P.1 

4.0 Methods 

Table 4-3. Larval growth estimates for entrainable fish larvae at DCPP based on literature 

citations. Growth estimates are used to estimate larval durations in Table 4-4. Growth rates are 

not listed for Cancer crabs because of step-wise growth increments between larval stages. Larval 

durations for crabs were taken directly from laboratory studies and are listed in Table 4-4. 

Family 

Species 

Cancridae 

Cancer antennarius 

Cancer gracilis 

Clupeidae 

Sardinops sagax 

Engrau lid idae 

Engraulis mordax 

Scorpaenidae 

Sebastes spp. KGB 

Sebastes spp. V/S. mystinus 

Larval Growth 

Rate (mm/d) 

— 

— 

0.238 

— ~~ 

0.445 

0.140 

0.140 

Reference 

Roesijadi 1976 

Ally 1975 

Miller 1952 

Methot and Kramer 1979 

Love and Johnson 1999 and 

Yoklavich pers. comm. 

Yoklavich et al. 1996 and 

Yoklavich pers. comm. 

Hexagrammidae 

Oxyiebius pictus 

Cottidae 

Artedius lateralis 

Orthonopias triads 

Scorpaenichthys marmoratus 

Sciaenidae 

Genyonemus lineatus 

Stichaeidae 

Cebidichthys violaceus 

Clinidae 

Gibbonsia spp. 

Gobiidae 

Coryphopterus nicholsi 

Paral ichthy idae 

Citharichthys spp. 

Paralichthys califomicus 

0.083 

0.083 

0.083 

0.300 

0.200 

0.248 

0.248 

0.273 

0.200 

0.280 

Freeman etal. 1985 

Freeman etal. 1985 

Freeman etal. 1985 

O'Connell 1.953; Moser 199 

Murdoch etal. 1989 

Stepien 1986 

Stepien 1986 

Steele 1997 

Kendall 1992; Sakuma 1995 

Allen etal. 1990 

TENERA E9-055.0 4-39 Final 316(b) Demonstration 

March 1,2000 
P.2 

4.0 Methods 

Table 4-4. Mean and maximum larval stage durations in days from hatching to entrainment 

estimated for fish larvae collected at DCPP. Maximum duration is based on the central 98% of 

the length frequency distribution and growth rates from the scientific literature (Table 4-3). Crab 

megalopal duration estimated from Roesijadi 1976 and Ally 1975. 

Family 

Genus and Species 

Cancridae 

Cancer antennarius (megalops) 

Cancer gracilis (megalops) 

Clupeidae 

Sardinops sagax 

Engraulididae 

Engraulis mordax 

Scorpaenidae 

Sebastes spp. KGB 

Sebastes spp. V /S. mystinus 

Hexagrammidae 

Oxyiebius pictus 

Cottidae 

Artedius lateralis 

Orthonopias triads 

Scorpaenichthys marmoratus 

Sciaenidae 

Genyonemus lineatus 

Stichaeidae 

Cebidichthys violaceus 

Clinidae 

Gibbonsia spp. 

Gobiidae 

Coryphopterus nicholsi 

Paral ichthy idae 

Citharichthys spp. 

Paralichthys califomicus 

Shortest larva Mean larva 

entrained (mm) entrained (mm 

— 

— 

2.4 ~ 

2.1 

3.3 

2.7 

3.2 

2.4 

2.6 

3.7 

1.1 

5.7 

4.1 

2.0 

1.3 

1.6 

5.5 

6.1 

4.2 

3.6 

4.1 

3.1 

3.6 

4.8 

2.4 

2.6 

6.4 

2.6 

2.6 

3.3 

Longest larva Estimated 

) entrained (mm) larval durations 

Mean-Max (d) 

— 

— 

19.1 

24.9 

5.6 

4.5 

5.2 

5.3 . 

6.1 

6.1 

5.5 

12.0 

12.0 

3.4 

3.5 

7.8 

42.7 

41.6 

13.3-70.6 

9.0-51.2 

6.2-16.4 

6.4-12.9 

10.4^-24.1 

8.9-34.9 

11.4-42.2 

3.6-8.0 

6.7-22.0 

• 

6.6-25.4 

9.0-31.6 

2.2-5.2 

6.7-11.0 

6.0-22.1 

TENERA E9-055.0 4-40 Final 316(b) Demonstration 

March 1,2000 
P.3 

4.0 Methods 

Table 4-5. Study grid survey start dates and the period of days used in 

calculations for each survey, for two sampling periods: June 1997 through July 

1998, and June 1998 through July 1999. The start date ofthe entrainment 

surveys that paired with the grid surveys generally started 24 hours after the 

beginning of each 72-hour grid survey. 

