P.2 

Is"-.-*-!* 

5 5 ? 

~ r -

z - -

- z = 

Diablo Canyon Power Plant 

M6(b) Demonstration Report 

PfenWof, 

March 1, 2000 

Document No. E9-055.0 

Prepared for. 

Pacific Gas and Electric Company 

77 Beale Street 

San Francisco, CA 94105 

Prepared by: 

d TENERA $ nvironmerrtal rvices 

n 
P.3 

1 Pacific Gas and 

"! Electric Company 

December 10. 1999 

David H. Oatley Pi.ibio '...*-...-

Vice Pies-dent- Diabln Carv.nn fi> Bo> ':•'• 

uppranonr. and fl.in! Manaicr ...il.i lii'-nc;: ' 

PG&E Letter DCL-99-588 

Mr. Roger Briggs. Executive Officer 

Central Coast Regional Water Quality Control Board 

81 Higucra Street Suite 200 

San Luis Obispo. CA 93401-3147 

Re: PG&E Diablo Canyon Submittal 

Diablo Canvon 3 16(h)Studv - Second Draft Resource* Assessment Report 

Dear Mr. Briggs: 

Your letter dated July 26. 1999 required PG&E to submit the DCPP 316(b) Study - Second Draft 

Resources Assessment Report by December 10, 1999. The requirements contained within this 

letter were modified based on agreements made by the Entrainment Technical Workgroup 

(ETWG) at the August 9, 1999 meeting as well as your subsequent letter dated August 25, 1999. 

Pursuant to these letters and the agreements made at the August 9, 1999 ETWG meeting, PG&E 

is hereby submitting the report which contains: 

1. A comprehensive assessment of all fish species previously selected by the ETWG, 

and the crab species identified by staff of the California Department of Fish and 

Game at the August 9, 1999 ETWG meeting. This assessment uses all the data 

collected from July 1, 1997 through the end of June 1998 for each assessment 

approach (Fecundity Hindcasting, Adult Equivalent Loss and Empirical Transport 

Model). The assessment also uses the available life history information for the 

identified species. Data verified through November 5, 1999 were used in the 

analyses presented in the assessments. 

2. A "compressed" version ofthe sampling results for all taxa (mean monthly density for 

each ofthe taxa collected), as well as charts showing the sampling results relative to the 

offshore grid. These charts for the grid are part of this draft report and present data that 

are analyzed in this report ( July 1997 - June 1998). Data verified through December 6, 

1999 are presented in the tables. 

3. A summary of all the sampling program data processed through November 5, 1999, 

including species composition and abundance. This data is provided in a common 

database format on CD ROM. The data on the CD represent all data verified 

through December 6, 1999. 

4. An evaluation ofthe intake structure including a comparison of potential alternative 

technologies that could be used to minimize any adverse effects identified in the 

resource assessment, and their associated costs. 

J 
P.4 

PG&E Letter DCL-99-588 

Mr. Briggs 

December 10, 1999 

Page 2 

This draft report is preliminary and provided for review by the Regional Board and the ETWG 

members. The methods used to analyze the current meter data for the ETM models were 

changed from the August 3rd report to reflect the recommendations of Dr. Jeffrey Paduah, an 

oceanographer with the U.S. Naval Post-Graduate School in Monterey, California. It is our 

understanding that PG&E will be provided comments on this draft report at the December 17, 

1999 ETWG Meeting. 

I certify under penalty of law that this document and all attachments were prepared under my 

direction or supervision in accordance with a system designed to ensure that qualified personnel 

properly gather and evaluate the information submitted. Based on my inquiry ofthe person or 

persons who manage the system, or those persons directly responsible for gathering the 

information, I certify that the information submitted is, to the best of my knowledge and belief, 

true, accurate, and complete. I am aware that there are significant penalties for submitting false 

information, including the possibility of fine and imprisonment for knowing violations. 

If you have any questions, please contact Anne Jackson of my staff at (415) 973-6523. 

fot 4>^\0 

David H. Oatle 

Enclosure 

99588/amj/kmo 

cc w/ attachments: 

Michael Thomas, CCRWQCB 

cc w/o attachments: 

Jennifer Soloway, CCRWQCB 

Laurie Kermish, EPA 

Alexis Strauss, EPA 

Brad Mahanes, EPA 

Daniel Meer, EPA 

v/Robyn Stuber, EPA 

Dave Mayer, TENERA 

Gregory Rueger, PG&E 

Anne Jackson, PG&E 

Kathleen Jones, PG&E 

Cal Gillies, PG&E 

Drew Squyres, PG&E 
P.5 

PG&E Lener DCL-99-588 

Mr. Briggs 

December 10, 1999 

Page 3 

bcc w/o attachments: 

Patricia Eckhardt, PG&E (77 Beale,B24A) 

Chris Ehrler, TENERA (DCPP - Trailer 123) 

John Steinbeck, TENERA (DCPP - Trailer 123) 

RMS (DCPP) 

Env. Ops. Central Files (104/5/2A) 

s:\enveng\submit\complete\DCL99588.doc 
P.6 

0" 

Or 

D 

0 

0 

0 

0 

0 

0 

0 

0 

0 

0 

0 

0 

David H. Oatley 

Vice President-Diablo Canyon 

Operations and Plant Manager 

Diablo Canyon Power Plant 

PO. Box 56 

Avila Beach, CA 93424 

805.545.6000 

Certified Mailing #Z 265-478-758 

Certified Mailing #Z265-477-912 

March 1,2000 

PG&E Letter DCL-2000-515 

Mr. Brad Mahanes (2243A) 

U. S. Environmental Protection Agency 

Office of Enforcement and Compliance Assurance 

401 M Street, S.W. 

Washington, D.C. 20460 

* Ms. Robin Stuber 

U.S. Environmental Protection Agency, Region 9 

CWA Standards and Permit Office, Water Division 

75 Hawthorne Street 

San Francisco, CA 94105 

Re: PG&E Diablo Canyon - Clean Water Act Section 308 Request Submittal -

Diablo Canyon 316(b) Demonstration Report 

Dear Ms. Stuber and Mr. Mahanes: 

Pursuant to Alexis Strauss' letter dated September 22, 1999, Pacific Gas & Electric 

(PG&E) is hereby submitting the Diablo Canyon Power Plant (DCPP) 316(b) 

Demonstration Report. The DCPP 316(b) study was initiated in October, 1996 with 

sampling completed in June, 1999. The sampling design and methods ofthe study, 

selection of target taxa, and formulation of the three assessment methods (Tenera 

1997a; Tenera 1997b; Tenera 1998a) were overseen by the Entrainment Technical 

Work Group (ETWG) established by the Central Coast Regional Water Quality Control 

Board (CCRWQCB). 

The enclosed DCPP 316(b) Demonstration report follows two draft preliminary 

assessment reports dated August 2nd, 1999, and December 10*. 1999. The purpose of 

these preliminary reports was to provide the CCRWQCB, Environmental Protection 

Agency (EPA), and the ETWG an opportunity to review a comprehensive application of 

the three assessment approaches (adult equivalent loss, fecundity hindcasting, and 

proportional entrainment) on the selected target species. These draft reports 

contained the life history information, assumptions, and values for each target species, 

as well as the methodology to be used in applying the three assessment approaches. 

They were provided to the ETWG with the goal of obtaining agreement on the 

information, methodology and assumptions that would be applied in this demonstration 

report. 
P.7 

0' 

0 

0 

0 

0 

PG&E Letter DCL-2000-515 

Mr. Mahanes and Ms. Stuber 

March 1,2000 

Page 2 

Additionally, included with this submittal is a CD ROM which contains the following 

information: 

Appendix G 

Appendix H 

Appendix I 

Current Meter Data 

Entrainment and Grid Length Data 

Entrainment and Grid Survey Data 

o Adjusted Inshore Volume 

o Intake Cove Plankton Tow Data 

o Power Plant Intake Flow 

o Wind Data 

0 

0 

o

x 

0 

0 

D 

D 

0 

0 

D 

0 

0 

I certify, under penalty of law, that this document and all attachments were prepared 

under my direction or supervision in accordance with a system designed to ensure that 

qualified personnel properly gather and evaluate the information submitted. Based on 

my inquiry of the person or persons who manage the system, or those persons directly 

responsible for gathering the information, I certify that the information submitted is, to 

the best of my knowledge and belief, true, accurate, and complete. I am aware that 

there are significant penalties for submitting false information, including the possibility 

of fine and imprisonment for knowing violations. 

If you have any questions, please contact Anne Jackson of my staff at (415) 973-6523. 

Sincerely, 

David H. Oatley 

Enclosure 

2000515/amj/kmo 

cc w/ attachments: 

Resident Inspector, David Proulx (includes CD) 

U.S. Nuclear Regulatory Commission 

Diablo Canyon Power Plant 104/5 

Regional Administrator 

U.S. Nuclear Regulatory Commission 

Region IV 

611 Ryan Plaza Drive, Suite 400 

Arlington, TX 76011-8064 

IMamm^mamm 
P.8 

I d" I 

PG&E Letter DCL-2000-515 

Mr. Mahanes and Ms. Stuber 

March 1,2000 

Page 3 

cc w/ attachments (con't): 

Steven D. Bloom 

NRC, Project Manager 

One White Flint North 

11555 Rockville Pike 

Rockville, MD 20852-2738 

Document Control Desk 

U.S. Nuclear Regulatory Commission 

Washington, D.C. 20555 

Chris Ehrier 

TENERA 

P.O. Box 400 

Avila Beach, CA 93424 (Hand Delivery) 

John Steinbeck 

TENERA 

P.O. Box 400 

Avila Beach, CA 93424 (Hand Delivery) 

Dave Mayer 

TENERA 

One Market, Spear Tower, Suite 1850 

San Francisco, CA 94105-1018 

Cal Gillies 

PG&E 

Diablo Canyon Power Plant 

P.O. Box 56 

Avila Beach, CA 93424 (Hand Delivery) 

Anne Jackson (includes 2 CD's) 

PG&E 

P.O. Box 770000 

San Francisco, CA 94177 (3 copies - Company Mail) 

Pat Eckhardt 

PG&E 

P.O. Box 770000 

San Francisco, CA 94177 (Company Mail) 

Kathleen Jones (includes CD) 

PG&E 

P.O. Box 770000 

San Francisco, CA 94177 (3 copies - Company Mail) 
P.9 

r"' 

W\J 

PG&E Letter DCL-2000-515 

Mr. Mahanes and Ms. Stuber 

March 1,2000 

Page 4 

cc w/o attachments: 

Mr. Roger Briggs, Executive Officer 

Central Coast Regional Water Quality Control Board 

81 Higuera Street, Suite 200 

San Luis Obispo, CA 93401-3147 

Jennifer Soloway 

State Water Resource Control Board 

Office of the Chief Counsel 

901 "P" Street 

Sacramento, CA 95812-0100 

Michael Thomas 

Central Coast Regional Water Quality Control Board 

81 Higuera Street 

San Luis Obispo, CA 93401-3147 (Hand Delivery) 

Laurie Kermish 

Environmental Protection Agency, Region IX 

Office of the Regional Counsel 

75 Hawthorne Street 

San Francisco, CA 94105-3901 

Alexis Strauss 

Environmental Protection Agency 

CWA Standards & Permits Office 

75 Hawthorne Street 

San Francisco, CA 94105-3901 

Daniel Meer 

Environmental Protection Agency 

Chief of Clean Water 

CWA Compliance Office, Region IX 

75 Hawthorne Street 

San Francisco, CA 94105 

Gregory Rueger 

PG&E 

P.O. Box 770000 

San Francisco, CA 94177 (Company Mail) 
P.10 

0" 

0 

0 

D 

0 

0 

0 

0 

0 

0 

0 

0 

0 

0 

0 

0 

D 

0 

0 

Pacific Gas and 

Electric Company 

March 1,2000 

PG&E Letter DCL-2000-514 

David H. Oatley 

Vice President-Uiablo Canyon 

Operations and Plant Manager 

Diablo Canyon Power Plant 

PO. Box 56 

Avila Beach, CA 93424 

805 545.6000 

Mr. Roger Briggs, Executive Officer 

Central Coast Regional Water Quality Control Board 

81 Higuera Street, Suite 200 

San Luis Obispo, CA 93401-3147 

Re: PG&E Diablo Canyon Submittal -

Diablo Canyon Power Plant - 316(b) Demonstration Report 

Dear Mr. Briggs: 

In accordance with your letter dated July 26, 1999, Pacific Gas & Electric (PG&E) is 

hereby submitting the Diablo Canyon Power Plant (DCPP) 316(b) Demonstration 

Report. The DCPP 316(b) study was initiated in October, 1996 with sampling 

completed in June, 1999. The sampling design and methods ofthe study, selection 

of target taxa, and formulation ofthe three assessment methods (Tenera 1997a; 

Tenera 1997b; Tenera 1998a) were overseen by the Entrainment Technical Work 

Group (ETWG) established by the Central Coast Regional Water Quality Control 

Board (CCRWQCB). 

The enclosed DCPP 316(b) Demonstration report follows two draft preliminary 

assessment reports dated August 2nd, 1999, and December 10th, 1999. The purpose 

of these preliminary reports was to provide the CCRWQCB, Environmental Protection 

Agency (EPA), and the ETWG an opportunity to review a comprehensive application 

of the three assessment approaches (adult equivalent loss, fecundity hindcasting, 

and proportional entrainment) on the selected target species. These draft reports 

contained the life history information, assumptions, and values for each target 

species, as well as the methodology to be used in applying the three assessment 

approaches. They were provided to the ETWG with the goal of obtaining agreement 

on the information, methodology and assumptions that would be applied in this 

demonstration report. 

Additionally, included with this submittal is a CD ROM which contains the following 

information: 

Appendix G 

Appendix H 

Appendix I 

Current Meter Data 

Entrainment and Grid Length Data 

Entrainment and Grid Survey Data 

o Adjusted Inshore Volume 

o Intake Cove Plankton Tow Data 

o Power Plant Intake Flow 

o Wind Data 
rr 

P.11 

m PG&E Letter DCL-2000-514 

•5 Mr. Briggs 

March 1,2000 

Page 2 

I certify, under penalty of law, that this document and all attachments were prepared 

under my direction or supervision in accordance with a system designed to ensure 

that qualified personnel properly gather and evaluate the information submitted., 

Based on my inquiry of the person or persons who manage the system, or those 

persons directly responsible for gathering the information, I certify that the 

information submitted is, to the best of my knowledge and belief, true, accurate 

and complete. I am aware that there are significant penalties for submitting false 

information, including the possibility of fine and imprisonment for knowing violations. 

If you have any questions, please contact Anne Jackson of my staff at (415) 973-6523. 

Sincerely, 

David H. Oatley 

Enclosure 

2000515/amj/kmo 

cc w/ attachments: 

Michael Thomas (includes CD) 

Central Coast Regional Water Quality Control Board 

81 Higuera Street 

San Luis Obispo, CA 93401-3147 (Hand Delivery) 

cc w/o attachments: 

Resident Inspector, David Proulx (includes CD) 

U.S. Nuclear Regulatory Commission 

Diablo Canyon Power Plant 104/5 

Regional Administrator 

U. S. Nuclear Regulatory Commission 

Region IV 

611 Ryan Plaza Drive, Suite 400 

Arlington, TX 76011-8064 

Steven D. Bloom 

NRC, Project Manager 

One White Flint North 

11555 Rockville Pike 

Rockville, MD 20852-2738 

PG&E Letter DCL-2000-514 
P.12 

m PG&

E Letter DCL-2000-514 

Mr. Briggs 

March 1,2000 

Page 3 

cc: w/o attachment (con't.) 

Document Control Desk 

U.S. Nuclear Regulatory Commission 

Washington, D.C. 20555 

Jennifer Soloway 

State Water Resource Control Board 

Office of the Chief Counsel 

901 "P" Street 

Sacramento, CA 95812-0100 

Laurie Kermish 

Environmental Protection Agency, Region IX 

Office of the Regional Counsel 

75 Hawthorne Street 

San Francisco, CA 94105-3901 

Alexis Strauss 

Environmental Protection Agency 

CWA Standards & Permits Office 

75 Hawthorne Street 

San Francisco, CA 94105-3901 

Brad Mahanes 

U. S. EPA 

Office of Enforcement & Compliance 

Assurance 

401 M Street, S.W. 

Washington, DC 20460 

Daniel Meer 

Environmental Protection Agency 

Chief of Clean Water 

CWA Compliance Office, Region IX 

75 Hawthorne Street 

San Francisco, CA 94105 

i/Robyn Stuber 

U.S. Environmental Protection Agency 

CWA Standards & Permits Office, 

Water Division 

75 Hawthorne Street 

San Francisco, CA 94105 

Dave Mayer 

TENERA 

One Market, Spear TowerSuite 1850 

San Francisco, CA 94105-1018 
P.13 

m PG&

E Letter DCL-2000-514 

} Mr. Briggs 

March 1,2000 

Page 4 

cc: w/o attachment (con't.) 

Chris Ehrler 

TENERA 

P.O. Box 400 

Avila Beach, CA 93424 (Hand Delivery) 

John Steinbeck 

TENERA 

P.O. Box 400 

Avila Beach, CA 93424 (Hand Delivery) 

Gregory Rueger 

PG&E 

P.O. Box 770000 

San Francisco, CA 94177 

Cal Gillies 

PG&E 

Diablo Canyon Power Plant 

P.O. Box 56 

Avila Beach, CA 93424 (Hand Delivery) 

Anne Jackson 

PG&E 

P.O. Box 770000 

San Francisco, CA 94177 (3 copies) 

Pat Eckhardt 

PG&E 

P.O. Box 770000 

San Francisco, CA 94177 

Kathleen Jones 

PG&E 

P.O. Box 770000 

San Francisco, CA 94177 (3 copies) 
J M 4 

i 

i 

| Diablo Canyon Power Plant 

! 

i 

I 

• March 1, 2000 

316(b) Demonstration Report 

Document No. E9-055.0 

TENERA Project Manager: 

Chris Ehrler 

I 

I 

I 

I 

| 

I 

I 

I ® TENERA 

I 

I 

I 

Prepared for. 

Pacific Gas and Electric Company 

77 Beale Street 

San Francisco, CA 94105 

Prepared by. 

Environmental 

Services 

One Market, Spear Tower, Suite 1850, San Francisco, CA 94105 

(415) 536-4744, FAX (415) 536-4714 

P.O. Box 400, Avila Beach, California 93424 

(805) 595-2407, FAX: (805) 545-6960 
P.15 

Table of Contents 

TABLE OF CONTENTS 

Section Page 

1.0 EXECUTIVE SUMMARY i-l 

2.0 INTRODUCTION 2-i 

3.0 BACKGROUND 3-i 

4.0 METHODS 4-1 

4.1 Criteria for Selection of Target Organisms 4-1 

4.2 Entrainment 4-3 

4.3 Impingement '. 4-10 

4.4 Description of Entrainment Analytical Methods 4-11 

5.0 RESULTS 5-1 

5.1 Overview 5-1 

5.1.1 Entrainment 5-1 

5.1.2 Impingement 5-5 

5.2 Assessment of Effects on Target Taxa 5-20 

5.2.1 Cancer crabs 5-20 

Brown rock crab {Cancer antennarius) 5-22 

Slender crab {Cancer gracilis) 5-33 

5.2.2 Pacific sardine {Sardinops sagax) 5-65 

5.2.3 Northern anchovy {Engraulis mordax) 5-96 

5.2.4 Rockfishes (Family Scorpaenidae) 5-125 

KGB rockfish complex 5-127 

Blue rockfish complex 5-142 

5.2.5 Painted greenling {Oxylebiuspictus) 5-195 

5.2.6 Sculpins (Family Cottidae) 5-215 

Smoothhead sculpin {Artedius lateralis) 5-217 

Snubnose sculpin {Orthonopias triads) 5-222 

Cabezon {Scorpaenichthys marmoratus) 5-229 

5.2.7 White croaker {Genyonemus lineatus) 5-275 

5.2.8 Monkeyface prickleback {Cebidichthys violaceus) 5-298 

5.2.9 Kelpfishes '. 5-318 

5.2.10 Blackeye goby {Coryphopterus nicholsi) 5-337 

5.2.11 Flatfishes (Family Paral ichthy idae) 5-364 

Sanddabs {Citharichthys spp.) 5-364 

California halibut {Paralichthys californicus) 5-372 

6.0 EVALUATION OF ALTERNATIVE INTAKE TECHNOLOGIES 6-1 

7.0 DISCUSSION 7-1 

8.0 CONCLUSION 8-1 

9.0 LITERATURE CITED 9-1 

TENERA E9-055.0 i Final 316(b) Demonstration 

March 1,2000 
P.16 

Table of Contents 

TABLE OF CONTENTS 

(continued) 

APPENDIX A DCPP 316(b) DEMONSTRATION STUDY: PHASE 1 -ENTRAINMENT STUDY 

DESIGN, I. SAMPLING LOCATION. 

APPENDIX B DCPP 316(b) DEMONSTRATION STUDY: PHASE 1 -ENTRAINMENT STUDY 

DESIGN, II. SELECTION OF TARGET ORGANISMS, SAMPLING METHODS, AND 

GEAR TESTING. 

APPENDIX C DCPP 316(b) STUDY: PHASE 3-SAMPLING PLAN AND MODELLING EVALUATION. 

APPENDIX D DCPP 31 6(B) ENTRAINMENT STUDY, FIELD AND LABORATORY PROCEDURES. 

APPENDIX E DCPP 316(B) STUDY: COMPARISON OF ENTRAINMENT LARVAL DENSITY IN 

PAIRED SAMPLES: ONE-VS. TWO-NETS. 

APPENDIX F ESTIMATING TOTAL ENTRAINMENT MORTALITY USING THE DELTA METHOD. 

APPENDIX G NUMBER OF SAMPLES COLLECTED AND LABORATORY PROCESSED. 

APPENDIX H ESTIMATED MEAN DENSITY OF LARVAE COLLECTED AT DCPP. 

APPENDIX I ESTIMATED NUMBER OF TARGET TAXA LARVAE ENTRAINED PER WEEK. 

