0.96 0.89 0.85 98 0.98 0.84 0.82 98 Event 10 1 APR 1.00 0.95 0.95 205 0.99 0.95 0.94 112 Event 11 8 APR 0.99 0.98 0.97 102 1.00 0.96 0.96 110 0.94 0.62 0.58 116 Event 12 15 APR 0.99 0.97 0.96 113 *0.01 Event 13 22 APR 1 .00 0.96 0.96 224 1.00 0.01 280 200 *"

Event i4 29 APR 1 .00 0.95 0.95 243 1.00 .0.02 0.02 1 .00 0.88 0.88 49 1.00 7-0.02 0.02 51 Event 15 6 MAY 0.01 0.98 0.96 0.94 157 0.98 0.01 173 Event 16 13 MAY ý,.Ol 1 .00 0.95 0.95 125 0.99 Jb0.01 0.01 1 23 Event 17 20 MAY 1 .00 0.96 0.96 106 0.99 70.01 0. 01 129 Event 18 28 1AY 0.99 0.97 0.96 103 1.00 :0.01 0.01 134 Event j9 3 JUN 1.00 0.96 0.96 104 1.00 0.00 .98 Event 22 24 JUN 0.95 0.99 0.96 0.95 130 1.00 0.95 136 Event 43 18 NOV *,

1.00 0.97 0.97 155 1.00 *0.98 0.98 161 Event 44 25 NOV 0.99 0.95 0.94 155 1.00 o.94 o 0.94 158 Event 45 2 DEC 0.99 0.99 0.98 189 0.98 P0 .96 0.95 187 Event 46 9 DEC Mean (arithmetic) survival(a) 0.99 0.97 0.96 0.99 0.52 0.50 Standard deviation(a) 0.01 0.02 0.03 0.02 0.47 0.46 (a) Cbntrol and pool data' not included.

TABLE 4i13 GENERAL LINEAR MODEL RESULTS (coefficients of determination - r 2 ) L MEAN SURVIVAL VALUES FOR SAND SHRIMP RELATIVE TO VARIOUS THERMAL VALUES TESTED AT OCNGS, JA1*UARY THROUGH DECEMBER 1985 Discharge Ambient Held All Temperatures <12 (C) _12 (C)

Thermal gonditions Iiil Latent Total .Initial Latent Intiial Col lection temperiature r2 0.074 0.203(a) 0.071 0.119 0.071 Q0.001 0.385 0.546(a) 0.548(a) 2 0.564(a). o.91 (a)

Mean holding r 0.078 .0.225(a) 0.081 0.594 0.373 0. 70 2(b) 0 . 7 0 3(b) 2 Maximum holding r 0.071 0.298(b) 0.124 0.001 0.230 0.074 0..572(a) 0.662(b) 0.663(b)

Delta T 12 Ir 0.073 0.002 0.007 0.118 0.078 0.113 0.021 0.020 0.0991 Mean survival - 0.990 0.966 0.956 0.990 0.954 0.945 0.078 0.074 (a) Significant at p - 0.05.

(b) Significant at p = 0.01.

TABLE 4-14 MEAN LENGTH (mm), STANDARD DEVIATION, AND NUMBER OF SAND SHRIMP BY CONDITION AT THE TERMINATION OF 96-HOUR POST-IMPINGEMENT LATENT EFFECTS TESTS CONDUCTED AT OCNtS p*Rt4 JANUARY TIrUR DC KMRCEER 1 QR*

OCNGS FRO14 JANUARY THROUGH DECEMBER I QRS Sample Live Stunned Dead Event Mean SD Number Mean SD Number Mean SD Number 1 50.5 5.6 346 46.5 6 '8 4 2 48.4 6.6 411 44.3 2.5 3 38.0 1.4 2 3 49.5 5.9 299 47.6 6.5 9 47.0 2.8 2 53..00 6.2 82 5 50..3 4..2 6 52.5 6.4 1 89 54.5 11.1 4 49.7 7.8 11 7 51.7 5.7 139 52 ;1 188 49.5 .5.5 13 8 6.0 9 49.9 6.2 341 54.5 6.7 26 10 49.3 7.5 376 47.9 11.8 9 11 51.7 5.8 195 50.8 8.4 4 12 53.3 6.8 157 54.1 5.7 46 13 51.6 6.6 205 52.4 7.0 277 14 48.8 6.0 216 49.0 48.4 5.9 199 15 49.6 6.6 41 47.4 6.2 56 46.7 5.6 182 16 47.5 5.7 137 17 44.6 4.3 117 44.0 3.9 124 18 42.9 5.0 95 41.8 4.9 130 19 44.9 5.8 93 43.9 6.1 136 22 44.1 6.8 94 43.5 6.6 99 43 48.9 4.0 227 43.0 1 47.9 2.4 9 44 47 . 8 3.1 292 41.0 1 43.0 2.9 4 45 47.0 4.2 292 47.5 5.3 15 46 50.0 4.7 332 46.6 5.2 10

TABLE 4-15 SURVIVAL ASSOCIATED WITH LATENT EFFECTS TESTINGr T

OF WIN1ER..ERAT FLOUNDE R AT Af'.yq fNflhlWl UIT (RnU TAUTTA'IV W1',D i.1(U tU 1 I nor

., snos .fttwn U iat.. .,a.Ja A ,pp2 I ______________________

Test

-Number 'Initial Laftent Toa _tL Initial ILaten -N Event 1 28 JAN Event 4 19 FEB 1.00 I1.00 1.00 7 1 .00 1.00 1.00 2 7+1 Event 5 25 FEB 1 .00 1.00 1.00 1 Event 6 1 4 MAR 1.00 1.00 1.00 78 Event 10! 1 APR 1.00 0.00 0.00 Event 11: 1 8 APR .1.00 1.00 1.00 1 Event 13! 22 APR 1.00 1.00 1.00 1 .00 Event 14, 7 0.00 29 APR 1.00 1.00 1.00 1 Event 17; 20 MAY 1.00 1.00 1.00 2 1.00 Event 22! 24 JUN 1.00 1.00 1.00 1 0-.00 0.00 .5 Event 421 11 NOV 1.00 1.00 1.00 1 1.00 Event 43i 18 NOV 1.00 1 .00 1.00 4 1..00 1.00 3 Event 441 25 NOV 1.00 1.00 1.00 1 Event 1.00 1 .00 1.00 1 45! 2 DEC 0.97 1 .00 0.97 29 Event 1 .00 04 .97 0.97 31 461 9 DEC 0.94 0.97 0.91 33 1'.00 1.00 1.00 36 Event 47! 16 DEC 1.00 0.95 0.95 61 0

87 0.97 0,85 84 Event 48i 23 DEC 0.98 1.00 0.98 108 1 .00 1.00 0.09 0.99 105 Event 49' 30 DEC 0.98 1.00 0.98 46 1.00 1.00 49 Mean (arithmetic) survival(a) 0.98 0.99

0.97 0.99 0-!97

0. 096 Standard! deviation(a)

0.02 0.02 0.03 0.01 oý-o6 0.06 (a) Calculated for events when 20 or more organisms were tested.

TABLE 4-16 THERAL PARAMETERS ASSOCIATED WITH LATENT EFFECTS TESTING OF-WINTER FLOUNDER AT OCNGS CONDUCTED FRCK JANUARY THROUGH DECEMBER 19-85 Ambient (C) DischarL~e-(C)

Test -Mean Max. .. Mean Max.

Number Date Collection Hold Hold Collection Hold Hold Event 1 28 JAN Event 4 19 FEB 3.8 3.5 7.4 1.6 Event 5 25 FEB 8.5 8.4 8.9

.Event 6.1 4MAR 6.7 8.8 Event 11 1.4.4.

1 8 APR 10.5 Event 13 11.5 11.5

Event 14 22 APR 20.1 17.1 20.0 20.1 29.7 30.3 Event 17 29 APR 16.7 17.4 21.9.

20 MAY 23.1 22.2 23.3 Event 22 24 JUN 26.6 24.6 27.9 26..8 24.6 36.1 Event 42 11 NOV 13.2 13.4 14.3 Event 43 18 NOV 11.9 12.8 16.2 11.9 16.4 21.0 Event 44 25 NOV 9.2 10.0 11.3 9.2 18.0 19.8 Event 45 2 DEC 11.0 7.9 10.5 11.0 15.8 18.0 Event 46 9 DEC 5.4 6.1 7.5 5.5 '14.9 15.8 Event 47 16 DEC 3.8 3.3 4.2 3.9 5.6 9.7 Event 48 23 DEC 1.6 1.2 2.5 1.6 10.7 11.8 Event 49 30 DEC 1.3 2.0 4.5 1.4 12.5 14.5

TABLE 4-17 MEAN FORK LENGTH (mrm), STANDARD DEVIATION, AND NUM-ER OF WINTER FLOUNDER BYtONDITION AT THE TERMINATION OF %-HOUR POST-IMPINGEMENT LATENT EFFECTS TESTS CONDUCTED AT, OCNGS FROM JANUARY THROUGH DECENBER 1985 Sample Live Stunned Dead Event Mean SD Nmber Mean SD umb er Mean- SD Number 1 236.9 86.1 8 4 197.5 112.4 2 6 225.2 72.1 77 13 -- 298.6 - 4/.5. . 7:

14 31-8.0 1 17 214.5 48.8 2

- *2410 .- - - -180-.2--60-i6--

42 320.0 1 43 267.6 65.1 7 44 289.0 ý261 .9. 2 45 1 88.3 86.1 58 205.5 123.7 2 46 121.0 16.0 66 114.7 29.7 3 47 122.5 33.6 110 293.7 15.9 3 301.6 71.5 16 48 130.5 59.1 207 96.0' 5.0 3 49 162.2 83.8 119 96.5 24.7 2

TABLE 4-18 GENERAL LINEAR MODEL RESULTS (coefficients of determination - r 2 ) AND MEAN SURVIVAL VALUES FOR WINTER FLOUNDER RELATIVE TO VARIOUS THERMAL VALUES TESTED AT OCNGS, JANUARY THROUGH ýDECEMBER 1985 Ambient Held Discharee Held

- All Temperatures S_11.9 (C) >20.1 (,)

Initial Latent Toa Thermai Conditions Initial Latent Total . 1hitiAl Latent Total : -

Collection temperature r2 0.125 <0.001 0.002 0.030 0.007 0.010 0 0.

Mean holding r2 0.146 <0.001 0.002 0.665(a) 0.632(a) 0.641(a) 0 0 0 2

Maximum holding r 0.147 0.002 <0.001 0.001 0.001 <0.001 0 0 0 Delta r 0.135 0.010 0.005 0.637(a)" 0.637(a) 0.642(a) 0: 0 0 Mean survival 0.992 0.936 0.929 0.997 0.978 0.976 1.0 0 (a) Slignificant at p - 0.05.

TABLE 4-19 COMPARISON OF INITIAL AND LATENT IMPINGEMENT SURVIVAL (propori :ion) 'BETWEEN CONVENTIONAL AND RISTROPH VERTICAL TRAVELING SCREENS. OCNGS. 1 Q7 5-1 QRC I Ristroph Conventional Screens -" Screens OCT 76i(n)

AUG 75- SEP 76 - s1 78(9 AUG 7?(ý . OCT, 75- JAN. 85 -

AUG 7 7 (b) AUG 78 DEC 85 Sopec es Thermal hLIat SurvivalL Sunxiv.3l N Bay anchovy Initial 0.25 338 1.00 52 1.00 151 0.53 541 0.72 2,800 Ambient latent 0.25 44 0.07 27 0.04 80 151 0.27 1 .111 Heated latent 0.00 40 0.12 25 0.00 71 0.02 toI 136 0.06 870 Atlantic silverside Initial 0.87 24 1.00 144 1.00 86 0.99. 254 0.97 3,388 Ambient latent 0.60 15 0.82 .%2 90 0.70 "k) 46

0.78.7 151 0.83 1,766 Heated latent 0.67 6 0. 1..,76 54 0.67 . 39

0.69.1.& 99 0.69 1,066 Winter flounder Initial 1.00 4 1.00 6 1.00 4 1.00/ 14 0.99 699 Ambient latent 1 .00 4 1.00 4 1.00 '2 1 .00: . 10 0.94 371 0 1.00 2 1.00 2 1 .00 ,*s 0 4 0.78 320 Heated latent Sand shrimp Initial 0 1.00 30 1.00 192 1.00 222 0.99 6,845 Ambient latent 0 0.87 15 0.96 92 0.92 "72 107 0.96 3,304 Heated latent 0 0.73 15 0.78 86 0.76 .?c7. 101 0.51 2,308 (a) Derived f rc Table 17, IA (1977).

(b) Derived from Table 74, IA (1978).

(c) Derived from Table 74, IA (1979).

'4 p

I TABLE 4-20 COMPARISON OF TOTAL IMPINGEMENT SURVIVAL (proportion) BETWEEN CONVENTIONAL AND RISTROPH VERTICAL TRAVELING SCREENS. OCNG. lq7'-1 QR* _

MORNNA Ristroph

- Convyntional Screens Screens Weighted HMean Thermal OCT 75 - SEP 76 - SEP 77 - OCT 75 - JAN 85 -

Spec ies AUG 76 SAUG -78 DEC 85 AUG 77 AUG 7 8 Bay anchovy Ambient 9Y 0.06 c3 0.07 ?6 0.04 '? 0.06 */ 0.19 Heated //Cu 0.00 6 0.12 /0c) 0.00 76 4?* 0.01 ?* 0.04 Atlantic silverside 4,Ambient ?C) 0.70 / 0.82 ]?C 0.70 ;.3 0.77 2u 0.80 Heated qlI 0.58 3e) 0.70 33 0.67 3;,- 0.68 33 0.67 Winter flounder Ambient 1.00 1.00 1.00 1.00 7 0.93 Heated 1.00 1.00 1.00 0.77 0

Sand ihrimp Ambient 11 0.87 4' 0.96 ',* 0.92 - 0.95 Heated Q-7 0.73 0.78 r,1 0.76 -c, 0.50

5., IMPINGEMENT-SCREEN COLLECTION EFFICIENCY, The efficiency of intake screens in removing organisms from the condenser cooling-water flow is important in this study because it has a direct bearing on the accuracy of impingement estimates. The studies described in this chapter involved the time required for organisms to pass from the Ristroph screens to the end of the screenwash discharge pipe, the overall efficiency of the screens, and efficiencies associated with various com-ponents of the screening system. Specific methodologies are described in Section 2.3.

5-~TINE-OF-PAS SAGE. STUDIES, Experiments were conducted to determine the time required for impinged organisms to be transported from in front of the screens through to the screenwash-discharge system. This information was necessary for the proper design of subsequent screen-efficiency experiments. It is also important for any future impingement sampling programs at Oyster Creek that involve intermittent screenwash modes. Samples can be timed to ensure that all organisms impinged on the screens during intermittent screen-hold periods are collected. This was not a concern during the 1984-1985 impingement abundance study because screens were always in the continuous wash mode.

The traveling screens can be operated in either a fast-rotation or slow-rotation mode. During the fast-rotation screenwash mode, the screens travel 1 ft in 5 seconds. This mode is generally employed during per-iods. of high impingement to reduce screen clogging. During the slow-rotation screenwash mode, the screens travel 1 ft in 23.5 seconds. This screenwash speed is generally employed during periods of low impingement, reducing wear and tear on the screen components. Time-of-passage studies were conducted during both the slow- and fast-rotation modes.

In November 1984, a series of experiments were conducted involving the release of buoyant foam balls (-1-1.5 in. diameter) downstream of the trash racks and upstream of the Ristroph screens (Figure 2-3). Recov-eries were made at the end of the screenwash discharge pipe (Figure 2-1).

The Ristroph screens were in the fast-rotation mode. The foam balls began to appear as early as the third minute after release, and appeared as late as 12 minutes after release in one test (Table 5-1). Most returns came'during'-the fourthý minute after release,...and-minutes 4,-5,. .

and 6 accounted for 83 percent of the returns.

In early May 1985, a second series of time-of-passage experiments were conducted using preserved Atlantic silverside (Table 5-2). In the fast-rotation screenwash mode, the vast majority (91 percent) exited the screenwash discharge during the fourth minute after release. These results were similar to those described for the experiments with foam balls in the fast-rotation mode. In the slow-rotation mode, the 12th minute produced the highest number of returns. In this mode, the returns

.mwe ore protrac enieed;;-

-in-t -It bgVt 6-produced -1t-pwrcent-of -th-e . . .

returns. The time of maximum returns was 8 minutes later with the slow-rotation than with the fast rotation.

5-1

This information on time-of-passage provided the basis for properly designing the sampling periods in the .efficiency studies described below.

The data also demonstrate that any sampling of screenwashes after an intermittent hold period should extend at least 20 minutes,* if not 30 minutes.

5.2 OVERALL SCREEN EFFICIENCY Overall screen efficiency refers to the percent return of test objects that were placed in the intake in front of the screens, either up-or downstream of the trash racks. In May 1985, andý again in November, a series of efficiency tests were conducted using preserved Atlantic silverside. Recaptures were made in the impingement sampling pool.

The~ resul ts -are shown, in .Table 5-.

During. the series of tests in May 1985, return of released specimens

(,. ., -screen--ef-fiviency)--averaged--9O-perceit-. --itren--urttrer-e;-w-conducted in November 1985, a large decrease in efficiency was observed-53 percent was the average, compared to 90 percent in May.

The selective sizes of Atlantic silversides used as the tag/release objects may have introduced a bias in the results. The potential bias was investigated by determining the length distribution of the released fish and comparing these data with the length distribution of the recap-tured specimens. During 1-2 May 1985, adult Atlantic silverside ranging in size from 70 to 125 mm FL were released in the intake, recovered in the sampling pool, and remeasured. The similarity of percent returns by size class (Table 5-4) indicates that no strong size selectivity was exerted by the screening system. Size selectivity is ruled out as the reason for the decrease in overall screen efficiency from May to November 1985.

The 90 percent overall efficiency recorded in May 1985 may be considered-

"best-case" efficiency. Considering that 88 percent overall efficiency was recorded in November 1984 using foam balls, it is reasonable to con-clude that efficiency was high and did not change from November to at least through May 1985. Based on this, the estimated number of organisms impinged during this period (Chapter 3) is considered to be about 10 per-cent lower than the actual number. Strictly speaking, the results for preserved Atlantic silversides can only be directly applied to impinge-ment of dead Atlantic silversides, or a species of similar size and shape, such as bay anchovy. However, the similar overall efficiencies for Atlantid' silvieside -and f-odm- U.611 -objedtsi:dif buoyancy, provides some confidence that the results-may be extrapolated to other organisms.

5.3 EFFICIENCY OF ISO.ATED SCREENING SYSTEM COMPONENTS Concurrent with the November 1985 studies described above, and again in early January 1986, experiments were conducted to determine efficiencies associated with various parts of the screening system. Overall screen efficiency at this time was only about 50 percent (November data, Table wh) r ld S-u gis)ofanisms of te s. rred.p i....ht into where losses of organisms occurred.

5-2

I, . -

The percent return of released, preserved Atlantic silverside varied according to the release point (Table 5-5). Efficiency increased the closer the release point was to the sampling pool. Less than one-half of the Atlantic silversides placed against the screen face (Point C) were recovered. Placing the fish directly in a screen-panel trough (Point D) increased returns to 72 percent. Ninety-three percent of fish placed in the low-pressure sluice behind the screens were recovered in the sampling pool. -

The incremental changes in efficiency with release point (Table 5-5) can be used to partition fish losses among components of the screening system. There is a relatively minor loss of organisms between the low-

.pressi*re sluici'dand' the'sampling'pOb6Ul( 1000 93 ---i'7 percent) -The+cause -...

is unknown, but it may involve individual fish getting trapped in turbu-lence caused by water-cushion jets located at Screen Housing No. 6, or

. in turbulence in the expansion chambers of the fish return sluice.

Subtracting the efficiency for the screen-panel trough release point (72 percent) from that for the low-pressure sluice (93 percent) yields a 21 percent loss of fish due just to travel up the screen face,' travel over the top of the screen drive structure, through the wash jets, and into the debris trough. Losses probably occur when the screen panel is up-ended and the trough contents are cleaned by water jets. The organ-isms could be lost by falling through rubber seals located between the debris trough and the screen housing and entering the cooling water flow behind the screens, or by accumulating on the seals themselves. Visual inspection has verified that the latter does occur.

Contact with the screen face does not completely ensure that a fish will enter a screen panel trough. Twenty-six percent (72 - 46 percent) are lost between the screen face and screen-panel troughs (Table 5-5).

Actually, there was little difference in efficiency among release points upstream or downstream of the trash racks (Table 5-3, November) or on the screen face (Table 5-5). Combining results for these three release points results in an average loss of fish of about 48 percent. This loss can be due to numerous factors such as passage through the screen mesh, gilling in the mesh, passage around the screen panels, passage under the screen structure, accumulation in turbulence located in front of the screen face, or even loss by being consumed by predators. Visual inspec-tion has confirmed that gilling of the tagged organisms occurred.

Te reductiion in overa b~creen effticincy-btenMy-idNvdt-18~~*~

was attributed to deterioration and failure of several screen-system com-ponents. Plant personnel confirmed those failures (Vouglitois 1986, per-sonal communication). It was reported that the low-pressure screenwash manifold became clogged by mussel shells and other debris in July 1985, and thereafter functioned only marginally. Because the low-pressure wash sprays remove organisms from the screens, their failure probably contrib-uted to the decrease in efficiency of the screening process documented during November 1985. Power plant maintenance personnel reported that

............... he.rub lp..deigedto keep organisms and debris from falling back into the cooling water behind'the screens had de eiorated+aan a-*

a debris was observed falling past the flaps. This also would have con-tributed to reduced efficiency.