Analysis 

Surveys 

Survey Start Date 

Period 3 

Jul 21, 1997 

Aug 25, 1997 

Sep 29, 1997 

Oct 20, 1997 

Nov 17, 1997 

Dec 10, 1997 

Jan 22, 1998 

Feb 26, 1998 

Mar 18, 1998 

Apr 15, 1998 

May 18, 1998 

Jun 8, 1998 

Analysis Period 4 

Surveys Jul 21, 1998 

Aug 26, 1998 

Sep 16, 1998 

Oct 6, 1998 

Nov 11, 1998 

Dec 9, 1998 

Jan 12, 1999 

Feb 3, 1999 

Mar 17, 1999 

Apr 14, 1999 

May 24, 1999 

Jun 23, 1999 

Period Start 

Jul 4, 1997 

Aug 8, 1997 

Sep 12,1997 

Oct 10, 1997 

Nov 3, 1997 

Nov 29, 1997 

Jan 1, 1998 

Feb 9, 1998 

Mar 8,1998 

Apr 1, 1998 

May 2, 1998 

May 29, 1998 

Jul 3, 1998 

Aug 8, 1998 

Sep 6, 1998 

Sep 26, 1998 

Oct 24, 1998 

Nov 25, 1998 

Dec 26, 1998 

Jan 23, 1999 

Feb 24, 1999 

Mar 31, 1999 

May 4, 1999 

Jun 8, 1999 

Period End 

Aug 7, 1997 

Sep 11 

Oct 9 

Nov 2 

Nov 28 

Dec 31 

Feb 8 

Mar 7 

Mar 31 

May 1 

May 28 

Jul 3 

Aug 7 

Sep 5 

Sep 25 

Oct 23 

Nov 24 

Dec 25 

Jan 22 

Feb 23 

Mar 30 

May 3 

Jun 7 

Jul 2 

1997 

1997 

1997 

1997 

1997 

1998 

1998 

1998 

1998 

1998 

1998 

1998 

1998 

1998 

1998 

1998 

1998 

1999 

1999 

1999 

1999 

1999 

1999 

Days 

35 

35 

28 

24 

26 

33 

39 

27 

24 

31 

27 

36 

36 

29 

20 

28 

32 

31 

28 

32 

35 

34 

35 

25 

TENERA E9-055.0 4-41 Final 316(b) Demonstration 

March 1,2000 
PACIFIC OCEAN 

Entrainment 

Sampling 

Locations 

P.4 

4.0 Methods 

Diablo Cove 

Intake 

4 ^ Structure 

\ Intake 

• \ Cove 

Boat Dock 

DCPP 

LEGEND 

Cliff Top 

Intertidal Zone 

0 250 500 V 

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

TENERA E9-055.0 4-42 Final 316(b) Demonstration 

March 1.2000 
P.5 

4.0 Methods 

Traveling Vvater Screen 

Circulating Water Pump Motor 

i 

Bongo 

Plankton 

-UfitS 

Valve Open 

M^F/ir" pump Impeller 

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

entrainment sampling sites. 

TENERA E9-055.0 4-43 Final 316(b) Demonstration 

March 1,2000 
4.0 Methods 

P.6 

Morro Rock 124° w 120'W 116cw 

DIABLO CANYON 

POWERPLANT 

and araa of detail 

; Montana 

tate Parle 

Diablo Canyon Power. Plant 

y ________________________! 

JurrertMefilp 

- West Breakwater 

-4T N 

-38° N 

84°N 

Onshore 

Current 

1 0. 1kmColumns = A - H 

Depth Contours 

- * V 60 meters 

-~— 40 meters 

- ^ - 20 meters 

Avila 

Beach 

Point San Luis 

A 

121° True North 

Alongshore 

Current 

Figure 4-3. DCPP 316(b) study grid and depth contours. 

TENERA E9-055.0 4-44 Final 316(b) Demonstration 

March 1. 2000 
P.7 

4.0 Methods 

DCPP Intake 

Cove 

Figure 4-4. An example of the "ping-pong" sampling track employed in grid ceil 

sampling; the starting cell (Fl) and the initial southward direction ofthe transect were 

randomly selected. All 64 cells are sampled during the 72-hour survey period, weather 

permitting. DCPP's Intake Cove is located east of the juncture between cells El and Dl. 

TENERA E9-055.0 4 ^ 5 Final 316(b) Demonstration 

March 1,2000 
P.8 

4.0 Methods 

Field's Cove 

PACIFIC OCEAN 

Intake Cove 

Surface Plankton Tow 

DCPP 

Intake Structure 

% 

100 m 

/ 

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

TENERA E9-055.0 4-46 Final 316(b) Demonstration 

March 1.2000 
m 

z 

m 

£ 

m 

<P o 

Ol 

01 

O 

hu 

3 

u. 

W 

ca 

Q) TO 

M 

NJ 3 

o =-. 

o o 

O 3 

ENTRAINMENT 

Lab processing for FISH 

Lab processing for MEGALOPS 

Lab processing for ZOEA 

GRID 

Lab processing for FISH 

Lab processing for MEGALOPS 

Lab processing for ZOEA 

-only partial survey workup 

INTAKE COVE 

Lab processing for FISH 

1996 

OTNI D 

1997 

J | F | M | A | M | J | J | A | S | 0 | N | D 

1998 

J | F | M| A | M| J | J | A | S| 0 | N | D 

1999 

J | F | M | A | M | J 

. ," ,'!'»» 'iA , ^js^Waaiu^Si^iiiiH^aainbtecoltoctlona n _.,.*_,,",- «-2«« , *•*,, ,.,•> -', 

?••*••' •» .-.,'- _weeWy sanples pcocesse^taj^ 

Analysis Period J1) j Analysis Penod ii. 

Analysis Period (3) | 

only processed surveys paired w/grid 

• -

-. • *$:,, .^.*.>- : weekiysarnples prttoiws^ „ , , £-,..- * 

Analysis Penod (1) | Analysis Period (2) 

Analysis Period (3) | 

* * l-iiTr- .\«;..«^FAviiwe*y.sampiesp 

Analysis Kenoo(i) j " •• 

| Analysis Period (3) | 

;_D 

••'Al Ml' .' r^Otfb?itMyfl^^ X-l K 

>?*£v -."?*» ,-,._<**,''monthly samples "prbeessea Ibr.lwval fishes,-'.«--., ,i*»; *„ < „- , , 

Analysis Penod (3) \ Analysis Penod (4) 

v;_w^*Sv^&i&*a^ ^ r, f;'- 'A " 7 ,. V 

Analysis Period (3) | Analysis Penod (4) 

.mmm 

' . - • 

. - , '<,• k, .. •<.&>»-.. • s.,WaMt|^JittailUi;Cd^:iMatfikti_SA\taMcttHtfeaens.i-»nvj>V •**•-f1-- -..r "••:_.,,^-?.r>« ^ 

: • 

Iprocessed for larval fishes | |ptocessed forlarval fishes) | J 

* zoea not removed from these samples. 

" zoea density substituted for October and November 1996 

Anajysis Period (1): October 23,1996 - September 30,1997 

Anaiysis Period (2): October 1, 1997 - September 30,1998 

Analysis Period (3): July 1, 1997 - June 30.1998 

Analysis Period (4): July 1,1998 - June 30,1999 

Figure 4-6. Summary of entrainment, study grid, and Intake Cove surface 

plankton tow sample collection, laboratory processing, and analysis periods. 
(a) 

P.10 

4.0 Methods 

7K 

Onshon Movement 

NP 

± 

K 

(b) 

< • > 

Figure 4-7. Two approaches for calculating Ps based upon water current measurements: (a) For 

species dispersed throughout the sampling grid (small rectangle), both alongshore and onshore 

components are used to calculate Ps ~-=&, where Nc is the larval population estimate ofthe 

NP 

offshore grid and Np is the estimate of larval abundance ofthe population of inference; (b) For 

^ L nearshore species, only the alongshore component is used to calculate Ps

 = — , where Lc is the 

length ofthe offshore grid and Lp is the estimated alongshore movement through the offshore 

grid. 

TENERA E9-055.0 4-48 Final 316(b) Demonstration 

March 1.2000 
P.11 

4.0 Methods 

a) Year 1 - April 1,1997 through July 1,1998 

500 

400 

CO 

CQ 

o 

CJ 

Q. 