APPENDIX J RESULTS OF T-TESTS AND KOLMOGOROV-SMIRNOV TESTS ON LENGTH 

FREQUENCY DATA FROM PAIRED ENTRAINMENT AND STUDY GRID SAMPLES. 

APPENDIX K GENETIC IDENTIFICATION OF LARVAL SEBASTES SPP. 

APPENDIX L TECHNOLOGIES THAT DO NOT HAVE DEMONSTRATED COMMERCIAL OPERABILITY 

OR RELIABILITY AT POWER PLANTS OF A SCALE SIMILAR TO DCPP. 

APPENDIX M TECHNOLOGIES THAT ARE CURRENTLY AVAILABLE BUT WOULD NOT REDUCE 

IMPINGEMENT OR ENTRAINMENT TO LEVELS LOWER THAN OBSERVED AT DCPP. 

APPENDIX N TECHNOLOGIES AND METHODS CURRENTLY AVAILABLE AND PROVEN EFFECTIVE 

AT FACILITIES OF THE SAME SIZE AS DCPP BUT DETERMINED TO NOT BE 

EFFECTIVE AT DCPP. 

TENERA E9-055.0 Final 316(b) Demonstration 

March 1,2000 
P.17 

K List of Tables 

| LIST OF TABLES 

Section and Table Number 

" ' 1.0 EXECUTIVE SUMMARY 

• 2.0 INTRODUCTION 

3.0 BACKGROUND 

• 3-1 Presence and magnitude of El Nino and La Nina events 

4.0 METHODS 

B 4-1 List of target taxa selected for assessments 

^ 4.2 Pigment groups, parturition peak periods, and seasonality of preflexion rockfish,,. 

. 4-3 Larval growth estimates for entrainable fish larvae at DCPP 

V 4-4 Mean and maximum larval stage durations from hatching to entrainmnet for fish 

^ larvae collected at DCPP 

4-5 Study grid and paired entrainment survey dates 

I 5.0 RESULTS 

5.1 Overview 

• 5.1-1. List ofthe larval fish taxa collected during DCPP 316(b) Demonstration .. 

W 5.1-2. Total abundance, weight, and average biomass of impinged fishes at DCP 

5.1-3. Biomass of impinged crabs at DCPP 

• 5.2 Target Taxa Effects Assessment 

W 5.2.1 Cancer crabs 

5.2.1-1. Schedule of estimated fecundity by age for brown rock crab 

• 5.2.1 -2. Estimated number of brown rock crab zoea and megalops entrained, 

*>• w estimated FH, and sensitivity analyses of FH estimates 

5.2.1-3. Duration of planktonic zoeal and megalopal stages of brown rock crab.. 

B 5.2.1-4. Brown rock crab monthly estimates of PE 

3 5.2.1-5. Schedule of estimated fecundity by age for slender crab 

5.2.1-6. Duration of planktonic zoeal and megalopal stages of slender crab 

• 5.2.1-7. Estimated number of slender crab zoea and megalops entrained, 

• . estimated FH, and sensitivity analyses of FH estimates 

5.2.1-8. Slender crab monthly estimates of PE 

• 5.2.2 Pacific sardine {Sardinops sagax) 

5.2.2-1. Percent maturity of female Pacific sardines 

fc 5.2.2-2. Life table for Pacific sardine 

• 5.2.2-3. Estimated fishing mortality rates on Pacific sardine 

5.2.2-4. Estimated total annual entrainment of sardine larvae 

• 5.2.2-5. Estimated total annual adjusted entrainment of sardine larvae 

P 5.2.2-6. Estimate of number of FH females for two study years 

5.2.2-7. Pacific sardine sensitivity analyses of FH. 

g | 5.2.2-8. Estimate of number of AEL adults for two study years 

• 5.2.2-9. Pacific sardine sensitivity analyses of AEL 

5 2 2-10 Pacific sardine monthly estimates of PE 

TENERA E9-055.0 iii Final 316(b) Demons 

^ March 1 

Page 

3-8 

4-36 

,, 4-37 

4-39 

4-40 

4-41 

5-8 

P 5-15 

5-16 

. 5-41 

5-42 

5-43 

5-44 

5-45 

5-45 

5-46 

5-47 

5-76 

5-76 

5-77 

5-78 

5-78 

5-79 

5-79 

5-81 

5-81 

5-84 

tration 

,2000 
P.18 

List of Tables 

LIST OF TABLES 

(continued) 

Section and Table Number Page 

5.2.3 Northern anchovy {Engraulis mordax) 

5.2.3-1. Estimated total annual entrainment of northern anchovy larvae 5-106 

5.2.3-2. Estimated total annual adjusted entrainment of northern anchovy larvae... 5-106 

5.2.3-3. Survivorship of northern anchovy 5-107 

5.2.3-4. Estimate of number of/"//females for two study years 5-108 

5.2.3-5. Northern anchovy sensitivity analyses of FH. 5-108 

5.2.3-6. Estimate of number of AEL adults for two study years 5-110 

5.2.3-7. Northern anchovy sensitivity analyses of AEL 5-110 

5.2.3-8. Northern anchovy monthly estimates of PE 5-112 

5.2.4 Rockfishes (Family Scorpaenidae) 

5.2.4-1. Rockfish pigment groups and parturition periods 5-156 

5.2.4-2. Estimated total annual entrainment of KGB rockfish larvae 5-158 

5.2.4-3. Estimated total annual adjusted entrainment of KGB rockfish larvae 5-158 

5.2.4-4. Age at sexual maturation and longevity for three species in the KGB 

rockfish complex 5-159 

5.2.4-5. Estimate of number of FH females for two study years 5-159 

5.2.4-6. KGB rockfishes sensitivity analyses of FH. 5-160 

5.2.4-7. Three-year survival ofthe KGB rockfish complex larvae 5-162 

5.2.4-8. Estimate of number of AEL adults for two study years 5-162 

5.2.4-9. KGB rockfishes sensitivity analyses of AEL 5-163 

5.2.4-10. KGB rockfishes monthly estimates of PE 5-165 

5.2.4-11. Estimated total annual entrainment of blue rockfish larvae 5-166 

5.2.4-12. Estimated total annual adjusted entrainment of blue rockfish larvae 5-166 

5.2.4-13. Estimate of number of FH females for two study years.. 5-166 

5.2.4-14. Blue rockfish complex sensitivity analyses of FH 5-167 

5.2.4-15. Three-year survival of for the blue rockfish complex 5-169 

5.2.4-16. Estimate of number of AEL adults for two study years 5-170 

5.2.4-17. Blue rockfish complex sensitivity analyses of AEL 5-170 

5.2.4-18. Blue rockfish complex monthly estimates of PE 5-172 

5.2.5 Painted greenling {Oxylebiuspictus) 

5.2.5-1. Estimated total annual entrainment of painted greenling larvae 5-202 

5.2.5-2. Estimated total annual adjusted entrainment of painted greenling larvae ... 5-202 

5.2.5-3. Painted greenling monthly estimates of PE 5-203 

5.2.6 Sculpins (Family Cottidae) 

5.2.6-1. Summary of known demography for four closely related cottid 5-235 

5.2.6-2. Estimated total annual entrainment of smoothhead sculpin larvae 5-235 

5.2.6-3. Estimated total annual adjusted entrainment of smoothhead sculpin larvae 5-236 

5.2.6-4. Smoothhead sculpin monthly estimates of PE 5-237 

5.2.6-5. Estimated total annual entrainment of snubnose sculpin larvae 5-238 

5.2.6-6. Estimated total annual adjusted entrainment of snubnose sculpin larvae.... 5-238 

5.2.6-7. Snubnose sculpin monthly estimates of PE 5-239 

TENERA E9-055.0 iv Final 316(b) Demonstration 

March 1,2000 
P.19 

I 

t 

i 

a 

i 

i 

i 

§ 

t 

i 

i 

i 

l 

t 

i 

i 

i 

I 

I 

List of Tables 

LIST OF TABLES 

(continued) 

Section and Table Number Page 

5.2.6-8. Estimated total annual entrainment of cabezon larvae 5-240 

5.2.6-9. Estimated total annual adjusted entrainment of cabezon larvae 5-240 

5.2.6-10. Cabezon monthly estimates of PE 5-241 

5.2.7 White croaker {Genyonemus lineatus) 

5.2.7-1. Estimated total annual entrainment of white croaker larvae 5-283 

5.2.7-2. Estimated total annual adjusted entrainment of white croaker larvae 5-283 

5.2.7-3. Estimate of number of FH females for two study years 5-284 

5.2.7-4. White croaker sensitivity analyses of FH 5-284 

5.2.7-5. White croaker monthly estimates of PE 5-286 

5.2.8 Monkeyface prickleback {Cebidichthys violaceus) 

5.2.8-1. Estimated total annual entrainment of monkeyface prickleback larvae 5-305 

5.2.8-2. Estimated total annual adjusted entrainment of monkeyface 

prickleback larvae 5-305 

5.2.8-3. Monkeyface prickleback monthly estimates of PE 5-306 

5.2.9 Kelpfishes 

5.2.9-1. Estimated total annual entrainment of kelpfish larvae 5-324 

5.2.9-2. Estimated total annual adjusted entrainment of kelpfish larvae 5-324 

5.2.9-3. Kelpfish monthly estimates of PE 5-325 

5.2.10 Blackeye goby {Coryphopterus nicholsi) 

5.2.10-1. Larval mortality statistics for three sympatric gobiids 5-347 

5.2.10-2. Estimated total annual entrainment of blackeye goby larvae 5-347 

5.2.10-3. Estimated total annual adjusted entrainment of blackeye goby larvae 5-347 

5.2.10-4. Estimate of number of FH females for two study years 5-348 

5.2.10-5. Blackeye goby sensitivity analyses of FH 5-348 

5.2.10-6. Estimate of number of AEL adults for two study years 5-350 

5.2.10-7. Blackeye goby sensitivity analyses of AEL 5-350 

5.2.10-8. Blackeye goby monthly estimates of PE 5-352 

5.2.11 Flatfishes (Family Paralichthydae) 

5.2.11-1. Life table for speckled sanddab 5-378 

5.2.11-2. Estimated total annual entrainment of sanddabs larvae 5-379 

5.2.11-3. Estimated number of eggs spawned per season by speckled sanddabs 5-379 

5.2.11-4. Estimate of number of FH females for two study years 5-380 

5.2.11-5. Sanddab sensitivity analyses of FH. 5-381 

5.2.11-6. Estimate of number of AEL adults for two study years 5-382 

5.2.11-7. Sanddab sensitivity analyses of AEL 5-382 

5.2.11-8. Sanddab monthly estimates of PE 5-385 

5.2.11-9. Average spawn per female California halibut 5-386 

5.2.11-10. Mortality rates for juvenile California halibut 5-386 

5.2.11-11. Estimated total annual entrainment of sanddabs larvae 5-387 

TENERA E9-055.0 v Final 316(b) Demonstration 

March 1.2000 
P.20 

List of Tables 

(continued) 

Section and Table Number Page 

5.2.11-12. Estimated total annual adjusted entrainment of sanddabs larvae 5-387 

5.2.11-13. California halibut monthly estimates of PE 5-388 

6.0 EVALUATION OF ALTERNATIVE INTAKE TECHNOLOGIES 

6-1 Listing ofthe alternative technologies evaluated 6-29 

6-2 Estimated equivalent adults, months of peak density, and evaluation of 

susceptibility to entrainment for target crab and fish taxa 6-30 

i 

LIST OF TABLES f 

1 

I 

I 

I 

I 

I 

I 

I 

i 

i 

i 

I 

i 

i 

i 

i 

TENERA E9-055.0 vi Final 316(b) Demonstration 

March 1,2000 
P.21 

1 

I 

t 

1 

1 

I 

I 

I 

I 

I 

I 

f 

1 

I 

I 

i 

i 

i 

List of Figures 

LIST OF FIGURES 

Section and Figure Number . Page 

1.0 EXECUTIVE SUMMARY 

2.0 INTRODUCTION 

3.0 BACKGROUND 

3-1 Location of Diablo Canyon Power Plant 3-9 

3-2 Cross-section diagram of DCPP intake structure 3-10 

3-3 DCPP daily cooling water flow - October 1996-June 1999 3-11 

3-4 Unit 1 traveling screen assemblies 3-12 

3-5 Bathymetry of nearshore region between Point Buchon and Point San Luis 3-13 

3-6 DCPP wind and water current patterns October 1996 through June 1999 3-14 

3-7 Mean monthly ambient subtidal seawater temperatures 3-15 

4.0 METHODS 

4-1 Diagram of DCPP Power Plant, Intake Cove and Entrainment Sampling 

Locations 4-42 

4-2 Cross-section view ofthe intake structure illustrating the location ofthe 

entrainment sampling sites 4-43 

4-3 DCPP 316(b) survey grid and depth contours 4-44 

4-4 An example ofthe "ping-pong" sampling track employed in grid cell sampling..:.... 4-45 

4-5 Diagram of DCPP Intake Cove surface plankton tow sampling tow 

sampling locations 4-46 

4-6 Summary of entrainment, study grid, and Intake Cove surface tow sample 

collection and laboratory processing and analysis periods 4-47 

4-7 Two approaches for calculating Ps based on water current measurements 4-48 

4-8 Cumulative upcoast/downcoast and onshore/offshore movement of water at the 

DCPP current meter 4-49 

5.0 RESULTS 

5.1 Overview 

5.1-1. Weekly mean entrainment densities of red sea urchins and purple sea urchins 5-17 

5.1-2. Cooling water pump (CWP) daily water flow at Diablo Canyon (1985-1986). 5-18 

5.1-3. Comparison offish abundance and weight for impingement at DCPP 5-19 

5.2 Target Taxa Effects Assessment 

5.2.1 Cancer crabs 

5.2.1-1. Weekly mean density of brown rock crab zoea and megalops larvae at the 

DCPP intake 5-48 

5.2.1-2. Monthly mean density of brown rock crab megalops larvae in the 

study grid 5-51 

5.2.1-3. Total annual entrainment mortality of brown rock crab megalops larvae 

as a function ofthe reciprocal ofthe fraction ofthe population at risk 5-55 

TENERA E9-055.0 vii Final 316(b) Demonstration 

March 1,2000 
List of Figures 

(continued) 

Section and Figure Number Page 

5.2.1-4. Rock crab landings from ports of Avila and Morro Bay 5-56 

5.2.1-5. Weekly mean density of slender crab zoea and megalops larvae at the 

DCPP intake 5-57 

5.2.1-6. Monthly mean density of slender crab megalops larvae in the 

study grid 5-60 

5.2.1-7. Total annual entrainment mortality of slender crab meaglops larvae 

as a function of die reciprocal ofthe fraction ofthe population at risk 5-64 

5.2.2 Pacific sardine {Sardinops sagax) 

5.2.2-1. Weekly mean density of sardine larvae at the DCPP intake 5-85 

5.2.2-2. Monthly mean density of sardine larvae in the study grid 5-86 

5.2.2-3. Length frequency of sardine larvae from all entrainment samples 5-90 

5.2.2-4. Length frequency of sardine larvae from paired entrainment and 

study grid survey samples 5-91 

5.2.2-5. Annual mean density of sardines larvae from weekly Intake Cove 

plankton tows..... 5-92 

5.2.2-6. Total annual entrainment mortality of sardine larvae as a function ofthe 

reciprocal ofthe fraction ofthe population at risk 5-93 

5.2.2-7. PFMC management area containing the spawning population ofthe 

Pacific sardine 5-95 

5.2.3 Northern anchovy {Engraulis mordax) 

5.2.3-1. Commercial landings of northern anchovy at the ports in the Morro 

Bay area 5-113 

5.2.3-2. Weekly mean density of northern anchovy larvae at the DCPP intake 5-114 

5.2.3-3. Monthly mean density of northern anchovy larvae in the study grid 5-115 

5.2.3-4. Length frequency of northern anchovy larvae from all entrainment 

samples 5-119 

5.2.3-5. Length frequency of northern anchovy larvae from paired entrainment 

and study grid survey samples 5-120 

5.2.3-6. Annual mean density of northern anchovy larvae from weekly Intake 

Cove plankton tows 5-121 

5.2.3-7. Total annual entrainment mortality of northern anchovy larvae as a 

function ofthe reciprocal ofthe fraction ofthe population at risk 5-122 

5.2.3-8. PFMC management area containing the spawning biomass ofthe central 

subpopulation of northern anchovy 5-124 

5.2.4 Rockfishes (Family Scorpaenidae) 

5.2.4-1. Weekly mean density of KGB rockfish complex larvae at the 

DCPP intake 5-173 

5.2.4-2. Monthly mean density of KGB rockfish complex larvae in the 

study grid '. 5-174 

5.2.4-3. Length frequency of KGB rockfish complex larvae from all entrainment 

samples 5-178 

TENERA E9-055.0 viii Final 316(b) Demonstration 

March 1,2000 
I 

i 

List of Figures 

LIST OF FIGURES 

(continued) 

Section and Figure Number Page 

5.2.4-4. Length frequency of KGB rockfish complex larvae from paired 

entrainment and study grid survey samples 5-179 

5.2.4-5. Annual mean density of KGB rockfish complex larvae from weekly 

Intake Cove plankton tows 5-180 

5.2.4-6. Total annual entrainment mortality of KGB rockfish complex larvae as a 

function ofthe reciprocal ofthe fraction ofthe population at risk 5-181 

5.2.4-7. Yearly abundance of KGB rockfish complex measured by two 

independent methods 5-183 

5.2.4-8. Weekly mean density of blue rockfish complex larvae at the DCPP intake 5-184 

5.2.4-9. Monthly mean densities of blue rockfish complex larvae in the study grid 5-185 

5.2.4-10. Length frequency of blue rockfish complex larvae from all entrainment 

samples 5-189 

5.2.4-11. Length frequency of blue rockfish complex larvae from paired 

entrainment and study grid survey samples 5-190 

5.2.4-12. Annual mean density of blue rockfish complex larvae from weekly 

Intake Cove plankton tows 5-191 

5.2.4-13. Total annual entrainment mortality of blue rockfish complex larvae as a 

function ofthe reciprocal ofthe fraction ofthe population at risk 5-192 

5.2.4-14. Yearly abundance of blue rockfish complex measured by two 

independent methods 5-194 

5.2.5 Painted greenling {Oxylebiuspictus) 

5.2.5-1. Weekly mean density of painted greenling larvae at the DCPP intake 5-204 

5.2.5-2. Monthly mean density of painted greenling larvae in the study grid 5-205 

5.2.5-3. Length frequency of painted greenling larvae from all entrainment 

samples 5-209 

5.2.5-4. Length frequency of painted greenling larvae from paired entrainment 

and study grid survey samples 5-210 

5.2.5-5. Annual mean density of painted greenling larvae from Intake Cove 

plankton tows 5-211 

5.2.5-6. Total annual entrainment mortality of painted greenling larvae as a function 

ofthe reciprocal ofthe fraction ofthe population at risk 5-212 

5.2.5-7. Mean number of painted greenling observed along subtidal benthic 

transects 5-214 

5.2.6 Sculpins (Family Cottidae) 

5.2.6-1. Weekly mean density of smoothhead sculpin larvae at the DCPP intake.... 5-242 

5.2.6-2. Monthly mean density of smoothhead sculpin larvae in the study grid 5-243 

5.2.6-3. Length frequency of smoothhead sculpin larvae from all entrainment 

samples 5-247 

5.2.6-4. Length frequency of smoothhead sculpin larvae from paired entrainment 

and study grid survey samples 5-248 

TENERA E9-055.0 ix Final 316(b) Demonstration 

March 1,2000 
List of Figures 

LIST OF FIGURES 

(continued) 

Section and Figure Number Page 

5.2.6-5. Annual mean density of smoothhead sculpin larvae from Intake Cove 

plankton tows 5-249 

5.2.6-6. Total annual entrainment mortality of smoothhead sculpin larvae as a 

function ofthe reciprocal ofthe fraction ofthe population at risk 5-250 

5.2.6-7. Mean number of Cottidae observed along subtidal benthic transects 5-252 

5.2.6-8. Weekly mean density of snubnose sculpin larvae at the DCPP intake 5-253 

5.2.6-9. Monthly mean densities of snubnose sculpin larvae in the study grid 5-254 

5.2.6-10. Length frequency of snubnose sculpin larvae from all entrainment 

samples 5-258 

5.2.6-11. Length frequency of snubnose sculpin larvae from paired entrainment 

and study grid survey samples 5-259 

5.2.6-12. Annual mean density of snubnose sculpin larvae from Intake Cove 

plankton tows 5-260 

5.2.6-13. Total annual entrainment mortality of snubnose sculpin larvae as a 

function ofthe reciprocal of die fraction of die population at risk 5-261 

5.2.6-14. Mean number of snubnose sculpin observed along benthic transects 5-263 

5.2.6-15. Weekly mean density of cabezon larvae at the DCPP intake 5-264 

5.2.6-16. Monthly mean density of cabezon larvae in the study grid 5-265 

5.2.6-17. Length frequency of cabezon larvae from all entrainment samples 5-269 

5.2.6-18. Length frequency of cabezon larvae from paired entrainment and 

study grid survey samples 5-270 

5.2.6-19. Annual mean density of cabezon larvae from Intake Cove plankton tows 5-271. 