5-3

According to GPU Nuclear personnel, the screening structures are to be overhauled and upgraded in 1986. An intensified maintenance program will be instituted that will include regular cleaning of screenwash pipes in order to reduce biofouling and consequent clogging. When these measures are in place, the overall efficiency of the Ristroph screens should return to about 90 percent.

5.4

SUMMARY

Using foam balls and preserved fish, a series of release-recapture expe-riments were conducted to determine both the length of time it takes for an organism to move through the screenwash system, and the efficiency of i

the syte.4ý ý Th time, from releas .of ,obj!ectýs in -.front.-of_ the- tr ave Ling screens until they appeared inthe sampling pool (i.e., time-of-passage) ranged from 3 to 24 minutes. However,. results for preserved Atlantic s*_ -erside s ta- t -vA -ma-utes when screens were in the fast-rotation mode, and between 11 and 16 minutes during the slow-rotation mode. These results have implications for any future impingement studies at Oyster Creek. If intermittent screenwash modes are used in the future (they were not used in the 1984-1985 study), time-of-passage and screen speed will have to be taken into account to ensure the collection of all impinged organisms.

Overall collection efficiency of the screenwash system was calculated as the percent of objects released at the front of the system that show up in the sampling pool. Two different sets of results were obtained, depending on when tests were conducted. Based on tests conducted in November 1984 and May 1985, screen efficiency was about 90 percent.

In November 1985, the efficiency dropped to about 50 percent. At this time, based on release experiments in different parts of the system, it was determined that significant losses of organisms were taking place both in front of the screens, and during contact of organisms with the screens.

The decrease in screen efficiency may have been the result of deteriora-tion of various components of the screening system after May 1985. GPU Nuclear personnel confirmed this deterioration and outlined plans for renovation of the screening structures in 1986, along with an improved maintenance program. This should greatly increase the efficiency of the screening system.

sized organisms entering the cooling system during the study period are at least 10 percent greater than those actually collected and reported (Chapter 3).

5-4

TABLE 5-1 NUMBER RECOVERED BY MINUTE AFTER RELEASE OF BUOYANT FOAM BALLS INTO THE FOREBAY OF THE OCNGS INTAKE STRUCTURE ON 7-20 NOVEMBER 1984 USING FAST SCREEN SPEED Minutes .Date/(time)

Since 7 NOV 84 7 NOV 84 13 NOV 84 20 NOV 84 20 NOV 84 Total Release (1325) (1345) (1410) 15 (

-(153 8) Combined 1 0 0 0 0 0 0 2 0 0 0 0 0 0 4 5 12 3 8 13 41 5 .3 .4 2 7 5 2.1 6 2 1 4 3 1 11 7 2 0 0 0 1 3 8, 1 0 0 0 0 .1 1 0 3 0 0 4 9

1 0 0 0 0 1 10 11 0 0 0 0 0 0 12 0 0 1 0 0 1 13 0 0 0 0 0 14 0 0 0 0 0 15 0 0 0 0 Number released 20 20 20 20 20 100 Number recovered 17 19 14 18 20 88

,W;: 1V

TABLE 5-2 NUIBER RECOVEREDBY MINUTE AFTER RELEASE OF PRESERVED ATLANTIC SILVERSIDE INTO THE FOREBAY OF THE OCNMS INTAKE STRUCTURE ON 1-2 MAY JQRS Time Fast -Revolution Slow Revolution (minutes) Test I Test 2 Test 3 Total Test 1 Test 2 Test 3 Total 1 0 0 0 0 0 0 O0 0 2 0 0 0 0 0 0 0 0 3 0 3 0 3 0 0 0 0 4 69 29 60 158 0 1 1 2 0 0' 2, 3 5 0 1 0-6 0 1 7 0 0 1 1 0 0 0 0 0 ....

9 1 0 0 : 1 0 0 0 0 0 1 1 10 0 2 0 3 3 6 11 0 0 0 .0 4 9 5 18 12 0 0 0 0 19 4 30 53 13 0 1 0 1 9 15 3 27 14 0 0 0 0 10 3 10 23 15 0 0 .0 1 7 0 0 7 16 0 0 0 0 7 2 2 11 17 0 0 0 0 2 0 0 2 18 0 0 0 0' 2 0 0 2 19 0 0 0 0 0 0 0 0 20 0 0 0 0 0 0 0 0 21 0 0 0 0 0 0 0 0 22 0 0 0 0 0 0 0 0 0 1 1 0 -0 0 0 23 0 24 0 1 0 J1 0 0 0 0 25 0 0 0 0 0 0 0 0 26 0 0 0 0 0 0 0 0 27 0 0 0 0 0 0 0 0 28 0 0 0 0 0 0 0 0 29 0 0 0 0 0 0 0 0 30 0 0 0 0 0 0 0 Number released 150 150 150 450 150 150 150 450

~ ~.

Number recovered 73 38 63 174 60 38 54- 152 Note: Number recovered in this table refers to those recovered by dip net as soon as they exited the discharge pipe. Those missed by dip'nets were recovered from a backup net after tests were terminated. These latter recoveries could not be used in calculating . ...time of passage.

. a. ... . . . . . . . ........ . . . ........

TABLE 5-3 RESULTS OF OVERALL SCREEN EFFICIENCY STUDIES USING PRESERVED AT1.ANTTC SILVERSTDE. MAY AND NOVEMBER 1985 Release Number Number Percent Date - Released 1-2 MAY 1985 A 150 133 89.

150 141 94 150 123 82 150 135 90 150 141 94 150 138-150 132 88 150 141 94 May Total 1,200 1,084 90 13-21 NOV 1985 A 100 54 54 B 25 12 48 25 12 48 25 9 36

.25 19 76 25 9 36 25 10 40

'100 61 61 November Total 350 186 53 Note: A = upstream of trash racks.

B =,downstream of trash racks.

.~ ~

TABLE 5-4 PERCENT OF RELEASED AND RECOVERED ATLANTIC SILVERSIDE BY SIZE CLASS AND SCREEN SPEED USED. IN OCNGS INTAKE-SCREEN EFFICIENCY STUDIES OF t-1 MAY 1QR'.

Size - - Fast - Slow 1 Slow 2 Class Percent Percent Percent Percent Percent Percent Tagd Recovered (MM) a Recvered Tazze &coere 70 0 0 0 0 1 1 0 0 1 1 1 0 75 80 5 4 1 1 3 3 13 . m. 14 - -' 20:---,.,' -23

90. 27 25. 22 21 23 25 95 19 20 23 26 23 25 105 11 14 13 11. 7 7 110 6 8 4 4 6 1 115 3. ..2 .5 4 2 . 1 120 0 0 1 1 2 3 125 1 1 0 0 '0 0 Number released or recovered 150 133 150 141 150 132

.TABLE 5-5 RESULTS OF SCREEN EFFICIENCY STUDIES USING PRESERVED ATLANTIC SILVERSIDE AND DIFFERENT RELEASE POINTS, 13-21 NOVEMBER -1985 AND 3 JANUARY 1986 Percent, Number Released Number Recovered EfficiencyX Release Pint C' 25 13 52 25 10 40 Total (C) 50 23 46

__ D 24 75 25 20 80 26 17 65 25 17 68 Total (D) 100 72 72 25 25 100 25 25 100 25 20 80 Total (E) 75 70 93 Note: C = face of Ristroph screen D = screen panel trough at.water surface E = upper (low pressure) sluice Refer to Figure 2-3, Chapter 2.

6.. DILUTION PUMP: ENTRAINABLE-SIZED ORGANISMS This program. provides estimates of abundance of important ichthyoplankton and zooplankton taxa -that were entrained through thei dilution pumps at OCNGS between September 1975 and August 1981. Density data"(from con-denser entrainment sampling programs) for. ichthyoplankton and macrozoo-.

plankton were available only from this time period. Microzooplankton entrainment programs were conducted only between September 1975 and Aug-ust 1976; thus, dilution-entrainment estimates are restricted to that time period. The available plankton density data were derived from col-lectionsa made .in the .condenser cooling-water, discharge. These data were used -in conjunction with dilution-pump volume data to 'aiculate teuesti-mated number of organisms that passed through the dilution pumps.

.Yearly-abundance estimates (Tables 6-1 -through 6-3)--were derived -by-.using mean weekly densities because this is the form in which the historical, data exist in GPU Nuclear's OCEAN computer files. The annual estimates for condenser entrainment in the tables differ slightly from those provided in previous progress reports by Ichthyoiogical Associates (1977, 1978) because the latter were based upon mean monthly densities.

Further, in previous progress reports by EA (1981, 1982), annual entrain-ment estimates incorporate the combined dilution and condenser cooling-water flow volumes. In this report, separate estimates are provided for dilution pump and condenser entrainment.

The data in Tables 6-1 through 6-3 establish that dilution-pump entrain-ment is about equal to condenser entrainment. Adding the two estimates together for any taxon in any year gives the total estimated number entrained through the OCNGS cooling system. Except for the period September 1976 - August 1977, bay anchovy eggs were the most abundant ichthyoplankton form entrained. From September 1975 through August 1976, nearly 28 billion eggs were estimated to have been entrained 'through -

the combined condenser and dilution systems. The larvae of bay anchovy, winter flounder, and sand lance were also abundant at times, depending on the study year. Among the macrozooplankton, mysid shrimp and zoeae-of the sand shrimp (Craggjon were usually most abundant. Over 72 billion mysid shrimp were estimated to have passed through the cooling system between September 1976 and August 1977. Based on microzooplankton den-sities measured between September 1975 and August 1976, various forms of

- copepods, ,particularly. Acartia,. were most abundant, followed by rotifers and polychaete larvae. In this time period, roughly 70 trillion micro- "

zooplankton traversed the cooling system. Complete discussions of the entrainment phenomenon at OCNGS are found in previous annual progress reports by IA (1977, 1978) and EA (1981, 1982).

6-1

TABLE 6-1 ESTIMATED NUMBER (x 106) OF SELECTED ICHTHYOPLANKTON PASSED LROUGH THE CONDENSER AND DILUTION PUMPS AT OCNGS FROM SEPTEMBER 1975 THROUGH AUGUST 1 981 SEP 1975L- AUG 1976 SEP 1976 - AUG 1977 SEP 1977 - AUG 1978 Condenser Dilution Condenser Dilu ion Condenser Dilution Silverside larvae 15.81 12.15 5.72 3.68 38.28 31.27 B*y anchovy 'larvae 1,152.09. 1,185.82 457.41 29* .71 497.35 533.39 Bayanchovy eggs 14,135.76 13,535.11 196.71 17M.04 1,994.76 2,158.24 Winter -lounder larvae 116.25 140.86 850.84 86ý.00 597.58 635.09 Sand lanice larvae 27.57 36.92 109.77 109.35 142.28 151.69 Goby larvae 614.02 591.79 101.19 84.19 160.19 162.60 Naked g~by juveniles 6.71 7.77 0.41 0.21 0.77 0.84 Blenny larvae 11.56 10.54 18.19 12.24 17.38 14.35 Northeri pipefish juVeniles 54.38 48.42 7.16 5.39 36.53 3 8.29

__ __TABLE 6-1 (Extended)

S.EP 197 8.- AUG 1979 SEP 1979 - AUG 1980 SSEP 19 80 - AUG 1981 Condenser Dilution ;'.Cond enser Condenser Dilution Dilution Silverside larvae 66.50 55.52 5.14 1.71 105.56 98.94 Bay anchovy larvae 1,270.35 1,412.46 144.12 135.26 314.06 318.98 Bay anchovy eggs 3,029.43 3,241.40 475.44 322.38 3,818.59 3,914.51 Winter flounder larvae 1,077.08 808.80 (a) (a) 126.05 128.36 Sand lance larvae 11,294.87 .1,389.67 (a) (8) 133.67 147.90 Goby larvae 85.64 97.21 188.49 144.17 181.79 202.61 Naked gobi juveniles 0.27 0.31 1.82 1 . 81 1.93 2.91 Blenny larvae 4.01 4.40 8.43 6.26 4.12 4.37 Northern pipefish juveniles 30.69 33.29 17.37 14.48 42.06 39.03 (a) Plant was shut down when' these forms would have been present.

TABLE 6-2 ESTIMATED NUMBER (x 107) OF MACROZOOPLANKTON PASSED THROUbH THE CONDENSER AND DILUTION PUMPS AT OCNGS FROM SEPTEMBER 1975 THROUGH AUGUSIT 1981" SEP 1975 - AUG 1976 SEP 1976.-

Condenser Dilutionl AUGA977 SEP 1977 - AUG 1978.

Condenser Vil.tion Condenser.

Family . sidae- 1 41!6.04 1 ,228.95 1,903.90 1 ,*77.42 898.27 909.28 752.12 1,042.77 1,557.64 1,6,95.03 855.80 876.04 59.55 - 77.31 101.30 192.56 53.40 47.52 Cr~jbtii toeae 916.95 678.86 107.43 202.91- 873.55 82 8.43 f i undet. 13.25 88.98 19.02 A 9.28 55.07 58.71 Cal-lnekte* sp. zoeae 3.28 3.09 1.26 1.85 1.70 1.87 ta sp.-ne meg, 9.99 8.86 32.18 ;23.46 10.32 .8.33 gejjj tubularis 2.20 2.13 2.24 I 3.48 13.93 12.23 31.50 29.68 8.59 11.47 98.04 61.99 0 0 0.20 0.22 24.39 18.53

_.tubeirculat-um 0.29 0.32 0.47 0.52 170.42 107.60 Gammaridae 0.16 0.23 1.36 1.36 1.16 1.17 Ctenophura 47.81 48.49 1.42 1.51 91.47 83.60

____ _ *TABLE 6-2 (Extended)

SEP 1978 AUG 1979 SEP 1979 - AUG 1980 SEP 1980 - AUG 1981 Dilution Condenlser Dilotion *, ondenser Diltijg Family Myjsidae 196.11 .217.24 1,690.68 1,569.92 i 1,489.95 1,665.77 veomysis americana 637.82 657.63. 1,382.24 1,296.22 1,431.14 1 ,338,80 Myidozsi bigelRXL 37.93 42.53 77.22 75.67 72.55 73.75 Crangon zoeae 416.88 363.91 240.52 161.86 377.02 407.74 Craneon undet. 27.28 29.21 6.00 5.63 40.67 43.70 Callinecies op. zoeae 0.71 0.80 1.65 1.53 0.10 0.01 ap. meg.

sineG.r& 0.41 0.44 4.94 3.17 3.56 3.26 Ceravus iubularis 0.33 0.32 1.73 1.77 16.75 17.11 CoroDbiui sp. 4.96 4.81 32.05 28.25 89.16 96*69.

C. aschelusicum 1.86 I

94 3.18 3.05 8.59 9.28 C. tuber latuj 15.69 15.36 1'.78 *1.73 2.83 2 .95 Gammarid*e 2.68 2.74 0.08 0.04 0 0 Ctenophoja 74.11 86.85 234.88 188.66 18.28 16.13

TABLE 6-3 ESTIMATED NUMBER (x 109) OF' SELECTED MICROZOOPLANKTON PASSED THROUGH THE CONDENSER AND DILUTION PUMPS AT OCNGS FROM SEPTEMBER 1975 THROUGH AUGUST 1-976 Dilution Copepod nauplii 18,060.90 17,720.20 1,203.43 1,376.50 kAcrtia gIai Adartaia tfa 865.53 934.39 Acartia spp. 3,643.79 3,687.18 Qithgni cola~ya 23.77 28.02

...932.25 974--3'6"':* ...***""'

Oith2na spp.

Paraal9ai rassirostris 1.15 1.21 Rotifers 4,769.21 4,573.78

......682-27 ..

.- -'lve---rvaervae:.

Mulinia..lateralis 63.53 "48.80 140.62 124.25 Ba~rixac..*.le arv.ae.. ..... 6..60 6..88 3,792,18 Polychaete larvae 3,227.45 PoIvdora spp. larvae 5.73 5.82 Gastropod larvae 618.40 547.91

7. DILUTION PUMP: IMPINGEABLE-SIZED ORGANISMS The passage of impingeable-sized fish and macroinvertebrates through the OCNGS dilution pumps represents a potential impact additive to any effect of screen impingement. The dilution-pump flow volume represents nearly 60 percent of the total cooling water flow. Thus, screen impingement rates alone substantially underestimate the total number of :organisms passing through the OCNGS cooling system. The present program was designed to measure the abundance of impingeable-sized fish and macro-invertebrates going through the dilution pumps and to determine- their

--initial condition :(liye, dead, stunned) aftFer pump paas.age.. From this,.

comparisons may be made to screen impingement data to. estimate .the total effect of the OCNGS cooling system on impingeable-sized organisms.

--. 7 ;J GENERAL -SPECIES COMPOSITION-AND ABUNDANCE. . ..............

Dilution collections from December 1984 into December 1985 yielded 108 taxa of fish, invertebrates, and herpetiles. Of the total species compo-sition, 85 forms were finfish, 19 were invertebrates, and 4 were herpe-tiles. Five species constituted 95 percent by number of the total catch of organisms passing through the dilution pumps (Table 7-1). The annual sampling catch of all species during the study period was 479,518 speci-mens; of this total 175,496 were fish (36.6 percent), 304,015 were inver-tebrates (63.4 percent), and 7 were herpetiles (<1.0 percent). The total weight of all specimens (not counting organic material) collected from the dilution pumps during the study year was 1,426.6 kg. Of this total, 614.0 kg (43.0 percent) were fish weight, 811.8 kg (56.9 percent) inver-tebrate weight, and 0.8 kg (<1 percent) herpetile weight. Thirteen taxa accounted for more than 95 percent of the total estimated organism weight (Table 7-2).

The seasonal distribution of sampling catches from .the dilution-pump discharge is illustrated in Figure 7-1. The two highest peaks are during spring and late fall. As discussed in Chapter 3, the two periods of the year with rapidly changing water temperature appear to generate increased movement of fish and macroinvertebrates and, thus, interaction with the OCNGS cooling system.

The day-night distribution of organisms collected from dilution pump passage., is' presented in Table 7-3. Most organisms were&.more., abundant *.. . ,.

in night samples.

Because dilution-pump samples were larger and more frequent than screen-impingement samples, the annual sampling catch was much higher for the former (Table 7-1 vs. 3-1). However, the annual estimated numbers of many organisms passed through the dilution pumps was inordinately high, compared to annual screen-impingement estimates. Dilution estimates were higher by factors of: 2.3 for sand shrimp, 179 for bay anchovy, 6.9 for grass shrimp, 14.3 for Atlantic silverside, and 2.6 for blue ab. Ths numbesdo'nd"elte 't--thd---t

............. ia~iim v-i-f'ferentialiu-n-f1ow .......

volume; at most, dilution flow can be 1.5 times greater than the con-denser flow (i.e., screen impingement). Possible reasons for these differences are proffered later in this chapter.

7-1

7.2 DISCUSSION OF SELECTED SPECIES Several of the more abundant species are discussed with regard to abun-dance and temporal distribution. Generally, the periods of occurrence and peak abundance of species passing through the dilut.ion pumps is -the same as that' described in detail in' Chapter 3 for screen-impingement.

In addition to the differences in annual abundance between the dilution and screen-impingement programs mentioned above, there were some differ-ences in occurrence and periods of peak abundance that are illustrated below for several of the more abundant species.

7.2.1 Sand Shrimp Sand shrimp was the most numerous organism collected. A total of 201,058 specimens was collected during the study period; this total accounted for 66.1 percent of the total invertebrate catch (41.9 percent of total organism catch) (Table 7-1). A total of 169,.8kg was collected but, because of the small size of individual sand shrimp, this accounted for only 14.6 percent of total invertebrate catch weight (11.9 percent of total organism-catch) (Table- 72). The period of-maximum- abundance ranged from December 1984 through mid-June, with another peak occurring during the latter part of November 1985 into early December (Tables .7-4 and 7-5). The greatest estimated weekly abundance was 11.1 million spec-imens during the' first week of December. The estimated annual abundance for sand shrimp was 38.7 million specimens weighing 23,468 kg (Table 7-6). Night catches accounted for 98 percent of the total catch (Table 7-3). Based on examination of initial condition 30 minutes after collec-tion, sand shrimp survived passage of the dilution pumps very well; the proportion recorded as alive exceeded 90 percent (Table 7-7)Y.

For the period during which the dilution and screen-impingement sampling ,

programs overlapped, periods of occurrence and peak abundance were gener-ally similar (Tables 7-4 and 3-4). After the dilution-sampling program started during the, week of 10 December 1984, the first abundance peak in both the dilution and screen-impingement programs occurred during the week of 17 December 1984. Both programs showed a'decrease into February 1985, then a second peak in late April; the peak for screen impingement occurred one week earlier than that for dilution (Tables 7-4 and 3-4).

Abundances in both programs then decreased throughout the remainder of the concurrent sampling programs. In the screen-impingement program, abundance decreased to zero between 29 July and 14 October. Although

... relatively* low-.in.,number., * *sand-.shrimp .,were-ocollected: in *the. ,d~ilution ....... ,

program throughout this period. These subtle differences in occurrence and abundance peaks 'between the dilution and screen-impingement programs are thought to be a result of different sampling, efficiencies in the' two programs, and this was investigated' in a special study, described in the next section (7.3).

7.2.2 Blue Crab Blue crab was the 4th most numerous organism collected from the OCNGS iu ond sc arge A total- s ecimens o........ .542 ..............

cent of the total invertebrate catch (3.7 percent of total organism catch) (Table 7-1). With regard to weight, this species accounted for 7"2

the greater part of both the -invertebrate catch (59.4 percent) and total organism catch .(32 percent); 460.8 kg -were collected during the etudy year (Table 7-2). Blue crabs appeared in large numbers throughout the warmer part. of the study period with the peak estimated weekly abundance occurring during mid-July (363,640 individuals); maximum estimated weight of blue crabs entrained in a week was 9,313 kg during this -same week.