3 

CD 

CU 

E o 

2 

300 

200 

100 

to -100 

o 

u 

c 

_5 

o Q 

-200 

-300 

^400 

-500 

-600 

-700 

-800 

2/98 

-100 0 100 200 300 

Offshore Onshore 

Kilometers 

b) Year 2 -April 1,1998 through July 1,1999 

-. Kilometers 

Upcoast oast Downc 

500-

400: 

300 i 

CM 100i 

Of 

-100i 

-200 j 

-300-i 

JU/9 

15/9 

.719 ) 

.6/9 

3/Q11/9 

679 ^Kfl 

f 1/9 »1 

2/9 1 „ 

4/9 f 13/9 

-400-

-500-

-600-

-700 

nnn. 

5/9 / 

6/9 i 

7/9 V» 

-100 0 100 200 300 

Offshore Onshore 

Kilometers 

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

Diablo Canyon current meter station (current meter station is located at the cross-hairs). 

TENERA E9-055.0 4-49 Final 316(b) Demonstration 

March 1,2000 
P.12 

Blank Page 
P.13 

(SI 

© 

re 
P.M 

5.0 Results 

5.0 RESULTS 

This section is divided into a general overview ofthe data collected during the entrainment and 

impingement studies at DCPP, results of various modeling analyses on selected target taxa, and a 

summary ofthe taxa assessments. 

5.1 Overview 

The following is a general overview ofthe data collected and analyzed for the DCPP Section 

316(b) Demonstration. Density estimates of target organisms were determined from plankton 

collections at the intake structure, in the Intake Cove, jind in the study grid. The sections that 

follow present and discuss the results of analyses of individual target taxa chosen by the ETWG. 

5.1.1 Entrainment 

Entrainment is defined as the capture and inclusion of organisms in the cooling water of power 

plants (Schubel and Marcy 1978). Organisms become entrained in the cooling water system at 

DCPP once they pass through the traveling screens and cannot escape. Larval stages offish and 

invertebrates are usually weak swimmers and generally enter the flow passively. 

5.1.1.1 Weekly Abundance Estimates of Entrainment 

There were 8,804 subsamples collected at the entrainment sampling location from October 23, 

1996 through June 1999. In accordance with the ETWG agreement, larval fishes, Cancer crab 

larvae, and sea urchin larvae were identified and enumerated from a portion of these subsamples. 

Cancer crab megalops were processed from 5,524 subsamples, larval fish from 4,693 

subsamples, and Cancer crab zoea and strongylocentrotid sea urchins from 636 subsamples 

during laboratory processing. The data for sea urchins were collected for informational purposes 

only and were not used in assessing entrainment effects per agreement with the ETWG. 

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

March 1,2000 
P.15 

5.0 Results 

Cancer spp. crabs 

Zoeal stages of Cancer antennarius, C. anthonyi, C. gracilis, C. productus, and two Cancer spp. 

identifications left at the generic level were found in the entrainment subsamples. One 

unidentified Cancer species (sp. A) was confirmed late in the study to be Cancer jordani (P. 

Reilly, CDF&G, Monterey, CA). There were 96,295 zoeae identified and enumerated from the 

636 entrainment subsamples processed. The mean density of each stage by species is presented in 

Appendix H. In general, zoeal stage 1 individuals were most abundant, and zoeal stage 5 

individuals were least abundant. 

The megalopal stage of Cancer spp. crabs was also identified and enumerated from entrainment 

subsamples. Megalops of Cancer antennarius, C. anthonyi, C. gracilis, C. magister, C. 

productus, and at least two generic identifications of Cancer spp. and C. jordani were recorded. 

In the 5,524 entrainment subsamples processed for megalops, 4,887 individuals were identified 

and enumerated. Cancer antennarius and C. gracilis megalops were more abundant than other 

Cancer species megalops (Appendix H). 

The species chosen by the ETWG for analysis were Cancer antennarius and C. gracilis (Tenera 

1997b). Additional information on the demography and results ofthe three assessment models for 

these two species is presented in Section 5.2.1. 

Fishes 

There were 98,593 larval fishes identified and enumerated from 4,693 entrainment subsamples 

(Appendix H). Of these, -98% were placed into 178 different taxonomic categories ranging from 

ordinal to specific classifications (Table 5.1-1) while the remaining ~2% were placed into one of 

three categories: unidentified larval fish (0.4%), unidentified damaged larval fish (0.2%), or 

unidentified larval fish fragment (1%). Adults of these taxa live in a variety of habitats, from 

intertidal and shallow subtidal to deep-water and pelagic habitats. The taxa in highest abundance 

were those whose adults were generally found close to shore, in shallow water. One exception 

was the thirteenth most abundant taxon, the northern lampfish (Stenobranchius leucopsarus), 

whose adults are found to depths of 3,000 m (Miller and Lea 1972). 

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

March 1,2000 
P.16 

5.0 Results 

The ETWG chose 14 larval fish taxa (Table 4-1) for detailed assessment using the FH, AEL, and 

ETM approaches. Results of these analyses are presented separately in subsequent sections. 

Sea Urchins 

The ETWG agreed that only metamorphosing and recently metamorphosed juvenile sea urchins 

would be removed, identified, and enumerated from the entrainment subsamples, but that no 

assessment of entrainment effects would be made. Due to the small size ofthe echinopluteus 

larvae, it was assumed that many would be extruded through the net mesh used, resulting in an 

underestimate of their abundance. 

A total of 5,966 sea urchin larvae was found in the 636 subsamples processed. The weekly mean 

density of Strongylocentrotus fransiconus and S. purpuratus individuals collected at the intake 

during the period October 1996 through June 1998 is presented in Figure 5.1-1. The density of S. 

purpuratus was greater than S. fransicanus during most surveys where individuals of both 

species were present. Both species were most abundant during the spring and summer, with 

highest densities of S. fransicanus present in March 1997 and S. purpuratus peak densities 

observed during June 1997. A greater density of both species occurred during 1997 than in 1998. 

Generally, only a few individuals were collected during the fall or winter. A summary ofthe data 

for all entrainment surveys is presented in Appendix H. 

5.1.1.2 Monthly Abundance Estimates in the Study Grid 

A total of 6,141 subsamples was collected during the monthly study grid surveys conducted from 

July 1997 through June 1999. As agreed with the ETWG, larval fish were identified and 

enumerated from 3,061 subsamples, megalops were identified and enumerated from 3,066 

subsamples, and zoea and urchins were identified and enumerated from 128 subsamples during 

laboratory processing (Appendix G). 