5.2.6-20. Total annual entrainment mortality of cabezon larvae as a function of 

the reciprocal ofthe fraction ofthe population at risk 5-272 

5.2.6-21. Yearly abundance of cabezon measured by two independent methods 5-274 

5.2.7 White croaker {Genyonemus lineatus) 

5.2.7-1. Weekly mean density of white croaker larvae at the DCPP intake 5-287 

5.2.7-2. Monthly mean density of white croaker larvae in the study grid 5-288 

5.2.7-3. Length frequency of white croaker larvae from all entrainment samples.... 5-292 

5.2.7-4. Length frequency of white croaker larvae from paired entrainment and 

study grid survey samples 5-293 

5.2.7-5. Annual mean density of white croaker larvae from Intake Cove 

plankton tows 5-294 

5.2.7-6. Total annual entrainment mortality of white croaker larvae as a function 

ofthe reciprocal ofthe fraction ofthe population at risk 5-295 

5.2.7-7. Annual commercial landings of white croaker in the Morro Bay area 5-297 

5.2.8 Monkeyface prickleback {Cebidichthys violaceus) 

5.2.8-1. Weekly mean density of monkeyface prickleback larvae at the 

DCPP intake 5-307 

5.2.8-2. Monthly mean density of monkeyface prickleback larvae in the 

study grid 5-308 

TENERA E9-055.0 X Final 316(b) Demonstration 

March 1,2000 

I 
P.25 

List of Figures 

LIST OF FIGURES 

(continued) 

Section and Figure Number Page 

5.2.8-3. Length frequency of monkeyface prickleback larvae from all 

entrainment samples 5-312 

5.2.8-4. Length frequency of monkeyface prickleback larvae from paired 

entrainment and study grid survey samples 5-313 

5.2.8-5. Annual mean density of monkeyface prickleback larvae from 

Intake Cove plankton tows 5-314 

5.2.8-6. Total annual entrainment mortality of monkeyface prickleback larvae as a 

function ofthe reciprocal ofthe fraction ofthe population at risk 5-315 

5.2.8-7. Yearly abundance of monkeyface prickleback measured by two 

independent methods 5-317 

5.2.9 Kelpfishes 

5.2.9-1. Weekly mean density of kelpfish larvae at the DCPP intake 5-326 

5.2.9-2. Monthly mean density of kelpfish larvae in the study grid 5-327 

5.2.9-3. Length frequency of kelpfish larvae from all entrainment samples 5-331 

5.2.9-4. Length frequency of kelpfish larvae from paired entrainment and 

study grid survey samples 5-332 

5.2.9-5. Annual mean density of kelpfish larvae from Intake Cove plankton tows.. 5-333 

5.2.9-6. Total annual entrainment mortality of kelpfish larvae as a function ofthe 

reciprocal ofthe fraction ofthe population at risk 5-334 

5.2.9-7. Mean number of kelpfish observed along subtidal benthic transects 5-336 

5.2.10 Blackeye goby {Coryphopterus nicholsi) 

5.2.10-1. Weekly mean density of blackeye goby larvae at the DCPP intake 5-353 

5.2.10-2. Monthly mean density of blackeye goby larvae in the study grid 5-354 

5.2.10-3. Length frequency of blackeye goby larvae from all entrainment samples 5-358 

5.2.10-4. Length frequency of blackeye goby larvae from paired entrainment 

and study grid survey samples 5-359 

5.2.10-5. Annual mean density of blackeye goby larvae from Intake Cove 

plankton tows 5-360 

5.2.10-6. Total annual entrainment mortality of blackeye goby larvae as a 

function ofthe reciprocal ofthe fraction ofthe population at risk 5-361 

5.2.10-7. Mean number of blackeye goby observed along subtidal benthic 

transects 5-363 

5.2.11 Flatfishes (Family Paralichthydae) 

5.2.11-1. Weekly mean density of sanddab larvae at the DCPP intake 5-389 

5.2.11-2. Monthly mean density of sanddab larvae in the study grid 5-390 

5.2.11-3. Length frequency of sanddab larvae from all entrainment samples 5-394 

5.2.11-4. Length frequency of sanddab larvae from paired entrainment and 

study grid survey samples 5-395 

5.2.11-5. Annual mean density of sanddab larvae from Intake Cove 

plankton tows 5-396 

TENERA E9-055.0 xi Final 316(b) Demonstration 

March 1,2000 
P.26 

List of Figures 

LIST OF FIGURES 

(continued) 

Section and Figure Number Page 

5.2.11-6. Total annual entrainment mortality of sanddab larvae as a function 

ofthe reciprocal ofthe fraction ofthe population at risk 5-397 

5.2.11-7. Commercial landings of sanddab species in the Morro Bay area 5-399 

5.2.11-8. Weekly mean density of California halibut larvae at the DCPP intake 5-400 

5.2.11-9. Monthly mean density of California halibut larvae in the study grid 5-401 

5.2.11-10. Length frequency of California halibut larvae from all entrainment 

samples 5-405 

5.2.11-11. Length frequency of California halibut larvae from paired 

entrainment and study grid survey samples 5-406 

5.2.11-12. Annual mean density of California halibut larvae from Intake Cove 

plankton tows 5-407 

5.2.11-13. Total annual entrainment mortality of California halibut larvae as a 

function ofthe reciprocal ofthe fraction ofthe population at risk 5-408 

5.2.11-14. Commercial landings of California halibut in the Morro Bay area 5-410' 

6.0 EVALUATION OF ALTERNATIVE INTAKE TECHNOLOGIES 

6-1 Alternative intake technologies evaluation flow chart 6-31 

6-2 Plan view ofthe proposed expansion ofthe DCPP intake 6-32 

6-3 Sectional view ofthe proposed expansion ofthe DCPP intake 6-33 

6-4 Schematic drawing of potential siting of mechanical draft cooling towers 6-34 

6-5 Schematic drawing of potential siting of natural draft cooling towers 6-35 

6-6 Monthly density of all fish larvae collected in weekly entrainment 

surveys conducted from Oct 1996 to Sep 1998 6-36 

TENERA E9-055.0 xii Final 316(b) Demonstration 

March 1, 2000 
P.27 

Acknowledgments 

ACKNOWLEDGMENTS 

Fish illustrations included in this document were used with permission from Dr. Bob Lea, 

California Department of Fish and Game in Monterey, California (from Miller and Lea 1972), or 

were modified from Hart (1973). Crab illustrations were modified from Morris et al. (1980). 

List of Preparers 

Jay C. Carroll, M.S. 

Chris P. Ehrler, M.S.* t 

John B. Hedgepeth, Ph.D. 

David Innis, M.S. 

Kim J. Kubasek,,M.S., M.Ap.Stat. 

Edward A. Laman, M.S.* t 

David L. Mayer, Ph.D.* t 

John Skalski, Ph.D.* t 

John R. Steinbeck, M.S.* t 

Benjamin T. Stephens, M.S. 

JeffW.Tupen,B.S. 

* Entrainment Technical Work Group Member 

t Tiburon Resource Impact Assessment Colloquia Attendee 

Entrainment Technical Work Group (ETWG) Members 

Gregor M. Cailliet, Ph.D. t Moss Landing Marine Laboratories (RWQCB Consultant) 

Patricia Eckhardt t Pacific Gas and Electric Company 

Anne Jackson t Pacific Gas and Electric Company 

Deborah Johnston t California Department of Fish and Game 

Roger Nisbet, Ph.D. t University of California at Santa Barbara(RWQCB Consultant) 

Peter Raimondi, Ph.D. t Consultant to the League for Coastal Protection 

Allan Stewart-Oaten, Ph.D. t University of California at Santa Barbara(RWQCB Consultant) 

Robyn Stuber t United States Environmental Protection Agency 

Michael Thomas t Central Coast Regional Water Quality Control Board 

t Tiburon Resource Impact Assessment Colloquia Attendee 

TENERA E9-055.0 xiii Final 316(b) Demonstration 

March 1,2000 
P.28 

Acknowledgments 

Tiburon Resource Impact Assessment Colloquia Attendees 

Bill Dey 

Jim Doyle 

Rimmon Fay, Ph.D. 

Cal Gillies 

Jeff Hayes 

Wim Kimmerer, Ph.D. 

Melody Kreimes 

Steve Lindley, Ph.D. 

Valerie Loeb, Ph.D. 

Alec MacCall, Ph.D. 

Brad Mahanes 

Keith Parker 

Paul Smith, Ph.D. 

Dave Sommerville 

Applied Science Associates (Pacific Gas and 

Electric Company consultant) 

Pacific Gas and Electric Company consultant 

California Earth Corps 

Pacific Gas and Electric Company 

Pacific Gas and Electric Company 

Romberg Tiburon Research Center 

Meeting Facilitator 

Independent consultant 

Moss Landing Marine Laboratories 

National Marine Fisheries Service 

U.S. Environmental Protection Agency 

Data Analysis Group 

National Marine Fisheries Service 

Pacific Gas and Electric Company 

Taxonomic and Technical Consultants 

Allen Andrews 

Rick Feeney, Ph.D. 

Guillermo Hen-era 

Bill Isham 

Gary Jordan 

Bob Leos 

Barbara MacCall 

Gerry McGowen, Ph.D. 

Mary Nishimoto 

Deborah Oda 

Dawn Outram 

Jeffrey Paduan 

Paul Reilly 

Laura Rogers-Bennett, Ph.D. 

Jim Rounds 

Wade Smith 

Jason Stannard 

Russell Vetter, Ph.D. 

Johnson Wang, Ph.D. 

TENERA E9-055.0 xiv Final 316(b) Demonstration 

March 1,2000 
P.29 

Acknowledgments 

Technical and Support Staff (Tenera) 

Mike Behrens 

Jim Blecha 

Jenna Borberg 

Louisa Bravo 

Wendy Bums 

Bessie Cajal 

Lisa Calderon 

Ernesto Calix 

Crystal Cienfuegos 

April Cole 

Hilary Corcoran 

Julia Cucinella 

Christina DeMeritt 

Melody DeMeritt 

Dan Dugan 

Barbie Dugan 

Kimberly Duncan 

Paul Dunn 

Frank Fenner 

Michelle Fortin 

Joanna Grebel 

Jennifer Hammer 

Andrew Harmer 

Susan Helberg 

Joanna Iwanicha 

Ana James 

Tom Jones 

Ben King 

Heather Knapp 

Gregory Kowalke 

John Lindsey 

Rebecca Makowski 

Derek Markolf 

Connie McBride 

Natalie McKinney 

Richard Moran 

Michael Moss 

Christina Muller 

Armie Parrilla 

Jason Patterson 

Steve Pengilley 

Shelly Peters 

Eunice Pierce 

Carol Raifsnider t 

Jeff Reinhardt 

Cathlin Rice 

Catherine Salter 

Judah Sanders 

Ed Schuster 

Nancy Siepel 

Ryan Silverthome 

Kauileen Smith 

Keith Speidel 

Jim Strampe 

Scott Taylor 

Doug Wampler 

Jacob Williamson 

Earl Wilson 

TENERA E9-055.0 xv Final 316(b) Demonstration 

March 1,2000 
P.30 

Glossary 

GLOSSARY OF TERMS AND ABBREVIATIONS 

AEI 

AEL 

ambient 

ASW 

BTA 

°C 

CalCOFI 

compensation 

CV 

CTD 

CWP 

CWS 

Davidson Current 

deme 

demography 

density dependence 

Adverse Environmental Impact: According to USEPA (1977), "adverse 

aquatic environmental impacts occur whenever there will be entrainment 

or impingement damage as a result ofthe operation ofa specific cooling 

water intake structure. The critical question is the magnitude of any 

adverse impact." 

Adult Equivalent Loss: Forecasts the number of adults that would have 

resulted from the number of entrained larvae, had they survived 

entrainment. Calculated using estimates of natural mortality rates 

applied to various life stages. 

Describes the conditions and factors that are present in the natural 

environment. 

Auxiliary seawater pump supply cooling water to the safety related 

component cooling water heat exchangers that maintain the operating 

temperature of vital plant equipment. 

Best Technology Available: In USEPA regulations, refers to intake 

technology that is the best available to minimize AEI. 

Degrees Centigrade (or Celsius) 

California Cooperative Oceanic Fisheries Investigations 

The ability ofa [fish] population to offset, in whole or part, reductions in 

numbers caused by impacts from natural and/or man-induced stresses. 

Coefficient of variation: A statistical quantity computed as the standard 

enor of a sample divided by die mean. 

A data recording instrument used to measure ocean water conductivity 

[salinity] and temperature as a function of depth. 

Circulating water pumps supply cooling water from the Pacific Ocean to 

the condensers to condense exhaust steam from the low pressure turbines. 

Cooling water system: Includes portions ofthe DCPP intake structure, 

circulating water pumps, conduit tunnels, condensers, and discharge 

stmcture. 

Northward flowing cunent along the western US coast, usually during 

the fall and winter. 

A local population of organisms which is geographically isolated but not 

genetically isolated (i.e., through larval dispersal). 

The study of population statistics; specifically density, distribution, and 

vital rates ofa population of organisms. 

Adjustment of vital rates (e.g., fecundity, mortality, somatic growth) in 

response to changes in population density; see compensation. 

TENERA E9-055.0 xvi Final 316(b) Demonstration 

March 1,2000 
P.31 

Glossary 

GLOSSARY (continued) 

ENSO 

El Nino 

entrainment 

ETM 

ETWG 

FH 

gpm 

growth overfishing 

impingement 

km 

La Nina 

m 

m

3

/d 

MLLW 

MT 

North Pacific Gyre 

NPDES 

NPV 

El Nino-Southern Oscillation: Naturally occuning climatologic and 

oceanographic condition consisting of anomalous cooling and warming 

events. 

Ocean warming condition in the eastern Pacific that occurs when trade 

winds weaken over the central and western Pacific. Coastal upwelling is 

reduced resulting in widespread declines in nearshore productivity; an 

extreme phase ofthe ENSO phenomenon. 

Passage of small planktonic marine life through the power plant CWS. 

Empirical Transport Model: A mathematical model that estimates the 

total annual probability of mortality {PM) associated with entrainment 

using PE estimates. 

Entrainment Technical Work Group 

Fecundity Hindcasting: The number of larvae entrained are hindcast to 

the number of eggs by applying mortality estimates; the number of eggs 

is then used to estimate the number of adult females that would have 

produced diat quantity of eggs. 

Gallons per minute (0.0038 mVmin) 

Fishing pressure that eliminates young fishes before they can spawn, as 

in the live-fish fishery. 

Entrapment of macroscopic organisms on the intake traveling screens. 

Kilometer (0.62 miles) 

An oceanographic phenomenon that occurs when trade winds strengthen 

over the tropical Pacific, increasing the amount of cold, nutrient rich 

water brought to the surface in upwelling cunents; generally results in 

high primary productivity; an extreme phase ofthe ENSO. 

Meter (3.28 feet) 

Cubic meters per day (measure of flow rate; 264 gallons/ m3) 

Mean lower low water; the elevation defined as 0.0 m (ft) 

Metric ton; (1,000 kg; 2,205 pounds) 

Clockwise gyre in the, north Pacific Ocean that creates a southward 

movement of water along the western coast ofthe United States (i.e., 

California Cunent). 

National Pollutant Discharge Elimination System 

Net Present Value of cash flow: The economic measure of evaluating 

proposed projects including capital and maintenance costs, and the . 

cumulative lost revenue, discounted to a present value using an after-tax 

discount rate. 

TENERA E9-055.0 XVII Final 316(b) Demonstration 

March 1,2000 
P.32 

Glossary 

GLOSSARY (continued) 

#/m3 

PE 

1M 

population 

P. 

recruitment 

overfishing 

RWQCB 

species 

SST 

stock 

subpopulation 

surplus production 

traveling screens 

USEPA 

upwelling 

Number of organisms per cubic meter of water (density of organisms) 

Proportional Entrainment: A mathematical value comparing die number 

of larvae entrained to the number of larvae available in the source water 

body. 

Total annual mortality probability due to entrainment 

The individuals ofa given species or taxon within a defined 

geographical area. 

The proportion of die population of inference represented by the number 

of larvae in the study grid, (i.e., number of larvae at risk in die study 

grid) / (number of larvae in die population of inference). 

Instantaneous rate of increase 

Fishing pressure that limits the amount of larvae a population produces 

by taking primarily older, more fecund adults and leaving behind young, 

less fecund individuals. 

Regional Water Quality Control Board (Central Coast) 

A group of similar organisms diat produce fertile offspring. 

Sea surface temperature 

A managed unit ofa fish subpopulation available to a fishery. 

A group of individuals ofa species which interbreeds but is 

reproductively isolated from odier such groups. 

In fisheries biology, production above and beyond an equilibrium level 

that can be harvested without substantially depleting a population; a 

population in equilibrium occurs when recmitment (or emigration) 

balances mortality (or immigration); see compensation. 

A series of rotating meshed baskets at the intake stmcture designed to 

remove material and debris in the cooling water flow. 

United States Environmental Protection Agency 

Offshore transport of surface waters that results from steady northwest 

winds and causes cold, deep, nutrient-rich water to rise to the surface. 

Instantaneous mortality rate 

TENERA E9-055.0 XVIII Final 316(b) Demonstration 

March 1,2000 
P.33 

1.0 Executive Summary 

1.0 EXECUTIVE SUMMARY 

Section 316(b) ofthe Federal Water Pollution Control Act Amendments of 1972 (Clean Water 

Act) requires that Diablo Canyon Power Plant (DCPP) cooling water intake structure represents 

the best technology available (BTA) to minimize adverse environmental impacts (AEI) as 

defined by the USEPA. This report provides information to the Central Coast Regional Water 

Quality Control Board (RWQCB) in response to the requirements in Section 316(b). The report 

follows previous reports that described the sampling design and methods ofthe study, selection 

of target taxa, and formulations ofthe three assessment approaches (Tenera 1997a and b; Tenera 

1998a) for approval by the RWQCB. PG&E also submitted two preliminary assessment reports 

to the Central Coast RWQCB, USEPA, and the ETWG (Tenera 1999a and b) that provide a 

comprehensive application ofthe three assessment approaches to entrainment effects on the 

selected target taxa. 

Entrainment Technical Work Group 

The Entrainment Technical Work Group (ETWG) was assembled by the RWQCB to assist their 

staff in reviewing the design and implementation ofthe 316(b) demonstration at DCPP. The 

ETWG was composed of PG&E and their consultants, RWQCB and their consultants, a 

consultant to the League for Coastal Protection, the California Department of Fish and Game, 

and USEPA. The ETWG assisted in developing criteria to assess the effects ofthe DCPP intake. 

Impingement 

The cooling water intake system at DCPP entrains and impinges larval, juvenile, and adult fishes 

and invertebrates. Entrainment occurs when organisms smaller than the 0.95 cm mesh ofthe 

traveling screens pass through the screens and enter the cooling water system. Impingement 

occurs when organisms too large to pass through the mesh are held against the screens by the 

water pumped through the plant. Once entrained, larval mortality was assumed to be 100%. 

Estimates of impingement were very low based on a review ofthe 1985-86 DCPP impingement 

TENERA E9-055.0 1-1 Final 316(b) Demonstration 

March 1,2000 
P.34 

1.0 Executive Summary 

study (Tenera 1988a). The ETWG determined that additional impingement studies were not 

required at DCPP because ofthe low levels of impingement. 

Assessment Approaches 

Pacific Gas and Electric (PG&E) and its consultants, in cooperation with other members ofthe 

ETWG, employed three population assessment approaches to determine the entrainment and 

impingement effects ofthe DCPP intake. Estimates of entrainment loss, and the demographic 

data collected from the scientific literature, were used to parameterize two demographic 

approaches to estimating entrainment effects: Adult Equivalent Loss {AEL) and Fecundity 

Hindcasting^FTf). The AEL method forecasts the number of adults that would have survived 

from the estimated number of entrained larvae, as if they had survived entrainment, using 

knowledge of mortality rates other than from entrainment by the power plant (i.e., natural 

mortality). The FH method is similar except that the number of larvae entrained are hindcast to 

the number of eggs, and the number of eggs is then used to estimate the number of female adults 

that would have produced them. 

A third method, the Empirical Transport Model {ETM), estimates an average annual larval 

mortality due to entrainment per individual taxon, using estimates of proportional entrainment 

{PE) that compare the number of larvae entrained in one day to the number of available larvae in 

the source water body. Larval mortality is calculated after PE is weighted by the estimated 

fraction ofthe total population affected and compounded by the time larvae are susceptible to 

entrainment. Data collected during the study period from a cunent meter located offshore of 

DCPP was used to estimate this fraction (Ps) using either alongshore cunents (for nearshore 

species) or both alongshore and onshore cunents (for those more widely distributed species). 

Target Organism Selection 

The ETWG selected the organisms targeted for study: larval fishes, Cancer spp. crab zoea and 

megalops larvae, and metamorphosing larval and juvenile Strongylocentrotus spp. sea urchins. 

The individual taxa were chosen based on a set of criteria following USEPA Draft Guidelines 

TENERA E9-055.0 1-2 Final 316(b) Demonstration 

March 1,2000 
1.0 Executive Summary 

(USEPA 1977) and described in Tenera (1997b), that included constraints imposed by the 

availability of data to estimate population-level effects. 

Sixteen target taxa were identified for assessment of entrainment effects using criteria based on 

USEPA guidance on 316(b) studies, and recommendations ofthe ETWG and other experts: 

Brown rock crab 

Slender crab 

Pacific sardine 

Northern anchovy 

Blue rockfish complex 

KGB rockfish complex 

Painted greenling 

Smoothhead sculpin 

Snubnose sculpin 

Cabezon 

White croaker 

Monkeyface prickleback 

Clinid kelpfishes 

Blackeye goby 

Sanddabs 

California halibut 

Sampling 

Entrainment and study grid sampling provided data for estimating entrainment abundance and 

abundance in the nearshore area defined by a study grid centered on the DCPP intake. Collection 

ofthe DCPP entrainment samples took place once per week from four permanently moored 

sampling stations located directly in front ofthe intake structure. The study grid contained 64 

sampling cells in an eight cell by eight cell pattern and extended a distance of 17.4 km alongshore 

(8.7 km to the north and south) and an average distance of 3.0 km offshore. 

The sampling surveys were conducted during 1996-1999 and divided into annual periods for 

analyses. Where it was possible, the estimates of annual entrainment were scaled to better 

represent long-term trends for a taxon by using data from surface plankton tows collected at the 

mouth ofthe DCPP Intake Cove starting in 1990. The analysis periods provided two annual 

estimates for comparing FH and AEL and two years of paired entrainment and study grid survey 

for comparing annual estimates of larval mortality PAI using ETM. 