The period of minimum abundance extended from early December 1984 'through mid-March (Tables 7-4 and 7-5). The estimated annual catch'was 3.4 mil-lion specimens weighing 93,460 kg (Table 7-6). Night catches accounted for 89.8 percent of the total number of blue crabs (Table 7-3). Initial survival of blue crabs (85 percent) was slightly less than that of sand shrimp' (Table. 7-.7). .

Differences in occurrence and weekly abundance of blue crabs between the dilution and screen-impingement programs were small. Peaks in April and

--- Julyrvetra--** -ame in -the -two programs; however ,.-a peak.-in. abund-ance..-i-n June 198f occurred one week later in the screen program (Tables 7-4 and 3-4). Between 9 January and 22 February 1.985, no blue crabs were col-lected in dilution samples. A small number of crabs were collected in the (screen) sampling pool that resulted in projections of up to 2,500 crabs impinged in one week during that period. These differences are small, however, and do not suggest, for blue crabs at least, great dif-ferences in sampling efficiencies between the two' programs.

7.2.3 Bay Anchovyh2.

The bay anchovy was the most abundant fish species collected from the dilution pumps. A total of 145,462 specimens constituted 82.8 percent of the total fish catch (30.3 percent of total dilution catch) (Table 7-1). Bay anchovy ranked first in terms of fish weight (58.2 percent of fish catch; 21 percent of total catch). One prolonged period of maximum anchovy abundance occurred. This period extended from the first week in April to the first week of December (Table 7-4). During the second week of May, the maximum estimated weekly abundance for this species was 9,733,570 specimens weighing 27,972 kg. The period of minimum estimated weekly abundance occurred January - March 1985. The annual estimated number entrained was 35,077,637; total estimated weight was 83,694 kg (Table 7-6). Night catches account for 57 percent of the annual anchovy catch (Table 7-3).

.i-nit-ialt sur-vival ,--of .:*this- ,specieSa-was ,_relatively.,Poor. ,( Tab e 7o,-x-7). .

two percent survived duripg the day and only 27 percent at night, for a combined average of 42 percent.. Although low, this initial survival rate was higher than that for screen-impinged bay anchovy (14 percent).

Although this appears to indicate that passage through the dilution pumps is less damaging than being impinged on the traveling screens, the possi-bility exists, as discussed below and in Section 7.3, that not all bay anchovies caught in the dilution-sampling gear actually passed through the dilution pumps.

Comparison of weeklye-s.mird aby-du tW-fi the ailutin-rogr'------ .

(Table 7-4) and the screen-impingement program (Table 3-4) reveals some large differences. In the screen-impingement program, a spring peak occurred during the week of 22 April consisting of an estimated 101,000 7-3

bay anchovies. In contrast, the spring peak in the dilution program was three weeks earlier, and consisted of an estimated 3 million anchovies.

Through the remainder of the concurrent study period, dilution estimates ranged from 100,000 to 800,000 per week (Table 7-4). During that same period, screen-impingement estimates ranged from zero to 49,000 per week.

Four different weeks in that period (early June - early October) produced no anchovies in screen-impingement samples, whereas weekly dilution esti-mates for those same weeks were as high as 396,300. These differences in the magnitude and timing of abundance peaks and occurrence may have been the result of the dilution-sampling gear collecting anchovies that had not passed through the diiution pumps, and possibly different size-selectivity-in the- two samplingo.programs. I These. issues. arde eioped,......,

further in Section 7.3.

7.2.4 Atlantic Silverside Atlanticsilverside was the 2nd most abundant fish species collected from the OCNGS dilution pumps; 16,502 specimens accounted for 9.4 percent of the total fish catch (3.4 percent of total organism catch). Atlantic silverside ranked 2nd in fish weight with 100.3 kg, accounting for 16.5 percent of the total fish catch (7.0 percent of total organism catch).

This species was present throughout the study period with maximum abun-dance occurring from mid-March to mid-May and a second smaller period of high abundance occurring from mid-November to the first week of December (Table 7-4). The peak estimate of weekly abundance occurred during the first week of April (659,390 individuals). The period of minimum esti-mated weekly abundance occurred during the warmer part of the year from late August through mid-October. The peak weekly estimate of entrained weight was 4,008 kg, which occurred during the first week of April. The annual estimate of number entrained was 3.98 million and total estimated weight was 23,896 kg (Table 7-6). Fewer Atlantic silverside were col-lected during night sampling (40 percent) compared to daytime sampling.

Initial survival was high for this species; over 90 percent were recorded as live (Table 7-7).

Although the timing of abundance peaks of Atlantic silverside in the dilution and screen-impingement programs was the same (Tables 7-4 and 3-4), the magnitude of abundance in the dilution program was much higher.

Based on differential flow-volumes alone, dilution abundance should have been no more than 1.5 times higher than screen abundance, yet, on samples compared to the screen-sampling pool. Just as with bay anchovy, there was evidence that not all Atlantic silversides caught in the dilu-tion sampler had passed through the dilution pumps (Section 7.3).

7.2.5 Other Species Among other relatively abundant organisms, the fourspine stickleback, northern pipefish, weakfish, summer flounder, and winter flounder all exhibited distributions of weekly abundance similar to those for the screen-impingement program (Taib es 7i an 3-3 . U o species thartexhib- ..................................

ited contrasting distributions were Atlantic menhaden and bluefish. In the dilution program, the primary period of occurrence of Atlantic men-haden was from mid-April into early July 1985 (Table 7-4). The highest 7-4

weekly estimate was 29,030 during the week of 15 April. In the screen-impingement program, estimates of weekly abundance were much lower and the peak (1,500 specimens) was in the week of 19 November 1984 (Table 3-4). May and early June 1985 produced the highest weekly estimates of abundance for bluefish; a total of 152,220 specimens were estimated to have passed through the dilution pumps in the week of 27 May. A much smaller peak in screen-impingement (1,260 specimens) occurred three weeks later than the dilution peak.

In addition to these large differences in periods of peak occurrence for some species, estimates for all major species were considerably higher in o the,:

.. dilution;,progrpam...compared ,,to, screen.imipingement. For. example,- annual.

estimates of dilution passage, compared to screen impingement were 1.8 times higher for blueback herring, 3.9 times for winter flounder, 6.9 times for grass shrimp, and 62 times for bluefish (Tables 7-4 and 3-4).

Although results of studies are presented in the next section that sug-gest differences in abundance between the dilution and' screen-impingement programs may be related to differences in sampling efficiency for cer-tain species, this is not sufficient to explain higher estimates for all species.

One factor that has not been discussed thusfar, and that could represent a major influence on relative abundance in dilution passage and screen impingement,' is the behavior of the organisms in question. As organisms move down the intake canal toward the intake structures (Figure 2-1),

there is a point at which the organisms must turn either left, into the condenser intake and screen area, or right into the dilution intake area.

The movement of the Ristroph screens (and perhaps other, unknown, fac-tors), with associated vibration and turbulence, may provide greater alarm cues to approaching organisms. Such alarm cues may be lacking in the dilution intake, at least until a point is reached where an organism cannot return against the dilution intake current. Although this hypoth-esis has not been proven (and perhaps cannot be proven with present methodologies), it seems quite plausible in light of the consistently greater number of organisms passing through the dilution pumps, compared to the condenser-intake screening system.

7.3 DILUTION SPECIAL STUDIES Several special studies were undertaken.to provide information regarding theefficacy,.of

, theiluton samplin gear th, respec to represen-,

tative nature of the data collected and how these data are related to impingement collection information. Three 'special studies were under-taken to assess the following aspects of dilution pump sampling.

1. Do flowmeters adequately represent the volume of water sampled by the dilution sampler?

2. Can it be assumed that all organisms collected by the dilution gear have passed through te 'dilution pumps?

7-5

3.o Does the dliluti6n collection gear catch .the same sized organisms as the impingement collection gear?:",

Summaries. of each study are presented .in the following sections..

7.3.1 Accuracy oof Dilution Sa-muling Gear Volume Determination at OCNGS' There are three dilution pumps located aet!OCNGS 'that discharge into four ports, of which.only the easternmost is sampled (Figure .2-1). PUmp. I discharges. primarily into the two westernmost ports, Pump 2's discharge is distributed across all four ports, and -Pump.3's flow is directed primarily into the easternmost port. The flow in the easternmost port

'"" is therefore dependent0on which of seven pump-operaitng-o nfigurations exists-at-the time of sampling. Operational modes are listed below in order of decreasing flow rates.

1. All pumps on 2 ... Pumps 2.-and ...3.-on

3. Pumps I and 3 on

4. Pump 3 on

5. Pumps 1 and 2 on

6. Pump 2 on

7. Pump I on The "standard method" used to measure the volume sampled involved suspen-sion of a flowmeter in the discharge port at a point where the mouth of the collection gear is located when the gear is deployed (Section 2.5).

Subsequent to initiating' sampling in November 1984, an additional flow-meter was mounted on the collection gear outside of the mouth to acquire additional flow information for each sample. The gear-mounted informa-tion was compared with the standard method results for samples collected from Sample Events 22-27, 31, 33, and 35. Use of information from these events allowed investigation of six pump-operating conditions. The infor-mation was examined separately for surface and bottom collections. The number of observations and the results are listed on Table 7-8. Table 7-7 provid es a monthly sMar oif-dIuti-onpmp-operatingo igurat ion .

frequency by month, based on the configurations encountered during the sampling program; these data were derived from either direct observations by the sampling crews or from NPDES Form EN-025 on file at OCNGS.

The differences between measured flow rates (m/sec) for standard versus gear-mounted meters (based' on data in Table 7-8) are listed below as the proportion difference between the mean gear-mounted values relative to the standard values.

7-6

Pumps Surface Bottom 2+3 -0.14 -0.05

1+3 -0.18 ;-0 .10 3 -0.01 -0.02 1+2 0.19 -0.10 2 0.23 0.65 1 0.87 0.89 Negative differences reflect higher readings from the gear-mounted meter; positive differences reflect higher readings from the standard flowmeter.

-,The :as~sumption ý.is -.made ,.that,,.,at ,,least w.,,henu higherfflows. are present (pump.

configurations 2 +3, +1+3-, or 3), the higher-reading flovmeter. is, more.

accurate. The values display a range of -18 to +89 percent. However, based on the annual operational-mode frequencies. displayed in Table 7-9, almos t 95 percent of the dilution-pump operational mode is attributable to use of Pumps 1+3, 2+3, and 3. The values for the remaining three modes display the greatest difference but are of little consequence because those modes were seldom encountered during the sampling program.

Dropping those data reveals a range of differences of -1 8 to -4 percent.

These results suggest that the standard flowmeter system tends to under-estimate the actual flow through the sampling gear and, hence, the vol-ume sampled. The underestimates appear to be inconsequential when only Pump 3 is operating for both surface and bottom samples. Likewise, the differences in measured flow rates are less for the bottom samples--

5 percent for Pumps 2+3 and 10 percent for Pumps 1+3.

Surface flow readings display a greater difference between standard and gear-mounted, meters, ranging from -14 to -18 percent. It appears as if the differences listed above are related directly to the magnitude of the flow that actually passes through the easternmost dilution port.

The greatest positive differences (when the gear-mounted meter yields a lower reading than the standard) occur when the least flow passes through the sampled port; the greatest negative differences (the gear-mounted meter yields a higher reading than the standard) occur when the great-est flow passes through the port. This suggests that the differences in measured flows may be due to alteration of the turbulence patterns between the center of the port and the east side of the port where the gear-mounted meter is positioned.

A-caiseý,ýý-can-be- ade. ýto <acept ,ýthek-stand ardflo~ qread ingsa , forI~

volume determinations because the sampling gear is deployed in the center of the discharge port. However, if there are significant changes in the horizontal flow profile, it is reasonable to assume that the worst case would be the flow measured by the gear-mounted flowmeter. Thus, although all abundance estimates (Section 7.1) are based on standard flow deter-minations, it is probable that for surface collections the densities could be underestimated by as much as 18 percent for the two most proba-ble pump-operating configurations.

7-7

7.3.2 Collection of Organisms Not Passed Through the.

Dilution Pumvs at OCNGS The: presence of submerged, columnar, cathodic-protection anodes near the mouth of the dilution ports precluded placement of sampling gear directly in the mouth of the port. The gear was deployed 7.2 m downstrea- of the mouth of the discharge port, thus the mouth of the sampling collar was open to any organisms that- can swim up the dilution discharge. Occasion-ally, surface samples collected unusually high numbers of schooling fish;,

such as bay anchovy, Atlantic menhaden, and Atlantic silverside, in excellent condition. The abundance of these species was not reflected in the bottom samples. These facts, coupled with observations of schools.

-ie discharge ar.eaasugges thataome abundancedata from the dil.ution.sampling program may be biased upwards by ..the collec-tion of fish that have not passed through the dilution pump system.

A tag-release and recapture study was conducted to determine whether fish passing through the dilution pumps were uniformly recaptured in surface and bottom samples. Four exploratory releases were conducted using the dilIu tion pu-m'p 'sys6t-em . 'LiLv'e'," tafg'g--

ed'Atl'aniticsierdererlsd in front of the dilution pump intake after the dilution sampling gear was deployed. One hundred fish were released for each test. The collection gear was retrieved after one-half hour, and the tagged and untagged Atlantic silverside were counted. The density of the tagged returns pro-vides an indication of expected catches for bottom versus surface samples. The relationship between these values was then subjectively compared to relationships between surface and bottom catches for regu-larly scheduled samples collected during the same weeks.

Table 7-10 presents the number of live Atlantic silversides collected for each of two week's sampling (24 samples per week) and the volume for each sample. Table 7-11 presents the density of the live silverside catch for each sample. The density of the returned tagged fish is listed below.

Density (No./1.000 m Release Date Surface Bottom

.5 APR 85 2.29 1.35 11 APR 85 3.44 3.56 same order of magnitude and there is no clear indication that a strong difference exists between surface and bottom collections. The results from Table 7-11 reveal that during the week of 2-5 April 1985 the catches appeared to be of the same order of magnitude for 14 of 24 samples; the remaining 10 samples have a substantially higher (8-45 times greater) surface catch. Samples collected during the following week have only one sample set that shows a substantial difference between surface and bottom catch densities.

7-8"

The great differences in surface and bottom catch densities between the two weeks of regular sampling suggest that since passage through the pumps should not result in great differences in. surface and bottom abun-dance, then the source of extra silversides could be due to the collec-tion of fish that reside in the dilution discharge waters.

Although schools of Atlantic silverside were not reported inside the dilution discharge area, other species were observed to school in that area, i.e., Atlantic menhaden and bay anchovy. The route by which these fish entered the dilution discharge is unimportant; they may have passed through the dilution pumps prior to the sampling period or they may have travel~ed,ý'upi theý,, Oyster -Creekl di-scharge.,ýcanal-.iý.ý.ý The ,per,,tinent t,,issue .is.<

that the capture of these individuals causes the apparent catch density to be greatly inflated. Periods when this situation may have been extant were highlighted in Section 7.2.

7.3.3 Comsarion of Size Selectivity of Dilution Samvling Gear to Impineement Sampling Gear at OCNGS The sampling apparatus deployed in the discharge of the dilution pumps was designed to collect impingeable-sized organisms. To this end, the same size mesh was used in the collection collar as is used on the vertical traveling screen panels. Likewise,* the dilution live car was outfitted with the same size mesh as the pool collection net. It was observed by field collection crews that smaller individuals seemed to be collected by the dilution gear than were caught in the pool sampler.

In an effort to verify this observation, live sand shrimp (Cagon septemsinosa) were collected from selected dilution and impingement samples, and total length determined to the nearest mm for each specimen.

Data were pooled into 2-mm size classes and the length distribution of the catches was nonparametrically compared between gears using the Kolmogorov-Smirnov two-sample test (Siegel 1956).

Results of this effort are presented on Tables 7-12 and 7-13. Results of the statistical analysis of the data reveal that the differences between the length distributions are significant at a - 0.001. The smallest size sand shrimp collected from the screens was 40 mm in length, the largest was 71 mm in length, and the mean size collected was 52 mm. The sizes of sand shrimp collected by the dilution sampling gear ranged from 29 to 65-mm; the mean size collected was 46 mm total length.

Sand shrimp of 29-40 mm total length were not collected by the pool gear (these size categories accounted for only 1 percent of. the screen catch).,

most likely because they were not stopped by the screen panel mesh.

These size classes were, however, retained by the dilution pump sampler; almost 25 percent of the dilution pump sampler catch was composed of 29-40 mm specimens. Catch of sand shrimp of the 41-54 mm size class represented approximately the same percent of the catch for both gears, 67 percent of the pool catch and 64 percent of the dilution catch.

Larger.sand shrimp.. appeared more frequently in pool collections. Size

..s

.. . _...i _.--.....

class >54 mm represented 30 percent ote c.ch3n the p6l- and Oi ... ..

cent in dilution pump collections.

7-9

Further evidence that the dilution gear collects smaller individuals of a species is illustrated in Figures 7-2, 7-3, and 7-4. Mean weights per individual for blue crabs, bay anchovY, and sand shrimp, when plotted for screen and dilution samples over the study year, are clearly lower for dilution samples. In the fall 1986 collections, sand shrimp dropped com-pletely out of;'pool collections, but they were still caught in dilution samples.

It is evident that the traveling screens of the condenser intake are less efficient than the dilution discharge sampler for collecting small sand shrimp. The traveling screens appear to be selectively retaining larger specimens of these organisms, as well as bay anchovy and blue crab

... .. whe pnred to dilution pum- 'catcheS.. Asin*l*'aa siutuatio- rabl y exists for other invertebrates and fishes that have a wide range of sizes represented in their populations, e.g., grass shrimp and fourspine s t; ickivOre-eb ust-

-- x incomparing the-i-i-nun~ ?e--etween-these gears for this reason.

7.4 ..... SUIOMY From December 1984 to December 1985, weekly collections were made to determine the number and weight of (screen) impingeable-sized organisms that pass through the dilution pumps. The total annual collection con-sisted of 479,518 specimens (1,427 kg) distributed among 108 taxa of fish, invertebrates, reptiles, and amphibians. Five species made up over 96 percent of the catch: sand shrimp (201 ,058 specimens), bay anchovy (145,462), grass shrimp (81,850), blue crab (17,542), and Atlantic sil-verside (16,502). The number of organisms passing through the dilution pumps was highest during two periods--December 1984 - January 1985 and April-May 1985. Weekly maximum peaks were 79,481 specimens in the first week of December and 43,406 in the last week of April. For most organ-isms, passage through the dilution pumps took place primarily at night.

Bay anchovy (56.7 percent at night) and Atlantic silverside (40.3 per-cent) were exceptions.

Based on initial condition observations made 30 minutes after collection, the large majority of most species survived the experience. Well over 80 percent of species such as sand shrimp, blue crab, winter flounder, summer flounder, northern pipefish, and Atlantic silverside were recorded as live after pump passage. Relatively fragile species such as bay anchovy and blueback herring fared less well--only 54 and 42- percent, Swere' oserve alive and undmageed.

The catch of organisms that passed through, the dilution pumps, was dis-tributed similarly to the catch .from the Ristroph screens. Large winter and spring peaks were evident in both sampling programs, due largely to the influence of. the very abundant sand shrimp. The distinctive periods of-occurrence and abundance for individual species was the same. Peaks for some species in winter and spring (e.g., sand shrimp and Atlantic silverside) occurred in both the dilution and screen-impingement sam-prles. Bluefish and weakfish ve programs.

7-10

The main difference in the results of the dilution and screen-impingement programs was in the magnitude of organism abundance. The number of organisms captured in the dilution program was much higher than in the screen-impingement program because sampling of the dilution-pump dis-charge was more frequent and intensive. However, the weekly and annual estimates of the number of organisms passing through the dilution pumps were many times greater than corresponding estimates for screen impinge-ment. An estimated 100 million organisms passed through the dilution pumps during the study year, compared to an estimated 22 million organ-isms impinged. For selected abundant species, annual dilution-passage estimates were: sand shrimp, 38.8 million; bay anchovy, 35.1 million; Atlantic silverside,' 3.9 million; blue crab, 3.4 million; and bluefish,

' 6.3 1 Tee etmae were higher n f or screen-impingement by factors of 2.3, 179.0, 14.3, 2.6, and 62.0, respectively. Based on flow-volume differentials alone (i.e., dilution

... .. pumps v.,. .condenser pumps capacities), the estimates for dilution-pump passage should have been no more than 1.5 times greater than screen-impingement estimates.

One factor that may have influenced the high estimates for dilution-pump passage was the relative efficiency of the dilution-sampling gear vs. the Ristroph screens, fish return, and sampling pool. In one aspect of this evaluation, strong circumstantial evidence was developed that some organ-isms may have entered the dilution-sampling gear without having passed through the dilution pumps. At times, large schools of bay anchovy, Atlantic menhaden, and Atlantic silverside frequented the discharge canal, and some of these may have entered the net from downstream rather than from upstream through the dilution pumps. This mechanism is sus-pected to have contributed to the extremely high number of bay anchovies captured in the dilution gear in May 1985. In addition, it was estab-lished that the dilution gear captured a greater proportion of smaller organisms than did the screen-sampling system. Smaller specimens of sand shrimp, Atlantic silverside, and bay anchovy, for example, may have passed through the Ristroph screens, yet were retained in the dilution-sampling gear. This would have inflated the ultimate weekly and annual dilution estimates for such species. Although these factors may have contributed to higher dilution-passage estimates, they appear insuffici-ent to have caused all of the large differentials in estimated numbers between the dilution and screen-impingement programs.

... a, 0e* fac*tor that was not measured during this study' but that could have been the primary influence on large dilution estimates, is organism behavior. As organisms move down the intake canal and approach the con-denser and dilution pump intakes, they have a "choice" between the two.

The consistently higher estimates of dilution passage suggests that organisms may more often take the dilution route, perhaps to avoid noise and turbulence associated with the screening system in the condenser intake.