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

March 1,2000 
P.17 

5.0 Results 

Cancer spp. crabs 

The five Cancer crab zoeal stages were removed from the half of the subsamples preserved in 

formalin and collected during the March and April 1998 grid surveys. The ETWG decided not to 

require that zoea be removed from the remainder ofthe grid subsamples collected during this 

study. 

Zoeal stages of Cancer antennarius, C. gracilis, C. anthonyi, C. productus, C. jordani, and at 

least one unidentified Cancer spp. were found in the subsamples from the two study grid surveys 

that were processed. A total of 27,270 zoea was removed and identified from the 128 grid 

samples processed. The mean density of each stage by species is presented in Appendix H. 

Generally, recently hatched stage 1 zoea were the most abundant and older stage 5 zoea were 

least abundant. 

The megalops stage of Cancer antennarius, C. gracilis, C. anthonyi, C. productus, C. magister, 

C. jordani, and at least one unidentified Cancer spp. were found in the study grid samples. In the 

3,066 grid samples processed for megalops, 6,599 individuals were removed and identified. The 

mean density of megalops by species for each survey is presented in Appendix H. Cancer 

antennarius and C. gracilis megalops were more abundant than the megalops of other Cancer 

species. The ETM assessment of tiiese two species only uses megalops data because zoea were 

not processed from all ofthe paired study grid surveys per agreement by the ETWG. 

Fishes 

There were 43,785 larval fishes identified and enumerated from the 3,163 study grid subsamples 

that comprised 175 different taxa ranging from ordinal to specific levels of classification. Adults 

of these taxa live in a variety of habitats, from intertidal and shallow subtidal to deep-water and 

pelagic habitats. The taxa in highest abundance in the grid subsamples were those whose adults 

were typically pelagic or subtidal; more intertidaliy or nearshore distributed species were found 

in lower abundance in the study grid. 

TENERA E9-055.0 5-4 Final 316(b) Demonstration 

March 1,2000 
.18 

5.0 Results 

Sea Urchins 

Sea urchins were identified from the half of the subsamples preserved in formalin during only the 

March and April 1998 study grid surveys. The ETWG decided not to require that sea urchins be 

sorted from the remainder ofthe study grid subsamples and agreed that the data would not be 

assessed using a mathematical modeling approach (Tenera 1997b). There were 764 

Strongylocentrotus spp. found in the 128 subsamples processed. The mean density of 

S. purpuratus in March and April of 1998 appeared to be greater than S.fransicanus during those 

months (Appendix H). 

5.1.1.3 Weekly Intake Cove Surface Tows 

There were 27,062 larval fishes identified and enumerated from 660 Intake Cove surface 

plankton tow samples collected between 1990 and 1998. The ETWG agreed that only the samples 

from the 7 mo period of December through June of each year would be processed and analyzed 

for each year because these months are generally the period of peak larval abundance for most 

species. The taxa present in these samples were similar to those found in the entrainment and 

study grid samples (Appendix H). As mentioned previously, these data were used to generate a 

nine-year average of larval abundance. This index calculated from this long-term average was 

then used to scale the estimates of annual entrainment for each taxon. 

5.1.2 Impingement 

There were 66 taxa representing 29 families of bony fishes, sharks, rays, and eels identified from 

impinged material collected during the 1985-86 DCPP study (Table 5.1-1). Some taxa, such as 

thomback rays, were collected in higher numbers and biomass at Unit 2 despite more frequent 

sampling at Unit 1. The densities of impinged fishes for Units 1 and 2 were compared during a 10 

d period when pump and traveling screen operations between units were similar (PG&E 1988). 

The densities of impinged skates and rays were greater on the Unit 2 screens than at Unit 1 

(PG&E 1988). Impingement rates for both units were similar for rockfishes and total bony fishes 

(PG&E 1988). 

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

March 1,2000 
P.19 

5.0 Results 

The CWP did not operate continually during the impingement sampling (Figure 5.1-2). 

Equipment repairs on Unit 1 resulted in periods when pumps or traveling screens were not in full 

operation. Unit 2 was in the final stages of construction and testing during the DCPP Section 

316(b) impingement study, which also limited the number of days when the pumps were 

operational and traveling screens were sampled. Although impingement sampling was scheduled 

to occur on the same day each week, it was adjusted several times due to operations at the intake. 

A total of 51 d was sampled for Unit 1, and 24 d were sampled for Unit 2. Unit 2 began operating 

on a more regular basis by October 1985. There were eight days of sampling when both Units 1 

and 2 were fully operational for 24 hr (Figure 5.1-2). 

Many fishes live within the intake forebays without becoming impinged. Diver observations and 

underwater video ofthe DCPP traveling screens during pre-operation (Behrens and Larsson 

1979) and operation (PG&E 1988) have recorded both large and small fishes freely swimming 

throughout the forebays in front ofthe traveling screens. During the impingement study, divers in 

the Intake Cove on August 21, 1985, observed over 100 juvenile yellowtail/olive rockfishes in 

front ofthe Unit 1 bar racks (PG&E 1988), yet only one rockfish was collected during the two 

August impingement surveys. 

The number of fishes, their combined weight, and the amount of debris collected during each of 

the 24-hour surveys were compared for samples collected at Units 1 and 2 (Figure 5.1-3). There 

does not appear to be a relationship between the number or weight of fishes and the amount of 

debris collected by Unit 1. The largest number of fishes was collected from Unit 1 during late 

June 1985 when the amount of debris collected was low. The total weight of fishes was low 

because most ofthe individuals were young-of-the-year rockfishes ca. 60-80 mm in length. At 

Unit 2, the greatest number and weight of fishes impinged did not consistently occur when the 

amount of debris was heaviest. The largest amount of debris was collected during late December 

1985. During that period, the weight ofthe fishes in the collection was high, but the number of 

individuals was low. 

TENERA E9-055.0 5-6 Final 316(b) Demonstration 

March 1,2000 
P.20 

5.0 Results 

A total of 1,314 Cancer antennarius was collected in impingement samples from February 1985 

through March 1986. Ninety-seven percent ofthe crabs were juveniles, having an average weight 

of about 3 g. Table 5.1-2 presents the standardized biomass (g/million m^ of water entrained) of 

Cancer crab species impinged at DCPP. Among the various species of Cancer crabs, C. 

antennarius were impinged at the highest rate. The overall impingement rate of Cancer crabs was 

similar for both power plant units. 