TENERA E9-055.0 1-3 Final 316(b) Demonstration 

March 1,2000 
P.36 

1.0 Executive Summary 

Results of Assessment 

Variation of FH and AEL estimates between the years 1996-97 and 1997-98 appeared to be 

taxon-specific, but was likely also influenced by the El Nino event that occuned along the 

central California coast during the fall, winter, and spring seasons of 1997-98. For example, 

estimates of FH and AEL for both Pacific sardine and northern anchovy increased markedly 

between the first and second year ofthe study. The spawning biomass for both of these species is 

typically centered south of Point Conception, and was likely displaced northward with the northflowing El Nino cunents present in the second year. White croaker FH and AEL also appeared 

to increase slightly, which may also be due to additional transport northward during the El Nino 

year. Other species appeared to be somewhat less affected by El Nino-related transport since 

FH and AEL remained relatively constant or changed only slightly between years (e.g., KGB 

rockfishes, blue rockfish complex, blackeye goby, and sanddabs). These fishes probably have 

more localized spawning populations that were less affected by the El Nino event. 

For some taxa, multiple assessment methods were applied to a known reference population or to 

fishery harvest data. For other taxa, assessment of impacts was limited to reporting the number 

of individuals lost to the population, or to a mortality estimate that was specific to an area where 

there is little knowledge ofthe adult population size. For example, demographic data on egg and 

larval mortality for blackeye goby allowed the application of multiple assessment approaches, 

but the absence ofa stock assessment or fishery data precluded a context for the estimates. 

For taxa where all three assessment methods were completed, comparison among the results 

illustrated the usefulness ofthe multiple assessment approach. While the range and variance of 

life history parameters and population estimates were sources of uncertainty in our estimates, we 

determined our areas of uncertainty through model comparison. Where both FH and AEL 

estimates exist, assuming a 50:50 sex ratio and aligning the ages of recruitment and maturation, 

the models were compared directly using the relationship AEL = 2FH presented in previous 

assessment reports (Tenera 1999a, b). The results from the demographic approaches were in 

similar units of either adult females {FH) or adults {AEL). 

TENERA E9-055.0 1-4 Final 316(b) Demonstration 

March 1,2000 
1.0 Executive Summary 

The FH and AEL model estimates, when ages were aligned, were in close agreement for northern 

anchovy and the blue rockfish complex. Results for these taxa provided assurance that the 

parameters used in the models (and thus the assessments) for these two taxa are reasonably 

accurate for central California populations. In the example ofthe blue rockfish. the FH and AEL 

estimates were used to extrapolate population-level effects and then were compared to local 

fishery landings. Applying the range of PM estimates for this taxon (0.001-0.02) calculated 

using alongshore cunents and extrapolating density offshore to these same fishery data provided 

an estimate of loss to the fishery of 15-292 kg of whole fish. Using an estimate of approximately 

0.5 kilogram per live fish, the percentage catch equaled 29-584 adult fish. This estimate also 

agreed with aligned estimates of2FH{\ 14-273) and AEL (142-353). 

Age at assessment needed to be considered when interpreting the large FH estimate for brown 

rock crab. The estimated number of reproductive adults using the FH model was extrapolated to 

known fishery-sized animals using estimates of adult mortality because females are reproductive 

before they enter the fishery. This reduced the FH estimate by an order of magnitude. 

Assessments of entrainment effects on taxa that had very little demographic information were 

limited to ETM estimates. However, the availability of data on populations from sport or 

commercial fisheries provided context for assessments on some of these taxa (e.g., California 

halibut, cabezon, and monkeyface prickleback). The absence of catch data or stock assessments 

for other taxa limited the ability to assess entrainment effects on their populations with any 

methodology. Limited species' life history information imposed limitations on which methods 

could be used to assess entrainment effects on a particular taxon. 

Taxa that are not commercially or recreationally harvested were primarily small, nearshore 

fishes. As might be expected due to the shallow water, shoreline location ofthe DCPP intake 

structure, several of these taxa were entrained in relatively high numbers, resulting in large PAI 

estimates. For example, adult kelpfishes that occur in rocky, nearshore habitat had one ofthe 

highest PM estimates (ca. 30-40%). Other taxa with nearshore distributions, including 

smoothhead sculpin, snubnose sculpin, and monkeyface prickleback, also had relatively large 

TENERA E9-055.0 1-5 Final 316(b) Demonstration 

March 1, 2000 
P.38 

1.0 Executive Summary 

PSI estimates. Their greatest larval abundance occuned in the cells closest to shore in the study 

grid; a distribution that was consistent with their adult distributions. 

Estimates of PKI for some ofthe species that have broader adult distributions (e.g., blackeye 

goby and California halibut) were also high. Blackeye goby larvae (PA/ ca. 20%), distributed 

throughout the survey grid, also occuned as adults from the intertidal zone out to depths of 30m. 

The high PSI for blackeye goby, in part, may have resulted from the high density of adults 

directly in front ofthe intake structure. Although California halibut PAI estimates were high, 

particularly during the July 1998-June 1999 period, the estimates are based on a limited number 

of larvae. Although low in abundance in entrainment California halibut was included in the list 

of target taxa because ofits sport and commercial fishery importance. 

Estimates of PAI for species with more widespread, pelagic larvae (e.g., Pacific sardine and 

northern anchovy) were low. Impacts on commercially and recreationally harvested species with 

subtidal or pelagic distributions were minimal. For cases where all three assessment approaches 

were applied, the effects detected were relatively small, appeared to be localized, and thus would 

not affect the overall adult populations. These conclusions were supported by results for taxa 

such as KGB rockfishes where the estimated low levels of entrainment effects were conoborated 

by corollary data that showed no consequent adult abundance or larval production decreases. 

Several small, nearshore fishes were included in the assessment because of their high abundance 

in entrainment samples. There was very little available information describing the demography 

of these taxa which limited the applicable assessment approaches to ETM. The ETM results 

showed that entrainment could remove over 10% ofthe annual larval production of several of 

these nearshore and intertidal taxa in an area from one to eight times the study grid area 

(52 km2). In some of these cases, corollary data indicated that entrainment only removed surplus 

production since there were no apparent long-term declines in local adult populations, or in the 

weekly intake cove plankton tows conducted since 1990. For those nearshore taxa that did not 

display decreasing adult abundance, it was apparent from their length-frequency distributions 

that they were exposed to entrainment mortality for only a brief portion of their early 

TENERA E9-055.0 1-6 Final 316(b) Demonstration 

March 1,2000 
P.39 

1.0 Executive Summary 

development. In contrast, for kelpfish and snubnose sculpin, whose adult abundance appeared to 

be decreasing, the length-frequency distributions indicated a longer exposure to entrainment. The 

combination of length-frequency analyses, ETM estimates, and other conoborating data support 

the conclusion that the local subpopulations of most nearshore taxa are not experiencingjpngterm declines in abundance due to entrainment. 

Conclusion 

United States Environmental Protection Agency (USEPA) criteria for determining the extent of 

adverse environmental impacts (AEI) focus on population-level effects. The results presented in 

this 316(b) study provide the necessary assurance that the DCPP cooling water intake system is 

not causing widespread or long-term population-level effects on the target taxa. Since DCPP is 

not causing population-level effects, no consideration of alternative cooling water intake 

structure technologies for minimizing AEI is necessary. However, this report does include an 

assessment of alternative technologies in response to a requirement by the Central Coast 

RWQCB. The conclusion of this alternative technologies assessment is that the existing cooling 

water intake structure is the best technology available for DCPP. 

TENERA E9-055.0 1-7 Final 316(b) Demonstration 

March 1,2000 
P.40 

Blank Page 
P.41 

i 2.0 Introduction 

2.0 INTRODUCTION 

The purpose of this study is to determine ifthe Diablo Canyon Power Plant (DCPP) intake is 

causing an adverse environmental impact and, if so, what type of intake structure represents the 

best technology available to minimize that impact. The results will also be used to project the 

long-range effects on taxa where estimates of their populations are available. The estimates of 

entrainment and impingement effects on target taxa presented in this report will be used in 

recommending any action that may be required to comply with Section 316(b) ofthe Federal 

Water Pollution Control Act Amendments of 1972 (Clean Water Act). 

2.1 USEPA Section 316(b) Background 

Section 316(b) ofthe Clean Water Act regulates cooling water intake stmctures and requires that 

"the location, design, construction, and capacity of cooling water intake structures reflect the 

best technology available [BTA] for minimizing adverse environmental impact [AEI]." Although 

the EPA attempted to establish regulations in the mid-1970s, these mles were set aside by the 

courts on procedural grounds. As a result there are cunently no regulations in effect for 

implementing Section 316(b). 

To date, USEPA has not reissued Section 316(b) regulations and, instead, has allowed state and 

federal permit writers to implement Section 316(b) on a case-by-case basis. To make Section 

316(b) decisions, permit writers have relied on other cases and on USEPA's (1977) informal 

draft "Guidance for Evaluating the Adverse Impact of Cooling Water Intake Structures on the 

Aquatic Environment: Section 316(b) P.L. 92-500." 

In California, the State Water Resources Control Board (SWRCB) and the Regional Water 

Quality Control Boards (RWQCB) are authorized to implement the Section 316(b) requirement. 

In the case of DCPP, the permit applicant is obligated to provide the Central Coast RWQCB with 

TENERA E9-055.0 2-1 Final 316(b) Demonstration 

March 1,2000 
P.42 

2.0 Introduction 

the "best information reasonably available"1 to assist it in fulfilling its decision-making 

responsibility. 

As is clear from the statute, the permit writer must consider two basic issues in making a finding 

that an intake technology meets BTA criteria for minimizing AEI: 

1. Whether or not an AEI is caused by the intake and, if so, 

2. What intake stmcture represents BTA to minimize that impact. 

The usual approach for a 316(b) demonstration is to consider the question of BTA only if a 

determination has been made that a facility is causing an AEI. However, in response to a 

requirement from the Central Coast RWQCB, PG&E is providing an alternative technology 

assessment as a part of this demonstration report (Section 6) and discusses BTA in Section 7 of 

this report, even though a determination of AEI has not been made. 

2.1.1 Adverse Environmental Impact (AEI) Standard 

Since there are no regulations defining AEI, permit decisions must be based on the USEPA's 

long-standing AEI interpretations and previous 316(b) decisions. In several guidance documents 

issued since the 1970's, the USEPA has indicated that assessment of AEI should be based on an 

evaluation of population level effects, not just losses of individual organisms. In its 1975 Draft 

BTA Guidelines, the USEPA stated that "[ajdverse environmental impacts occur when the 

ecological function ofthe organism(s) of concern is impaired or reduced to a level which 

precludes maintenance of existing populations....".2 Additionally, in the 1976 Development 

Document, released in conjunction with the EPA's previous Section 316(b) mles, the USEPA 

said that "[t]he major impacts related to cooling water use are those affecting the aquatic 

ecosystems. Serious concerns are with population effects that...may interfere with the 

' Boston Edison Company (Pilgrim Station), Case No. 78-7 (May 3 1978). 

:

 USEPA, Draft Guidelines to Determine Best Available Technology for the Location, Design, 

Construction, and Capacity of Cooling Water Intake Structures for Minimizing Adverse Environmental 

Impact Section 316(b) P.L. 92-500 (December 5, 1975), p 8. 

TENERA E9-055.0 2-2 Final 316(b) Demonstration 

March 1,2000 
P.43 

2.0 Introduction 

maintenance or establishment of optimum yields to sport or commercial fish and shellfish, 

decrease populations of endangered organisms, and seriously dismpt sensitive ecosystems."3 The 

EPA has looked to population level effects in evaluating AEI in specific permit decisions. One 

such example was in a decision on Seabrook Power Station in New Hampshire. In Seabrook I. 

the Administrator determined that the estimated loss of 100 billion Mya clam larvae through 

entrainment would not have a "significant effect" on the local clam population.4 On remand, the 

USEPA Administrator in Seabrook II determined that entrainment mortality would not have an 

adverse impact on abundance and distribution of plankton "even though the total 

biomass... killed may amount to hundreds or thousands of tons per year." He cited the ability of 

clams to reproduce rapidly, their wide distribution in the area beyond the immediate vicinity of 

the plant, and their transient nature.5 Upon review ofthe Seabrook II decision, a circuit court 

upheld the Administrator's decision and indicated that the issue in assessing AEI is whether 

intake losses would "affect the ability [offish species] to propagate and survive."6 

2.1.2 Best Technology Available (BTA) Standard 

The second issue to be considered in making a Section 316(b) decision is whether the existing 

intake structure represents BTA to minimize adverse environmental impacts if they are 

occurring. Determination of BTA for any cooling water intake requires 

• consideration ofthe technical and engineering feasibility of alternative intake technologies, 

3

 Development Document for Best Technology Available for the Location, Design, Construction, and 

Capacity of Cooling Water Intake Structures on the Aquatic Environment: Section 316(b). (1976 

Development Document) USEPA Eflluent Guidelines Division, Office of Water and Hazards Materials, 

April 1976. 

4

 In the Matter of Public Service Co. of New Hampshire: Seabrook Station I and II, NPDES Appeal No. 

76-7 (Decision ofthe Administrator, June 10, 1977) (Seabrook I). 

5

 In the Matter of Public Service Co. of New Hampshire, et al.: Seabrook I and II. NPDES Pennit 

Application No. NH0020338 Case No. 76-7 (Decision on Remand August 4, 1978 Seabrook II). 

6

 Seacoast Anti-Pollution League v. Costle, 597 F.2d 306,309,311 (1" Cir. 1979). 

TENERA E9-055.0 2-3 Final 316(b) Demonstration 

March 1,2000 
P.44 

2.0 Introduction 

• the potential for an intake technology to reduce or eliminate the "adverse environmental 

impact," 

• the potential for the technology to produce other environmental impacts reducing its net 

benefit, and 

• the cost ofthe technology in relation to its potential environmental benefits. 

Although no reference to cost is made in Section 316(b), legislative history suggests that 

Congress intended that costs be considered in 316(b) determinations. Specifically, a statement by 

the spokesman for the House Conferees indicates that Congress intended the "best technology 

available" to be interpreted to mean the "best technology available commercially at an 

economically practicable cost."7 Additionally, in responding to comments during the drafting of 

its 1977 Draft Guidance, the USEPA said that BTA is the technology or group of technologies 

that minimize adverse impacts to the greatest possible degree at a cost that is not "wholly 

disproportionate" to the environmental benefits. This standard was also applied by the USEPA 

Regional Administrator in the Pilgrim decision that states, "a decision regarding the required 

degree of minimization calls for a determination that die costs involved are not wholly out of 

proportion to the adverse environmental impact being avoided."8 

2.1.3 Status of Future 316(b) Regulations 

Cunently, the USEPA is developing regulations for implementing Section 316(b) ofthe Clean 

Water Act. This effort is the result ofa 1993 lawsuit brought by the Hudson Riverkeeper and 

several environmental groups alleging that the USEPA had failed to perform a "nondiscretionary duty" to promulgate Section 316(b) regulations.9

 In its effort to draft these 

7

 188 Cong. Rec. H 9130 (daily ed. Oct. 4, 1972) (remarks of Congressman Clausen). 

8

 "Determination Regarding Issuance of Proposed NPDES Permit No. MA 0025135", dated March 11, 

1977, regarding Boston Edison's Pilgrim Units 1 and 2. 

9

 Cronin v. Browner, 898 F. Supp. 1052, 1063 (S.D.N.Y. 1995). 

TENERA E9-055.0 2-4 Final 316(b) Demonstration 

March 1,2000 
2.0 Introduction 

regulations, the USEPA has held several public meetings to obtain input from interested parties 

and has also requested some facilities to respond to questionnaires to provide data that the 

USEPA deems relevant. As a result ofa settlement agreement reached by the USEPA and the 

Hudson Riverkeeper plaintiffs, the USEPA will issue final 316(b) regulations by August 2001. 

However, the USEPA recently requested from the court that they be given a time extension and 

allowed to bifurcate the regulations. If die request is granted, the USEPA would issue final 

regulations for new facilities by May 2002 and presumably less stringent regulations for existing 

facilities by April 2004. 

2.2 DCPP Study Development Process 

The Central Coast RWQCB assembled a team of experts to assist their staff in reviewing the 

design and implementation of the 316(b) demonstration at DCPP. This team, the Entrainment 

Technical Work Group (ETWG), has met periodically since 1996 to discuss topics relevant to 

assessing entrainment and impingement effects at DCPP. The ETWG approved the design for the 

DCPP 316(b) demonstration, including the selection of die organisms targeted for study (larval 

fishes, Cancer spp. crabs, and metamorphosing and juvenile Strongylocentrotus spp. sea 

urchins). The individual taxa were chosen by the ETWG for assessment based on criteria agreed 

to and described by Tenera (1997b) that included the statistical qualities ofthe data for a taxa 

and the availability of suitable life-history information to meet assessment model requirements. 

These criteria were, in turn, based on criteria described in USEPA Draft Guidelines (USEPA 

1977). The ETWG and the RWQCB's consultants will present their final recommendations 

regarding the 316(b) demonstration study for consideration by the Central Coast RWQCB at 

their July 14, 2000 meeting. 

Several approaches to assessment were developed by PG&E, its consultants, and additional 

members ofthe Entrainment Technical Work Group (ETWG). These assessment approaches are 

fecundity hindcasting {FH. Alec MacCall, NOAA/NMFS, Tiburon Laboratory, pers. comm.; 

Tenera 1998a), adult equivalent loss {AEL: Horst 1975; Goodyear 1978), and empirical transport 

modeling {ETM: Boreman et al. 1978, 1981). Previous reports submitted to the ETWG for 

TENERA E9-055.0 2-5 Final 316(b) Demonstration 

March 1,2000 
P.46 

2.0 Introduction 

review and approval detailed the sampling design and methods ofthe study, selection of target 

taxa, and formulations ofthe three assessment methods (Tenera 1997a; Tenera 1997b; Tenera 

1998a). Two preliminary assessment reports were also presented using these three approaches. 

The first (Tenera 1999a) presented an assessment for three ofthe target fish taxa for the period 

July 1997 through June 1998, while the second presented results for all 16 target taxa (crabs and 

fishes) for the same one year period (Tenera 1999b). Results in these reports demonstrated how 

available life history information could be incorporated into assessment calculations, what 

influence life history information would have on results, and how results ofthe three approaches 

could be interpreted together. In this report, the methods are described, the principles embodied 

in diese methods are summarized, and the results are presented using one or more of these 

assessment approaches, as appropriate, for the 16 target taxa studied. 

2.3 Standards for Assessment 

The USEPA (1977) draft guidelines acknowledge that the determination ofthe extent of AEI 

when it is occuning is difficult to assess. They state: 

Adverse aquatic environmental impacts occur whenever there will be 

entrainment or impingement damage as a result ofthe operation ofa specific 

cooling water intake structure. The critical question is the magnitude of any • 

adverse impact. The exact point at which adverse aquatic impact occurs at any 

given plant site or water body segment is highly speculative and can only be 

estimated on a case-by-case basis... 

In light of these obvious difficulties, the document (USEPA 1977) also provides some general 

guidelines for determining the extent of AEI. These involve determining the "relative biological 

value ofthe source water body zone of influence for selected species and determining the 

potential for damage by the intake stmcture" based on the following considerations ofthe value 

ofa given area to a particular species: 

• principal spawning (breeding) ground, 

migratory pathways, 

• nursery or feeding areas, 

numbers of individuals present, and 

• 

• 

TENERA E9-055.0 2-6 Final 316(b) Demonstration 

March 1,2000 
P.47 

2.0 Introduction 

• other functions critical during the life history. 

Following this general approach provided by the USEPA (1977), additional criteria can be 

evaluated that are specific to the marine environment around Diablo Canyon, unique to marine 

aquatic animals, and directly applicable to the present 316(b) entrainment study: 

• distribution (pelagic, subtidal, nearshore subtidal & intertidal); 

• range, density, and dispersion of population; 

• population center (source or sink); 

• magnitude of effects; 

• long-term abundance trends (e.g., Intake Cove plankton tows, 

subtidal fish observations, fishery catch data); 

• long-term environmental trends (climatological or oceanographic); 

and 

• life history strategies (e.g., longevity and fecundity). 

By assessing the relative value of each of these criteria for a particular target taxon examined in 

the present study, we will be able to better assess the extent ofthe impact that the loss of these 

animals has on the local environment and the population at large. 

2.4 Report Organization 

Section 3 of this report presents a background on the power plant and its environmental setting. 

Methods used for data collection and the formulation of each assessment models are contained in 

Section 4. Section 5 presents the results ofthe study, including assessments for each ofthe 

target taxa as separate subsections. Taxa are organized in phylogenetic order from the most 

primitive to the more evolutionarily advanced species, a standard form of organization in 

scientific publications. Each taxon's subsection provides a summary ofits demography, 

entrainment estimates, and assessment results. An evaluation of alternative intake technologies 

available to minimize entrainment and impingement is presented in Section 6. A summary 

discussion of all results and their interpretations is provided in Section 7, which is followed by 

Section 8: Conclusions. A listing ofthe literature cited is presented in Section 9. Fourteen 

TENERA E9-055.0 2-7 Final 316(b) Demonstration 

March 1,2000 
P.48 

2.0 Introduction 

appendices present previous reports, results summary tables, and other supporting information. 

These appendices are as follows: 

Appendix A: DCPP 316(b) Demonstration Study: Phase 1 -Entrainment Study 

Design, I. Sampling Location 

Appendix B: DCPP 316(b) Demonstration Study: Phase 1 -Entrainment Study 

Design, II. Selection of Target Organisms, Sampling Methods, and 

Gear Testing 

Appendix C: DCPP 316(b) Study: Phase 3-Sampling Plan and Modelling 

Evaluation 

Appendix D: DCPP 316(b) Entrainment Study, Field and Laboratory Procedures 

Appendix E: DCPP 316(b) Study: Comparison of Entrainment Larval Density in 

Paired Samples: One-vs. Two-nets 

Appendix F: Estimating Total Entrainment Mortality using the Delta method 

Appendix G: Number of Samples Collected and Laboratory Processed 

Appendix H: Estimated Mean Density of Larvae Collected at DCPP 

Appendix I: Estimated Number of Target Taxa Larvae Entrained per Week 

Appendix J: Results of t-tests and Kolmogorov-Smirnov tests on length 

frequency data from paired entrainment and study grid samples 

Appendix K: DNA Analysis of Larval Sebastes spp. 