7-11

79,481 0

30 z

D)ECI JAN I:FEB I MARI APR 1 MAY I JUN I JUL 'AUG I SEP I Figure 7-1. Sampling catch of fish and macroinvertebrates entrained through the Oyster Creek uclear Generating Station dilution pumps, December 1984 - December 1985 (asterisk indicates puml not operating).

120-

Pool

--- Dilution 100-80-CL

, 60-4-.

40-C 0

20 :

NOV DEC "JAN FEB MAR APR, MAY JUN JUL AG SEP OCT NOV DEC Figure 7-2. Mean monthly weight-per-individual of blue crab from screen (pool) impingement and dilutio n pump samples at OCNGS. November 1984 - Decem .ber 1985.

5-i U Dilution 4-C CG 3 EI MI ChI A001-41 NOV FEB MAR APR MAY JUN JUL

ýFigure 7-3. Mean monthly weight-per-individual of bay anchovy from aol)impingement and dilution pump samples at OCNGS, November 1984 - 1985.

1I.4

-* Pool

. ,-=, Dilution

/ , 2-

"* 1.0-ALA 01.8 3'. *

= 0.4- -

0.2-NOV DEC zJAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC Figure 7-4. Mean monthly weight-per-individual of sand shrimp from screen (pool) impingement and dilution pump samples at OCNGS, November 1984 - December 1985.

TABLE 7-1 TOTAL NUMER COLLECTED, PERCENT COMPOSITION, AND CUMULATIVE PERCENT OF FINFISH, OTHER VERTEB RATES, AND MACROINVERTEB RATES 1ThAINE LR, E..IL ,-UMPS...AT-fOCN.S.,,-DEEMB-ER--L984----.--

THROUGH DECENBER 1985 Cumulalrive".

Spec ies.. Number Percent Percent Sand ý.=sUrimp 201,058 41.93 41.93 Bay' anehovy 145,462 30.34 .72.26 "iass. shrimp 81,850 17.07 89.33 Bltue-:crab .,, .,... ..........

.92. Atlan tic silverside 16,502 3.44 96.43 Fourspine stickleback 3,511 0.73 97 .17 Inland ul~yerside.--------. Q'7 q 1,522 6.32 97.90 Northern pipefish 1,521 0.32 98.22 Ribbon worm 1,430 '* 0.30 98.52 Lady -crab r 751 0.16 9-8.67 Lesser blue crab 497 0.10 ,

98. 78 Atlantic needlefish 494 0.10 98.88 RBlueback- herring 474 0.10 98.98 Atlantic menhaden '462 0.10 99.08 Class Scyphozoa (jellyfish) 455 .0.09 99.17 Mummichog 384 0.08 99.25 Winter .-fllounder 282. 0.06 99.31 Brown shrimp 248 0.05 99.36 American sand lance 229 .0.05 99.41 Naked goby 219 0.05 99.46 American eel 217 0.05 99.50 Smallmouth flounder 0.04 99.54 Spotted hake 172 0.04 99.57 Three spilie 4sticklebac k 159 0.03 99.61 Anchoa (anchovy) sp. 151 0.03 99.64 Rough silverside 132 0.03 99.67 Lined seahorse 130* 0.03 99.69 Windowpane 118 0.02 99.72 109 0.02 99.74 Crevalle jack 94 0.02 99.76 Oyster toadfish 90 0.02 99.78 Halbeak .85 0.02' Spot 80 0.02 99.81 Striped anchovy 80 0.02 99.83 Horseshoe crab 64 0.01 99.84 Sheepshead minnow 63 0.01 99.86 Rock crab 57 0.01 99.87 Hogchoker 45 0.01 99.88 Northern stargazer 42 0.01 99.89 Striped cusk-eel 41 0.01 99.90 Striped searobin 39 '0..01 99.90 37 0.01 99.91 Gray snapper 0.01 99. 92 Menidia (silverside) sp. 26 0.01 99.92

TABLE 7-1 (Cont.)

Cumulative Si~ec ies Number Percent Percent-Alewife 25 0.01 99.93 Seaboard goby 25 0.01 99.93 White perch 23 0.00 99.94 But terfish 23 0.00 99.94 Planehead filefish 20 0.00 99.95 16 0.00 99.96 Goby family 16 0.00 99.96 Many-ribbed hydromedusa 15 0.00 99.96 Tautog 15 0.00 99.96 Spider crab 12 0.00 99.97 Conger eel 12 0.00 99.97 Banded killifish 10 0.00 99.97 Herring (Alosa op.) 10 0.00 99.97 Striped mullet 9 0.00 99.98 Red hake 7 0.00 99.98 Silver perch 6 0.00 99.98 Portunus aibbesi (crab) 6 0.00 99.98 Needlefish family 5 0.00 99.98 Sea lamprey 4 0.00 99.98 American shad 4 0.00 99.98 Rainwater killifish 4 0.00 99.98 Grubby 4 0.00 99.98 Spotf in butterfly fish 4 0.00 99.98 shrimp 4 0.00 99.99 Penaeid Anchovy family 3 0.00 99.99 Striped blenny 3 0.00 99.99 Gizzard shad 3 0.00 99.99 Northern kingfish. 3 0 .00 99.99 Northern sennet 3 0.00 99.99 Striped burrfish 3 0.00 99.99 Fowler's toad 3 0.00 99.99 3 0.00 99.99 Cobia 3 0.00 .99..9.9'..

Spotfin moj arra 99.9

. .. . Striped killifish, 2 0.00 99.99 .

Eas tern mudminnow 2 0.00 99.99 Gobiosoma (goby) sp. 2 0.00 99.99 Northern searobin 2 0.00 99,99 Di4mond-back terrapin 2 0.00 99.99 White mullet 2 0.00 99.99 Northern. puffer 2 0.00 99.99 Silverside family 2 0.00 Lookdown 100.00 2 0.00 Mantis shrimp 2 0.00 100.00 Inshore lizardf ish 100,00 2 0.00 Atlantic croaker 1 0.00 Silver hake 1 "0.00 100.00 Mud crab 1 0.00 100.00

TABLE 7-1 (Cont.)

Cumulative Species Number Atlantic herring 1 0.00 100.00 White hake -1 0.00 100.00 Killifish family 1 0.00 100.00 Rock gunnel 1 0.00 100.00 Chain pickerel 1 100.00 0.00 Agujon 1 0.00 100.00 1~ ,*: ,10 lO ..0,,O0*J,."ý."ý,;.7,, ..4...

0.00 Atlantic shore octopus 1 0.00 100.00 Black sea bass 0.-00 100.00 1

Perm-it-Green frog 1 0.00 100.00 Libinia (spider crab) sp. 1 0.00 100.00 Fundulus.(killifish) qp!e 1 O'.00 Orange filefish 0.00 100.00 Frogs, toads 0.00 100.00 Fish fragments 0.00 100.00 Organic material 0.00 100.00

TABLE 7-2 TOTAL WEIGHT COLLECTED (g), PERCENT COMPOSITION,

.... ................... C. T E_PERCOENT . ..

OF....

FINFISHE ........

OTHER....

D VERTEBRATES, 6......

AMD HACROINVERTEB RATES ENTRAINED THROUGH TEE DILU *TN PUM4PS AT OCNGS. DECEMBER 1984 THROUGH DECEMBER 1985 Cumulative Soecies . wight- P~erc ent Percent-*

Organic material 7,485,330' 0.00 0.00 Blue crab 460,815 32.30 32.30 305,163 21.3 9 53.69

-, Bay anchovy.--, ...°":"

65.:;60d... ....

Sand shrimp 169,841 11'. 91 Atlantic menhaden 106,257 7.45 73.05 80.08 Atlantic silverside 100,288 7.03 H~rse-sl cr.b ..97i-133 6 8.. . 88.

Grass shrimp 35,959 2.52 89.41 Winter flounder 2 9,2 81 2.05 91.46 Class Scyphozoa (jellyfish) 20,494 1.44 92.89 Ribbon worm 8,57 8, 0.60 93.50 American eel 8,227 0.58 94.07 Blueback herring 7,434 0.52 94.59 Weakfish 6,574 0.46 95.05 Lady crab 6,352 0.45 95.50 Oyster toadfish 5,447 0.38 95.88 Rock crab 5,428 0,38 96.26 Summer flounder 4,631 0.32 96.59 Northern pipefish 4,145 0.29 96.88 Brown shrimp 3,769 0.26 97.14 White perch 3,279 0.23 97.37 Inland silverside 3,014 0.21 97.58 Fourspine stickleback 2,853 0.20 97.7 8 Hogchoker 2,709 0.19 97

97 Bluefish 2,694 0.19 98.16 Alewife 2,.487 0.17 98.34 Spot 2,184 0.15 98.49 Smallmouth flounder 1,617 0.11 98.60 Windowpane 1,565 0.11 98.71 Lesser blue crab 1,481 0.10 98.82 Gizzard shad 1,2 96 0.09 ...98.91

. Americansand lance,.,, 1 ,287. 99.00 Spider crab 1,202 0.08 0.08 99.16 Mummichog 1,120 Tautog. 1,118 0.08 99.24 Planehead filefish 1,053 0.07 99.31 Striped cusk-eel 1,037. 0.07 99.38 Atlantic needlefish 907. 0.06 99.45 Diamond-back terrapin 788 0.06 99.50 Spotted hake 746 6.:05 99.56 Conger eel 637 0..04 99.60 Many-ribbed Ihydromedusa 436 0.03 99.63 Threespine stickleback. 419 0.03 99.66 Northern stargazer 396 0.403 99.69

TABLE 7-2 -(Cont.)

Sp~ecies Weig-ht Percent Percent Red hake 3190 0.03 99.71 Rough silverside 3187 0.03 99.74 Lined seahorse 3 38 0 .02 99.77 Striped anchovy 2!63 0.02 99.78 Hal fbeak 2 52 0.02 99.80 Gray snapper 2:51 0.02 99.82 Northern kingfish 2 25 0.02 99.84 Naked goby -,;-' % ý-:: -"-ýs 24- . 02' Striped searobin 1 99 0.01 A- uco* -p -- 99.86 60- ......... G-.0i-1--=

Northern puffer .1 57 0.01 99.89 Crevalle jack 1 49 0.01 99.90 Orange filefish 1 22 0.01 99.91 Brief squ'd 09 06.01 99.91 Libinia (spider crab) s p. 1 07 0.01 99.92 Black sea bass 1 04 0.01 99.93 Sheepshead minnow 97 0.01 99.94 Inshore liz ardfish 82 0.01 99.94 Butterfish 77 0.01 99.95 Striped mullet 76 0.01 99.95 Cunner 71 0.00 99.96 Portunus aibbeui (crab) 63 0.00 99.96 American shad 50 0.00 99.96 Silver perch 44 0.00 99.97 Herring (Alosa sp.) 43 0.00 99.97 Striped killifish 38 o.0o 99.97 Mantis shrimp 38 0.00 99.98 Banded killifish 34 *0.00 99.98 Grubby 31 0.00 99.98 Sea lamprey 30 0.00 99.98 Fish fragments 30 0.00 99.98 Menidia (silverside) sp. I30 0.00 99.99 Penaeid shrimp I29 0.00 99.99 Seaboard goby I2U

0.00 99,99 Spotfin butterflyfish 16 0.00 99.99

.Gobyfami y 14 0.00 99.99 N*or*".thern 'earob in!".

Lookdown 11 0.00 99.9.9 Silver hake IO 0.00 99.99 Striped blenny .0 .0.00 100.00 Northern, sennet 6 0.o0 100.00 Needlefish f4mily 5 *.00 100.00 Rainwater killifish 4 0'.00 100.00 Rock gunnel 4 0.00 100.00, Fowler.'s toad 4 0.00 100.00 Cobia 4 0.00 Anchovy family 3 .0.00 ,100.00 Striped burrfish: 3 0.00

TABLE 7-2 (Cont.) ,

Cumulative Soecies Wejabt Percent Spotf in moj arra 3, 0.00 100.00 Eastern mudminnow 2 0.00 100.00 Gobiosoma (goby) sp. 2 0.00 100.00 Atlantic herring 2 0.00 100.00 White mullet 2 0.00 100.00

,Si-iverside --family,,.-,,., 2 0.00 100.00, Callinectes (blue crab) sp.- 2 0.00 100.00 Green frog 2 0.00 100.00 Atlantic croaker 2 100.00 2 0.00 100.00 Mud crab 1 100.00 White .hake 0 o00 1 100.00 Killifish family 0.00.

1 100.00 Chain pickerel 0.00 1 0.00 100.00 Aguj on 0.00 1 0.00 100.00 Atlantic shore octopus 0.00 1 100.00 Permit 1 100.00 Fundulus (killifish) sp, °

TABLE 7-3 DAY-NIGHT COMPARISONS OF NUMBERS OF SELECTED ORGANISMS COLLECTED FROM THE DILUTION PUMP DISCHARGE AT OCVS, DECEMBER 19Qt TWR(ICH DER(BRRV 1 QR*

DECEMB ER 19 A&THROUGH DECEM ER 1 9 SK Number Percent Species DayNight N~iaht Bay anchovy 62,167 81,293 56.7 Sand shrimp 4,445 196,662 97 . 8 Blue crab .1,798 15,747 89.8 Northern pipefish 141 1,38D 90.7 Weakfish 1 108 99.1 B luef ishý 3964, - ,26-.,

Summer flounder 11 26 70.3 Bluebaek herrn. . .101 f ---

' 173--

Atlantic silverside 9,858 6,644 40.3 Winter flounder 34 246 87.9 Atlantic menhaden 79 383

.~

TABLE 7-4 WEWJLY ESTIMATED NUMBERS OF SELECTED SPECIES PASSED THRCOJGH THE DILUTION PUMP DISCHARGE AT OCNs.- DECEMBER i QPA TIIRAWH DECEMBER 1 qRr Atlantic Say Atlsntic Vourspine Northern Sumer Vinter Inland 8and Gres a at Menhaen Anchoy Silverside titekleback PinUefih 'Bluefish eaUish un Flounder Iflverside Blue Crab I1 DEC 84 290 22,600 21,020 100.940 1,801,500) 1,280 860 0 0 0 2,960 270 47,150 950 2,457.730 18 DEC 84 300 8,830 35,360 L40,240 1 0 0 2,439,050 18,246 2,420 0 1,940 0 2 744.640

-26 DEC, 84 920 14,930 32.500 61,550 1,080 0 120 2.980 0 1.891 ,120 73,198 0 2 '763,270 2 JAN 85 530 -27.140 .150 0 1,456,390 6,591. 6,700 4,890 13,020 0 0 2.050 0 1 .600,310 0 . 910 1,228,060 25,450 0 1 .574.180 9 JAN 85 2.870 2,500 18,180 .54,300 790 0 0 0 16 JAN 85 83,710 0 1,278,650 4,371 0 1 422,600 380 380 3,750 780 0 0. 2,400 0 0 2,066,620 35,774 0 2. 81.390 23 JAN 85 430 0 7,380 .:e36.390 350 0 0 690 0 0 1,080,890 26,529 0 1 .1 0 ,57 0 29 JAN 85 0 0 34,610 '-22,150 150 0 0 1,640. 190 0 199,920 1,010 0 i237,910

.12 tE 85 0 0 15,720 . 4,530 270 0 0 2,070 2,860

F2 FES 85 171,56o 3,634 0 395,520 0 0 115,860 *42,250 0 0 00 0 1,400 7,610 5 MA4 85 0 300 93,620 -39,070 1,500 0 0 0 960 1,390 383,180 6,533 200 605,020 12 M'. 85 0 370 53,150 45,860 7,260 0 0 0 1 ,420 2,590 692,500 14,592 6,990 1 J004,080 808,650 13,694 800 I J320,SI0 g9 MAR85 0 300 262,820. 27,460 .40,920 0 0 0 360 1,920 I::25 MAR 85 0 0 322,550 . 38,570 39,430 0 0 0 0 5,160 680,36o 18,666 35,790 1 J354,100 2 APR :85 .0 7,780 6590390 33,290 47,320 0 0 0 730 15,040 502.710 22,579 73,230 1 V611,260 9 APR 85 220 477p580 377,350 14,250 32.070 0 0 0 1,260 2,870 475,420 61,918 21.470 21075,080 16 APR .85 29.030 686,540 520,500 - 13,490 16.800 0 0 540 3.600 1.178,900 74,213 145,170 31417,510 23- APR 85 0 00 0 804,900 110,095 191,110 3f231.290 1,470 '815,280 *240,620 2 8.700 13,990 0 3,080 3,520 46,530 8,540 0 0 1,510 20,320 2,848,800 103,763 91456,690 30 APR 85 270 5,096.810 238,940 8,430 ,00 7 kAY 85 4.920 2,953,690 . 45,590 2,240 2,760 9,900 630 180 21,890 752,620 45.072 74,770 4,362,710 14 MAY 85 940 9,733,570 173,140 1 ,360 3,660 0 17000 130 2,920 49,750 843,960 20,189 47,800 11 5079,740 0 275.000 12,709 36,190 l)8583,B50 21 :AY 85 5,570 1,256,060 70,810 410. 1,510 43,450 0 0 0 46,430 29t Y 85 6,000 6,138,880 68,340 710 4.470 152,220 0 210 0 47,340 1,081,940 43,004 173,480 8:141 .120 70.580 9.585 164.940 1!921,180 4 JUN 85 2,1z70 1,275,040 90,530 0 180 35,080 0 0 190 163,170

i. JUN 85 2,740 396,290 7,440 0 980 6,570 0 0 0 3,920 135,670 18,829 271,360 1 ;059,920

... 18 :JU.N85! :'720 . 438,260 7,530 170 110 4,590 0 0 23,270 58,520 5,578 130,430 1732,030 96,700 10,650 177,880 710,530 2a jUN 85 2,510. 290,720 3,650 0 1,130 7.910 140 0 960 1 JUL 85 1,110 517,720 3,650 210 -2,090 9,980 570 0 i,050 71,680 3,730 211,640 892,940 8 JU*L 85 540 127J90 3i480 0 550 8,470 It0 0 0 9.610 13.6i0 1,729 157,260 371,110 1.5 J L 85 160 186,740 2,420 0 3,570 9,150 950 510 110 9,280 22,130 1,454 363,640 661.910 Z3, JUL*.85 0,. 75,170 .4,310 0 340 900 730 380 0 7,760 10,390 672 303,520 1463,620 s30JuL 85 0 151.940 1,830 28M 1,470 3,490 6,680 1,000 0 770 2,260 310 279,710 491.820

6 AUG 85 0 775,580 2.980 0 130 3,040 5.590 0 0 5,020 8,440 544 108,250 945,090 13 AUGO 85 140 527,700 4,820 0 1,720 80 4,580 200 340 140 12,460 409 115.680 693,490 20 AUG 85 0 0 750 0 700 150 0 0 3,750 420 63,110 372,090 273,070 3,160* 1,910

-27 AUQ 85 130 230,670 !.,160 0 690 5,320 990 230 0 350 l'io 169 58,590 330,850 3 SEPt85 0 420 1,710 0 0 0 0 8600 205 54,920 1393,710 0 314,050 1,750 530 0 '2,380 0 730 1 .330 291 17,450 1140,850 10 s4 85 140. 104,290 240 - 0 290 11,7 SEP 85 410 550 160 1 ,54) 0 0 1,370 267 16,360 1335,970

. 0 298,630 650 0 **16,970 24 SEP 85 .0 492,790 460 1.380 2,720 0 0 240 2,010 161 534,940 0 240 I OCT 85 0 775,020

230 - 0 38D 380 220 400 0 0 1,2 20 1,960 314 10,250 I 819,940

.8 o'85 " 0 185,390 590 140 0 0 1,740 0 430 1.027 5,900 221,230 0

I5 OCT 65 0 64,120 90 - 0 460 150 *0 170 0 0 240 146 1,260 71,970 1.9NOV 85 4,000 155,990 23,160

0 7.840 0 0 280 150 3,830 204,240 21,009 30,600 675,170 24 N60 85 2,030 173,470 252,870 :150 17,010 0 0 0 460 0 1 ,966,90 81,696 4,960 3i,278,320 I DEC:85 8,840 26,510 139,310 -4,900 74,680 0 0 0 38,310 0 111,26,510 628,218 0 171,82 9,870 Note: 'Total column includes organisms not listed separately.