A report reviewing the 1985-86 DCPP impingement study was prepared and submitted to the 

ETWG (Tenera 1988). The ETWG detennined that additional impingement studies were not 

required at DCPP based on this report that showed that the plant had generally low rates of 

impingement. 

TENERA E9-055.0 5-7 Final 316(b) Demonstration 

March 1,2000 
P.21 

5.0 Results 

Table 5.1-1. Phylogenetic list of fishes collected during the Diablo Canyon Power 

Plant 316(b) study following primarily the AFS list of Common and Scientific Fish 

Names (Robins et al. 1991) and secondarily the classification adopted by Moser 

(1996). 

Order 

Suborder Family Genus & Species 

Clupeiformes 

Clupeidae 

Engraulididae 

Salmoniformes 

Argentinoidei 

Argentinidae 

Bathylagidae 

Microstomatidae 

Salmonoidei 

Osmeridae 

Stomiiformes 

Gonostomatidae 

Stemoptychidae 

Phosichthyidae 

Chauliodontidae 

Stomiidae 

Aulopiformes 

Alepisaurioidei 

Synodontidae 

Paralepididae 

herrings 

Etrumeus teres (DeKay 1842) 

Sardinops sagax (Jenyns 1842) 

anchovies 

Anchoa compressa (Girard 1858) 

Engraulis mordax Girard 1854 

Argentine 

Argentina sialis Gilbert 1890 

blacksmelt and smoothtongues 

Bathylagus ochotensis Schmidt 1938 

Bathylagus pacificus Gilbert 1890 

Leuroglossus spp. 

Leuroglossus stilbius Gilbert 1890 

pencilfishes 

Microstoma spp. 

smelts 

lightfishes 

Cyclothone spp. 

Cyclothone signata Garman 1899 

hatchetfishes 

Sternoptyx spp. 

highseas lightfishes 

Vinciguerria lucetia (Garman 1899) 

Vinciguerria poweriae (Cocco 1838) 

dragonfishes 

Chauliodus macouni Bean 1890 

scaly dragonfishes 

Stomias atriventer Garman 1899 

lizardfishes 

Synodus lucioceps (Ayres 1855) 

barracudinas 

Lestidiops ringens 

(Jordan & Gilbert 1880) 

Common Name 

round herring 

Pacific sardine 

deepbbdy anchovy 

northern anchovy 

Pacific argentine 

popeye blacksmelt 

Pacific blacksmelt 

smooth tongues 

Califomia 

smoothtongue 

dusky pencilsmelt 

bristlemouths 

showy bristlemouth 

hatchetfish 

Pacific lightfish 

highseas lightfish 

Pacific viperfish 

blackbelly dragonfish 

Califomia lizardfish 

slender barracudina 

(continued) 

TENERA E9-055.0 5-8 Final 316(b) Demonstration 

March 1,2000 
P.22 

5.0 Results 

Table 5.1-1. (cont'd) 

Order 

Suborder Family 

Myctophiformes 

Myctophidae 

Gadiformes 

Gadidae 

Merlucciidae 

Ophidiiformes 

Ophidiidae 

Bythitidae 

Batrachoidiformes 

Batrachoididae 

Gobiesociformes 

Gobiesocidae 

Atheriniformes 

Atherinidae 

Genus & Species 

lanternfishes 

Ceratoscopelus townsendi 

(Eigenmann & Eigenmann 1889) 

Diaphus theta 

Eigenmann & Eigenmann 1890 

Diogenichihys atlanticus (Taning 1928) 

Hygophum atratum (Garman 1899) 

Nahnobrachium regalis (Gilbert 1892) 

Nannobrachium ritteri (Gilbert 1915) 

Nannobrachium spp. 

Protomyctophum crockeri (Bolin 1939) 

Stenobrachius leucopsarus 

(Eigenmann & Eigenmann 1890) 

Symbolophorus californiensis 

(Eigenmann & Eigenmann 1889) 

Tarletonbeania crenularis 

(Jordan & Gilbert 1880) 

Triphoturus mexicanus (Gilbert 1890) 

cods 

Microgadus proximus (Girard 1854) 

hake 

Merluccius spp. 

Merluccius productus (Ayres 1855) 

cusk-eels 

Chilara taylori (Girard 1858) 

Ophidion scrippsae (Hubbs 1916) 

brotulas 

Brosmophycis marginata (Ayres 1854) 

Cataetyx rubirostris Gilbert 1890 

toadfishes 

Porichthys notatus Girard 1854 

clingfishes 

Gobiesox spp. 

Gobiesox maeandricus (Girard 1858) 

Rimicola spp. 

silversides 

Atherinops affinis (Ayres 1860) 

Atherinopsis californiensis Girard 1854 

Leuresthes tenuis (Ayres 1860) 

Scomberesocidae sauries 

Cololabis saira (Brevoort 1856) 

Common Name 

dogtooth lampfish 

California headlight fish 

longfin lantemfish 

thickhead lantemfish 

pinpoint lampfish 

broadfin lampfish 

lanternfishes 

Califomia flashlightfish 

northern lampfish 

California lantemfish 

blue lantemfish 

Mexican lampfish 

Pacific tomcod 

hake 

Pacific hake 

spotted cusk-eel 

basketweave cusk-eel 

red brotula 

rubynose brotula 

plainfin midshipman 

clingfish 

northern clingfish 

kelp clingfish 

topsmelt 

jacksmelt 

California grunion 

Pacific saury 

(continued) 

TENERA E9-055.0 5-9 Final 316(b) Demonstration 

March 1,2000 
P.23 

5.0 Results 

Table 5.1-1. (cont'd) 

Order 

Suborder Family Genus & Species Common Name 

Lampridiformes 

Trachipteroidei 

Trachipteridae 

Beryciformes 

Stephanoberycoidei 

Melamphaidae 

Gasterosteiformes 

Gasterosteoidei 

Gasterosteidae 

Syngnathoidei 

Syngnathidae 

Scorpaeniformes 

Scorpaenoidei 

Scorpaenidae 

ribbonfishes 

Trachipterus altivelis Kner 1858 

bigscales 

Melamphaes spp. 

Melamphaes parvus Ebeling 1962 

Poromitra crassiceps (Gilnther 1878) 

sticklebacks 

A ulorhynchus flavidus Gill 1861 

pipefishes 

Syngnathus spp. 