Appendix L: Technologies that do not have demonstrated commercial operability 

or reliability at power plants ofa scale similar to DCPP 

Appendix M: Technologies that are cunently available but would not reduce 

impingement or entrainment to levels lower than observed at DCPP 

Appendix N Technologies and methods cunently available and proven effective 

at facilities ofthe same size as DCPP but determined to not be 

effective at DCPP 

TENERA E9-055.0 2-8 Final 316(b) Demonstration 

March 1,2000 
P.49 

3.0 Background 

The traveling screen assemblies are equipped with a high pressure seawater wash system, and 

screens are rotated either automatically or manually. When the screens rotate, impinged debris, 

fishes, and invertebrates are rinsed from the screens into a trough that slopes to a central refuse 

sump area (Figure 3-4). In Fall 1997, a grinder system was installed to decrease the size of all 

material before it entered the sump. All material in the sump is then pumped back to the ocean at 

the landward end ofthe west breakwater. Automatic operation ofthe screens occurs in one of 

two ways: by timed cycles or by hydrostatic pressure. Timers are typically set to initiate a 40-

minute screen wash once every four hours. The screens also rotate automatically when a height 

differential of approximately 20 cm across the screen surface is detected. Manual operation of 

the traveling screens occurs whenever necessary, especially when heavy accumulations of kelp 

threaten the safe operation ofthe intake system. During these times continuous screen washing is 

usually necessary. 

3.2 Environmental Setting 

3.2.1 Bathymetry 

The bathymetry ofthe nearshore region between Point Buchon and Point San Luis is 

characterized by sloping bedrock and soft-bottom flats, with steeper relief generally increasing 

from the south to the north (Figure 3-5). The majority ofthe nearshore region near Pt. San Luis, 

from the shoreline to -2 km offshore, is less than 40 m in depth, while the conesponding 

nearshore region off Point Buchon is 60-80 m in depth. Rocky pinnacles are relatively common 

out to the 40 m contour, in contrast to the relatively flat bottom typical ofthe 40-100 m region. 

Within the geographic area bounded by Point Buchon and Point San Luis, several prominent 

rocky ridges extend from the shoreline out to about the 20 m contour, especially noticeable at 

Point Buchon, Lion Rock, and Pecho Rock. 

TENERA E9-055.0 3-3 Final 316(b) Demonstration 

March 1,2000 
P.50 

3.0 Background 

3.2.2 Ocean Current Patterns 

The nature and origin of processes stmcturing the nearshore cunents in the vicinity of Diablo 

Canyon are fairly complex, reflecting dynamics of seasonal cunents, winds, and tidal cycles. The 

general cunent pattern near Diablo Canyon is composed of three cunents: the constant cunent, 

the smoothed cunent, and the residual cunent (Safaie 1986). The constant cunent has a period of 

greater than 30 d and results from large-scale, southward and northward flows related to the 

California and Davidson cunents, respectively. The smoothed cunent, with a period of 1-30 d. is 

primarily driven by wind; the residual cunent, with a period of less than 1 d, is controlled largely 

by both.tide fluctuation and wind. 

The following paragraphs discuss the mechanics ofthe constant and smoothed cunent 

components summarized in Safaie (1986). The residual cunent component was not discussed as 

completely in Safaie (1986), presumably because the magnitude and duration of this cunent is 

relatively minor compared to that ofthe constant and smoothed cunents. In addition to these 

regularly-occuning cunents, the mechanics of periodic El Nino and La Nina oceanographic 

events are described. Finally, the hydrology and water chemistry ofthe nearshore region of 

Diablo Canyon during the study period October 1996-June 1999 are summarized. 

In general, two major types of cunents exist off the coast of California: shore parallel and shore 

normal (perpendicular). The shore parallel currents include constant cunents: the southwardflowing California Cunent and the northward-flowing Davidson Cunent. The California Cunent 

originates from the clockwise North Pacific Gyre, which creates a southward flow along the 

western coast of North America. This cunent is present year-round along the California coast, 

but is typically displaced offshore by the northward flowing Davidson Cunent in the fall and 

winter. The Davidson Cunent is formed by a deeper-water, counter-clockwise gyre in the 

California Cunent present between Cape Mendocino (Mendocino County) and Point Conception 

(Santa Barbara County). The Davidson Cunent is sometimes refened to as the California 

Undercunent, particularly during the spring and summer when it is a deeper-water phenomenon. 

Ofthe two, the Davidson Cunent is weaker and more diffuse than the California Cunent. As 

such, cunent reversals can, and do, commonly occur during the winter. 

TENERA E9-055.0 3-4 Final 316(b) Demonstration 

March 1,2000 
P.51 

3.0 Background 

Smoothed cunents in the vicinity of Diablo Canyon (Safaie 1986) include shoreward and 

seaward cunents that originate from seasonal onshore and offshore winds, respectively. These 

seasonal, perpendicular cunents are of minor magnitude relative to the shore-parallel cunents, 

but their consequent downwelling and upwelling events are important to the nutrient cycling and 

productivity ofthe Diablo Canyon nearshore region. 

The California Cunent ecosystem is characterized by seasonally high levels of primary 

production when northwesterly winds predominate and cause coastal upwelling to occur, 

typically in the spring and summer of each year. Upwelling occurs because the northwesterly 

winds generate Ekman transport of surface waters due to the Coriolis Force, resulting in a net 

movement of surface waters perpendicular to the wind direction: to the right in the northern 

hemisphere and offshore relative to the California coast. 

3.2.3 El Nino Southern Oscillation and Ocean Water 

Temperatures 

The El Nino Southern Oscillation (ENSO) in the eastern Pacific Ocean typically consists ofa 

warm water El Nino phase followed by cooler water temperatures during a subsequent La Nina. 

However, the effects ofthe ENSO are not limited to ocean waters as they also affect the 

atmospheric/oceanic circulation (Rasmusson and Wallace 1983). Much ofthe interannual ocean 

variability on decadal and sub-decadal time scales can be attributed to El Nino events that have 

significant impacts on the global ocean's heat budget and ecosystems (Barber and Chavez 1986: 

Cane et al. 1986). Its global impacts (Rasmusson and Wallace 1983) are most apparent in the 

eastern Pacific (Barber and Chavez 1983) where the influence of El Nino can be detected from 

the southern tip of Chile to Alaska (Enfield and Allen 1980). It remains unclear whether the 

primary impacts ofthe ENSO anive via ocean or atmospheric circulation, but the fact remains 

that these impacts are significant in the coastal waters of Central California (e.g., Lenarz et al. 

1995; Chavez 1996; Schwing et al. 1997; Lynn et al. 1998). 

Moderate to weak La Nina conditions prevailed along the central California coast from 1995 

through early 1997 (Schwing et al. 1997) when one ofthe strongest El Niiio events recorded this 

TENERA E9-055.0 3-5 Final 316(b) Demonstration 

March 1,2000 
P.52 

3.0 Background 

century began to develop (Lynn et al. 1998). During the first year of field sampling conducted at 

DCPP (October 1996-September 1997), this weak La Nina may have, atypically, contributed to 

higher than normal sea surface temperatures (SST) observed off California and Mexico as the 

result of anomalous wind relaxation events (Schwing et al. 1997). The El Nino that had been 

developing in the westem tropical Pacific since early Spring 1997 anived along the coast of 

California in Fall 1997, bringing higher than normal SST and suppressing upwelling activity 

along the length ofthe coast. This El Nino event continued into the summer of 1998 (Lynn et al. 

1998) and was followed by another La Nina beginning in Fall 1998 and extending at least to the 

end ofthe field sampling operations at DCPP in June 1999. 

The continuing cycle of ENSO events has also had dramatic effects on the primary and 

secondary production ofthe California Cunent ecosystem. Primary production, measured as 

chlorophyll concentration, decreased during warmer El Nino years—1992 and 1997—and rose in 

the cooler La Nina years—1991 and 1995 (Chavez 1999). Total phytoplankton biomass 

demonstrated similar trends: declining in 1992 and 1997 and rising in 1995 when the average 

temperature was close to the climatological mean, 13.5°C. Chavez (1999) also notes that over the 

10-year period 1988-1998, SST have gradually risen while levels of nitrate, chlorophyll, primary 

production, and certain phytoplankters (e.g., centric diatoms) have declined, effectively reducing 

the overall productivity ofthe California Cunent ecosystem. The changes to the ecosystem at 

these fundamental levels may have dramatic consequences for the remainder ofthe ecosystem, 

which supports a diverse assemblage of marine birds, mammals, and fishes. Lynn et al. (1998) 

also notes that "mean macrozooplankton abundance during the spring of 1998 was the lowest in 

the 50-year CalCOFI time series," further confirming the findings of Chavez and MBARI. 

3.2.4 Ocean Currents and Temperatures during the Entrainment 

Study Period (October 1996 - June 1999) 

The DCPP 316(b) study period was characterized by a series of climatological and 

meteorological ENSO events (Table 3-1) that are known to have dramatic effects on ocean 

ecosystems, oceanic and atmospheric cunents, and on productivity in the California Cunent. 

TENERA E9-055.0 3-6 Final 316(b) Demonstration 

March 1,2000 
P.53 

3.0 Background 

Field sampling was initiated during an anomalously warm La Niiia event that occuned during the 

fall of 1996 and continued through the fall of 1997 (Schwing et al. 1997). In the fall of 1997, one 

ofthe strongest El Niiio events recorded this century occuned along the California coast and 

continued through the summer of 1998 (Lynn et al. 1998). The fall and winter of 1998-99 were 

subject to a more typical cold water La Nina phase that continued through the end of field 

sampling operations in June 1999. 

Data collected during the study period from the single cunent meter and meteorological 

observation station at DCPP showed that nearshore cunents were largely controlled by 

prevailing wind conditions (Figure 3-6). During those infrequent periods when wind speeds 

were negligible (i.e., less than 2 nautical miles per hour), longshore constant cunents 

predominated. 

Mean monthly water temperatures near DCPP during the study period October 1996 through 

June 1999 ranged from 17.5°C in November 1997 to 10.5°C in April 1999 (Figure 3-7). While 

maximum temperatures occuned at various times throughout the year (e.g., November 1997 and 

August/September 1998), annual temperature minimums were consistently present during the 

month of April. These temperature minimums generally conesponded to seasonal offshore winds 

and consequent coastal upwelling. The continuing influence ofthe ENSO throughout the study 

period may explain the inconsistent interannual timing of recorded maximum temperatures. 

Overall, nearshore seawater temperatures during the study period deviated appreciably from 

long-term patterns. The mean seawater temperature recorded for November 1997 was the 

warmest since records began in 1976 (Figure 3-7). This was rivaled only by temperatures 

recorded in the summer/fall of 1983 and 1984, another strong El Nino event. 

TENERA E9-055.0 3-7 Final 316(b) Demonstration 

March 1,2000 
P.54 

3.0 Background 

Table 3-1. Presence and relative magnitude of El Nino (W) and La Nina (C) events from 1996 

through 1999 in the tropical Pacific: relatively strong events are noted with (+), relatively weak 

events with (-), and C* denotes anomalously warm La Niiia conditions postulated by Schwing et 

al. (1997). Blank cell in 4* quarter of 1999 represents non-ENSO (= normal) period. Table 

combines data from Schwing et al. (1997) and the NOAA ensoyears.html page at www.noaa.gov. 

Year 

1996 

1997 

1998 

1999 

1" Quarter 

C* 

C* 

W+ 

c+ 

ryni 

c* 

w 

w 

c 

Quarter 3

rd

 Quarter 

C* 

W+ 

cc4

th

 Quarter 

C* 

W+ 

c 

TENERA E9-055.0 3-8 Final 316(b) Demonstration 

March 1,2000 
P.55 

3.0 Background 

124

 C W 120° W 116-W 

DIABLO CANYON 

POWER PLANT 

42* N 

3 8 ; N 

34=* N 

ESTERO 

BAY 

Point 

Buchon 

MORRO 

• BAY 

10 km 

DIABLO CANYON 

POWERPLANT 

PACIFIC 

OCEAN 

Ana of Detail AVLA 

BEACH 

Point San Luis 

Field's Cove 

Intertidal Zone 

DIABLO CANYON 

POWER PLANT 

Unit 2 

PACIFIC 

OCEAN 

rsi 

100 m 

Meteorological Tower 

Breakwaters W^.^^^J^. 4 

- ^ 

Patton Cove ••' 

Figure 3-1. Location of Diablo Canyon Power Plant. 

TENERA E9-055.0 3-9 Final 316(b) Demonstration 

March 1,2000 
P.56 

3.0 Background 

Traveling Water 

Screen 

.Intake Gate 

fia^ac^JQ-JLTM 

High Tide +3.2 - f • 

Low Tide -2.6" 

Flow 

Elev. - 31.5 TraMr 

P 

Circulating Water Pump 

(CWP) 

^sssizzir^^^m^^ 

8-12 diameter 

/

conduit to 

power plant 

10 20 30 40 50 60 

Scale in Feet 

Figure 3-2. Cross-section diagram of DCPP intake structure showing water flow path. 

Elevations are based on mean sea level (modified from PG&E 1988a). 

TENERA E9-055.0 3-10 Final 316(b) Demonstration 

March 1,2000 
H 

m 

z 

m 

73 

> 

m 

<P 

o 

in 

oi b 

2800 

2600 

2400 

2200 

O) 

E, 

o 

2000 

CO 

SL 

co 

2 O 

u 3> 

ai 

r* S2. 

M U 

O =*. 

o o 

O 3 

§ 1800 

3 

E 

tu 

1600 

1400 

1200 

1000 

PDT 

PDT 

ends 

/ 

V. "HW 

K \ 

U1 Force Outage 

Ground (use fire 

MC 1-1 CO 

22-30 Nov 96 

Bdays 

U1 P&D Shell 

4 Nov 96 

<1 day / 

y A 

Ut Cold reheat line repair 

11-13 Apr 97 

1 • dey 

_.--"^ U2 MFWP 2-1 trip 

due to dogged 

control filter and vlv 

29 Mar-4 Apr 97 

6 2 days 

' 

IfJ 

II 

/ 

r J 

U22- PS4 D Kelp Feb 98 

2 days 

/ 

U2 MSIV FCV-44 

closure 24-26 Oct 97 

2 days 

\K 

\ \ 

r \ \ / \ \ 

U2 MFWP loss of \ u2Manua , deanin g 

suction pressure \ 4 . 10Se p 9 7 

2-5 Jul 97 \ 5day , 

3 days \ 

\ 

U2 PSD SheOs 

17&24Aug97 

2 days 

_r 

P

° T Cooling water flow 

e n ^s

 standardized to average 

daily volume (May-Jun 99) 

. 

I 15 Aug 98 

0.7 days; 

4-6 Sep 98 

1.5days. , 

U1 Manual cleaning 

18-23 Sep 98 

5 days 

-*• 

' 

1 • \ • 

/ 

/ 

/ / 

U2 PSD Kelp 

28-29 Nov 98 

4.2 days 

I A 

U1 Man. Shutdown 

RCP Oil Cooler 

17-25 Dec 99 

U1 PSD Kelp 

1-5 Dec 98 

4.2 days 

and 

U2 Manual Shutdown 

1-6 Dec 98 

5 4 days 

1R8 Refueling Outage 2R8 Refueling Outage 

19 Apr-2Jun 97 14 Feb-28 Mar 98 

44 days 42 days 

1 — : i I 1 I 1 1 1 1 1 1 1 1 *• ' t 1 1 1 \ 1 1 — 

I fT 

—• 

' 

' 

\ 

A A 

1 U2 Manual cleaning 

\ 25-30 Apr 99 

1 5.8 days 

l 

U1 PSD Shell 

23-24 Mar 99 

0 5 days 

1R9 Refueling Outage 

7Feb-15Mar99 

35 days 

—i 1 1—i—i 1 i i-i 

Oct Nov Dec Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Jan Feb Mar Apr May Jun 

Figure 3-3. DCPP daily cooling water flow - October 1996-June 1999. 

w 

o 

00 

B> 

O 

TtJen 
P.58 

3.0 Background 

Figure 3-4. Unit 1 traveling screen assemblies photographed in 1985 during an impingement 

collection. 

Traveling Screen 

Housing 

Collection Basket 

(refuse sump below) 

TENERA E9-055.0 3-12 Final 316(b) Demonstration 

March 1, 2000 
P.59 

3.0 Background 

Depth Contours in 

10 Meter increments 

Figure 3-5. Bathymetry of nearshore region between Point Buchon and Point San Luis. 

TENERA E9-055.0 3-13 Final 316(b) Demonstration 

March 1,2000 
P.60 

3.0 Background 

Figure 3-6. DCPP wind and water current patterns October 1996 through June 1999. 

TENERA E9-055.0 3-14 Final 316(b) Demonstration 

March 1,2000 
3

.61 

3.0 Background 

a.) July 1976 - August 1999 

18.0 T 

17.0-• 

Graph expanded below in "b" 

10.0 

9.0

 J

 -

Sfc t ff RffS^S S 851 6 8 18 &-Sp 8? 8 8? S 5 S 8ffi5?SlfiifiS>S>8ffi8 

b.) October 1996 - June 1999 

18 i 

10 

Oi Oi Oi Oi Oi Oi 

Sr? -^ n i CD TJ 

o> <n o Oi o> cn cn cn 

m 

a 

Figure 3-7. Mean monthly seawater temperatures near DCPP. 

TENERA E9-055.0 3-15 Final 316(b) Demonstration 

March 1,2000 
P.62 

Blank Page 
P.63 

4.0 Methods 

4.0 METHODS 

The Environmental Protection Agency EPA guidance on Section 316(b) demonstrations 

recognizes that it is not practical to analyze the impacts on all organisms that may be entrained 

by cooling water intake operations (USEPA 1977). Generally only some groups or species of 

organisms in the vicinity ofa facility are targeted for collection and analysis. Target organisms 

are those having certain characteristics that make them suitable for detecting or forecasting 

impacts to an ecosystem under investigation (Cairns and Pratt 1989; Jones and Kaly 1996). 

4.1 Criteria for Selection of Target Organisms 

The initial criteria used to select appropriate target organisms at DCPP were developed by the 

Environmental Protection Agency (USEPA 1977). Discussions with the DCPP Entrainment 

Technical Working Group (ETWG) were instrumental in guiding the use ofthe criteria at DCPP. 

Meetings with the ETWG and other invited experts at theTiburon Impact Assessment Colloquia 

(October 1996 and October 1998) also helped refine these criteria for application at DCPP. 

USEPA guidance on 316(b) defines target organisms as those that meet at least one or more of 

the following criteria: 

1. representative, in terms of their biological requirements, ofa balanced, indigenous 

community offish, shellfish, and wildlife; 

2. commercially or recreationally valuable (e.g., among the top ten species landed—by 

dollar value); 

3. threatened or endangered; 

4. critical to the structure and function ofthe ecological system (i.e., habitat formers); 

5. potentially capable of becoming localized nuisance species; 

6. necessary, in the food chain, for the well-being of species determined in 1-4; and 

7. meeting criteria 1-6 with potential susceptibility to entrapment/impingement and/or 

entrainment. 

TENERA E9-055.0 4-1 Final 316(b) Demonstration 

March 1,2000 
P.64 

4.0 Methods 

The DCPP ETWG added three additional criteria for selecting target organisms for the 

entrainment study at DCPP: 

8. identifiable to die species level; 

9. entrained in sufficient abundance to allow for impact assessment, i.e. allowing the 

model(s) constraints to be met and confidence intervals to be calculated; and 

10. having local adult and larval populations (i.e., source not sink species). For example, 

northern lampfish {Stenobrachius leucopsarus), relatively abundant as entrained larvae, 

is a sink species because it is an offshore and deep water species whose larvae become 

widely separated from dieir viable environment and enter coastal waters. 

Target organisms meeting these criteria included larval fishes, larval Cancer spp. crabs, and 

larval sea urchin. The final list of target organism taxa (Table 4-1) was determined by the ETWG 

(May 1999) based mainly on the data collected during this study and the above listed criteria. 

Other potential target organism groups reviewed by the ETWG for possible inclusion in this 

study but subsequently rejected by the ETWG included kelp spores, fish eggs, abalone larvae, 

squid, and Pismo clams. The risk ofa significant impact on adult kelp populations by entrainment 

of kelp spores was determined to be negligible due to the large number of spores produced along 

the coast. Additionally, it is not possible to identify die species of kelp based on gametes or 

spores. Fish eggs were not included because they are difficult to identify and most ofthe taxa 

included in die final entrainment evaluation have egg stages diat are not likely to be entrained: 

they either have demersal/adhesive eggs or are internally fertilized and extrude free-swimming 

larvae. Abalone larvae were not included because they are at low risk from entrainment and 

cannot be effectively sampled or identified during early life stages when they would be 

susceptible to entrainment (Tenera 1997b). Young squid are also unlikely to be entrained because 

they are competent swimmers immediately after hatching. Pismo clam larvae were not included 

because there is no suitable substrate for settlement in the vicinity of DCPP, and the duration of 

their pelagic phase is too short to enable them to reach appropriate settling habitat in significant 

numbers after spawning in the Diablo Canyon region (Sandra Owen, CDF&G, Long Beach, CA, 

pers. comm.). 

TENERA E9-O55.0 4-2 Final 316(b) Demonstration 

March 1,2000 
P.65 

4.0 Methods 

4.2 Entrainment 

This section presents a summary ofthe sample collection and laboratory processing methods. A 

more detailed presentation ofthe entrainment and study grid collection methods can be found in 

• Appendix A—DCPP 316(b) Demonstration Study: Phase 1, Entrainment Study Design, I. 

Sampling Location 

• Appendix B—DCPP 316(b) Demonstration Study: Phase 1, Entrainment Study Design, 

II. Selection of Target Organisms, Sampling Methods, and Gear Testing 

• Appendix C—DCPP 316(b) Demonstration Study: Phase 3, Sampling Plan and 

Modelling Evaluation 

• Appendix D— DCPP 316(b) Entrainment Study, Field and Laboratory Procedures 

i 

Sea urchin larvae were originally chosen by the ETWG as a target organism, but laboratory 

experiments showed diat die early stages of larval urchins are small enough to be pass through 

the 335 um net mesh. The only urchin developmental stage that appeared to be effectively 

captured during sampling were metamorphosing and recently metamorphosed individuals. 