TABLE 7-5 WEEKLY ESTIMATED WEIGHTS (kg) OF SELECTED SPECIES PASSED THROUGH I IE DILUTION PUMP DISCHARQE AT QCNGSa DECEMRER 1494 THROUGH DECEMBER 1QRr%

I Atlantic Day Atlantic, Vourap18 Uortberu Summer Vinter Inland "Sand Craes

t M--ad'n Ancovy 11varsde AtfukouAuAk aP*fih. Blis k Flnder H[ounder 1xiversi a .~Shrimn. hri IBlue aL i -k.aL..

l.:-DEC 84 0.30 36.30 80.60' 80.80 3.40 0.00 0.00 0.00 793.30 0.30 1,673.50 20.82 2.30M 3,096.4 I . DEOC84 0.30 17.00 123 .80 33.70 2.10 0.00 0.00 0.00 11*.60- 377.60 0.00 2,03 1.80 8.32 6.901 3,200.6 26 1EC 84 0.50 23470 49.70 2.80 0.00 0.00 0.10 946.00 0.00 1;'661.00 39.20 0.00! 3,411.1 2 JAM,85 58.70 11.40 48.50: 20.90 0.50 0.00 0.00 0.00 582.20 0.00 1177.10 3.44 14.601 2,199.3 9 JAN.85 2.20: 3.50 56.70 47.00 1.90 0.00 0.00 0.00 145.30 **0.001 16 J*8 1 i001.30 11.47 0.00! 1,600.3 o5 0.40 13.10 6B.60 0.40 0.00 0.00 0.00 432.40 0.00: 1,040.70 23 JAN 85 0.306" 1.54 0.00! 1,743.6 0.00 20.20: 21.20 0.30 0.00 0.00 0.00 105.20 0.00 1 4139.00 9.36 0.001 1,497.6

.29,JAN 45 0.00 0.00 104.30 12.50 0.10 0.00 0.00- 0.00 218.90 0.10 1 ',571 .90 6.81 0.001 1,010.6 12 F08 5j 0.00 .0.00 106.80. 6.40 1.30 0.00 0.00 0.00 -332.20 985.60 4.401 0.97 0.00i, 1,641.3

-22 -0.00 0.00 8M1.20. 55.00 0.00 0.00 0.00 0.00 186.90 457.80 10.50 2.24 0.00 2,041.6

".5 HA 85 0.00 2.30 904.00O 53.00 5.30 0.00 0.00 0.00 186.10 3.10 664.70 4.63 0.400 2,1913 12 MAR85 0.00 2.70" 547.00,. 66.70 35.10 0.00 0.00 0.00 4.201 1G332.10 283.00 11.98 57.00. 3,506.6 1-9 MAR85 0.00 0.30 1,710.60,e 21.00 94.30 0.00 0.00 0.00 67.70 2:20 .*881.20 5.60, 6.13 9.70i 3,311.5 25- AR 85 0.00 0.00 2,227.40./ 29.10 91.00 0.00 0.00 0.00 0.00 '700.80 8.22 2 APO 851. 0400 26.50 4,008.30 24.10 111.00 0.00 0.00 0.00 41.10 19.10

~.560. 10 9.53 139.701 381.30*

3,643.3 5,789.9 9 APR 65 75.80 1,321.40 2,494.90o: 12.70 73.70 0.00 0.00 0.00 130.30 3.20 496.70 26.74 87.30 5,595.6 16 APR 85 11.984.40 1,686.70 3,377.10' 12.40 36.30 0.00 0.00 0.00 51.20 4.001 1 .277.20 26.90 23 APR 85 2,570:200 22,873.1 629.50 2,025.10 1,667.40 8.20 28.40 0.00 0.00 0.00 355.60 4.70 ,754.10 38.98 5,660 00 - 13,061.7 30 APr 85 81.10 16,968.20 1,823.60 10.10 24.90 0.00 0.00 0.00 139.80 33.701 2'.613.70 44.61 2.251.20j 25,738.3 7 MA Y 85 1.121.10 4,641.80 30.350 2.70 6.50 9.20 0.00 0.70 0.20 38.70 :1588.50 25.31 1,879.801 16,132.5

.14 *.Y85 315.50 27,971.70 1,235*.90.- 1.90 12.70 0.00 0.00 26.00 223.20 ,674.10 81.60 9.58 1.606.101 33,806.7

'21 *AY 85 121.30 2M52.50 526.50, 0.50 5.40 40.50 0.00 0.00 . 0.00 82.60 185.30 6.87 1,381.00 5,584.7 29 HAY 85 297.10 12,241.90 454.10C 0.70 12.90 143.80 0.00 2.70 0.00 73.00 '618.10 24.87 4..J UN 85 3,399.001 23,842.4

.76.30 2,81.9.80 622.30,1: 0.00 0.40 50.60 71.30 0.00 9.50 261.40 ,*33.10 3.52 6,970.001 19,749.3-11 JUN 85 .202.70 610.10 47.:50 0.00 4.40 17.20 0.00 0.00 0.00 159.60

. 5.90 7.33 4015.401 6,952.1 8.JUN 85 2.20 2,620.90 16.60 0.50 1.30 45.30 0.00 0.00 0.00 -67.10 6.10-. 99.80 5.95 5,958.50. 11,912.0 25 JUN 85 65.20 726.80 0.00 5.60 49.00 0.00 7.20 0.00 1.501 61.20 6.90 7,584.50 10,257.8 I -JUL*5 4.50 1,349.50 6.40 *0.30 10.90 35.90 0.00 189.40 0.00 2.40 T47'.30 2.63 6,263.901 9,298.9 a JUL 85 1.20 17700 3.00* 0.00 1.00 24.50 63.00 0.00 0.00 9.20 3.70 0.60 4.347.301 4,781.1 15 JUL 65 0.20 278.20 2.30<; .0.00 9.50 26.00 322.70 19.10 0.60 8.50 9.10 1.80': 0.72 9,312.70 10,468.1 23 JUL 85 0.00 62.10 0.00 0.60 2.80 0.30 16.10 0.00 2.60 0.24 4.30 4,398.30i 4,726.1 30 JUL 45 0M00 121.40 .1.30, .0.10 2.20 2.00 103.00 23.30 0.00 0.50 0.60 0.10 4,788.10 5,188.0 6 AUG 85 0.00. 1,655.80 6.307 0.00 0.30 37.60 110.90 0.00 0.00 10.30 i 4.30 0.39 5.762.401 7,860.1 i3 AUG.85 : 0.10. 761.10 11.10< 0.00 6.00 17.50 15.30 16.50 8.40 - 0.30 6.10 0.31 5,098.30 6,258.1 20 AUC:85 0.00 351.70 0.00 3.90 0.00 5.30 10.40 0.00 - 0.00 3.60 0.32 2,711.60 3,273.9 27:..AUG 0.5 .1.70 305.70 .2.90 *0.00 1.40 28.70 8.40 10.00 0.00 2.00 0.501 0.15 2,062 501 2.941.6 3 SEP 85 0.00 264.90 3.50 0.00 1.30 11.40 0.00 0.00 0.00 0.00 ! 0.70 0.13 1,854.80i 2,244.2 10 SEP 85 0.60 101.30 0.40,' 0.00 1.50 0.00 1.40 287.00 0.00 1.601 1.10 0.12 590.70 1,124.2 t7 SEP 85 0.00 308.50 1.60 0.00 1.20 4.30 0.20 328.90 0.00 0.00 1 1.40 0.26 635.90 1,725.3 24 SEP 85 0.00 526.70 1.00, 0.00 4.8o 4.90 4.70 0.00 0.00 0.70 2.10 0.17 546.70 1,399.5 1 OCT. 85 0.00 449.70 0.20 0.00 0.90 .1.70 3.60 13.50 0.00 0.50 0.13 339.401 1,013.3

8. OCT' 85 0.00 108.10 1*50. 0.00 0.20 0.00 0.00 0.90 0.29 199.90 0.00 0.00; 334.70 1 842.4.

S w35 OCT 85 0.D00 112.00 0.80 0.00 3.90 14.60 0.00 78.40 0.00 0.50 0.22 122.20 447.9

-19 NOV 85 5.30 482.70 216.20 0.00 55.30 0.00 24 NOV 85 0.00 110.10 84.20 9.40 350.50 20.70 336.60 2,433.1 0.10 14.20 60.50 0.00 2.90 0.00 0.00' 7 5.90 0.00 6.40 0.40o 1.93 0.30 193.3 1 DEC 85 4.90 2.00 34.507 0.30 12.20 0.00 0.00 0.00 41.80 0.201 472.10 13.68 0.00 759.2 note: Total column includes organisms not listed separately.

TAXA ENTRAInED NUMBER AND WEIGHT OF DECEMB ER .1984 ESTIMATED S, TABLE 7-6 TOTAL PUMPS AT OCNG THROUGH THE DILUTION 18 TRRWUGHEDEEMER v~eifft -(0) iNuber-Snecues Name 23,468,052 38,756,789 83,6 93,547 35,077,637 4,152,972 Sand shrimp 15,763,926 23,896,402 Bay anchovy 3,980,621 93,460,442 Grass shrimp 3,433,232 silverside . * .... '.*.....