Syngnathus californiensis Storer 1845 

Syngnathus leptorhynchus Girard 1854 

scorpion fishes, rockfishes, and 

thomyheads 

Sebastes aurora (Gilbert 1890) 

Sebastes diploproa (Gilbert 1890) 

Sebastes jordani (Gilbert 1896) 

Sebastes levis 

(Eigenmann & Eigenmann 1889) 

Sebastes mystinus 

(Jordan & Gilbert 1881) 

Sebastes paucispinis Ayres 1854 

Sebastes saxicola (Gilbert 1890) 

Sebastes spp. 

Sebastes spp. 1 / V_DeP 

Sebastes spp. D 

Sebastes spp. V 

Sebastes spp. V_ 

Sebastes spp. V D 

Sebastes spp. V_D_ 

Sebastes spp. VD e 

Sebastes spp. VD 

Sebastes spp. VP 

Sebastes VDp 

Sebastolobus spp. 

king-of-the-salmon 

bigscales 

linle bigscale 

crested bigscale 

tube-snout 

pipefishes 

kelp pipefish 

bay pipefish 

aurora rockfish 

splitnose rockfish 

shortbelly rockfish 

cow cod 

blue rockfish 

bocaccio 

stripetail rockfish 

rockfishes 

rockfishes 

rockfishes 

rockfishes 

rockfishes 

rockfishes 

rockfishes 

rockfishes 

rockfishes 

rockfishes 

rockfishes 

thomvheads 

(continued) 

TENERA E9-055.0 5-10 Final 316(b) Demonstration 

March 1.2000 
P.24 

5.0 Results 

Table 5.1-1. (cont'd) 

Order 

Suborder Family Genus & Species Common Name 

Scorpaeniformes (cont'd) 

Hexagrammoidei 

Hexagrammidae 

Cottoidei 

Cottidae 

Agonidae 

Cyclopteridae 

greenlings 

Hexagrammos spp. 

Ophiodon elongatus Girard 1854 

Oxyiebius pic tus Gill 1862 

Zaniolepis spp. 

Zaniolepis frenata 

Eigenmann & Eigenmann 1889 

Zaniolepis latipinnis Girard 1858 

sculpins 

Artedius spp. 

Artedius harringtoni (Starks 1896) 

Artedius lateralis (Girard 1854) 

Chitonotus / Icelinus 

Chitonotus pugetensis (Steindachner 1876) 

Clinocottus spp. 

Clinocottus analis (Girard 1858) 

Clinocottus embryum 

(Jordan & Starks 1895) 

Enophrys spp. 

Hemilepidotus spinosus (Ayres 1854) 

Icelinus spp. 

Icelinus guadriseriatus (Lockington 1880) 

Leptocottus armatus Girard 1854 

Nautichthys oculofasciatus (Girard 1858) 

OUgocottus spp. 

OUgocottus maculosus Girard 1856 

OUgocottus snyderi Greeley 1898 

Orthonopias triads Starks & Mann 1911 

Radulinus spp. 

Ruscarius creaseri (Hubbs 1926) 

Ruscarius meanyi Jordan & Starks 1895 

Scorpaenichthys marmoratus (Ayres 1854) 

Synchirus gilli Bean 1890 

poachers 

Odontopyxis trispinosa Lockington 1880 

Stellerina xyosterna 

(Jordan & Gilbert 1880) 

snailfishes 

Liparis spp. 

greenlings 

lingcod 

painted greenling 

combfishes 

shortspine combfish 

longspine combfish 

sculpin 

scalyhead sculpin 

smoothhead sculpin 

sculpin 

roughback sculpin 

sculpins 

wooly sculpin 

calico sculpin 

sculpin 

brown Irish lord 

sculpin 

yellowchin sculpin 

staghorn sculpin 

sailfin sculpin 

sculpin 

tidepool sculpin 

fluffy sculpin 

snubnose sculpin 

sculpin 

roughcheek sculpin 

Puget Sound sculpin 

cabezon 

manacled sculpin 

pygmy poacher 

pricklebreast poacher 

snailfishes 

Perciformes 

Percoidei 

Serranidae sea basses 

Paralabrax spp. 

Paralabrax clathratus (Girard 1854) 

sand basses 

kelp bass 

(continued) 

TENERA E9-055.0 5-11 Final 316(b) Demonstration 

March 1.2000 
P.25 

5.0 Results 

Table 5.1-1. (cont'd) 

Order 

Suborder Family 

Perciformes (cont'd) 

Percoidei 

Carangidae 

Haemulidae 

Sciaenidae 

Kyphosidae 

Pomacentridae 

Sphyraenidae 

Labroidei 

Labridae 

Zoarcoidei 

Bathymasteridae 

Stichaeidae 

Pholididae 

Blennioidei 

Clinidae 

Chaenopsidae 

Blenniidae 

Icosteoidei 

Icosteidae 

Genus & Species 

jacks 

Trachurus symmetricus (Ayres 1855) 

grunts 

Xenistius californiensis 

(Steindachner 1875) 

drums 

Atractoscion nobilis (Ayres 1860) 

Cheilotrema saturnum (Girard 1858) 

Genyonemus lineatus (Ayres 1855) 

Menticirrhus undulatus (Girard 1854) 

Roncador stearnsi (Steindachner 1875) 

Seriphus politus Ayres 1860 

Umbrina roncador 

Jordan & Gilbert 1882 

sea chubs 

Girella nigricans (Ayers 1860) 

damselfishes 

Chromis punctipinnis (Cooper 1863) 

barracudas 

Sphyraena argentea Girard 1854 

wrasses 

Oxyjulis californica (Gunther 1861) 

Semicossyphus pulcher (Ayres 1854) 

ronquils 

Rathbunella spp. 

pricklebacks 

Cebidichthys violaceus (Girard 1854) 

Chirolophis nugator 

(Jordan & Williams 1895) 

Plectobranchus evides Gilbert 1890 

gunnels 

clinid kelpfishes 

Gibbonsia spp. 

Heterostichus rostratus Girard 1854 

tube blennies 

Neoclinus spp. 

combtooth blennies 

Hypsoblennius spp. 