Therefore, the results of die entrainment sampling are presented for metamorphosing and recently 

metamorphosed sea urchins, but no assessment on die effects to die population is made based on 

agreement witii the ETWG. 

4.2.1 Sample Collection 

Entrainment and study grid sampling provided data for estimating entrainment abundances and 

abundances in the nearshore area defined by the study grid. The sampling plans were tailored to 

the methodology chosen for estimating future adult loss and population mortality. Three methods 

were chosen, developed fully in Section 4.4, and briefly described below. 

The estimate of entrainment loss and demographic data, collected from the scientific literature, 

was used to parameterize two demographic models of entrainment effects: Adult Equivalent Loss 

{AEL) and Fecundity Hindcasting {FH). The AEL method forecasts the number of adult survivors 

from the estimated number of entrained larvae, as if they had survived entrainment, using 

knowledge of mortality rates other than from entrainment by the power plant (i.e., natural 

TENERA E9-055.0 4-3 Final 316(b) Demonstration 

March 1.2000 
P.66 

4.0 Methods 

mortality). The FH method is similar except that the number of larvae entrained are hindcast to 

number of eggs, and the number of eggs is then used to estimate the number of female adults that 

would have produced them. A third method, the Empirical Transport Model {ETM), estimates an 

average annual larval mortality per individual due to entrainment, using estimates of Proportional 

Entrainment {PE), which compares the number of larvae entrained in one day to the number of 

available larvae in die source water body. A larval mortality is calculated after PE is weighted by 

an estimated fraction ofthe total population affected and compounded by the time larvae are 

susceptible to entrainment. The Phase 3 Sampling Plan (Table 2-1 in Tenera 1998a) describes the 

data required for AEL, FH, and PE. 

4.2.1.1 Entrainment Sampling 

Collection of die DCPP entrainment samples took place once per week from four permanently 

moored sampling stations located directly in front ofthe intake structure (Figures 4-1 and 4-2). 

Entrainment sampling occurred from October 1996 through June 1999, with details about the 

number of samples collected per survey presented in Appendix G. Surveys 01 and 02 were not 

processed because they were used to finalize sampling protocols and only 8 and 34 subsamples 

were collected, respectively. Therefore, the first complete survey was conducted on October 23, 

1996. The four fixed stations were sampled in a random order during each 3-hour survey cycle. 

Samples were collected over a 24-hour period from a boat moored approximately 10 m from the 

intake structure using a 0.71 m diameter bongo frame with two 1.8 m long, 335 urn white NitexTM 

mesh nets similar to the nets used by the California Cooperative Oceanic Fisheries Investigations 

(CalCOFI). The first 9 surveys were collected with 505 um, but due to possible extrusion of 

larval fishes observed in Surveys 8 and 9, subsequent surveys were collected with 335 um mesh 

(Tenera 1997b). Surveys 9 and 10 were completed on consecutive days, but only the data from 

Survey 10 was used in the analyses because samples were collected using the smaller mesh size. 

The bongo frame and nets were fished from the top to the bottom and back to the surface a total 

of eight times to filter approximately 40-50 m^ per net. At the surface, the net was turned as the 

upper portion ofthe frame hit the surface and was turned within approximately 13-25 cm ofthe 

bottom. The upward vertical lift speed ofthe nets was held constant at approximately 0.3 m/s 

TENERA E9-055.0 4-4 Final 316(b) Demonstration 

March 1,2000 
P.67 

4.0 Methods 

(~0.6 knots) using an electric winch. The downward speed ofthe nets (0.3-0.45 m/s) was 

determined primarily by gravity acting on the mass ofthe bongo frame and the drag resistance of 

the nets. Each 24-hour sample period was divided into eight 3-hour sampling cycles, with each 

station being sampled once per cycle. The sample contents of each net were initially preserved 

separately in either a solution of 5% buffered formalin or 70-80% ethanol. All samples were later 

transferred to ethanol before laboratory processing. A total of 64 subsamples (32 samples) was 

collected per day with a total of approximately 2,560-3,200 m-3 of water filtered per 24-hour 

survey period. 

4.2.1.2 Study Grid Sampling 

Sampling ofthe study grid was designed to provide the information on abundance and 

distribution of target organisms in the vicinity of DCPP diat is used in the ETM assessment. The 

data frorrt each study grid survey were paired with the corresponding entrainment survey to 

estimate an index of entrainment loss {PE): the ratio between the number of larvae entrained in 

one day to the number estimated in the study grid over a three day period. The boundaries and 

shape of die study grid were chosen based on the following criteria: 

• the grid would be large enough to characterize the larvae from the target groups 

potentially influenced by DCPP's cooling water intake operations, and 

• the grid would include a representative variety of local nearshore habitats. 

In establishing the study grid, the ETWG also considered that ocean currents in the area generally 

move both up and down the coast past DCPP. Currents also show inshore/offshore oscillations, 

but these occur less frequently and generally at a lower magnitude (Section 3.2.2). The study grid 

contained 64 cells in an eight cell by eight cell pattern (Figure 4-3) and was centered on the 

Intake Cove at DCPP. The northern extent ofthe grid was near Point Buchon and the southern 

half, a mirror image ofthe northern portion, extended to Point San Luis. The coastline between 

Point Buchon and Point San Luis makes a slight bend (approximately 20°) northward at DCPP. 

Tangents along the coastline from the tip ofthe west breakwater at DCPP defined the inshore 

margins ofthe study grid at 321° True (NW) and 121° True (ESE). The grid extends a distance of 

TENERA E9-055.0 4-5 Final 316(b) Demonstration 

March 1.2000 
P.68 

4.0 Methods 

8.7 km to both the north and south at an average distance of 3 km offshore. Lines dividing the 

study grid into eight partitions ran SSW (221° True) to a distance of 2.7 km offshore ofthe 

inshore margin. Regions inshore ofthe study grid dimensions were in shallow water with 

partially submerged rocks, making the areas unsafe for boat operations and sampling. 

The study grid was sampled monthly from July 1997 dirough June 1999. Two randomly 

positioned stations within each of die 64 cells ofthe grid were sampled using a 0.71 m diameter 

standard CalCOFI-style bongo frame with two 3.3 m long, 335 um white NitexTM mesh nets. The 

study grid was sampled continuously over 72 hours using a "ping-pong" transect to limit 

temporal and spatial biases in the sampling pattern and to optimize shipboard time (Figure 4-4). 

The starting ceil (constrained to the 28 cells on the perimeter ofthe grid) and the initial direction 

of die transect (constrained to die two cells diagonally, adjacent to the starting cell) were selected 

at random. When die adjacent diagonal cell had previously been sampled (e.g., cell Dl in 

Figure 4-4), one ofthe two adjacent cells in the direction of travel (El or E3) was randomly 

selected to be sampled next. 

Nets were fished in an oblique fashion following CalCOFI protocol (Smith and Richardson 

1977). The sampling depth was limited to within 3 m ofthe bottom depth to avoid damage or loss 

of sampling equipment and for safe operation of die vessel. Had larval fishes been concentrated 

in the 3 m near bottom, this sampling method would not detect them leading to underestimates of 

larval density that would increase estimates of PE. Two stations were sampled per grid cell with 

the station locations for each monthly survey being randomly-positioned, latitude/longitude 

coordinates within each cell. The random position of latitude and longitude for each grid cell 

station was generated using Microsoft ExcelTM macro code, designed to randomly select polar 

coordinates and to convert these coordinates to a Mercator Projection system used for 

navigational purposes. Latitude and longitude positions were located in the field using a 

MicrologicTM Global Positioning System (GPS) plotter. 

A total of 256 subsamples was collected during each 72-hr survey. At the end of each haul, the 

material collected in one bongo net was fixed in 5% buffered formalin for abundance and 

TENERA E9-055.0 4-6 Final 316(b) Demonstration 

March 1,2000 
P.69 

4.0 Methods 

composition analyses. The material in the second net was fixed in about 70-80% ethanol (ETOH) 

to be archived for possible future use in larval fish age and growth analyses. To minimize 

temporal variation between entrainment and study grid sampling, grid surveys were scheduled to 

bracket the 24-hour entrainment survey, overlapping by one day before and after the collection of 

entrainment samples. The paired sampling from July 1997 was an exception to this design, i.e. 

entrainment sampling occurred during the first 24 hours ofthe 72-hour grid survey. 

4.2.1.3 Intake Cove Surface Plankton Tow Sampling 

Weekly plankton samples were collected in the DCPP Intake Cove during the following periods: 

February 1990 dirough June 1990, January 1991 dirough June 1991, and then continuously from 

September 13, 1991 to the present. Three samples were collected at dawn once per week by 

towing a 0.5 m diameter, 335 um mesh standard plankton net in front of die intake structure to a 

location approximately even with die outer end ofthe west breakwater (Figure 4-5). The net was 

towed at a depth of about 1 m below the surface. Water flowing into the net was measured by a 

calibrated flowmeter. Approximately 40-50 m-3 of water was filtered per tow. The samples were 

preserved in 5% buffered formalin and later transferred to 80% etiianol. These samples were only 

processed for larval fishes. 

4.2.2 Laboratory Processing 

Laboratory sample processing procedures used during this study are presented in Appendix D. 

All larval fishes and the megalopal stages of Cancer spp. were sorted from either 32 or 64 

subsamples (four to eight per cycle) from each entrainment survey and from the formalinpreserved grid survey samples (two per cell). One ofthe two paired bongo nets represents a 

dependent subsample such that both to the paired nets comprise the complete sample or tow. The 

estimate ofthe mean larval density calculated after processing only 32 subsamples was on 

average similar to the estimate for all 64 subsamples (Tenera 1998b: Appendix E). All Cancer 

zoeal stages and juvenile urchins were sorted from one randomly selected entrainment sample 

from each ofthe 3-hour cycles, resulting in eight samples processed per sampling day. The zoea 

TENERA E9-055.0 4-7 Final 316(b) Demonstration 

March 1,2000 
J>.70 

4.0 Methods 

and urchins, sorted from the samples collected in the grid, were processed from one sample per 

cell for only two ofthe total number of surveys performed in the grid. 

Due to the large number of zoea and urchins, most samples were split before processing. Density 

estimates were calculated for each sample based on the number of individuals of each taxon and 

the volume of water filtered. For split samples, the density was mathematically adjusted for the 

level of splitting. For example, when a sample was divided into eight parts and one part was 

sorted, die number of each of die larval stages identified and enumerated was multiplied by eight 

to estimate die number in die sample. 

Not all ofthe target organism groups were sorted from all of die entrainment and grid survey 

samples, per agreement widi die ETWG (Figure 4-6). Larval fishes were sorted from weekly 

entrainment samples from surveys collected from October 1996 through September 1998 and 

from surveys diat paired with the grid surveys for the period of October 1998 through June 1999. 

Cancer crab megalops were sorted from entrainment samples collected from October 1996 

through June 1999. Cancer crab zoea and metamorphosing and recently metamorphosed sea 

urchins were sorted from entrainment surveys collected from December 1996 through June 1998. 

Samples during October and November 1996 were not sorted for zoea and urchins because these 

samples were collected with 505 um mesh nets and these organisms could possibly have been 

extruded through the mesh, resulting in underestimates of their density. These samples were used 

for larval fish and megalops because their generally larger size would lessen the chance of 

extrusion. Larval fishes and Cancer crab megalops were processed from two samples per cell 

during all of die grid surveys. As previously mentioned, Cancer crab zoea and metamorphosing 

and recently metamorphosed sea urchins were processed only from one sample per cell during 

surveys collected in March and April 1998. 

An on-site quality control program ensured that each ofthe sorters maintained a high level of 

accuracy in identifying target taxa in the samples. This program employed both on-site and offsite personnel to verify the identification and enumeration ofthe collected organisms. All data 

pertaining to the collection and laboratory processing of each ofthe samples were tracked using a 

TENERA E9-055.0 4-8 Final 316(b) Demonstration 

March 1,2000 
P.71 

4.0 Methods 

computer database. The procedures used in laboratory processing, identification, and quality 

control are included in Appendix D. 

A variety of general and specific references were used to identify the collected individuals. The 

larvae of several species in the DCPP area are at present poorly known or undescribed. Larvae 

for several taxa could only be identified into higher taxonomic categories, such as genus (e.g. 

Gibbonsia spp.) or family (e.g. Cottidae). Identification for larvae ofthe rockfishes (genus 

Sebastes) was especially troublesome. At least 72 species and 11 subgenera of rockfish live along 

the eastern Pacific coast of North America (Moreno 1993). Because of relatively recent 

speciation in this genus, many larval characteristics are shared over a wide range of species, 

making identification within this genus problematic (Moser et al. 1977; Moser and Ahlstrom 

1978; Baruskov 1981; Kendall and Lenarz 1987; Moreno 1990; Nishimoto in prep.). 

Identification of larval rockfish to die species level relies heavily on pigment patterns that change 

as the larvae develop. Currently, at least 5 of these 72 species can be reliably identified to the 

species level at larval developmental stages. They are the blue rockfish {Sebastes mystinus), 

shortbelly rockfish {S. jordani), cowcod {S. levis), bocaccio {S. paucispinis; Yoklavich et al. 

1996), and stripetail rockfish {S. saxicola; Laidig et al. 1995). Other species within this genus can 

only be resolved to broad sub-generic groupings based on pigment patterns (Nishimoto in prep.). 

Table 4-2 presents the rockfish pigment groups used in this study and the species reported in 

each group. 

Crab larvae also are sometimes difficult to separate to species. The first zoeal stage of brown 

rock crab (C. antennarius), yellow crab (C. anthonyi), and slender crab (C. gracilis) is similar in 

appearance; consequently, these species could not be separated at this stage. When these species 

metamorphose to the second zoeal stage, however, individual characteristics develop that allow 

their correct classification. Therefore, in calculating FH models for the two species of Cancer 

crabs, the proportion ofthe two species for zoeal stage II was assumed to be the same for the first 

zoeal stage. This ratio was used to estimate the numbers of zoeal stage I larvae for the two 

species. The species ofa few individual megalops and zoea could not be determined; therefore, 

identification of these individuals was left at the genus level, Cancer spp. 

TENERA E9-055.0 4-9 Final 316(b) Demonstration 

March 1,2000 
P.72 

4.0 Methods 

Lengths ofthe larval fish target taxa were measured using a computer imaging system. A quality 

assurance program for the operators ofthe system was conducted. Larvae from both entrainment 

and study grid samples were measured. 

4.3 Impingement 

An impingement study at DCPP was conducted from February 1985 through March 1986 to 

provide information on 

• taxonomic composition and abundance of impinged organisms 

• size of impinged fishes and selected macroinvertebrates 

• diel and seasonal patterns of impinged organisms, and 

• sex ratio and degree of gonadal maturity of selected impinged species. 

Impingement samples were collected once per week for a continuous 24-hr period. A requirement 

for sampling was that at least one ofthe two cooling water pumps (CWP) per unit be operating 

for the entire 24 hr. At times, collections were postponed because of equipment testing or 

maintenance that may have prevented the collection ofa complete 24-hr period. When possible, 

the sampling was re-scheduled for later die same week. Samples were not collected when kelp 

accumulation caused the collection baskets to overflow, potentially leading to a loss of organisms 

and inaccurate estimates of impingement rates. 

On a collection day, the traveling screens were rotated initially to ensure that they were clean 

before the sampling began. The troughs were also cleaned of all accumulated debris and 

organisms. The screens remained stationary for approximately 3.75 hr and then rotated and rinsed 

for 15 min. The impinged material was rinsed into the troughs and collected in metal baskets 

made of 0.635 cm steel mesh. All impinged material was removed from the baskets after each of 

these 4-hr periods (cycles), except during times of heavy kelp accumulation when the screens 

operated continuously. During continuous screen rotation the screen wash system was stopped, 

when possible, for 15 min per cycle to allow for the remova! ofthe samples from the baskets. The 

TENERA E9-055.0 4-10 Final 316(b) Demonstration 

March 1,2000 
P.73 

4.0 Methods 

impinged material from each unit was kept separate. All organisms were removed from the 

impinged material and returned to the laboratory for processing. A quality control program 

verified tiiat all organisms were removed during the sorting process. 

All fishes and selected invertebrates were identified to the lowest practical taxonomic category, 

counted, measured, and weighed. Invertebrates that were measured and weighed included 

caridean shrimps, decapod and pelagic red crabs, cephalopod molluscs, rock scallops, and sea 

urchins. All other invertebrates were recorded as either individual counts or as present and were 

not measured nor weighed. A quality control program ensured die accuracy ofthe data. 

It was assumed that all impinged organisms would not survive. Studies at other power plants 

where impingement losses are high normally combine impingement losses for a taxon with other 

projected adult losses from estimated entrainment. We did not combine impingement with 

estimates of projected entrainment losses because ofthe low impingement rate at DCPP and the 

time difference between the two studies. The results ofthe impingement study are included in the 

DCPP 316(b) Study Phase 3: Sampling Plan and Modelling Evaluation (Tenera, 1998a; 

Appendix C), and impingement mediodology is not described further. 

4.4 Description of Entrainment Analytical Methods 

The entrainment and study grid surveys were divided into annual periods for analysis 

(Figure 4-6). The entrainment surveys were divided into three analysis periods: 

• Period 1—October 23, 1996 through September 30, 1997 

• Period 2—October 1, 1997 through September 30, 1998 

• Period 3—July 1, 1997 through June 30, 1998 

Data for Period 3 were previously analyzed by Tenera (1999b), Preliminary Assessment of 

Entrainment Effects on Target Fish and Crab Taxa (July 1, 1997-June 30, 1998). Analysis Period 

3 overlaps Periods 1 and 2. It is presented here as the entrainment data for this time interval is 

used in the calculation of PE which is used in the ETM, which allows a comparison ofFH, AEL 

TENERA E9-055.0 4-11 Final 316(b) Demonstration 

March 1,2000 
P.74 

4.0 Methods 

and ETM calculations for the same 12 month time interval. Analysis for zoea for Period 1 was 

adjusted to December 1, 1996 through November 30,1997 because the samples from October 

and November 1996 were collected with a larger mesh net and not analyzed for crab larvae. 

Larval densities from samples collected during Periods 1,2, and 3 were used to calculate the total 

number of larvae entrained and project adult losses using FH and AEL methodology. The grid 

surveys were divided into two analysis periods for the purpose of providing two annual estimates 

of larval mortality based on the ETM mediodology. The monthly grid and paired entrainment 

surveys for diese 2 analysis periods are as follows: 

• Period 3—July 1, 1997 through June 30, 1998 

• Period 4—July 1, 1998 through June 30,1999 

The Intake Cove surface plankton tows were processed only for die consecutive seven month 

period of December dirough June, per agreement with the ETWG (Figure 4-6), as the peak in 

larval ichthyoplankton is generally during diese months. These samples were processed only for 

larval fishes. These data were used to adjust the number of larvae entrained during a year to a 

long-term average that was more likely to represent average effects. 

4.4.1 Total Annual Entrainment 

The density of each ofthe target organisms in die entrainment samples was used to estimate the 

total annual larval entrainment for each taxa {ET ). Daily entrainment estimates and their 

variances were derived from the mean density of larvae (number of larvae per cubic meter of 

water filtered) and calculated from the 32 samples collected during each 24-hr entrainment 

survey, using the methods described in the Phase 3 report (Tenera 1998a). In the few instances 

where the measured volumes in each paired net differed by more than 20%, the higher value was 

used under the assumption that one ofthe paired flowmeters had slowed due to kelp fouling, 

improper lubrication, or misalignment. Density estimates were multiplied by the DCPP daily 

intake flow volume to obtain the number of larvae entrained per day. The daily intake flow 

volume was calculated by multiplying the number of hours of operation of each ofthe pumps by 

TENERA E9-055.0 4-12 Final 316(b) Demonstration 

March 1,2000 
P.75 

4.0 Methods 

their rated design flow rate. One hundred percent mortality was assumed for all entrained 

organisms. To estimate weekly entrainment, the number of days that each sampling event 

represented was determined by setting the sampling date at the mid-point between sample 

collections. The daily cooling water intake volumes were then used to calculate entrainment for 

the period by summing the product ofthe entrainment estimates and the daily intake volumes for 

each approximate weekly period. These weekly estimates and their associated variances were 

then added to obtain annual estimates of entrainment and variance for each taxa. 

The annual estimate of entrainment {ET ) was calculated by adding a weekly entrainment 

estimate that was the daily entrainment estimate multiplied by the weekly volume of intake 

cooling water: 

*-m (D 

where 

v. = intake volume on die survey day ofthe /th weekly period (/'=1 ,...,52) 

Vt = total intake volume for the /'th weekly period (/=1,...,52) 

E, = the estimate of daily entrainment during die entrainment survey ofthe /th weekly period. 

The variance of ET was estimated as 

.— ^ A(VA Var{ET) = Z 

\

v

iJ 

Var{Ei), (2 ) 

using the sampling variances of entrainment on the survey day ofthe /'th weekly period, Var^). 

Equation 2 will underestimate the true variance because it does not incorporate the variance 

associated with the within-week ratio estimator 

TENERA E9-055.0 4-13 Final 316(b) Demonstration 

March 1,2000 
P.76 

4.0 Methods 

where ET is the estimated total entrainment for the /th week. It also does not incorporate daily 

variations in intake flow due to waves, tide, and other factors not measured by the power plant. 

As recommended by the ETWG, the estimates of annual entrainment were scaled to better 

represent long-term trends for a taxa by using data from Intake Cove surface plankton tows 

collected at DCPP, starting in 1990. These data provide an index of annual trends in larval 

abundance for the period of 1990-1998. This multi-year annualized index consists of five months 

(February-June) of larval fish density estimates in 1990, six months (January-June) in 1991, and 

seven months (December-June) in all subsequent years. The estimated annual entrainment was 

adjusted to die long-term average by the equation 

r 

(3) 

£"*- r=£r ' U, 

where 

P-AJJ-T ~ adjusted estimate of total annual entrainment to a long-term average, 1990—1998, 

/; = index value from DCPP Intake Cove surface plankton tows in the /'th year, and 

/ = average index value from DCPP Intake Cove surface plankton tows, 1990— 1998. 