Atlanticcrab . . ... i.. 788,403

~~~Bluet, 471,210 6 8*,751 Fourspine stickleback 342,906 5.67,495 inland silverside 306.,351. 1,919,068 Northern pipefish 261,232 1 ,404,145 154,839 5,497,663 Ribbon worm 116.798 1,729,217 Lady crab 91,624 212,859 (jellyfish)

Class Scyphozoa 91,130 162,155 Blueback herring 90,720 15,053,799 crab Lesser blue 79,3.80 242,579 Atlantic needlefish 78,331 6,873,150 Atlantic menhaden 71,573 367,275.

l4ummichog 56,921 618,272 Winter flounder 45,632 75,288 lance American sand 43,202 1,615,812 Brown shrimp 42,002 38,590 Smallmouth flounder 40,197 120,711 American eel 37,403 116,677 Naked goby 32,337 12,964 Spotted hake .30,718 30,338 Threespine stickleback 2 8,993 226,581 Lined seahorse 26,676 63,7 E3 sp.

AnchoA (anchovy) 25,942 710,181 Windowpane 21,481 51,929 Rough silverside 17,868 47,629 Weakfish 17,558 537,029 Striped anchovy 16,958 1 ,185,4 86 Halfbeak '16,330 Spot 16';265 toadfish 25,743,149*

Oyster 15,366 40,691" Crevalle jack 14,295 11,996 Horseshoe crab 13,623 1 Z20 8,452 Northern stargazer 12,440 1,339,216 Sheepshead minnow 10,792- 214,3310 Rock crab 9,17 8. 588,256 Summer flounder 9,085 36,818 Striped cusk-eel 7,624 265,531 Hogchoker 5,896 40 ,200 Striped searobin 5,885 1.9,847 Planehead filefish 5,878 7's,50 8 Gray snapper 5,0W6 But terf ish.. sp..

"e "(silverside)

TABLE 7-6 (Cont.)

Sbecies Name Number .Weight (g)

Seaboard goby 4,756 4,042 Alewife 4,746 538,054 White perch 4,284 657,212 Tautog 3,960 88,206 Goby family 3,406 * ' 2,905 Cunner 3,27 8 8,417 Many-ribbed hydromedusa 2,913 99,950 Spider crab 2,520 310,772 2,426 i'T* 19 8'A' Conger eel 5,829

-,B-a-nded-ki-l-.-i-fi sh 2.

,1-6-8 - . -;--79 .

Red hake 2,045 128,043 Striped mullet- 1,951 10,2 01 Herring (Alosa sp.) 1,590 7,202 Portunus ibbesi `(crab) 1,338 15,469 Silver perch 1,275 12,297 Penaeid shrimp 1,226 7,668 Striped burrfish 1,194 585 Spotfin butterflyfish 1,167 599 Rainwater killifish 995 907 Striped blenny 879 1,749 Belonidae Family 864 691 Inshore .lizardfish' 851 30,975 Grubby 8D7 7,500 Eastern mudminnow 730 1,020 Sea lamprey 695 4,71"1 689 686 Spotfin mojarra Lookdown 674 2,232 Fowler's toad 670 654-Northern kingfish 640 80,370 Gobiosoma (goby) sp. 636 634 Atlantic croaker 593 30 Cobia 589 770 American shad 553 6,83.5 Northern puffer 527 54,482 Gizzard shad 520 174,506 Anchovy family 467 467 White'mullet

Diamond-back terrapin 415 168,906 Northern sennet 413 919 Striped killifish 398 8,388 Silverside family 388 94 Northern searobin 319 2,030 Silver hake 295 2,91 8 Chain pickerel 285 320 Mud crab 262 434 Frogs, toads 254 26 Mantis shrimp 251 4,426

TABLE 7-6 (Cont.)

Species Name Number Weiaht (2)

Black sea bass 239 26,235 Callinectes (blue crab) sp. 211 187 Libinia (spider crab) up. 208 23,534 Agujon 201 89 183 201 Killifish family. 1 83 Rock gunnel 804 White hake 177 167 Atanti shore octopus "160 Orange filefish 150 35,637 Atlantic herring 141 265

.- Permit 134 142 Green frog i31 27 8 sp. 73 143 Fundulus (killifish)

TABLE 7-7 DAY-NIGHT COMPARISONS OF INITIAL CONDITIONS OF SELECTED 4PECIES COLLECTED FROM THE. OCNGS DTLUTION DISCHARGE. DECEMBER I OQP T14RR(GH DECEM.IBER -1 QfRi I

Day Percent Percent Percent Percent

Spec ies

um p Live Dead Percent Percent Stunned jUber Stunned !Dead Blueback: herring 101 70 17 14 373 50 32 18 Atlantic menhaden 79 45 11 *77 lR

44. 383 5 Bay anchovy 62,167 62 12 26 62 Atlantic silverside 83,293 27 11 62 9,858 95 2 3 6,644 91 6 Northern pipefish 3 141 93 0 7 1,380 Bluefi-sh 396 82 ,95 70 0

-0 5

W:eakfis 0 28 1,126 30 100 0 0 108 *68 Summer :flounder ': 11 1 7 25 81 18 26 92 4 4 Winter. flounder 34 97 3 0 246 94 3 "3 Sand shrimp *4,445 91 1 8 196,662 94 1 5 BAlue crab 1 1798 82 11 7 15,747 '87 9 4 Note: Slight discrepancies.between combined day-night totals in this table anki the totals in Table 7 are due to computer rounding error.

TABLE 7-8 COMPARISON OF STANDARD AND.GEAR-MOUNTED FLOWMETER READINGS UNDER VARIOUS DILUTTON-PUIMP OPERATIONAL MODES UNDER VARIOUS DILUTION-PUHP OPERATIONAL MODES Number -Flow Rate (mlsec) of Suiface Bottom -

Pumas Standard Gear-mounted Standard Gear-mounted 0.98 3-a 1.12 2+3 13 0.73 0.77 1+3 8 0. 90 X-45 1.06 0.60 0.66 3 0.74 x.1 0.75 0.45 0.46 1 +2 6 0.47 1.-5 0.38 0.39 0.43

]

2 0.312 Io 00524 0 ;20 0.27 ,4 0.035 0.20 0.025

TABLE 7-9 PERCENT (time) OPERATION OF VARIOUS DILUTION PUMP CONFIGURATIONS SAMPLED AT OCNGS, 1W't?4RKU 1 QR&. TRt*R fl(RNERKR 1 QR*

DECEMB ER I QPA THROUGH DErEMB ER 1 9 sK Oeratine Pumps Month DEC 84 0 0 0 9.67 0 90.33 0 JAN 85 0 0 0 0 0 100 0 FEB 85 2 0 0 0 0 98 0 MAR 85 22 0 0 32.25 27 17.75 1 APR 85 0 0 1.5 0 50.5 48 0

-MAY,85., 0 0 6..2" 088 JUN 85 0 7.5 0 55.75 36.5 0 JUL 85 ..............

O ---.......---- 8.-4-'---".... 0--...

0 2.

AUG 85 0. 3.25 49 45.75 0 SEP 85 0 0 6.25 0 76 17.75 0.

OCT 85 0 0 66.67 0 33.33 0 0 NOV 85 0 "'0 0. 0 .98 2 0 DEC 85 0 0 0 100 0 0 Annual mean 1.91 0.15 8.35 3.47 38.14 47.88 0.08

TABLE 7-10 NUMBER OF LIVE ATLANTIC SILVERSIDE COLLECTED BY DILUTION SAMPLING GEAR AT OCNGS DURING SPECIAL STUDIES

.2-5 April 1985 9-11 April 1985 Surface, Bottom Surface , Bottom 3 3 Number 3

_.m Number i 3 Number 3n Number _A_

33 1,724 12 1,364 62 2,013 27 1,522 23 1,705 19 1,364 67 1,%3 15 1,522 33 1,786 27 1,371 19 2,068 17 1 .522 25 .*1,364. 15 1 935 12 1,522, 7 1,6196 z.

13 1,719 17 1,364 1 , 522 63 1,724 .9 1,364 29 1.980 24 1,522 27 1,767 3 ,364 11:.364 17 1 ,991 39 1,522 70- .4,71.9 3. 1,362 27 ..59 1,522 6 1 i697 8 36 2,06 8 30 1,133 4 1,688 13 1,307 13 2,086 24 1,146 9 1,702 13 1,307 21 2,109 11 1,123 5 1,688 11 .1,307 10 2,116 16 1,142 8 .1,735 13 1,315 15 2,136 17 1,127 34 1,778 12 1,307 25 2,07 9 8 1,123 2 2,035 4 1.123 140 1,702 12 1,267 10 2,168 1 1,123 266 1,702 10 1,307 1,737 9 1,303 18 1,873 20 1,710 197 1,766 12 1,303 7 2,018 26 1,706 80 1,737 6 1,317 9 1,984 16 1,706 151 1,795 15 1,310 9 2,151 14 1,6%

85 1,727 15 1,303 7 1,884 13 1,706 140 1,761 39 1,303 5 2,006 13 1,706 353 1,746 9 1,484 8 2,006 1 1 706 168 1,751 3 1,484 509 2,012 10 1:706 Total 2,011 41.552 315 32,205 956 48,540 440 34,858 Note: m3 = volume sampled.

TABLE 7-11 NUMBER PER 1 ,000 m3 OF LIVE ATLANTIC SILVERSIDE COLLECTED

. AT OCNGS USED TO DETERMINE DEPTH DISTRIBUTION 2-5 April 1985 9-11 April 1985 Surface Bottom Surface Bottom 19.14 8.80 30.80 17.74 13.49 13.93 34.13 9.86 18.48 19.69 9.19 11.17 4.13 1 8.33 7.75 7.88 7.56 12.46 8.59 15.11 36.54 6.60 14.65 15.77 2.20."2 18.54- z 40.72 2.20 13.53 38.76 2.37 9 . .95 6.23 20.94 5.29 9.95 9.96 9.80 2.96 .8.42 4.73 14.01 4.61 9.89 7.02 15.08 19.12 9.18 12.03 7.12 82.26 9..47 0.98 3.56 156.29 ,7.65 4.61 0 .89 55.27 6.91 9.61 11.70 111.55 9.21 3.47 15.24 46.06 4.56 4.54 9.38 84.12 11.45 4.18 8.25 49.22 11 .51 3.72 7.62 79.50 29.93 2.49 7.62 ' ,

202.18 6.06 3.99 0.59 95 . 95 2.02 252.98 5.86 Mean 4 8.40 9,78 19.70 12.62

TABLE 7-1,2 TNUMBER 7 AND PERCENT BY SIZE CLASS OF SAND- SHRIMP COLLECTD BY DILUTION SAMPLER AUT~ YUDTLIPPUWIVP Unfli aAILUTDD Aq nPIwo l 0O MADPU 1 00C Qum1I JAlLhowiffJAWM.A Lux"I HU~LSEoZ EA& .JuLuIJ Am& "mumfl~L1A U S.ize Number i Percent

.Cia s 8 18 MAR 20 MAR 28 MAR 27 MAR 18 MAR 2 6MAR 28 MAR 27 MAR Dilution Dilution Poo 2 9-30 0 2 0 0 0 0 0 4' 31-32 0 .7 0 I 0 3

1 0 33-34 0 .3 0 0 5 0 0 35-36 0 13 0 5 0 5 0 5 37-38 0 19 0 5 8 0 3 9-40 I 17 01 0 8 7 41-42 5 18 5 11 6 7 8 1.1 43-44 5 32 10 8 6 13 15 8 45 -46 10 25 7 19 13 10 11

'20 2Q 47-48 13 25 5 7 16 10 8 49-50 6 28 8 9 8 11 12 5i,-52 6 18 6 7 8 7 9 53-54 7 11 5 6 9 4 8 6 2

"55-56 4 18 4 2 5 7 57-58 12 6 7 4 15 2 11 4 60 1 4 3 1 1 2 5 61.-62 5 ..2 3 0 6 1 5 0 63-64 2 3 3 0 3 5 65-66 0 0 0 0 0 0 0 67-68 0 0 0 0 0 0 0 0 6 9-,.70 2

0 .0 0 3 0 71472 1 0 0 0 1 0 0 Sum 80 252. 66 97 100 100 100 1op

TABLE. 7-13 NUMBER AND PERCENT BY SIZE CLASS OF SMD SHRIMP SAMPLER AT OCRGS (data pooled by station) , 18-28 MARCH 1985 Size Pool Dilution Pool Dilution Pool Dilution Class Sum Sum Sum Sum Cumulative Cumulative Pare ant Percent*

Percent 29-30 0 6 0 2 0 2 31-32 0 8 0 2 0 33-34 0 3 1~ 0 18 0 5 35-36' 0 0 5 0 10 37-38 24 0 0 0 _L 39-40 25 7 1 24 41-42 10 29 7 8 .8 32 43-44 15 40 10 11 18 44 45-46 17.. 12 13 29 '56 47-48 18 32 12 9 42 66 49-50 14 37 10 11 51 76 51-52 12 25 8 7 60 83 53-54 12 17 8 5 68 88 55-56 8 20 5 6 73 94 57-58 19 10 13 3 86 97 59-60 4 5 89 3 11 98 61-62 8 2 5 95 99 63-64 5 3 3 0 98 100 65-66 0 1 0 0 98 100 67-68 0 0 0 0 98 100 6 9-70 2 0 1 0 99 100 71-72 1 0 I 0 100 100 Total 146 349 100 100

8.' POST-ENTRAINMENT LATENT EFFECTS

'This program was designed to evaluate the latent effects of condenser entrainment on early life stages of the blue crab, bay anchovy, and winter flounder. The resulting data are used in conjunction with entrainment abundance estimates for 1975-1981 (Chapter 6) to calculate annual mortality. The results are provided below for bay anchovy eggs and larvae and winter flounder larvae. With the possible exception of a few specimens, neither blue crab zoeae nor megalopae were collected.

Data are grouped and analyzed by sample event, i.e', a 3-day period with-

":ýin each week. during which collections were.made. The alues used in. this.

approach are means derived for each sample event weighted by the number of specimens collected or held. 'The rationale for this approach is based on the assumption that conditions encountered during a collection week

..... (sample-event) prevail: throughout that period. , . . . ..

The number of organisms tested in the latent mortality program was depen-.

dent upon their density and period of availability. Program specifica-tions called for testing 24,000 bay anchovy eggs, 28,000 bay anchovy larvae, and 32,000 winter flounder larvae, each equally divided between ambient and discharge-temperature holding conditions. Requirements were met for bay anchovy eggs-over 46,000 were inspected for initial condi-tion and over 23,000 of these were held for latent observations. Because of low densities of bay anchovy larvae in intake waters, only about 13 percent of the target number of larvae were tested. For the same reason, only 22 percent of the target number of winter flounder larvae were tested. Specifications also called f or testing of zoeaed and megalopae of blue crabs,. but these forms were so scarce as to preclude any meaningful test efforts.

There were three measures of entrainment survival used during the course of this study--initial, latent, and total. Initial survival refers to initial survival at the discharge, corrected (using intake collection data) to account for any target organisms having entered the gear already dead, or having been killed by' the collection gear. Latent survival is survival after-96 hours (or to egg hatch in the case of bay anchovy.

eggs), corrected for latent mortality in corresponding intake collec-tions. Total' survival is the product of initial and latent survival.

Computational detail'is provided in Section 2.7.8. Each.of these suri-val components.,was examined independently to delineate short-term.. and..

long-term effects.

In an effort to determine factors that may affect each of these values, linear regressions were performed using survival values as dependent variables and relating changes to the following independent variables:

intake water temperature at the time of collection, .discharge water temperature at the time of collection, delta-T at &e time of collection, mean.holding water temperature, and maximum holding water temperature.

Chlorine was not'detected in condenser dishcarge water during any sam-pling event, and therefore was not included as an independent variable.

8-1

The final calculations involved integration of the entrainment survival data and existing entrainment abundance data. Entrainment abundance data were collected at OCNGS from 1975 through 1981. Plant-operational data, inwaradsng-

....... eor-a - -a*lg-*i*

wai'iriTu-f-t* *- -, - .

Once a reliable relationship was established for entrainment survival, that relationship was applied to the existing abundance database to pro-vide estimates of the number of target organisms killed by entrainment at OCNGS throughout the period.

8.1 BAY ANCHOVY EGGS Bay anchovy egg survival was determined by criteria outlined in Section 2.6. Eggs were held until they either hatched or were observed to be dead or, undevelopeyd -by-"the 'endi'dof he-'tes t".""The as"su"ption was`made' that . "' f if an egg did not hatch, it was dead.

8.1 .1 Inital 3ufrvival A total of 46,520 bay anchovy eggs were inspected for initial survival--

20,22T..-were.. collected from ..the intake and ,43 -were .-collected-.from- the discharge. Initial entrainment survival ranged from 20.9 to 83.4 percent (Table 8-1); the weighted mean for all events combined was 49.8 percent.

The high variability exhibited by these values prompted investigation by regression analysis. The relationship of initial entrainment survival was examined relative to the thermal parameters listed above. Results of this analysis are listed in Table 8-2. All the tested thermal param-eters, except intake water temperature, were related to initial entrain-ment survival. The highest correlation coefficient (r - -0.930, p <0.01) was found to exist between discharge collection temperature and initial entrainment survival; i.e., lower survival -estimates were related to-higher discharge temperatures.

Initial entrainment survival of bay anchovy eggs, pooled by sample event, exhibited maxima during events when minimal delta-T existed (Events 11, 16, and 17). Thus, in the absence of thermal effect, one must conclude that the derived mortalities (range,- 16.6-22.1 percent) for these .'events were caused solely by nonthermal, plant-passage effects (eg., pressure differentials, abrasion). The mean mortality ascribable to these effects was 18.8 percent. This: value can only be assumed to be representative over, a discharge...temperature range of 25.9-27.0 C. (with. a delta-T <3.7 C)

(Table 8-1),

8.1.2 Latent Survival Latent survival (hatch success) was determined for 23,341 bay anchovy eggs--13,33 4 were collected from the intake and 10,007 from *the dis-charge. Hatch success at the intake ranged from 19.2 to 100 percent; hatch success at the discharge ranged from.0.0 to 96.3 percent (Table 8-3). The-,minimum value at the. intake occurred during saple .Event: 6.

The, incubation system during' that: event proved to be.: inadequate-1 for holding i~n that. the...system clogged and.:overflowed, resulting in a. sub--

stantial Ioss .o* test specimens.o. For- this reason, lazeont survival cal-culationsi., for total entrainment do not. include. values- obtained during

8-2

sample Event 6. Excluding these suspect values, intake hatch success ranged from 45.4 to 100 percent and discharge values range from 0 to

.. .96.3. 3 ercent.. . .. . . . . . . ... . . . . .

Figure 8-1 presents information for intake and discharge hatch success.

Regression. analyses revealed that intake hatch rate was highly correlated to intake temperature at the time of collection (r - 0.872, p < 0.01)

(Table 8-4). The distribution of data points in Figure 8-1 suggests that an optimum temperature existed between 26 and 27 C, when the mean hatch rate was 92.2 percent. Intake temperatures of 22.4-24.2 C yielded a mean hatch rate of 59.8 percent. The lower hatch rate at lower temperatures may reflect naturally reduced hatching success of bay anchovy eggs earlier in the spawning. season. . * .- , ..

Discharge hatch survival was shown to be highly correlated to the maximum exposure temperature encountered throughout the collection and holding period- (r-- .935, p < 0-.01) and to the discharge++temper-ature at--the time of collection (r = -0.870, p < 0.0). Figure 8-1 reveals that latent survival after plant passage is quite high, when the maximum exposure temperature is between 26 and 27 C (mean hatch rate ; 95.7 percent).

Hatch rate declined for temperatures in the range of 31-37 C and reached zero at temperatures of 38 C and above.

Entrainment latent survival (discharge hatch success/intake hatch suc-cess) values range from 0 to 113.2 percent (Table 8-1). In two cases, discharge hatch success exceeded intake hatch success. This situation probably occurred as a result of weak specimens at the discharge being killed immediately after plant passage (as measured by initial survival).

Weaker specimens at the intake did not experience plant passage and thermal shock effects but succumbed during the ensuing incubation period*

Entrainment latent survival regression analyses revealed a relatively high correlation coefficient (r - -0.821, p < 0.01) relative to discharge collection temperature.

8.1.3 Total Survival Total entrainment survival of bay anchovy eggs is derived as the product of initial entrainment survival and entrainment hatch success. Total survival values ranked from O to 93.3 percent (Table 8-1). Regression analyses of total entrainment survival related to discharge collection temperature y.elded a high correlation coefficient (r -0.893,.M .. .

..p -. 0.01).. Basqed on..the liear., equation derived from* this ana.lysis, .

(Table 8-2), total entrainment effects range from 100 percent survival at discharge temperatures of about 24 C, 50 percent at 31 C, and zero survival at about 38 C (Figure 8-2)). With the exception of one sample event, the regression -line generated in this fashion appears. to be explainable, given that temperature appears to be the primary force affecting survival of bay anchovy eggs. during the entrainment process.

However, because of the low level. of%mortality ascribable to physical effects of plant passage (discussed- above) when delta-T is high, the portion of the regression lin in. Fi. . -2 below 27C is*

unrealistic. ýThe extension of the line to 100 percent ýsurvival at' 24 C is due to an anomalously (i.e., >10O0 percent) high latent survival during 8-3

sample Event 11 which, in turn, brought total entrainment survival to 93.3 percent (Table 8-1). Because average mortality due to physical effects is approximately 19 percent, the curve should be considered to be level at about 80 percent survival between 24 and 27 C. ..

The one anomalous data point on the total entrainment-survival regression line (Figure 8-2) was due to data obtained during sample Event 8. Review of the survival components for this sample event shows that initial entrainment survival appeared higher than expected for the discharge tem-peratures encountered and that the latent entrainment survival at the intake was lover than expected. These two components in unison served to drive the total entrainment-survival value upward. Factors unique to sample Event 8 that may have affected the initial and latent survival values are

1. The ambient intake temperature dropped 3 C and subse-

-quently-recovered-d-oriug-je-Yy Iiamp1?zg pe-ri-d-;-

this constituted the lowest temperatures at which bay anchovy eggs were collected at the intake.

2. The percentage of bay anchovy eggs that were unaccounted for during latent effects testing was 21.2; this was the greatest unaccounted-for egg loss for intake collection eggs except for Event 6 (Table 8-3).

Thus, it is possible that Event 8 results were subjected to a wide range of physical conditions during the sampling week and an unusually high latent effects testing uncertainty (due to egg loss at the intake).

8.2 BAY ANCHOVY LARVAE Bay anchovy larval survival was determined by criteria expressed in Section 2.6. Larvae were held for up to 96 hours0.00111 days 0.0267 hours 1.587302e-4 weeks 3.6528e-5 months or until they were determined to be dead at regular inspection times. The percent latent survival is determined as the proportion of live and stunned larvae that appear at a given observation time relative to the number of larvae stocked at the beginning of the test period.

8.2.1 Initial Survival A total of 6,870 bay anchovy larvae were inspected for initial condition during the sampling effort--3,396 from the OCNGS intake and 3,474 from I,

the discharge. Table 8-5 summarizes bay anchovy larvae ,initial survival.

bysample event(one week). Also included on this table are various thermal parameters related to OCNGS operation that were encountered during the sampling period. Figure 8-3 depicts initial survival at the two collection stations as a function of collection temperature. The derived values of initial entrairnent survival are also included as a function of discharge collection temperature.

The existence of a critical temperature is readily observable in Figure 8-3; discharge temperatures encountered when collection temperatures were 35.8 C and above resulted in minimal or no initial survival of bay anchovy larvae. At temperatures of.35 C or less, initial entrainment 8-4

survival ranged from 52.2 to 99.9 percent, and the weighted mean was 70.6 percent. The difference between this mean initial entrainment survival

.-.....beo

- - - - e g-n..O..prc~t.sr~vl sents an immediate mortality of about 30' percent that is ascribable to the mechanical effects of pump and condenser passage.

8.2.2 Latent Survival A total of 3,599 bay anchovy larvae were stocked for latent survival determinations--2,357 from the intake and 1,242 from the discharge.

Latent survival studies of bay anchovy larvae were not successful in that only a very small proportion of the larvae tested survived to

..-,,1.96 hours0.00111 days 0.0267 hours 1.587302e-4 weeks 3.6528e-5 months ., after, collection.. Comparison of,.intake aid ,discharge latent survival values determined for all specimens pooled over all sample events revealed no difference between the intake and discharge collec-tion stations (Table 8-6). This situation may be the result of holding S syste--effects. -Bay anchovy larvae. are. fragi-le-. and-very -mobile- forms, and are difficult to maintain in any artificial environment.

The possibility that holding container size and configuration vas a causal factor in the low survivals was considered during the study effort. Two different types of holding containers were used-open-type (i.e., screened) PVC containers that allowed water to circulate through the container and closed-type glass jars. Table 8-7 provides survival information for post-yolk-sac larvae held in each type of container.

A dramatic difference in latent survival was noticeable over the first 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months of holding; survival for larvae held in the'closed-type containers was much greater than larval survival in open-type containers (Figure 8-4). Clearly, some unknown factor(s) associated with the open contain-ers contributed to higher mortality through 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months . Latent, survival after 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months fell to very low levels regardless of the type of holding container used. This suggests that other holding system effects may have exerted delayed mortal effects on larval survival (e.g., feeding schedule and concentration of feed). These are considerations for future work that may involve bay anchovy larvae.