Hypsoblennius gilberti (Jordan 1882) 

ragfishes 

Icostens aenigmaticus Lockington 1880 

Common Name 

jack mackerel 

salema 

white seabass 

black croaker 

white croaker 

California corbina 

spotfin croaker 

queenfish 

yellowfin croaker 

opaleye 

blacksmith 

Pacific barracuda 

senorita 

California sheephead 

ronquils 

monkeyface eel 

mosshead warbonnet 

bluebarred prickleback 

clinid kelpfishes 

giant kelpfish 

fringehead 

blennies 

rockpool blenny 

ragfish 

(continued) 

TENERA E9-055.0 5-12 Final 316(b) Demonstration 

March 1,2000 
P.26 

5.0 Results 

Table 5.1-1. (cont'd) 

Order 

Suborder Family 

Perciformes (cont'd) 

Percoidei 

Trachinoidei 

Ammodytidae 

Gobioidei 

Gobiidae 

Genus & Species 

sand lances 

Ammodytes hexapterus Pallas 1814 

gobies 

Coryphopterus nicholsi (Bean 1882) 

Eucyclogobius newberryi (Girard 1856) 

Lepidogobius lepidus (Girard 1858) 

Lythrypnus spp. 

Lythrypnus dalli (Gilbert 1890) 

Lythrypnus zebra (Gilbert 1890) 

Typhlogobius californiensis 

Common Name 

Pacific sand lance 

blackeye goby 

tidewater goby 

bay goby 

gobies 

bluebanded goby 

zebra goby 

blind goby 

Scombroidei 

Scombridae 

Stromateoidei 

Centrolophidae 

Tetragonuridae 

Stromateidae 

Pleuronectiformes 

Pleuronectoidei 

Paralichthyidae 

Pleuronectidae 

Steindachner 1879 

mackerels 

Scomber japonicus Houttuyn 1782 

medusafishes 

Icichthys lockingtoni 

Jordan & Gilbert 1880 

squaretails 

Tetragonurus cuvieri Risso 1810 

butterfish.es 

Peprilus simillimus (Ayres 1860) 

lefteye flounders 

Citharichthys spp. 

Citharichthys sordidus (Girard 1854) 

Citharichthys stigmaeus 

Jordan & Gilbert 1882 

Hippoglossina stomata 

Eigenmann & Eigenmann 1890 

Paralichthys califomicus (Ayres 1859) 

Xystreurys liolepis Jordan & Gilbert 1880 

righteye flounders 

Embassichthys bathybius (Gilbert 1890) 

Eopsetta exilis (Jordan & Gilbert 1880) 

Errex zachirus (Lockington 1879) 

Hypsopsetta guttulata (Girard 1856) 

Lepidopsetta bilineata (Ayres 1855) 

Microstomus pacificus (Lockington 1879) 

Parophrys vetulus (Girard 1854) 

Platichthys stellatus (Pallas 1787) 

Pacific mackerel 

medusa fish 

smal leye squaretail 

Pacific butterfish 

sanddab 

Pacific sanddab 

speckled sanddab 

bigmouth sole 

California halibut 

fantail sole 

deepsea sole 

slender sole 

rex sole 

diamond turbot 

rock sole 

Dover sole 

English sole 

starry flounder 

(continued) 

TENERA E9-055.0 5-13 Final 316(b) Demonstration 

March 1,2000 
P.27 

5.0 Results 

Table 5.1-1. (cont'd) 

Order 

Suborder Family Genus & Species Common Name 

Pleuronectiformes 

Pleuronectoidei 

Pleuronectidae 

Soleioidei 

Cynoglossidae 

Unidentified Larval Fishes: 

righteye flounders 

Pleuronectes spp. 

Pleuronectes isolepis (Lockington 1880) 

Pleuronichthys spp. 

Pleuronichthys coenosus Girard 1854 

Pleuronichthys ritteri 

Starks & Morris 1907 

Pleuronichthys verticalis 

Jordan & Gilbert 1880 

Psettichthys melanostictus Girard 1854 

tonguefishes 

Symphurus atricauda — -

(Jordan & Gilbert 1880) 

righteye flounders 

butter sole 

turbots 

c-o turbot 

sponed turbot 

homyhead turbot 

sand sole 

California tonguefish 

Whole larval fishes 

Damaged larval fishes 

Larval fish fragments 

TENERA E9-055.0 5-14 Final 316(b) Demonstration 

March 1,2000 
5.0 Results 

Table 5.1-2. Total abundance, weight (grams), and average biomass (grams/million nP flow) of 

impinged fishes at Diablo Canyon Power Plant (DCPP) during 1985-86. Abundance and weight 

are totals for the sampling periods; biomass is the number of grams per million n>3 of water flow 

during the collection periods. 

Tason Scientific Name 

BON Y FISHES (Osteicbthyes) 

Engraulididae 

Batrachoididae 

Ophididae 

Gobiesocidae 

Atherinidae 

Gasterosteidae 

Syngnathidae 

Scorpaenidae 

Hexagrammidae 

Cottidae 

Agonidae 

Cyclopteridae 

Carangidae 

Sciaenidae 

Embiotocidae 

Labridae 

Pomacentridae 

Clinidae 

Stichaeidae 

Pholidae 

Scombridae 

Cynoglossidae 

Paralichthyidae 

Pleuronectidae 

Engrattlis mordax 

Porichthys notatus 

Chilara taylort 

Gobiesox maeattdricus 

Atherinops affinis 

Auloryhynchus flavidus 

Syngnathus californiensis 

Syngnathus spp. 

Syngnathidae unid. 

Sebastes atroviretts 

Sebastes carnatus 

Sebastesflavidus 

Sebastes jordani 

Sebastes melanops 

Sebastes mystinus 

Sebastes paucispinis 

Sebastes rastrelliger 

Sebastes serranoides 

• Sebastes serranoides/ftavidus 

Sebastes spp. 

Hexagrammos decagrammtts 

Oxyiebius pictus 

Zaniolepis /atipitmis 

Artedius creaseri 

Artedius carallinus 

Artedius lateralis 

Artedius notosplitotus 

Cottidae 

OUgocottus mtmtiasns 

OUgocottus rubellio 

Orthonopias triads 

Scorpaenichthys marmoratus 

Agonopsis sterlrhts 

Liparis mucosus 

Trachurus symmetricus 

Seriphus potitus 

Amphislichus argenteus 

Brachyistius fremitus 

Cymatogaster aggregata 

Embiotoca jacksoni 

Embiotoca lateralis 

Embiotocidae 

Hyperprosopon argenteum 

Micrometrus minimus 

Phanerodon furcatus 

Oxyjulis californica 

Chromis pttnetipimtis 

Gibbonsia erythra 

Gibbonsia melzi 

Gibbonsia montereyensis 

Gibbonsia spp. 