The variance for adjusted annual entrainment can then be expressed as 

fcr{EAdJ_T) = Var{rT)-(J\* 

h) (4) 

assuming the indices are sampled without error. Ignoring the sampling error ofthe indices will 

underestimate the true variance, but Equation 4 will account for the change in scale associated 

with multiplying the annual entrainment estimate by a scalar. The variance ofEMj_T, however, 

does not take into account the between-day, within-stratum variance, interannual variation, nor 

the variance associated with the indices used in the adjustment. Hence, the actual variance ofthe 

PAIIJ-T estimate is greater than the value expressed above. 

The Intake Cove surface tow index was assumed to have the relationship 

TENERA E9-O55.0 4-14 Final 316(b) Demonstration 

March 1,2000 
P.77 

4.0 Methods 

P{Ii) = CEi 

where 

£(/;) = expected value ofthe index for the /'th year, 

E, = entrainment for the /th year, and 

C = proportionality coefficient. 

Ifthis relationship holds true, then the interannual variance in the index has the relationship 

Var{Ii) = C2Var{Ei). 

Therefore, the coefficients of variation (CV) for / and E across n years have the relationship 

Var{I) \C2Var{E) 

CV(I) = 1-Jl— = 1 ». = CV{E). 

Hence, the CV for the Intake Cove surface tow index should be a measure ofthe CV for 

entrainment across years. In the case of estimates of Et and /,., the variances include sampling 

errors that may not be equal. Therefore, die CV of / was used to express the possible variation 

in entrainment across years. 

The use of adjusted entrainment in the FH and AEL models provides results that represent 

average long-term effects. The CV for / was used in propagating the variances ofthe 

entrainment effects and calculating the ranges of possible values for FH and AEL in sensitivity 

analyses. Sensitivity analyses were used to examine the effects of different input parameters on 

model results. 

Adjusted entrainment values were not used in calculating ETM results because the computation 

of ETM relies on a proportional entrainment {PE) ratio using estimates from paired entrainment 

and nearshore larval sampling. Moreover, ifthe assumptions ofthe ETM are valid, then the 

estimate already represents average long-term entrainment effects. Using adjusted entrainment in 

the FH and AEL models provides a better basis to compare results from all three models when 

TENERA E9-055.0 4-15 Final 316(b) Demonstration 

March 1,2000 
P.78 

4.0 Methods 

they are converted into a common currency through the use of population or fishery stock 

assessments. 

The length frequency distributions for the measured larvae from the paired entrainment and study 

grid surveys were tested for differences using a Kolmogorov-Smirnov 2 sample test (Zar 1984). 

Large differences between the two distributions may indicate diat the age distribution of 

entrained larvae is significantly different from the source population in the study grid. The mean 

larval lengths from die two distributions were tested for differences using a two-sample /-test. 

When variances were unequal between the two groups, Satterthwaite-adjusted degrees of 

freedom were used in the test (SAS Institute 1990). The statistical power of these tests to detect 

very small differences between the two groups will be very high because ofthe large sample 

sizes (Zar 1984). 

4.4.2 Fecundity Hindcasting (FH) 

The FH approach combines larval entrainment losses with adult fecundity to estimate the amount 

of adult female reproductive output eliminated by entrainment, assuming no compensatory 

reserve of die population. The loss of reproductive output (i.e., numbers of larvae) was used to 

hindcast the numbers of adult females possibly removed from die reproductively active 

population. These FH estimates require data on age-specific mortality from the egg and early 

larval stages up to entrainment. The fact that FH requires survivorship from a relatively short 

period of time (i.e., egg to larva) is an advantage of this approach. Fecundity and mortality from 

sources other than entrainment are integrated into an estimate of loss by converting the estimated 

number of entrained larvae backwards to reproductively active females (i.e., hindcasting). FH 

does not require additional sampling other than from the entrainment intake water, for estimates 

of larval abundance. These advantages may be offset by the need to (1) obtain or model agespecific mortality rates and total lifetime fecundities to predict the adult losses, and (2) secure 

information on the size ofthe adult population of interest to estimate population-level effects 

(i.e., relative losses). Therefore, the method was only used for those taxa where the minimal data 

of item (1), above, were available. With the broad generalization of ignoring any population 

TENERA E9-055.0 4-16 Final 316(b) Demonstration 

March 1,2000 
P.79 

4.0 Methods 

reserve (compensation), entrainment losses can be interpreted as population level impacts when 

FH estimates are applied as direct losses to an inferred population. 

4.4.2.1 Formulation 

The estimated total larval entrainment for a species {ET ) was used to estimate the number of 

breeding females needed to produce the number of larvae entrained. The estimated number of 

breeding females {FH) whose fecundity was equal to the estimated total loss of entrained larvae 

is calculated as follows: 

.—~ i " E 

FH = -LZ— 

PT '"

 S' (5) 

where 

w = number of weeks the larvae are vulnerable to entrainment, 

ETj = estimated total entrainment for the z'thweekly survey period (/' = 1,..., w), 

St = survival rate from eggs to larvae of the stage present in the /th weekly survey period, and 

Fr = average total life time fecundity for females, equivalent to the average numberof 

eggs spawned per female over their reproductive years. 

Equation 5 is based on die simplified case ofa single synchronized spawning by a species. For 

species with overlapping or continuous spawning, larval abundance would have to be specified 

by week and age class (i.e., Ey). However, we used the mean size of all larvae entrained at 

DCPP to estimate a representative age of larvae, and then estimated a survival rate to this 

representative age. Two input parameters in Equation 5 that may not be available for many 

species, and thus may limit the method, are average fecundity {FT ) and survival rates (5,) from 

spawning to entrainment. 

Larval age (duration from release or hatching to entrainment), needed for estimating survival, 

was calculated from growth rates and the minimum and mean size at entrainment. Estimates of 

growth rate appear in Table 4-3, and their use in survival estimation is discussed further when 

applied to specific taxa. 

TENERA E9-055.0 4-17 Final 316(b) Demonstration 

March 1,2000 
P.80 

4.0 Methods 

Adjusted annual entrainment can be incorporated in the FH method (Equation 5), assuming that 

average rates of survival are the same among years and study periods: 

FH= EMJ-

T 

(6) III * 

) - • 

where 

Sy age specific survival of eggs and larvae for they'tii age class (j = 1,..., n) and 

FT = expected number of eggs produced in a reproductive lifetime. 

In practice, survival was estimated by either one or several age classes, depending on the data 

source, to die estimated age at entrainment. The expected total lifetime fecundity FT was 

approximated by the expression 

FT = Average eggs/year • Average number of years of reproductive life 

= Average eggs/year 

Longevity - Age at maturation ^ (7) 

2 y 

The expected lengtii of reproductive life was approximated as die midpoint between tiie times of 

maturation and longevity. This approximation was based on the assumption ofa linear 

survivorship curve between these events (i.e., uniform survival). For exploited species such as 

northern anchovy and sardine, the expected number of years of reproductive life may be much 

less than predicted using this assumption. Therefore, the estimated longevity was based on the 

oldest observed individual caught by the fishery, rather than by tiie oldest recorded fish. 

Simulation, comparing exponential survival, shows that the calculation of FT will be negatively 

biased for species with short reproductive lifespans, and positively biased for those with longer 

durations. 

The variance of FH was approximated by the Delta method (Seber 1982): 

TENERA E9-055.0 4-18 Final 316(b) Demonstration 

March 1,2000 
P.81 

4.0 Methods 

Var{FH) = {FHf cv><t„)+Ypr«t?l)+cv"<n+-~{

*

)

*—^yi 

>=i (A-A,r 

where 

CW{EAdj_T)= CV of adjusted estimated entrainment (estimated by CV(I) when available), 

CV{Sj) = CV of estimated survival of eggs and larvae up to entrainment, 

CV(F) = CV of estimated average annual fecundity, 

AM = age at maturation, and 

AL = age at maturity. 

The behavior of estimator 7 for FH appears log-linear, suggesting that an approximate confidence 

interval can be based on die assumptions that \n{FH ) is normally distributed and uses the pivotal 

quantity 

z

 \nFH-\nFH 

\Var(FH) 

V FH2 

A 90% confidence interval for FHwas estimated by solving for FH and setting Z equal to 

+/-1.645, i.e. 

1645 ^ ^ VarlFH) 

FHe »

 F":

 to FHe » TM2 . 

4.4.2.2 Sensitivity Analysis 

In addition to calculating a confidence interval, a sensitivity analysis was performed where FH 

was recomputed by varying each input parameter {0) and using an additive error model for the 

entrainment parameter (£7 0r PMJ-T ) °f -^ -^^ SE{9) and using a multiplicative error model 

for the remaining parameters. The CV for / (i.e. the average surface tow index across years) was 

used in propagating the variances ofthe adjusted entrainment estimate for calculating the ranges 

of possible values for FH in the sensitivity analyses. An assumed CV of 1.0 (100%) was used in 

TENERA E9-055.0 4-19 Final 316(b) Demonstration 

March 1,2000 
P.82 

4.0 Methods 

calculating the other parameter estimates as Be * . This approach helps to identify how the 

parameters' variability influences FH. In addition, the following constraints to the modified 

parameter estimates were applied to assure reasonable ranges: 

• Survival <, 1 

• Age at maturity > one-half the original estimate of age at maturity 

• Age at maturity < the age halfway between the original estimates of age at maturity and 

longevity 

• Longevity > the age halfway between the original estimates of age at maturity and 

longevity 

• Longevity < twice the original estimated longevity 

4.4.2.3 Assumptions 

Fecundity hindcasting calculations assume the following: 

• Values of parameters from the literature represent the population parameters for die years 

and location ofthe Diablo Canyon study. 

• No population reserve or compensation counters entrainment mortality. 

• Reported values of egg mass are lifetime averages in order to calculate an unbiased 

estimate of lifetime fecundity. 

• Reproductive life expectancy can be accurately calculated by assuming that time of death 

is uniformly distributed between age-at-maturation and age-of-longevity. 

• Juvenile and egg survival rates are constant over time. 

• The loss ofthe reproductive potential of one female is equivalent to the loss of an adult 

female. 

4.4.3 Adult Equivalent Loss {AEL) 

The AEL approach uses estimates ofthe abundance of entrained or impinged organisms to 

forecast the loss of equivalent numbers of adults. The approach requires survival estimates (had 

the larvae not been entrained) from entrainment to an age at recruitment to the adult population. 

This model and the FH model both translate larval entrainment mortality into adult fish losses, 

which are familiar units to resource managers. Although AEL methodology does not require 

estimates of larval abundance in water volumes other than at the power plant intake, this 

advantage may be offset by (1) the need to obtain or model age-specific survival rates to predict 

TENERA E9-055.0 4-20 Final 316(b) Demonstration 

March 1.2000 
4.0 Methods 

the adult equivalent losses and by (2) the need for information on the size ofthe adult population 

of interest to estimate relative population effects. Similar to FH methodology, with an assumption 

that any population reserve (compensation) that could account for the entrainment loss is lacking, 

entrainment losses yield population level impacts when AEL estimates are interpreted as direct 

losses to an inferred population. 

4.4.3.1 Formulation 

Starting with the number of age classy larvae entrained {E}), it is conceptually easy to convert 

these numbers to an equivalent number of adults lost {AEL ) at some specified age class from the 

formula: 

AEL^EJSJ (8) 

where 

n = number of age classes, 

Ej = estimated number of larvae lost in ageclass j , and 

Sj = survival rate for the jth age class to adulthood (Goodyear 1978). 

Age-specific survival rates from larval stage to recruitment into the fishery (through juvenile and 

early adult stages) must be included in this assessment method. For some commercial species, 

survival rates are known for adults in the fishery; but for most species, age-specific larval 

survivorship has not been well described. 

When age-specific survival rates from larval stage to recruitment into the fishery were available, 

AEL was calculated using survival from a representative age ofthe entrained larvae at DCPP. 

This age was calculated by dividing the average larval length at entrainment (minus hatch length) 

by a literature-based growth rate (Table 4-3). Age-specific survivorship for any interval of time 

(t) was then calculated following the formula (Ricker 1975) 

TENERA E9-055.0 4-21 Final 316(b) Demonstration 

March 1,2000 
P.84 

4.0 Methods 

!L-e-* 

where 

N, = number of animals in the population at time /, 

N0 = number of animals in the population at time / = 0, 

N 

—-.= S (finite survivorship to time /), 

/*o 

e- 2.71828. ..(base ofthe natural log), and 

Z = instantaneous mortality rate. 

Survivorship to recruitment, to an adult age, was apportioned into several age stages, and AEL 

was calculated using die adjusted entrainment as 

AEL = P^-rilSj (9) 

where / n \ ^ 

.J A' 

n = number of age classes from entrainment to recruitment and 

Sj = survival rate from the beginning to end of the jth age class. 

The variance of AEL can be estimated using a Taylor series approximation (Delta method of 

Seber 1982) as 

Var{AEL) = AEL CK2(£„,._r) + £CK2(S,.) . (10) 

v >" ) 

An alternative analysis would be to compare AEL with the size ofthe adult population of interest 

or with fishery harvest data. This method converts numbers of adult losses into fractional loss of 

the population of interest (e.g., stock assessment). However, information describing adult stocks 

is limited for many species, and independent field estimates of survival from time of entrainment 

to adulthood are not available for some species. For some species where such information is 

unavailable, we can estimate this parameter by assuming a stationary population where an adult 

TENERA E9-055.0 4-22 Final 316(b) Demonstration 

March 1,2000 
4.0 Methods 

female must produce two adults (i.e., one male and one female). Overall survival {ST) can then 

be estimated from total lifetime fecundity {FT) by the quantity 

*?" — ----— ^ • ^ • £ 

J

r~i ^ ~ egg ^larvae ^aituln 

PT 

which leads to 

PTS^-S^ (11) 

Substituting Equation 11 into the overall form ofthe AEL equation where 

AEL = EAdJ_T-Sadull 

yields 

^ _

 2(P*J-T) 

(12) 

AEL = 

O egg ' O larva * r T 

where 

AELm2FH. (13) 

Without independent adult survival rates and assuming a 50:50 sex ratio, AEL and FH are 

deterministically related according to Equation 13, with an associated standard error of 

SE{AEL) = 2SE{FH). Equation 13 should be aligned so that the average female age is also the 

age of recruitment used in computing AEL. This alignment is accomplished by solving the 

simple exponential survival equation (Ricker 1975) 

N,=Nn-eZ(-^ 'o 

by substituting numbers of either equivalent adults or hindcast females, their associated ages, and 

mortality rates into the equation where, 

TENERA E9-055.0 4-23 Final 316(b) Demonstration 

March 1,2000 
P.86 

4.0 Methods 

N, = number of adults at time /, 

A^ = number of adults at time /„, 

Z= instantaneous rate of natural mortality, and 

/ = age of hindcast animals {FH) or extrapolated age of animals {AEL). 

This allows for the alignment of ages in either direction such that 2FH = AEL since they are 

either hindcast or extrapolated to the same age. 

The estimates of mortality calculated from the AEL and FH approaches can be compared for the 

same time periods for taxa where independent estimates are available for (1) survival from 

entrainment to recruitment into the fishery and (2) entrainment back to hatching. These 

comparisons serve as a method of cross-validation for the demographic approaches to impact 

assessment. 

4.4.3.2 Sensitivity Analysis 

A sensitivity analysis for AEL was computed in order to identify which parameters' estimates 

could be improved to increase the reliability ofthe estimate of adult losses. The analysis varied 

each input parameter {&), using (1) an additive error model for the entrainment parameter {ET 

or PAOJ-T ) ^y ±1.645££(0) and (2) a multiplicative error model {Oe w ) for survival 

parameters. These survival estimates used an assumed CK of 1.0 (100%) and were constrained < 

1. When estimates of survival to adult are unavailable, the sensitivity analysis performed for FH 

was applicable. The CVfor I was used in propagating the variances ofthe adjusted entrainment 

estimate for calculating the ranges of possible values for AEL in the sensitivity analyses. This 

approach helps to identify how a parameter's variability influences AEL. 

4.4.3.3 Assumptions 

Calculations of AEL using data on survivorship from entrainment to recruitment into the fishery 

assume the following: 

• Values in the literature on life history parameters represent the fish population in the 

years and location ofthe Diablo Canyon study. 

TENERA E9-055.0 4-24 Final 316(b) Demonstration 

March 1,2000 
P.87 

4.0 Methods 

• If survivorship values from the literature are limited to single observations, values are 

assumed constant over time or representative ofthe mean. 

• No population reserve or compensation counters entrainment mortality. 

• Survival rates used in the calculations represent the life stage ofthe larvae or fish. 

In some cases, survival rates estimated for a similar fish species were used. Should survivorship 

data from one species be substituted for another, there is the additional assumption that: 

• Values of survivorship for the two species are the same. 

For fish species where larval survival data are missing, expected survival could be estimated 

from fecundity and juvenile and adult survival data. However, in those cases where fecundity 

data were available, we did not have juvenile and adult survival estimates. To use fecundity data 

in calculating survival rates, there is the additional assumption that 

• The fish population is stationary in size such that each adult female contributes two new 

offspring to the population of adults during its lifetime. 

4.4.4 Empirical Transport Model (ETM) 

The ETM estimates the total annual probability of mortality {PM ) associated with entrainment 

and requires an estimate of proportional entrainment {PE) as an input. Proportional entrainment 

estimates daily mortality imposed by DCPP on local larval populations (i.e., in the study grid), 

assuming no other types of mortality exist. In this context, PE is called conditional mortality 

(Ricker 1975). PE was calculated using the ratio based on intake samples and study grid samples. 

In previous entrainment studies using the £7Mmethod, intake densities were assumed from 

weighted population concentrations (Boreman et al. 1981). The PE index is used in the ETM to 

estimate mortality rates resulting from cooling water withdrawals. As proposed by the U.S. Fish 

and Wildlife Service (Boreman et al. 1978, 1981), ETMhas been used to assess entrainment 

effects at the Salem Nuclear Generating Station in Delaware Bay, New Jersey and at other power 

stations along the east coast ofthe United States (Boreman et al. 1978, 1981; PSE&G 1993). 

Variations of this model have been discussed in MacCall et al. (1983) and used to assess impacts 

at the San Onofre Nuclear Generating Station (SONGS; Parker and DeMartini 1989). 

TENERA E9-055.0 4-25 Final 316(b) Demonstration 

March 1,2000 
P.88 

4.0 Methods 

The ETM estimates annual, conditional mortality due to entrainment, while accounting for the 

spatial and temporal variability in distribution and vulnerability of each life stage to cooling water 

withdrawals. The generalized form ofthe ETM incorporates many time-, space-, and age-specific 

estimates of mortality as well as information regarding spawning periodicity and larval duration. 

Most of this information is limited or unknown for the taxa being investigated at DCPP. Thus, the 

applicability ofthe ETMto the study at DCPP will be limited by die absence of empirically 

derived or reported demographic parameters needed as input to the model. Specifically, the 

length of time a larva is susceptible to entrainment must be estimated. However, die concept of 

summarizing PE over time with tiie ETM can be used to estimate entrainment effects over 

appropriate temporal scales, either by modeling or making assumptions about species-specific 

life histories. At DCPP, we employ a PE approach similar to the metiiod described by MacCall et 

al. (1983) and used by Murdoch et al. (1989) in (Parker and DeMartini 1989) their final Marine 

Review Committee (MRC) report to the California Coastal Commission for SONGS. The annual 

estimate of ETM is formed from the weighted average of 12 approximately monthly surveys 

which pair entrainment and study grid larval samples. 

4.4.4.1 Formulation of PE and ETM 

The general equation to estimate PE for a day on which entrainment was sampled is as follows: 

PE = -=& 

where 

N^ = estimated number of larvae entrained during the day, calculated as 

(estimated density of larvae inthe water entrained that day)x (design specified 

daily cooling water intake volume), 

Nc = estimated number of larvae in the study grid that day, calculated as 

64 

V [(estimated average density of larvae per cell)- (cell volume)] fori = 1,..., 64 grid cells 

TENERA E9-055.0 4-26 Final 316(b) Demonstration 

March 1,2000 
P.89 

4.0 Methods 

where the estimated cell densities are obtained from the 72-hour grid survey that contains the 24-

hour entrainment sampling period. 

The PE estimate for days when grid surveys were not done is the estimate for the nearest day to 

the monthly survey. In addition, an adjustment was made to the estimated number of larvae in the 

row 1 cells ofthe study grid to help compensate for the inability to safely collect samples inshore 

ofthe grid (Figure 4-3). The estimated volume ofthe water directly inshore ofthe study grid was 

multiplied by the density of larvae collected in the row 1 cells, except for cells A1, Dl, and El. 

Cell Al is more offshore than the rest ofthe cells in row 1, due to the bend in the coastline at 

Point Buchon. An adjustment was not done for the volume of water inshore of cell Al because a 

substantial volume would be added and the composition and abundance sampled in cell Al would 

not adequately represent inshore volumes. Columns D and E are directly offshore from the Intake 

Cove where entrainment samples were collected. The density estimate from entrainment 

sampling was used for the areas inshore of cells Dl and El. This estimated number of larvae 

inshore ofthe grid was added to the grid abundance number estimated for the cells in row 1 

before PE and ETM calculations were done. 

The ETWG recommended using entrainment samples in adjusting only the volumes inshore of 

cells Dl and El. The estimated number of larvae inshore ofthe grid cells Dl and El was 

somewhat larger than the estimated entrainment numbers used in PE because the sum of water 

volumes inshore of Dl and El (4.90 and 5.95 million m-3, respectively) is slightly greater than the 

daily flow through the power plant (9.60 million m^). However, the estimated entrainment 

density could be used to represent the remaining inshore volumes (total inshore volume excluding 

Al is 38.2 million m-3), in which case the PE value (and therefore estimated mortality) would 

decrease especially for those nearshore species not found commonly in the study grid. While not 

appropriate for taxa with larvae dispersed throughout the study grid, an adjustment to the 

unsampled inshore volumes may be reasonable for some nearshore species whose larvae are 

potentially more abundant closer to shore. 