8.3 WINTER FLOUNDER LARVAE Winter flounder larval survival was determined by criteria expressed in Section 2.6. Percent initial survival was derived as the sum of the live and, stunned larvae sorted at time of collection divided by the total num-

- 'bert' sorted f or.*Viabil-ity.* Sample .,error. due,; to, unsortedl larvaep is,*dis- .. .

cussed in Section 8.4. Latent survival is determined as the proportion of live and stunned larvae that appear at an observation time relative to the number of larvae stocked at the beginning of the test period.

8.3.1 Initial Survival A total of 6,934 winter flounder larvae were inspected for initial condi-tion during the sampling effort--3.,935 from the OCNGS. intake and 2,999 from the discharge. Table 8-8 summarizes initial survival-by sample event. Various thermal parameters are included on this table that are related to OCNGS operation: during the sampling efforts.. Figure 8-5 8-65

depicts the relationship of initial entrainment survival of winter floun-der larvae with delta-T encountered at the OCNGS condenser discharge.

. ........................ Ini-tiaL intak - _survivaL.r anges . . .........

metic mean of 83.6 percent. Initial discharge survival ranged from 31.8 to 92.0 percent; the mean survival was 64.4 percent.. Initial entrainment survival displayed a range of 36.0-96.0 percent with an arithmetic mean of 77.4 percent.

Initial entrainment survival was high and stable for events with a mean delta-T of 9.3 C or less (average 93.1 percent). Sample events with a mean delta-T of 10.6 or greater display a lower initial entrainment sur-vival with greater variability (average 53.9 percent survival). Thus, kpthere appe.ars to be a 7 percent mortalit.y- attributable to OCNGS. condenser passage with low (9.3 'C or less) delta-T and approximatelya 46 percent mortality associated with condenser passage with a high delta-T (10.6 C or mnrp)-

8.3.2 Latent Survival A total. of~ ,0 itrfon.4~a a~tce fo-r" la-ife~t su'_r~v'iv-al testing--3,094 from the intake and 1,906 from the discharge. Holding system failure during sample Event 2 resulted in acquisition of latent survival data for 72 hours8.333333e-4 days 0.02 hours 1.190476e-4 weeks 2.7396e-5 months only. Latent survival results, pooled by sample event, are displayed in Table 8-9. Latent survival at the intake after 96 hours0.00111 days 0.0267 hours 1.587302e-4 weeks 3.6528e-5 months ranged from 56.6, to 67.5 percent; mean latent survival at the intake was 61.9 percent. Latent survival at the discharge after 96 hours0.00111 days 0.0267 hours 1.587302e-4 weeks 3.6528e-5 months ranged from 5.6 to 65.7 percent; the mean was 28.4 percent. Unlike intake survival rates, which were relatively uniform, discharge latent survival appeared highly variable. Entrainment latent survival, derived as the quotient of discharge latent survival divided by intake latent survival, ranged from 9.6 to 97.3 percent (Table 8-10).

Figure 8-6 depicts entrainment survival curves for three situations--

delta-T at the time of collection of 3.5 C (sample event 5), delta-T of 5.8 C (Event 2, through 72 hours8.333333e-4 days 0.02 hours 1.190476e-4 weeks 2.7396e-5 months ), and delta-T of 9.3-11.1 C (Events 1, 3, and 4). Latent entrainment survival for collections with a delta-T of 3.5 C was essentially i00 percent after 96 hours0.00111 days 0.0267 hours 1.587302e-4 weeks 3.6528e-5 months ; there was little or no effect on the latent survival of winter flounder larvae that pass through the OCNGS condenser system. Latent entrainment survival of winter flounder larvae that were collected when delta-T was 5.8 C is about 84 percent; survival of larvae that were collected during events with a delta-T_ of 9.3-11 1,l, was, 20-3D percent.. ,The *hape .ohe.curves for the latter condition revealed that the forces exerting delayed mortality manifest themselves within the first 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months . Other, more delayed effects are visible between 72 and 96 hours0.00111 days 0.0267 hours 1.587302e-4 weeks 3.6528e-5 months , but the magnitude of these effects is small compared to effects of the first 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months .

The contribution of delta-T to intake, discharge, and entrainment latent survival was investigated using linear regression analyses. Table 8-11 displays the:relevant findings.i As expected from the above discussion, latent entrainment. survival was highly correlated (r = -0.977, p < 0.01) to delta-T at the time of collection.

ý8-6

8.3.3 Total Survival Total entrainment survival of winter flounder is the producit6 i-ni*i* .

entrainment survival and latent entrainment survival. Total entrainment survival values for winter flounder larvae ranged from 3.5 to 93.4 per-cent (Table 8-12). Regression analysis revealed that total entrainment survival was highly correlated (r - -0.982, p < 0.01) to delta-T (Table 8-13). Figure 8-7 illustrates the data set and regression line. Based on this display, winter flounder survival would virtually be 100 percent at or below delta-T of 3.2 C. Predicted zero survival would occur at a delta-T of 12.0 C; 50 percent survival was predicted to occur at a

. _delta-T of .7.6 *C. . -

8.4 FACTORS AFFECTING THE UTILITY OF ENTRAINMENT-SURVIVAL DATA 8 Sorting-Uncertaintv Considerations-The initial survival estimates discussed above were based on the propor-tions of live and dead organisms determined in the field immediately after sample collection. As is typical of studies of this type, the small size of the organisms, the short period of time allotted for sorting, and the heavy detrital content of the samples precluded the sorting of all organisms from a given sample. After initial sorting was completed, the remainder of each sample was preserved and subsequently examined microscopically in the laboratory. The number of eggs and/or larvae of the target species in the sample (i.e., the ones missed during the initial "live" sort) were recorded. These missed eggs or larvae represent "sorting error" or "sorting uncertainty."

Because of the different nature of live and dead Organisms, there is potential for selective bias in sorting either live or dead specimens during the initial field sort. For example, dead, nonmoving larvae may be more likely missed than live larvae, or, conversely, live, transparent larvae may more likely be missed than dead opaque larvae. Any bias in the initial sorting,ý therefore, confounds the live-dead categorization of the specimens remaining in the preserved sample. In an extreme case, if all missed specimens had been alive when preserved, actual initial survival was higher than reported (best case). Conversely, if all missed specimens had been dead when preserved, actual initial survival was lower than reported (worst case)i. Because this "sorting uncertainty" has

-implications not only,, in, the, .ini tial ssurvival determinations, but also*'

in the calculation of toltal" entrainment survival, it was nee 0.

evaluate the, influence of the uncertainty on survival estimates..

There was no sorting uncertainty issue with regard to bay anchovy eggs.

Characteristics of live and dead eggs (described in Chapter 2) are readily discernible under a microscope. Thus, any eggs missed in an initial sort could subsequently be correctly apportioned between. live and dead categories.

Winter flounder larvae data are presented by sample event in Table. 8-14.

Sorting uncertainty is calculated as.the number of larvae missed . :divided by the total number of larvae (initial. sort plus numher !missed)..-. .With the exception of the discharge sample..of Event. 1., ..sorting-uncerttainty. was 6,-7

quite low; the weighted mean sorting uncertainty, excluding the Event 1 discharge sample, was 8 percent. As a result of the low sorting uncer-tainty, the uncorrected initial survival is tightly bracketed by the best- and worst-case survival estimates for each sample. The Event I discharge sample differed in that there was a large sorting uncertainty (58 percent) and low initial (uncorrected) survival of 0.318. The fact that this low survival is so much lower than all others, including those for Event 3 with similar thermal conditions, leads to the belief that initial Sorting was biased for dead specimens, and that the actual initial survival may have been closer to the best case. However, any uncertainty associated with this sample event was minimal given that Sample Event 1 represented only 8 percent of the winter flounder larvae database.

Upon examination of the corresponding data for bay anchovy larvae (Table

.8-5), it.is immediately evident that sorting uncertainty_ was. higher than that for winter flounder larvae. Sorting uncertainty for bay anchovy ranged from 0.275 to 1.0 and the weighted mean was 0.518 (51.8 percent).

This higher sorting uncertainty was attributed to the smaller size of bay anchovy larvae and concomitant difficulty of seeing and picking individ-ual larvae from the samples. Because it proved impossible to hold bay anchovy larvae for 96 hours0.00111 days 0.0267 hours 1.587302e-4 weeks 3.6528e-5 months in either ambient or heated water (Section 8.2), latent survival could not be calculated. Thus, the relatively high sorting uncertainty had no impact on total entrainment estimates (which could not be made in any case). Nonetheless, it was important to know the effect of sorting uncertainty on initial survival estimates because of inferences drawn from the latter regarding short-term mechanical and thermal effects of entrainment.

Based on discussions in Section 8.2, no initial survival occurred when collection temperatures reached or exceeded 35.8 C. In these cases (representing approximately 31 percent of larvae tested), uncorrected initial survival and worst-case survival were essentially the same--

at or near zero. Sorting uncertainty had no effect on these estimates.

When collection temperatures were at or below 35 C, no thermal effect was evident (Figure 8-3) and the mean uncorrected initial entrainment survival at these lower temperatures was 70.6 percent. The resulting 30 percent mortality was ascribed to the mechanical effects of pump and condenser pressure. For these same temperatures, the weighted mean worst-case survival due to sorting uncertainty would be 33 percent, and the consequent mortality due to mechanical effects would be nearly 70 percent.

Thus, for bay anchovy, while mechanical effects of entrainment are identifiable, the relatively large sorting uncertainties precludes_

quantifying these effects with any confidence.' Thermal effects on initial entrainment survival are evident above 35 C and are not affected by sorting uncertainty.

8.4.2 Artificiality of Thermal Test Reeime The results obtained for bay anchovy eggs and larvae and winter flounder larvae are based on tests which exposed the test organisms to discharge temperature water for the entire %-hour holding period. In reality, 8-8

entrained organisms are only exposed to full-strength discharge thermal condenser discharge water and eventually mixes with Barnegat Bay receiv-ing waters). Therefore, the survival -values obtained by this study are probably more conservative (worst case) than what may exist in Oyster Creek and Barnegat .Bay. The thermal factors found to be highly corre-lated to ,total entrainment survival of bay anchovy eggs and winter floun-der larvae were thermal conditions encountered during collection, i.e.,

delta-T and discharge collection temperature. However, collection con-ditions (thermal) were also highly correlated with holding conditions; this was to be expected because the objective was to keep holding-thermal

- -conditions identical ,-toc.,olection-.thermal conditions. Because of this situation, there is no way to ascribe,' at.. least s tatistically, cause -

of mortality to either collection- or holding-temperature conditions.

Intuitively, the holding-system thermal regime was artificial and unreal-

.sticaly harsh. Examination- of- the..survival data. stro.ny suggests. that a holding-system thermal regime that mimicked natural temperature decay in Oyster Creek would have reduced mortality. Consequently, future studies of this type should incorporate a holding regime that includes a more Irealistic simulation of the thermal conditions encountered by organisms after condenser-system passage.

8.5 IMPACT OF CONDENSER PASSAGE The objective of this portion of the program was to apply the survival data derived from the present study to previous annual, estimates of con-denser passage. The results sought are "true" estimates of the total number of key forms killed by plant passage. Based on the discussion in the previous section regarding the artificiality of the thermal-holding regime, EA believes these mortality estimates are overestimates. As such they represent a very conservative assessment of 'the effect of condenser passage. Calculation methodologies are described in Chapter 2.

For both bay anchovy eggs and winter flounder larvae, the proportion estimated to have been killed in a given year was quite variable (Table 8-16). Depending on the year,ý 21488 percent of winter flounder larvae were projected killed by condenser passage. For bay anchovy eggs,* the range was 13-83 percent. These year-to-year differences for bay anchovy eggs may be attributed to differing thermal conditions among the years.

That is, naturally warmer years with higher ambient temperatures result

",,in: higher,-discharge -temperatures., and ,thus, .higher mortality. Winter flounder larval mortality appears more directly related to delta-T. ... ...-.

As described earlier in this chapter, few bay anchovy larvae survived holding, whether from the intake or the discharge. - Unknown deficiencies in the holding system were implicated. In lieu of complete survival tests, 100 percent mortality was assumed (Table 8-16-). It should be noted that survival of bay anchovy larvae in the closed-container expe-riments was just under 50 percent at 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months . Substantial survival may, in fact, occur under more natural conditions.

8-9.

8.6

SUMMARY

Post-impingement latent effects studies were conducted on bay anchovy eggs_-adid--airae --- bY--bif-A gTus t 1985. The sampling protocol involved collecting target organisms from both the intake and, discharge, and holding and observing them in both ambient and heated (discharge) water for 96 hours0.00111 days 0.0267 hours 1.587302e-4 weeks 3.6528e-5 months . Counts of live and dead organisms were used to calculate estimates of initial, latent, and total entrainment survival. The effect of sample-sorting uncertainty on these estimates was evaluated. The survival data was used in conjunction with organism abundance data and cooling-water flow data for the period August - September'1981 to estimate the annual number of organisms killed by passage through the condensers at OCNGS.

Over 46,oo000 ba awere collected and inspected for initial cgdi anI I).d 2 960. dOlf f then ta %,* held &W lmttaint! aI=Viyn1 obpr vations. Intil .- ,survivali, decereased,: with..i ¢x~eas.n ischarge. tempe*-

ture.' When:,deta-, was low, iniil, survival

vawa- abou* percent the corre*podn 19pretmotlt ?as Ascribed. 6' t'I ehn~a.

ef fecti dof"'plant passage. & a rvival (meaiuredWi b j i~tVF~

of bay anchovy eggs) was..,al:soh*ighbly. correlated.- to 4is*clargeo:.o1llection te~mpearatures.; Total entrainment survival, the mlti.pli~cation pro dict-of initial and. latent survi1vl, was primarily influenced by collection temperature. Regression of total survival proportions on discharge col-lection temperature revealed .ft. strong, relationship characterized. by:

hih survival,.,4 beow,',(poably abou81pre, given. the,.19- percent

'mori~ty due to mechanical effcts)ji:about 50t pe cent survival at 31 C; and zero survival at38 C. :Sor*ing uncertainty was not a factor because accurate live-dead determinations could be made for both live and pre-served eggs.. Estimates of the%- number of: bay ancho... eggs killed by entrainment ranged from. 60 million in. 1979-1980- to-W1.7 billon in 1 97 5-1:97.6.i- The, proportion-- kil:led&.%%of. th~e. total number: entrained*'anged from:11 . perc-ent in 979-8 to 45 percentin,197540976.:-

Collections of bay'anc b larvae yielded nearly 6,900 specimens for

,y`

examination of initial condition; about 3,600 of these were held for latent survival observations. ihiitial-.,aurvival was depevdent-- on -dis-,

charge-'.temperatures. Below 35 C initial survival averaged 71 percent; at 35.8 C and above, initial survival-was essentially zero. The 71 percent survival below 35 C, when subtracted from 100 percent, yielded about. 29. percent mortality that was attributed to the mechanical effects of condenser passage. Latent survival could not be-calculated because few larvae suivxed for 96' hours in eiter heat- or mbient: holding conditions. This was attributed to holding-system effects on these fragile larvae. Sorting uncertainty, due to the inability to accurately apportion preserved larvae (missed during initial sorts) into live and dead categories, averaged 52 percent. This rendered uncertain the estimates of initial survival. Consequently, the true mortality due to mechanical effects (stated as 29 percent above) could have been anywhere from 20 to 67 percent. Because latent mortality could not be calculated for bay anchovy larvae, 100 percent mortality was assumed in the esti-mates of annual numbers killed by entrainment. These values ranged from 144 million in 1979-1980 to 1.3 billion in 1978-1979.

8-10

Nearly 7,000 winter flounder larvae were collected and inspected ths-erahJd_~..~.g survival observations. Initial survival was a function of delta-T.. Belo a delta-T of 9.3 C, initial entrainment survival averaged over 90 per-cent. For two sampling events when delta-T exceeded 10.6 C, initial survival dropped to about 54 percent. Latent surviyal:.,after. 96 hours0.00111 days 0.0267 hours 1.587302e-4 weeks 3.6528e-5 months was._exmined.relative to difrn det1 values...-Atz:AI 0 3.5 :C I a tentr i al'a was e sseritial -:l00 percentA- 'a e

-Q latent, srial wias 84 percent.' Latent su vl-r 4~-

20-3:0 .pe~rcent when delta-T wa's between 9.3 and 11,~~ h4 iian mept survi.al::orwi*e,. flounder larvae proved big y c*d*rerare t .

fe .greionq analy.sis revealed that total entrainment survIval wouldb4e i artually 100 percent at or below a delta-T of 3.2C. ' ...- " '

survival was predicted to occur at a delta-T of 12 C. Fifty percent total survival was associated with a delta-T of 7.6 C. Sorting uncer-

._....ain-ties-for winter flounder larvae..were low and. thus survival estimates

.were not affected. Estimates of the number of winter flounder larvae killed by entrainment ranged from zero in 1979-1980 (plant was shut down) to 586 million in 1978-1979. The highest proportion of entrained larvae killed was 47 percent in 977-1 978.

7

.?

8-il

1.0-" U U.[

0.9- .

Intake Specimens Discharge Specimens II.

0.8-

.0.7-

U.K 2-0.6-

- EU M. 0 c 0.5- -U. 0 0 0 U 0 a0 0.4-S 0.3-0.2- 0 0.1-- S I S a,-

I AI I I I I I I I I I I I I ~I I .4.

I I I

-rw I* I I 20 21 22 23 24 25. 26 27 28 29 30 31 32 33 34 35 3.6 37 38 39 40 Collection Temperature (C)

Figure 8-1. Proportion of bay anchovy eggs that hatchcollected from the ntake and discharge of the Oyster Creek Nuclear Generating Station, Ma, - August 1985.

1.0' 0

0.9.

0.8-0.7- SI. = 2.784 - .073 (Disch arge Collection Temp.)

-- 0.7 0.6-

+' 0.5-

.S 0.4-41 Lu 0.3-0.2-0.1-

q0

25. 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 Discharge Collection Temperature (C)

Figure 8-2. Proportion of bay anchovy eggs that survive entrainment at sYstar Creek.

Nuclear Generating Station as a function of discharge tempetature.

1.0- A

'. Intake 0.9- 0 40 Discharge A*Entrainment 0.8-U 2 0.7- EU 0

U S0.6" U A

00.5- 0

,0

- 0.4- 0 II

- 0 .3-0.2-0.1-

_________________I 220 21, 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 Collection Temperature (C)

"Figure 8-3. Initial survival of bay anchovy larvae collected at the Oyster Croek IluclearGenerating Station intake and discharge as a function of collection temperatures. (Initial entrainment survival as a function of discharge collection temperature.) I

Intake -Open Cups G G Discharge - Open Cups

0. Intake - Closed Cups

-- --U Discharge - Closed Cups 0.7-0.

"L 0.6-0.5* S-n 0.4-0.3-0.2-0.1 3 .2 24 48 712 96 Hours After Collection Figure 8-4. Latent survival of bay anchovy larvae in open holding containers versus dosed holding containers during holding experiments at the Oyster Creek Nuclear ,eneretingStation, May - August 1985.

1, 1.0-0 0.9- 0 0.8-C 0.7-

.2 0 0.6-a.

2 0.5-p 0.4--'

0.3-0.2-0.1-I I I I I I I -I 'r_ I 1 2 3 4 5 6 7 8 9 10 .11 12 Delta-T (C)

Figure 8-5. Initial entrainment survival of winter flounder larvae as a function of delta-T at the Oyster Creek Nuclear Generating Station for studies conducted from February - March 1985.

mmiii .i~ ml I

1.

-a --- -- IF- - -ý -

a .- -- * --

oL 0.7- 0__0 **T 3.5 C 0- - 40 Delta-T = 5.8 C CL 0.6-

"Delta +1 S.D.

9.3-11.1 C

> T -1 S.D.

E 0.4-w 0.3-4-

B 0.2-0.1 I I I I I I 3 6 12 24. 48 72 96 Hours Since Collection Figure 8-. Latent entrainment survival of winter flounder larvae from low Delta-T and high Delta-T colleictions at the Oyster Creek Nuclear Generating Station from February - March 1985.

1.0--

0.9-C 0

0.8-0.7-S~-= 1.363-0.117 (Delta-TC) 0.6-Co 0.5- /

0.4-EU 0.3-j 0

0.2-0 0.1-II 0 I i. II I' . Ir -TI'. .

1 2 3 4 5 6 7 8 9 10 11 12 Delta-T (C)

Figure 8-7. Proportiqn of winter flounder larvae that survive entrainment at Oyster Creek Nuclear Generating Station as a function of Delta-T.

TABLE 8-1 THERMAL FACTORS AND POST ENTRAINMENT LATENT EFFECTS SURVIVAL VALUES FOR BAY ANCHOVY EGG STUDIES CONDUCTED AT OCNGS. MAY THROUGH AUGUST' 1985

-Temperature (C)

Sample Intake Discharge. Mean Maaximum Survival (Prouortion)

Collectrion Collection &old Exposure Delta-T Initial Latent Total 23.1 * :33.5 29.1 33.5 10.4 0.521 (a) (a) I 23.:1 28.5 7 32 32 8.9 0.506 0.787 0.390

.8 22 .2 33.4 29.9 33.4 11.2 0.696 1.118 0.770 22.8 34.9 32.5 35.2 12.1 0.431 0.685 0.29$

10 23.5 34.8 30.5 34.8 11.3 0.477 0.045 0.021 11 22.5 26.2 26.6 31.5 3.7 0.824 1.132 0.93ý 24.2 35.9 32.5 36.6 11.7 0.284 0.210 0.069 0.465 '0.420 0.195

. " 1.5013" 23.4 34.7 32.8 34.7 11.3

... 26.8 38.1 33.6 38.1 11.3 0.209 0 0 26.9 27 25.2 27 0.1 0.779, 1.000 0.7.79 "168