TENERA E9-055.0 4-27 Final 316(b) Demonstration 

March 1,2000 
P.90 

4.0 Methods 

The PE value represents the effects ofa number of processes operating over a day and is 

estimated in two year groups, each year having 12 approximately monthly surveys. Proportional 

entrainment was calculated for the 12 paired nearshore study grid and entrainment surveys 

conducted between July 1, 1997 and June 30, 1998, and for another 12 pairs from July 1, 1998 to 

June 30, 1999. To estimate specific PE ratios, each 24-hour entrainment abundance estimate was 

temporally paired with the abundance estimate from the 72-hour nearshore grid survey. 

The purpose ofthe DCPP study is to estimate entrainment effects within the study grid and 

attempt to extrapolate those effects to a population of inference. Boreman et al. (1981) point out 

that if any members ofthe population are located outside the study grid area, then the ETM will 

overestimate the conditional entrainment mortality for the entire population. In their study of 

entrainment by SONGS, Parker and DeMartini (1989) incorporated the inference population 

(which was an extrapolation to the entire Southern California Bight, an area extending about 500 

km) directly into their estimate of PE. In the following ETM analyses, PE is multiplied by the 

fraction ofthe population in the study grid area. Let Ps = (number of larvae at risk in the study 

grid) / (number of larvae in the population of inference). The fraction of larva being entrained 

from the population of inference on a given day is then the product 

PErP5. 

The boundaries ofthe population affected by entrainment could vary from local (e.g., a subarea 

ofthe study grid) to regional (e.g., fishery management units, zoogeographic range). For some 

species the area ofthe study grid may represent the population of inference and, in these cases, 

Ps = 1. For other species, the population of inference will likely be larger than the study grid. In 

fact, the population of inference depends both on the species and on what appeals usefully to 

intuition. Therefore, ETM is computed over a range of values of Ps for each ofthe target taxa. 

The curves from these functions can be used to determine the ETM at any value of Ps . The 

curves can also be interpreted as a continuous probability function representing the risk of 

entrainment to the larvae at different values of Ps . This representation replaces the need for 

sensitivity analysis for PM to the population of inference implied by Ps . Several approaches will 

be used to define the proportion ofthe population of inference for the different taxa groups. 

TENERA E9-055.0 4-28 Final 316(b) Demonstration 

March 1,2000 
P.91 

| 

s 

i 

i 

i 

i 

i 

4.0 Methods. 

These point estimates of Ps (and their ranges) will also be represented on the curves for each of 

the target taxa. This representation ofthe population at risk is more biologically meaningful than 

sensitivity analyses using confidence intervals around a single estimate of PM . 

If larval entrainment mortality is constant throughout the period and a larva is susceptible to 

entrainment over d days, then the proportion of larvae that escape entrainment in survey /' is: 

{\-PErPs)

d

. 

Larval duration from hatching to entrainment was calculated from growth rates using either the 

mean or maximum size at entrainment. The value for d was computed by dividing an estimate of 

growth rate into the change in length based on either the mean or maximum size at entrainment 

(Tables 4-3 and 4-4). Although the maximum larval size produces the longest duration of 

jfj susceptibility, larval entrainment probabilities may be age dependent. The mean size is used to 

illustrate the sensitivity of die estimate of population-wide mortality to larval duration of 

susceptibility. The mean length of target taxa larvae from all entrainment samples was calculated, 

,-jjp and length-frequency histograms were used to determine the central 98% ofthe distribution. The 

A minimum and maximum sizes used for analyses were determined after removing the largest and 

smallest 1% ofthe values. This procedure helped account for 1) outliers that were the result of 

larger post-larval fishes, 2) inadvertently measured larval fish fragments from the samples, 3) 

m shrinkage in preservation fluid, and 4) variations in hatch length. As a result, the larval lengths 

that were used to estimate ages were the 98% center interval of all the lengths. 

lt is possible that aging was biased, even though standard lengths of larval fishes (i.e., 

measurements of minimum, mean and maximum), and larval growth rates were applied to 

estimate the ages ofthe entrained larvae. It was assumed that larvae shorter than the minimum 

length ofthe central 98% ofthe distribution were just hatched and aged zero days. Subsequent 

ages were estimated using this length. Other reported data for various species suggests that 

hatching length can be either smaller or larger than estimated from DCPP samples, and indicates 

that the smallest observed larvae represent either natural variation in hatch lengths within the 

population or the phenomenon of shrinkage following preservation (Theilacker 1980). The 

TENERA E9-055.0 4-29 Final 316(b) Demonstration 

March 1,2000 
4.0 Methods 

possibility remains that all larvae from the observed minimum length to the greatest reported 

hatching length (or to some other size) could have just hatched, leading to overestimation of ages 

for all larvae. Both FH and AEL estimation use the mean and minimum sizes to estimate age at 

entrainment and are subject to similar biases. 

Twelve monthly survey periods were used to estimate larval mortality (PM ) due to entrainment 

for 2 one-year study periods. PM was estimated by the equation 

*-• (15 ) 

where 

PE, = estimate of proportional entrainment for the ith monthly survey (/'= 1,...,I2), 

Ps - estimated proportion ofthe fish population in the study grid, 

/ = annual proportion ofthe total larvae hatched during die ith monthly survey, and 

d = the estimated number of days of larval life. 

To establish independent survey estimates, it is assumed tiiat during each survey a new and 

distinct cohort of larvae is subject to entrainment. Each of tiie twelve surveys was weighted by / 

and estimated as the proportions ofthe yearly entrainment in all the days ofthe ith survey period. 

The survey dates (from July 1997 through June 1998 and July 1998 through June 1999) ofthe 

paired entrainment samples and number of days in the survey periods are found in Table 4-5. For 

each ofthe two years, the sum ofthe proportions equals one: 

/=^-andf;/ = l. 

IPJ '" 

The variance of PM was estimated using the Delta method (Seber 1982), and its formulation is 

presented in Appendix F. 

The estimate ofthe population-wide probability of entrainment {PEi • Ps ) is the central feature of 

the ETM approach (Boreman et al. 1981; MacCall et al. 1983). If a population is stable and 

TENERA E9-055.0 4-30 Final 316(b) Demonstration 

March 1,2000 

1 

I 
P.93 

4.0 Methods 

stationary, then PM also estimates the effects on the fully-recruited adult age classes when 

uncompensated natural mortality from larva to adult is assumed. 

4.4.4.2 Formulation of Ps 

The relationship between PM and Ps is represented by the sets of curves presented for each of 

the target taxa. Discrete values of Ps are also presented for each ofthe target taxa. These values 

are computed differently for three groups of taxa identified by the distribution of adults: 

• Offshore - Pacific sardine and northern anchovy 

• Subtidal - rockfishes, flatfishes, crabs, cabezon, white croakers, and blackeye gobies 

• Intertidal and shallow subtidal or nearshore sculpins, kelpfishes, pricklebacks, and 

greenlings 

The incorporation of Ps into die ETM is typically defined by the ratio ofthe area or volume of 

the study grid to a larger area or volume containing the population of inference (Parker and 

DeMartini 1989). If an estimate of die larval (or adult) population in the larger area is available, 

Ps can also be computed using die estimate ofthe larval or adult population in the study grid, 

defined by Ricker (1975) as the proportion ofthe parental stock. Ifthe distribution in the larger 

area is assumed to be uniform, then the value of Ps for the proportion ofthe population will be 

the same as the value computed using area or volume. For offshore and subtidal target taxa 

whose larval distribution extends to the offshore edge ofthe study grid, Ps will be calculated as 

the ratio 

PS=NC/NP 

where NG is the number of larvae in the study grid, and NP is the number of larvae in the 

population of inference. The numerator NG is presented is section 4.4.4.1 in the calculation of 

PE, i.e. 

64 _ 

N

c, =Z^-Z)*

-A.k 

*=l 

where 

TENERA E9-055.0 4-31 Final 316(b) Demonstration 

March 1,2000 
P.94 

4.0 Methods 

AQ = area of grid (G) cell k, 

Dk = average depth ofthe kth grid cell, and 

pik = density (per m^) of larvae in kth grid cell during survey /. 

NP was estimated by an offshore and alongshore extrapolation ofthe study grid densities, using 

water current measurements. First, a conceptual model was formulated to extrapolate larval 

densities (per m^) offshore ofthe grid 

— £V»V£ , "density, 

Ps=^& = ^ —— — (16) 

N

" LL>>AWA

D

J--density^ 

where 

LG = alongshore length of grid in they'th stratum, 

W} = width ofy'th stratum, 

LPj = alongshore length ofthe population in theyth stratum based on current data, 

Dj = average depth of theyth stratum, and 

density, = average density of larvae iny'th stratum. 

For tiiis model, the grid was subdivided into Kc alongshore strata (i.e., Kc =i rows in the grid) 

and the population into Kp > Kc alongshore strata. 

Formula (16) above describes discrete values in intervals ofa continuous function. Therefore, to 

ease implementation, an essentially equivalent formula incorporates the use of grid cell densities 

during the /th sampling period, pik, and integrates a linear extrapolation of density (per m^ 

calculated by multiplying pik by the cell depth) as a function of offshore distance, w: 

p< = • S; Nl ^(LP) 

N

c \

L

c J 

" rai\ 

+ LP • \ p{w)dw 

where 

Lp = alongshore length ofthe population {P) in the ith study period based on current data. 

TENERA E9-055.0 4-32 Final 316(b) Demonstration 

March 1,2000 
P.95 

4.0 Methods 

The limits of integration are from the offshore margin ofthe study grid, W0, to a point estimated 

by the onshore movement of currents or where the density is zero or biologically limited, Wmax. 

Note that this point can occur outside the study grid area. 

Note that the population number, Np, is composed of two components that represent the 

alongshore extrapolation ofthe grid population and the offshore extrapolation ofthe alongshore 

grid population (Figure 4-7). 

The alongshore and onshore current velocities were measured at a current meter positioned 

approximately 1 km west ofthe DCPP intake at a depth of approximately 6 m (Figure 4-3). The 

direction in degrees true from north and speed in cm/s were estimated for each hour ofthe 

nearshore study grid survey periods. Figure 4-8 shows the results of current meter analysis in 

which hourly current vectors were first rotated orthogonal to the coast by 49 degrees west of 

north (average of two tangents, Section 4.2.1.2). The movement of water was then tracked during 

the period from April 1997 through June 1999. A total alongshore length or displacement in 

kilometers can be calculated from these data using the range of both upcoast and downcoast 

movement over the larval duration period prior to each survey period. The maximum upcoast and 

downcoast current vectors measured during each survey period were added together to obtain an 

estimate of total alongshore movement. Onshore movement used to extrapolate densities offshore 

can also be calculated from this graph by excluding periods of offshore movement. Within this 

scenario, there are two subclasses: 

1. For species where the regression of density versus offshore distance has a negative slope, 

the offshore distance predicted where density is zero (i.e., integral of zero) will be 

calculated. The alongshore distance would be calculated from the water current data. 

2. For species where the regression of density versus offshore distance has a slope of >0, 

either the offshore distance from the water current data or an average distance based on 

the depth distribution ofthe adults offshore will be used. Literature values (e.g., 

CalCOFI) will be used to place a ceiling on both the distance and density values used in 

the offshore extrapolation. 

Parameter values needed in performing the extrapolation were obtained by using analysis of 

covariance based on all ofthe data from the surveys within the period July 1997 through June 

TENERA E9-055.0 4-33 Final 316(b) Demonstration 

March 1,2000 
P.96 

4.0 Methods 

1998. Another set of parameter values was calculated for the period July 1998 through June 

1999. A quadratic model was tested in the analysis 

*o=ai

+

P

w

u

 + r% + £ij 

where 

^—normally distributed error term with meai of zero, 

wy = distance for the ith observation in they'th survey, 

Su = larval density for the ith observation in they'th survey and 

°v> Pi 7-regression coefficients. 

A linear model produced a better fit in all cases: 

fiu=ai

+

P

w

y

+£>jA common slope, fi, for all surveys and unique intercepts, a,, for each survey were derived from 

the model. It is reasonable to assume a common slope, but differences in abundance between 

surveys required fitting different intercepts. The illustration below depicts three hypothetical 

survey periods. 

Density 

Distance 

Note that unique distances (i.e., intercepts) are used from each survey period when calculating 

NP. The value of Ps computed using this method to extrapolate increasing or decreasing 

densities offshore will result in non-uniform densities over the extrapolated area of inference. 

TENERA E9-055.0 4-34 Final 316(b) Demonstration 

March 1,2000 
P.97 

4.0 Methods 

Therefore, this value would not be equal to a Ps that is computed using the ratio of area or 

volume from the grid and the population of inference. The estimate of PM obtained using the 

extrapolated value of Ps will be compared for the Pacific sardine and northern anchovy to their 

fishery management areas and existing biomass estimates. The ratio ofthe extrapolated area to 

the fishery management area will be used to estimate the effects of entrainment on these 

populations. 

A Ps for nearshore taxa will be calculated using the alongshore length ofthe sampling grid, LG, 

and the total alongshore displacement, LP, to predict a coastwise fraction ofthe population of 

inference (Figure 4-7). The total alongshore displacement in the ith survey, Lp , includes both 

upcoast and downcoast movement calculated during a period equal to the larval duration before 

each survey. No onshore or offshore current movement was incorporated in the calculated 

population fraction: 

^ L L 

p -

 G

 — G 

4.4.4.3 Assumptions 

Assumptions associated with the estimation of PM include the following: 

• The samples at each survey period represent a new and independent cohort of larvae. 

• The monthly estimates of larval abundance represent a proportion of total annual larval 

production during that month. 

• The conditional probability of entrainment {PE,) is constant within monthly survey 

periods. 

• Ps accurately characterizes the fraction ofthe target population represented by the 

sampling grid. 

• Lengths and applied growth rates of larvae accurately estimate larval duration 

TENERA E9-055.0 4-35 Final 316(b) Demonstration 

March 1,2000 
P.98 

4.0 Methods 

Table 4-1. List of target taxa for assessment in DCPP 316(b) Demonstration. Target taxa, listed 

in phylogenetic order, were selected at the May 7, 1999 ETWG meeting. 

Common Name Scientific Name 

Brown rock crab 

Slender crab 

Pacific sardine 

Northern anchovy 

Blue rockfish complex 

KGB rockfish complex 

Painted greenling 

Smoothhead sculpin 

Snubnose sculpin 

Cabezon 

White croaker 

Monkeyface prickleback 

Clinid kelpfishes 

Blackeye goby 

Sanddab 

California halibut 

Cancer antennarius 

Cancer gracilis 

Sardinops sagax 

Engraulis mordax 

"f Sebastes spp. V / 5". mystinus 

^Sebastes spp. V_De/V_D_ 

Oxylebius pictus 

Artedius lateralis 

Orthonopias triads 

Scorpaenichthys marmoratus 

Genyonemus lineatus 

Cebidichthys violaceus 

Gibbonsia spp. 

Coryphopterus nicholsi 

Citharichthys spp. 

Paralichthys californicus 

t Sebastes spp. V7 S. mystinus, and Sebastes spp. V_De/V_D_ refer to pigmentation groups within 

the larval rockfish complex that were used as a taxonomic group in this study. 

TENERA E9-055.0 4-36 Final 316(b) Demonstration 

March 1,2000 
P.99 

4.0 Methods 

Table 4-2. Pigment groups, parturition peak periods (PPM), and seasonality of preflexion 

rockfish. larvae from Nishimoto (in prep.). 

The code for each group is based on the following 

letter designations: 

V_ = long series of ventral pigmentation (starts directly at 

anus) 

V = short series of ventral pigmentation (starts 3-6 

myomeres after anus) 

D_ = long series of dorsal pigmentation (4 or more in a 

continuous line) extending to above anus 

D = short series of dorsal pigmentation (4 or more in a 

continuous line) not extending to anus 

De = elongating series of dorsal pigmentation; scattered 

melanophores after continuous ones stop) 

d - develops dorsal pigmentation (1-2 or scattered 

melanophores) 

P = pectoral blade pigmentation 

p = develops pectoral pigmentation (1-2 or scattered 

melanophores) 

LETTER 

CODE SPECIES 

COMMON '77-'84 Parturition period N and C CA 

NAME SUBGENUS PPM (Wyllie Echeverria 1987) 

V_P Long ventral series, no dorsal, pectoral pigment 

5. chlorostictus greenspotted Sebastomus 

5. ensifer swordspine Sebastomus 

Apr-Sep 

Uncommon in central CA (Miller and 

Lea 1972) 

V D Long ventral series, short dorsal series, no pectoral pigment 

5. saxicola stripetail Allosebastes Jan Jan-Mar (Nov-Mar, Phillips 1964) 

V_D_ Long ventral series, short dorsal series, no pectoral pigment 

V De 

or 

V DeP 

or 

V_dep 

5. atrovirens 

S. chrysomelas 

S. maliger 

S. nebulosus 

S. semicinctus 

kelp Mebarus 

black and yellow Pteropodus 

quillback 

China 

halfbanded 

Pteropodus 

Pteropodus 

Allosebastes 

ND 

Feb 

Apr 

? 

ND 

ND 

Feb-Mar (Jan-May (Larson 1980)) 

Apr-Jul 

7 

Jan-Apr for southern CA (Love et al. 

1990) 

Long ventral series, elongating dorsal series, pectoral pigment 

S. auriculatus 

S. camatus 

S. caurinus 

S. dalli 

S. rastrelliger 

brown 

gopher 

copper 

calico 

grass 

Auctospina 

Pteropodus 

Pteropodus 

Allosebastes 

Pteropodus 

June 

Mar 

Feb 

0 

ND 

Dec-Jan, principally May-Jul (May, 

Larson 1980) 

Mar-May (May, Larson 1980) 

Feb 

Uncommon in central CA (Miller and 

Lea 1972) 

ND 

TENERA E9-055.0 4-37 Final 316(b) Demonstration 

March 1,2000 
P.100 

4.0 Methods 

Table 4-2. (continued). Pigment groups, parturition peak periods (PPM), and seasonality of 

preflexion Sebastes spp. larvae from Nishimoto (in prep.). 

LETTER 

CODE 

V 

VP 

Vdp 

VD 

SPECIES 

COMMON 

NAME SUBGENUS 

Short ventral series, no dorsal series, no pectoral 

S. aleutianus 

S. alutus 

S. brevispinis 

S. crameri 

S. diploproa 

S. elongatus 

S. macdonaldi 

S. miniatus 

S. nigrocinctus 

S. proriger 

S. rosaceus 

S. ruberrimus 

S. serriceps 

S. umbrosus 

S. wilsoni 

S. zacentrus 

rougheye 

POP 

silvergrey 

darkblotched 

splitnose 

greenstriped 

Mexican 

vermilion 

tiger 

redstripe 

rosy 

yelloweye 

treefish 

honeycomb 

pygmy 

sharpchin 

Zalopyr 

Acutomentum 

Acutomentum 

Eosebastes 

Allosebastes 

Hispaniscus 

Acutomentum 

Rosicola 

Sebastichtys 

Allosebastes 

Sebastomus 

Sebastopyr 

Sebastocarus 

Sebastomus 

Acutomentum 

Allosebastes 

Short ventral series, no dorsal series, various patterns 

(At smaller size might fit into group 

5. constellatus 

S. eos 

S. goodei 

S. helvomaculatu. 

S. levis 

S. melanostomus 

S. paucispinis 

S. rosenblatti 

S. rubrivinctus 

starry 

pink 

chilipepper 

• rosethom 

cowcod 

blackgill 

bocaccio 

greenblotched 

flag 

V above) 

Sebastodes 

Sebastomus 

Sebastodes 

Sebastomus 

Hispaniscus 

Eosebastes 

Sebastodes 

Sebastomus 

Hispaniscus 

'77-'84 

PPM 

ND 

Mar 

ND 

Jan 

Jul 

May 

NDSep 

ND 

7 

Jun 

Jun 

ND 

ND 

ND 

7 

Parturition period N and C CA 

(Wyllie Echeverria 1987) 

Jan-Mar (?) 

Nov-Mar (Nov-Mar, Larson 1980) 

Jan-Sep (Feb-Jul, Phillips 1964) 

May-Jul 

Sep (Nov, Moser 1967; Nov-Mar, 

Phillips 1964) 

Jul-Aug 

Apr-Jul 

Apr-Jul (?) 

ND 

May-Jun 

of pectoral pigmentation 

Apr 

ND 

Jan 

9 

Dec 

Feb 

Feb 

ND 

0 

Short ventral series, develops dorsal series, develops various 

(At stage 1-2 can 

S. entomelas 

S. flavidus 

S. melanops 

S. mystinus 

S. rufus 

S. serranoides 

confuse with V above due to lack of dorsal and 

widow 

yellowtail 

black 

blue 

bank 

olive 

Short ventral series, short dorsal i 

S. aurora 

S. babcocki 

S. gilli 

S. hopkinsi 

S. jordani 

S. ovalis 

S. pinniger 

Species without descriptions 

S. phillipsi 

aurora 

redbanded 

bronzespotted 

squarespot 

shortbelly 

speckled 

canary 

or illustrations 

chameleon 

Acutomentum 

Sebastosomus 

Sebastosomus 

Sebastosomus 

Acutomentum 

Sebastosomus 

.eries 

Eosebastes 

Rosicola 

Sebastosomus 

Acutomentum 

Sebastodes 

Acutomentum 

Rosicola 

7 7 

Feb 

Feb 

Feb 

Jan 

Feb 

Feb 

Apr 

May 

7 

Mar 

Feb 

May 

Dec 

Apr-May 

ND 

Nov-Jun (Nov-Mar, Phillips 1964) 

May-Jun 

Dec-Feb 

Feb-Apr 

Jan-May (Nov-Mar, Moser 1967) 

ND 

Jul 

jattems of pectoral pigmentation 

pectoral pigmentation.) 

Dec-Apr (Nov-Mar, Phillips 1964) 

Jan-Jul (Nov-Mar, Phillips 1964) 

Jan-May 

Nov-Jan (Nov-Jan, Wales 1952) 

Dec-May 

Jan-Mar 

Mar-May 

May 

Uncommon in central CA (Miller and 

Lea 1972) 

Feb-Mar 

Feb-Apr (Nov-Apr, Phillips 1964) 

May 

Dec-Mar (Nov-Mar. Moser 1967) 

Uncommon in central CA (Miller and 

TENERA E9-055.0 4-38 Final 316(b) Demonstration 

March 1.2000