.. 26.1 25.9 25.5 26.3 -0.2 0.834 0.913 0.762, 26.9 35.8 33.6 36.4 8.9 0.486. 0.140 0.0618 26.8 38 35.1 38 11.2 0.27- 0 0 -

(a) Entrainment latent and :total survival not determined because of holding system failure.

Note: Sample Events 1-5yielded few or no eggs for testing.

TABLE 8-2 RESULTS OF LINEAR REGRESSION ANALYSES PERFORMED ON VARIOUS RASURES BAY ANCHOVY EGGS SUBJECTED TO ENTRAINMENT AT OCNGS. MAY THR CGH AUGUST OF SURVIVAL OF 1985 -

i Correlation (r) Matrix Mean Maximum Intake Discharge Holding Exposure Initial Ltent

,TemzR En u Er.t Sur

.Discharge Temp 0.112 Mean Holding Temp 0.137 0.959 Maximum Exposure Temp 0.006 0.914 0.952 Delta-T -0.314 0.908 0.859 Initial Ent Sur 0.897

-0

199 -0.930 -0.890 -0.887 -0.805 Latent: Ent Sur -0.431 -0.821 -0 . 804 -0.777 -10.603 0.860

Total Ent Sur -0.281 *-0.893 -0.864 -0.825 -b .735 0.925 0.1964 Initial Entrainment Survival (S.)

(Se) = 2.047 - 0.046 (Discharge Collection Temperature) f2 .0.866 Latent Entrainment Survival (S )

(SP) = 3.329 0.084 "(Discharge Collection Temperature) r2 0.674 iiTotal Entrainment Survival (S;)

(5 T) 2.784 0.073 (Discharge Collection Temperature)

T r2 0.798 Note: Correlation coefficients (r absolute value), greater than 0.532 and r 2 ,alue~s greater than 0.2831 are significaqt at a -0.05. The corresponding values for Q m 0.01 are 0.6all and 0.437. resnertivPIv.'

S-TABLE 8-3 TR*ERAL FACTORS AND LATENT SURVIVAL VALUES FOR BAY ANCHOVY EGGS COLLECTED AT THE INTAKE AND. DISCAs* EOfOCNGSY, NAY THROUGH AUGUST 1985 _ _*_,

-Temperature (C) Survival Proportion Sample Intake. D1ischarge Maximum Intake Discharge Entrainment Egg Loss Collection Collec tion -Latent Delta-T Exposure Hatch Hatch at lIntalk 23.1 33.5 10.4 33.5 0.192 0.372 1.938 0.273 23.1 32 8.9 32 0.656 0.516 0.787 0.1 94 8 22.2 33.4 11.2 33.4 0.509 0.569

1.118 0.212

.9 ..22.*8 34-09 12.1 35.2 0.683 0 46 8 0.685 0.098 1 23.5 34.8 0.603 11.3 34.8 0.027 0.045 0.066 22.5 26.2 *3.7 31.5 0.454 0.514

- .1.132 0.172 12 24.2 350.9 11.7 36.6 0.624 0.]31 0.21 0.1O1 23.4 34,7 11.3 34.7 0.66 0.277 0.421 0.141 26.8 38.1 11.3 38.1 1 0 - 0 0.067

.16

.17 26.9 27, 0.1 27 0,963 0.963 -"1 0.138 26.1 25.9 -0.2 26.3 0.978 0.893 0.913 0.047

I. 8 26.9 : 35.8 8.9 36.4 0.78 0.409 0.14 0.145 20 126. 8 38 11.2 38 0.891 0 .0 0.144

.Not:" Sample Events 1-5 yielded few or no eggs for testing.-

TABLE 8-4 RESULTS OF LINEAR REGRESSION ANALYSES PERFORMED ON LATENT *URVIVAL OF BAY ANCHOVY EGqGS SII UECTrn TO ENTRAINMENT AT OCNGS.' MAY THROUGH-AUGUST 1* 1985 Correlation (r) Matrix Maximuo Discharge Exposuý: Intake Disoharge Intake

-TC L _Temv Delta-T TemID H0t9h Discharge Temp 0.109 Delta-T -0.272 0.925 Maximum Exposure Temp -0.005 0.941 0.893

Intake Hatch 0.872 0.031 -0.2 95 -0.1471 Discharge Hatch -0.087 -0.870 -0 .793 -0.935i 0.104 0O891 Entrainment Hatch ;.-0.408 -0.821 -0.636 -0.7771 -0.285 Intake Latent Survival (S 1)

IS) -1.325 + 0084 (Intake Collection Temperature)

r2 . 0.760' d

Discharge Latent Survival (

(S 2.579'- 0.067 (Discharge Collection Temperature) r 2 i0.756 Entrainment Latent Survival (S )

e (St)

T2 3.329 0.674

- 0.084 (Discharge Collection Temperature)

K, Note:. 7$See Table 8-2 for- critical values of r and r 2 at a - 0.05 and a - 0.011

TABLE 8-5 THERMAL FACTORS AND INITIAL SURVIVAL VALUES FOR BAY ANCHOVY

.. ........ ..................L RVAE---M THROUGH AUGUST 1985 Temperature (C)

Sample Intake Discharge Initial SurVival Event Collection Delleta-T Discharget Entrainment 12 23.3 35.0 11.7 0.905 0.487 0.538 13 23.4 34.7 11.3 (a) 0.500 0.500(b) 14 26.2 30.2 4.0 0.717 0.710 0.990 15 27.9 38.8 10.9 0.779 0' 26.8 27.2 0.4 0.693 0.532 0.768 16 17 26.1 25.9 -0.2 0.719 0.426 0.592 18 27.6 37.6 10.0 0.756 0.005 0-.00.7.

19 28.8 39.3 .10.5 0.378 0 0 20 25.5 35.8 10.3 0.789 0 0 21 27.3 38.6 11.3 0.616 0 0 (a) No larvae collected at intake.

(b) Assumes intake survival - 1.0.,

!.;* , ",...... ". i .'

TABLE 8-6 .

SUMMARY

OF NUMBER OF BAY ANCHOVY LARVAE STOCKED, NUMBER SURVIVING AT EACH OBSERVATION PERIOD, ýAND WEIGHTED MEAN PROPORTION SURVIVING AT EACH OBSERVATION PERIOD FOR TESTS CONDUCTED AT OCNGS. MAY THROUGH AUGUST 1985' Sample Number Hours After Collection Stacked 3_ 6 12 24 4 72 96 1antgke 12 47 27 26 19 15 0 0 0 13 0 0 0 0 0 0 0 0 "14, 4.83 58 56 6,.

53 0 15 399 149 98 10 377 0' 0 0 16 .--Z3Z . 6- - -2 2-17 396 261 187 167 .71 19 8 4 18 98 87 76 61 19 0 0 0 19 14 14 14 12 5 0 20 243 200 161 136 100 22 4 1 21 117 92 79 64 49 4 1 Total 2,357 1,260 949 765 301 49 15 8 Weighted me an 0.535 0.403 0.325 0.128 0.021 0.006 0.003 DigchaXzi 12 22 5 3 0 0 0 0 *0 13 12 9 6 6 0 0 0 14 49 370 29 25 1 0 0 15 0 0 0 0 0 ,0 315 255 25 15 16 703 197 2 2 455 264 221 182 73 0 4 4 17 18 1 0 0 0 0 0 0 0 0 0 19 0 0 0 .0 0 0 0

20 0 0 0 0 0 0 0 0 *0 0 0 0 S0- 0 21 Total 1,242 630 514 410 99 18 16 6 Weighted me an 0.507 0.414 0.330 0.079 0.014 0.005 0.005

TABLE 8-7

SUMMARY

OF NUMBER OF BAY ANCHOVY POST-YOLK-SAC LARVAE AND WEIGHTED MEAN PROPORTION SURVIVING AT EACH OBSERVATION PERIOD FOR TESTS COMPARING THE EFFICACY OF DIFFERENT HOLDING CONTAINERS FOR TESTS CONDUCTED AT OCN0S. MAY THROUGH AUGUST 1985 Sample Number Hours After Collection 472L - 9 Intake--Open Containers 12 47 27 26 19 15 0 0 0 13 0 0 0 0 .0 0 0 0

-- 1__...4 1 0

.6 25 3 3 0 15 219 57 13 4 0 0 16 645 106 24 11 3 3 2 2 17 109 55 16 10 8 5 5 4 Total 1 ,046 251 96 56 33 9 7 6 Weighted mean 0.239 0.094 0.054 0.032 0.009 0.007 0.003 Intake--Closed Containers 17 85 63 53 49 40 11 3 0 18 58 53 42 34 16 0 0 0 14 14 12 5 0 0 19 14. 0 147 136 111 95 77 17 3 1 20 97 81 70 56 4 1 I 21 44 347 290 246 182 32 7 2.

Total 401 Weighted mean 0.865 0.723' 0.613 0.454 0.080 0.017 0.005

TABLE 8-7 ACout.)

Sampte Nher~ - H&~Ys~Aft~C~tThetipu Event Stocked 3 . 6 12 24 4L .72 26 DisCharee--Onen Containers 12 22 5 3 0 0 0 0 0 13 0 0 0 0 0 0 0 0 14 4 1 1 1 1 1 0 0 15 0 0 0 0 0 0 0 16 325 55 24 8 4 2 2 2 17 .... 122 23/ 1. 14 7 3.

6..

Total .. 47.. 84 42_ -.. 16-. -- , 9 Weighted mean 0.178 0.089 0. 034 0.023 0.019 0.011 0.011 pischarage-Closed Containers 17 167 116 103 91 61 9 1 I 18 1 0 0 0 0 0 0 0 19 0 0 0 0 0 0 0 0 20 0 0 0 0 0 0 0 0 21 0 0 0 0' 0 0 0 0 Total 168 116 103 91 61 9 1 Weighted me an 0.690 0.613 0.542 0.363 0.054 0.006 0.006

TABLE 8-8 THERM FACTORS AND INITIAL SURVIVAL VALUES FOR WINTER FLOUNDER LARVAE COLLECTED AT THE OCNMSM FEBRUARY THROUGH MARCH 1985 w Total:- Total S.mple Collection Temperatre (C) .I Initial Survival Intake Discharge Total

-Intake llharee Delta-T .Inaike Dischiigi Entrainment 9.7 20.3 10.6 0.884 0.318 0.36 112 233 345 2 7.7 13.5 5.8 0.76 8 1,289 2,355 0.704 0 .917 1,066 3 7.2 18.3 .11.1 0.802 0.576 .0.718 1,422 953 2,375

4 9.7 19 9.3 0.767 0.703 0.917 993i 634 1,627 5 11.3 1,4.8 3.5 O 958 0.92 232 0 . 96 113

TABLE 8-9 NUMBER STOCKED AND LATENT SURVIVAL BY OBSERVATION HOUR OF WINTER FLOUNDER LARVAE COLLECTED AT OCNGS, FEBRUARY THROUGH MARCH 1985 Mean Sample Number Ln raT, r q"vm7-v wja 1 ' ( h-w 'nn"v-r) Delta-T Event Stocke 6 1L2 24 48L 72 96 _ (C) 1

91 0.890' 0.868 0 .846 0.813 0.692 0.626 0.582 2 207 0.947 0.908 0.884 0.792 0.700 0.609 ND

3. . 1,139 0.983 -0,975 0.952 0.909 0.802 0.717 4 761 0.976 0.961 0.924 0.854 0.699 0.607 0.566 O-*7-0--*-74.-- .-947- G-.-851- -- -.'16- -0,702 --0--.675 Discharge 1 73 0.507 0.408 0.338 0.286 0.211 0.141 0.056 10.6 2 252 0.841 0.774 0.754 0.675 0.583 0.488 0.405 5.8

3. 548 0.564 0.471 0.431 0.400 0.354 0.283 0.148 11.1 4 446 0.457 0.247 0. 186 0.175 0.159 0.155 0.152 9.3 5 102 0.990 0.922 0.863 0.824 0.804 0.765 0.657 3.5 atntainmn 1 164 0.570 0.470 0.400 0.352 0.305 0.225 0.096 10.6 2 459 0.888 0.852 0.853 0.852 0.833 0.801 ND 5.8 3 1 i687 0.574 0.483 0.453 0.440 0.441 0.395 0.227 .11.1 4 1,207 0.468 0.257 0.201 0.205 0.227 0.255 0.269 9.3 5 216 1.016 0.947 0.911 0.968 1.078 1.090 0.973 3.5 Note: ND = no data.

TABLE 8 THERMAL FACTORS AND LATENT SURVIVAL VALUES FOR

.......... . .ERI FLO*IM R -LUN LA-A*XC-*905 FEBRUARY THROUGH MARCH 1985 Sample Collection Temperature (C) Latent Survival(a)

Event Intake DIischarge Entrainmenlt 1 9.7 20.3 10.6 0.582 0.056 0.096 2 7.7 13.5 5.8 0.609 0.488 0.801 3 7.2 18.3 11.1 0.651 0.148 0.227 S0.566 . 0.269-5 11.3 14.8 3.5 0.675 0.657 0.973 (a) After 96 hours0.00111 days 0.0267 hours 1.587302e-4 weeks 3.6528e-5 months except Event 2 (72 hours8.333333e-4 days 0.02 hours 1.190476e-4 weeks 2.7396e-5 months ).

TABLE 8-11 RESULTS OF LINEAR REGRESSION ANALYSES PERFORMED ON LATENT SURVIVAL OF WINTER FLOUNDER LARVAE

. ...... *- - -U--- --

THROUGH MARCH 1985 Correlation (r) Matrix Intake Discharge Latent Latent De~a T Sur-Int _ * *Ri IZMSL -1m Discharge Temp 0.039 Delta-T -0.474... ý'.0.862 *,~'1<.'~&

Latent Sur-Int 0.074 -0.513 -0.490 Latent Sur-Dis 0.334 -0.916 -0.977 0.635 T~. f-mn4 Qtv-IIt n-90 -A - QAA/ .9 fl-Y.1 r. 0o m - - -j - 7 f f- %p."

Sd Discharge Latent Survival-(-S7)

(S = 0.920 - 0.077 (Delta-T degrees C) r 2 - 0.955 Entrainment Latent Survival (Se)

(Se) - 1.404 - 0.115 (Delta-T degrees C) r2 0.955 Note: Correlation coefficients (r, absolute value) greater than 0.811 and r 2 values greater than 0.658 are significant at a = 0.05.'

The corresponding values for a - 0.01 are 0.917 and 0.841, respectively.

TABLE 8-12 THERMAL FACTORS AND ENTRAINMENT SURVIVAL VALUES FOR

.... E.. .. V........... .. AT OCNGS- FEB RUARY THROUGH MARCH 1985 Entrainment Survival a)

Sample Collection TemDerature (C)

Event Intake Dischargg Delta- Initial Latent Total 1 " 9.7 20.3 10.6 0.36 0.096 0.035 2 7.7 13.5 5.8 0.917 0.801 0.735 3 7.2 18.3 11.1 0.718 0.227 0.163 4 9.7 19 9.3 0.917 0.269 0.247 5 11.3 14.8 3.5 0.960 0.973 0.934 (a) Latent survival after 96 hours0.00111 days 0.0267 hours 1.587302e-4 weeks 3.6528e-5 months except Event 2 (72 hours8.333333e-4 days 0.02 hours 1.190476e-4 weeks 2.7396e-5 months ).

TABLE 8-13 RESULTS OF LINEAR REGRESSION ANALYSES PERFORMED ON TOTAL SURVIVAL OF WINTER FLOUNDER LARVAE SUBJECTED TO ENTRAINMENT AT OCNGSl FEBRUARY THROUGH MARCH 1985 Correlation (r) Matrix Intake Discharge Initial Latent Tm2 T2m lSur-Ent Sur-Ent Discharge Temp 0.039 Delta-T -0.474 0.862 Initial Sur-Ent 0.092 -0.713 -0.675 Latent Sur-Ent,. 0.294 70.940 -0.97.7 0.723

...."."0.324 Total Sur-Ent -0.928 -.0. 982 0.743 0.999 Entrainment Total Survival (S)

T (S) T 1.363 - 0.117 (Delat-T degrees C) r2= 0.965 Note: See Table 8!-11 for critical values of r and r 2 at Q= 0.05 and a = 0.01.

-. 1 1. -- '... .m '10iliilmi

TABLE 8-14 TINVESTIGATION OF UNCERTAINTY ASSOCIATED WI., INITIAL SURVIVAL OF WINTER FLOUNDER LARVAE AT 0CNGS, FEBRUARY THROUGH MARCH 1986 Total Initial Initial Initial Initial Number Sample Uncorrected Number Worst-Case Best-Case Sorting of Delta-T Event -Survival -urvival Survival UncertainaM Laryae Larvae 1 I(a) 0.884 112- 0.762 0.9 0.138 130 D(b) 0.318 233 0.135 0.717 0.582 562 E(c) 0.360 345 0.177 0.797 692 10.;6 2 1 0.768 1 289 0.704 0.787 0.083 1,406 D 0.704 1,066 0.649 0.727 0.078 1,156 E 0-917. 2,355. 0 .922 0.926 2,562 5i~8 3 1 0.802 1 422.- 0.788 0 844 0.057

1,508 D 0.576 953 0.504 0.629 0 . 126 1,090 E 0.718 2,375 0.64 0.745 2,598 41 0.767 993 0.71 0.785 0.075 1,073 D 0.703 634 0.681 0.754 0.073 684 E 0.961

.0-917 1,627 0.959 1,757 9*,3 51 0.958 119 0.912 0.96 0.048 125 D 0.92 113 0.874 0.924 0.05 119 E 0.96 232 0.958 0.963 244 35 (a) I = Intake.

(b) -D Discharge.

.7 (c) E Entrainment Effects (+D/I).

I TABLE 8-15 INVESTIGATION OF UNCERTAINTY ASSOCIATED WITH INITIA, SURVIVAL OF BAY ANCHOVY LARVAE AT OCNGS. MAY THROUGH AUGUST 1985 T tal Initial Initial Initial Initial Sample Number Collection Uncorrected No. Worst-Case Best-Case Sorting Evnt of Temperature Suival Larvae UncrtxaintX (C)

12 I(a) 0.905 63 0.416 0.956 0.54 137 23.3 D(b) 0.487 76 0.157 0.835 0.678 236 35.0 E(c) 0.538 139 0.377 0.873 373 j1.7 13 1 NL(d) 0 NL 1.000 .1.000 23 23.4

. D 0-.500 24 0.245 0.755 0.51 49 34.7 E 0.500(e) 24 0.245(e) 0.755 7ý2 ý1.3 14 I 0.735 113 ,0.459 0.834 0.376 181 26.2 D 0,710 69 0.434 0.823 S E 0.389 11.3 30.2 O.966 . 182. 0.945 0.987 294 4.0 0.779 ,5121 .0.247 0 .930 0.683 i,613 27.9 0 ,145 0 0.869 0.869 1,105 38.8 0,: 657 0 0.934 2,718 0O.9 16.1D E O

693 1,392 0.433 0.808 0.375 ,228 26.8 0.532 1 329 0.293 0.742 0.449 2,411 27.2 0.768 2*721 0.677 0.918 4,639 10.4 17 I 0.721 596 0.453 0-.825 0.373 950 25.8 D 0.449 1 .039 0.325 0.600 0.275 i .433 26.1 E 0.622 1,635 0.718 0.727 ;,383 0.3 (a) I = Intake.

(b), D,, - Discharge.

(c) Entrainment ef fects (D/I).

(d) NL - No larvae.

(e)- Assumes discharge value (worst-case).

TABLE 8-15 (Cont.) "

Total Initial Initial Initial Initial Number Collection Sample Uncorrected No. Worst-Case Beet-Case Sorting of Temperature SurviLval. Survival Uncerainty Larvae.*

18 I 0.756 160 0.318 0.898 0.580 381 27.6 IM D 0.005 202 0.003 0.483 0.481 389 37.6 E

0.007 362 0.008 0.538 770 19 I 00389 36 0.079 0.876 0.800 180 28.8 D 0 115 0 0.477 0.477 220 39.3 E

0 151 0 0.545 400-lr5 20 I 0.789 318 0.532 0.858 0.326 472 25.5 D 0 326 0 0.480 0.480 627 35.8

E 644 0.560 1 ,099 0 0 10. 3 21 I 0.616 203 0.180 0.888 0.708 696 27.3 D 0 94 0 0.863 0.863 687 38.6 E 0 297 0 0.972 1,383 111.3

TABLE 8-16 TOTAL ESTIMATED NUMBER OF SELECTED ICHTHYOPLANITON TAI A ENTRAINED TURCUGH THE CONDENSER-COOLING SYSTEM4 AND ESTIMATED NUMBER KILLED LT OCNGS. 197'5-1QRI J&

. .... .. ... . . . . . . . . . ... . -I- . .. .. .. .. . . . . . . . . .5--1--

1 9-.. m 1 Winter Flounder Buy Ant~hnvv~Eocrn Buy Ant~hnvvI Lsavvn~

x-Anl Total Estimated Total E4timated Total ýstimated Killed(a)

Number(a) Number_(a)

SEP 1975 - AUG 1976 1.16 0.24 )I/' 141.36

.1116.85

11.52 11.52 SEP 1976 - AUG 1977 8.51 5.27 1.97 . 1.44 4.57 4.57 SEP 1977 - AUG 1978 5.98 5.28 0 1 *J; 112.17 0 4.97 19.95 4..97 SEP 1978 - -AUG 1.979 10.77 5.86 30.29 20.44 GQ/ 12.70 12.70 SEP. 1979 - AUG 1980 0.00 0..o0 - 4.75 0.60 R/* /(Z"1.44 1.44 SEP 1980 -AUG 1981 1.26 0.80 38.19 126.03 3.14 3.14 (a) x 108.

Note: Estimated number killed was based on entrainment survival equations in Table 8-2 (bay anchovy eggs) and Table 8-11 (winter flounder). Total mortality was assumed for bay anchovy larvae.

I

REFERENCES Boyle, M.'. 1978a. Northern kingfish, in Ecological Studies for the Oyster Creek Generating Station. Progress Report for the Period September 1976 - August 1977, Vol. 1. Fin- and Shellfish (T.R. Tatham, D.J. Danila, and D.L. Thomas, and Associates,9 eds.), pp. 202-204.

Ichthyological Associates, Inc., Ithaca, N.Y.

Boyle, H.F. 1978b. Striped bass, in Ecological Studies for the Oyster Creek Generating Station. Progress Report for the Period September 1976 - August '1977, Vol. 1. Fin- and Shellfish (T.R. Tatham, D.J. Danila, and D.L. Thomas, and Associates, eds.), pp. 182-184.

Ichthyological Associates, Inc., Ithaca, N.Y.

Danila, D.J., C.B. Milstein, and Associates, eds. 1979. Ecological

. .Studies for the Oyster Creek Generating Station. Progress Report for the Period September 1977 - August 1978. Ichthyological Associates, Inc., Ithaca, N.Y.

Ecological Analysts, Inc. 1981. Ecological Studies at Oyster Creek Nuclear Generating Station, Progress Report, September 1979 - August 1980. EA, Sparks, Md.

Ecological Analysts,' Inc. 1982. Ecological Studies at Oyster Creek Nuclear Generating Station, Progress Report, September 1980 - August 1981. EA, Sparks,' Md.

Ecological Analysts, Inc. 1983. Ecological Studies at Oyster Creek Nuclear Generating Station, Progress Report, September 1981 - August 1982. RA, Sparks,' Nd.

Fay, C.W., R.J. Neves, and G. Pardue. 1983. Species Profiles:

Life Histories and Environmental Requirements of Coastal Fishes and Invertebrates (Mid-Atlantic). Atlantic Silverside. Virginia Polytechnic Institute and State University, Blacksburg, Vas 14 pp.

Hall, L.W. , Jr., D.T. Burton, and P.R. Abell. 1982. Thermal response of Atlantic silversides (Menjdia menidi&) acclimated to constant and assymetric- fluctuating temperatures...... Arch, Hydrobiol. 94:318-325.

Hildebrandz S.F. and..W.C. Schroeder. 1928.. Fishes of Chesapeake Bay.

U.S. Bur. Fish:., Bull. 43. 366 pp.

Hoff, J.G. and J.R. Westman. 1966. The temperature tolerance of three species of marine fishes. J. Mar. Res. 24(2):131-140.

Ichthyological Associates. 1977. Ecological Studies for the Oyster Creek Generating Station. Progress Report for the:Peripod September 1975 August 1976 (T.R. Tatham, D.J. Danila, and.D.L., Thomas, eds..).

IA, Ithaca, N.Y.

Ichthyological Associates. 1978. Ecological Studies for the Oyster Creek Generating Station. Progress Report for the Period September 1976 - Augtust _197.7 (T.LTathmnq,D. Dabs n .L. Thomas,* eds.)....

IA, Ithaca, N.Y.

Ichthyological Associates. 1979. Ecological Studies for the Oyster Creek Generating Station. Progress Report for the Period September 1977 - August 1978 (T.R. Tatham, D.J. Danila, and D.L. Thomas, eds.).

IA, Ithaca, N.Y.

Jersey Central Power & Light Company. 1978. 316(a) and (b) demon-stration for the Oyster Creek and Forked -River Nuclear Generating Stations. JCP&L, Morristown, N.J.

Kurtz, R.J. 1978. Atlantic menhaden,

~ng-tain--P-ro inreas-Ecological Studies for the

aeC~ek ee Reot-r-f-o*-t-he--~Pezei- -- ......................

September 1976 - August 1977, Vol. 1. Fin- and Shellfish (T.R. Tatham, D.J. Danila, and D.L. Thomas, eds.), pp. 144-156. Ichthyological Associates, Inc., Ithaca, N.Y.

Metzger, F., Jr. 1979. Life history studies, in Ecological Studies for the Oyster Creek Generating Station. Progress Reportt for the Period September 1977 - August 1978 (D.J. Danila and C.B. Milstein, eds.),

pp. 69-87. Ichthyological Associates, Inc., Ithaca, N.Y.

Moore, D.W. 1978. Sand shrimp, in Ecological Studies for the Oyster Creek Generating Station. Progress Report for the Period September 1976 - August 1977 (T.R. Tatham, D.J. Danila, and D.L. Thomas, eds.),

pp. 242-250. Ichthyological Associates, Inc., Ithaca, N.Y.

Siegel, S. 1956. Nonparametric Statistics for the Behavioral Sciences.

McGraw-Hill, N.Y. 136 pp.

Sprague, J.B. 1969. Measurement of pollutant toxicity to fish.

I. Bioassay methods for acute toxicity. Water Res. (3):793-821.

Terpin, K.M., M.C. Wilie, and '.R. Holmstrom. 1977. Temperature preference, avoidance, shock, and swim speed studies with marine and estuarine organisms from New Jersey. Ichthyological Associates, Inc.,

Ithaca, N.Y. Bull. No. 17. 86 pp.

U.S. Atomic Energy Commission. 1974. Final Envirormental Statement

..Relatedto- 0peration of Oyster.: Creek- Nuclear; Generating,-Stat ion, - . * .

Washington.

U.S. Nuclear Regulatory Commission. 1978. Oyster Creek Nuclear Generating Station, Technical Specifications, Appendix "B" to License No. DPR-16. Washington.

Vouglitois, J.J. 1986. GPU Nuclear Corporation:. Personal communication.

APPENDIX A LIST OF SCIENTIFIC AND COMMON NAMES OF ORGANISMS COLLECTED IN IMPINGEMENT AND ENTRAINMENT SAMPLES, OYSTER CREEK NUCLEAR GENERATING STATION, 1984-1985

Scientific~ Name M Cnmm n Namrn Petromvzon marinus -Sea lamprey Elope saurus Ladyfish Aniuila rostrata American eel Con.er oceanicus Conger eel Alosa as tivalis Blueback herring Alosa useudoharengus Alewife Alosa sanidissima American shad Brevoortia tvrannus Atlantic menhaden Cluves. bau. *eg.Uts_ Atlantic herring Doosoma cedianum Gizzard shad

- " . -' Anchoa heysetus . .Striped anchovy .

Anchoa mitchilli Bay anchovy

,Umbra l3m1 Eastern mudminnow

. .... "_r*EO 1 Chain pickerel Synodus foetens finshore limar-dfish Opsanus tau Oyster toadfish Merluccius bilinearlis Silver hake roh i chuss Red hake Urophvcis tenuis White hake Uroiihvcis Spotted hake Ophidion marrinatum* Striped cusk-eel Hyporhamphus unifasciatus Halfbeak Str6ngvlurA marina Atlantic needlefish Tvlosurus a Agujon Cvnrinodon varietatus Sheepshead minnow Fundulus diaphanus Banded killifish Fundulus hiteroclitus Mummichog Fundulus maialis Striped killifish Lucania yarva Rainwater killifish Membras martinica Rough silverside

'Menidia menidia Atlantic silverside Menidia b Jijlja Inland silverside Aneltes auadracus Fourspine. stickleback Gasterosteus aculeatus Threespine stickleback Hipbocamy erectus Lined seahorse Snnathus us Northern pipefish k!2oi. americana White perch Cetittrovilotis itriata Black sea bass.

Enneacanthus obesus Banded sunfish.

Rachvcentron canadum Cobia Caranx.shinu. Crevalle jack vomer Lookdown Trachinotus f alcatus Permit:

a ris~eus. Gray snapper Eucinosetoms areenteus. Spotf in mojarra Stenatomun chry-soos Scup:

Blairdiella. chr:vsouia Silver perch Cvnosc i*o

suWi Weakfish Le:iostm';s xafnthuras Spot.

Ment~icirhus sa~ti "s qNorthern kingfish Micron, oi as undulatus Atlantic croaker

Scientific Name Common Name Tauta onitis Tautog Tautogolabrus adsversus Cunner Muil. cephalus Striped mullet ua. 1 curema White mullet Sphvraena boreais Northern sennet

.Astroscopus aultatus Northern stargazer Chasmodes boscuianus Striped blenny P a Rock gunnel Ammodvtes emericanusj American sand lance

.,.. ~. obiosoma.bosci. .. .Naked goby Gobiosom ainsburgi Seaboard goby Pexilue triacanthus Butterfish nIurlLIuru e arouLu Prionotus_ evolans Striped searobin Mvokocenhalus aenaeus Grubby Etropue. micros tomus .........

_Paralic~hthvs dentatus Smallmouth ... lounder..

Summer flounder Scoohthalmus aauosus Windowpane Pseudooleuronec tes americanus Winter flounder Trinec teaL maculatus Hogchoker Aluterus schoeofi Orange filefish Monocanthus hisvidus Planehead filefish Lac toohrvs cuadricornii Scrawled cowfish Sphoeroides maculatus Northern puffer Chilomvcterus schoepfi Striped burrfish Aeguorea app. Many-ribbed hydromedusa Octovus vulearis Atlantic shore octopus Lolliauncula brevis Brief squid Phylum Nemertea Ribbon worm

.Palaemonetes vulearis Grass shrimp Cranfon seotemspinosa Sand shrimp Sjuilla empusa Mantis shrimp Penaeus: aztecus Brown shrimp

Limulus volvohemus Horseshoe crab Paguius +'lon icarvuas Hermit crab Libinhia du a .. S.....pider .crab......

Cand~er irroratus Rock crab

- A 1' Call ineces. Saoid uS I .-. 'ý" 1ý'. 1."I., .Blue crab . ..

Callinec tes similis Least blue crab.

Carc inus maenasi Green crab Ovaljnea oceflatus Lady crab Portnus eibbiesi Portunu. . Zibbesi (crab)

.Rhthroiganopoeue harrisii Mud- crab Class Holothuroidea Sea cucumber Green frog Fowler~s. ..toad xalaiclemvs terranpin. Diamond-back ,"terrapin

K zc .ýN ý ), ., ,, ý -

See your respective discipline instructors for the structure of your JAMS and how they have been converted to the formats that are currently in ETUDE.

A new job aid has been developed to assist individuals when accessing their training and qualification records in Etude. The link to this job aid is located on the Training Home Page.

http://exelonwss.exeloncorp.comL/nuclear/oystercreek/octrainingldefault.aspx and then click on ETUDE in the upper left hand corner.

ML072080210

Contents

Text

SUMMARY

SUMMARY

SUMMARY

SUMMARY

SUMMARY

SUMMARY

SUMMARY

SUMMARY

Navigation menu

ML072080210

Text

SUMMARY

SUMMARY

SUMMARY

SUMMARY

SUMMARY

SUMMARY

SUMMARY

SUMMARY

Navigation menu

Search