Anoplarchtts pttrpurescens 

Ulvicola sunctaerosue 

Xerepes fttcorum 

Scomber japonicus 

Symphurus atricauda 

('ilharichlhys stigmaeus 

Xystreurys liolepis 

Pleuronectidae unid. 

Microslomns pacificus 

Plettrottichlhys coenosus 

Sharks and Rays (Chondrichthyes) 

Rajidac 

Torpedinidae 

Platyrhinidae 

Dasyatididae 

Chimeridae 

Raja binoculata 

Torpedo californica 

PlatyrhinoiiMs triseriata 

(Irotophus halteri 

Hydrolagus collet 

Common Name 

Total All Fi.hu: 

northern anchovy 

plainfin midshipman 

spotted cusk-eel 

notlhern clingfish 

topsmelt 

tubesnout 

kelp pipefish 

unidentified pipefish 

unidentified pipefish 

kelp rockfish 

gopher rockfish 

yellowtail rockfish 

shortbelly rockfish 

black rockfish 

blue rockfish 

boccacio 

grass rockfish 

olive rockfish 

olive/yellowtail rockfish 

unidentified rockfish 

kelp greenling 

painted greenling 

longspine combfish 

roughcheek sculpin 

coralline sculpin 

smoothhead sculpin 

bonyhead sculpin 

unidentified sculpin 

tidepool sculpin 

rosy sculpin 

snubnose sculpin 

cabezon 

southern poacher 

slimy snailfish 

jack mackerel 

queenfish 

barred surfperch 

kelp surfperch 

shiner surfperch 

black surfperch 

striped surfperch 

unidentified surfperch 

walleye surfperch 

dwarf surfperch 

white surfperch 

senorita 

blacksmith 

scarlet kelpfish 

striped kelpfish 

crevice kelpfish 

unidentified kelpfish 

high cockscomb 

kelp gunnel 

rockweed gunnel 

Pacific mackerel 

California tonguefish 

speckled sanddab 

fantail sole 

unidentified uirbot or sole 

dover sole 

C-0 turbot 

Total Fishes: 

big skate 

Pacific electric ray 

thornback ray 

round stingray 

sponed ratfish 

Total Sharks and Rays: 

02/05/85 - 03/31/85 

Unit I 

Abun. Weight 

11 1421 

1 23.8 

1 48 

1 70.2 

1 143 1 

1 58 

1 2734 

1 296.3 

1 6 4 

1 20 7 

9 844.5 

1 374 4 

1 202.1 

2 576.5 

Bio. 

6.49 

0 11 

0.02 

0 32 

0 65 

0.03 

1.24 

135 

0.03 

0.03 

009 

3.87 

170 

092 

2.62 

Uniti Unit 2 

Abundance 

262 

II 

2 

1 

7 

8 

2 

6 

2 

34 

1 

5 

2 

19 

7 

6 

1 

1 

1 

8 

7 

1 

1 

1 

2 

5 

1 

1 

1 

2 

2 

6 

17 

2 

3 

3 

2 

1 

1 

1 

8 

4 

2 

1 

1 

2 

2 

4 

9 

1 

1 

223 

3 

10 

23 

3 

39 

140 

1 

8 

1 

2 

6 

4 

1 

3 

1 

14 

1 

3 

9 

3 

2 

1 

2 

3 

4 

1 

3 

7 

3 

3 

1 

1 

2 

2 

2 

2 

1 

2 

100 

2 

4 

32 

1 

1 

40 

04/01/85 -

Uniti 

03/31/86 

Unit 2 

Weight 

I4441J 

10566 

2 6 

11.0 

145 

1435 

6 9 

0.7 

509.2 

84 

2073 

16 

3 9 

3264 

7.8 

484.7 

46.3 

21.4 

59 

29.3 

24 

744 

37.7 

2.3 

35 

3.1 

9.2 

292 

4.9 

3.0 

3294 

8.2 

10 0 

79 8 

212.3 

5174 

1907 

45.3 

23.0 

7.7 

3 6 

1095 

145.0 

164 

265 

3.3 

85 

801 7 

6.8 

4.7 

8692 

17 

328 

74.8 

6586.0 

860 

1830 2 

46874 

1251.7 

7855.3 

12746.2 

24.0 

658.2 

7.7 

55.5 

23.2 

40.2 

5.3 

21.9 

2.0 

144.5 

34 

152 1 

543.4 

16.2 

6.5 

29.0 

6.2 

12.8 

22.7 

7.8 

3868 

40.5 

29.1 

103.8 

4.1 

160 

66,7 

12.8 

4,7 

555 

23 4 

4 9 

7334 

3261.8 

73.6 

693 2 

7475.9 

407.9 

833.8 

94*4.4 

Unit 1 Unit 2 

Biomass 

65.64 

4.80 

001 

O.OS 

0.07 

065 

0.03 

<0.0l 

2.31 

004 

0.94 

0.01 

0.02 

1.48 

0.04 

2.20 

0.21 

0.10 

0.03 

0.13 

001 

0.34 

0.17 

.0.01 

0.02 

0.01 

0.04 

0.13 

0.02 

0.01 

ISO 

004 

0.05 

0 36 

097 

2.35 

0 87 

0.21 

0.10 

004 

0.02 

0.50 

0.66 

0 07 

0 12 

0.02 

004 

364 

003 

0.02 

3 95 

0.01 

0 15 

0 34 

29.94 

039 

8.32 

21.31 

569 

35.71 

148.21 

0.28 

765 

0.09 

065 

0.27 

047 

0.06 

0.25 

0.02 

168 

004 

1.77 

6.32 

0 19 

0.05 

034 

007 

0.15 

0.26 

0.09 

4.50 

0.47 

034 

1 21 

0 05 

0 19 

0 78 

015 

005 

065 

0.27 

0.06 

853 

37.93 

086 

806 

8693 

4.74 

9 70 

110.28 

TENERA E9-055.0 5-15 Final 316(b) Demonstration 

March 1,2000 
P.29 

5.0 Results 

Table 5.1-3. Biomass (grams/million m^ flow) of impinged Cancer spp. 

crabs at DCPP from April 1985 through March 1986. 

Species Unit 1 Unit 2 

21.69 

0.88 

1.97 

0.27 

Cancer antennarius 

Cancer anthonyi 

Cancer productus 

Cancerjordani 

Cancer magister 

Cancer spp. 

Cancer gracilis 

27.43 

0.02 

0.47 

0.42 

0.01 

0.03 

0.29 

0.01 

TOTAL 28.67 24.82 

TENERA E9-055.0 5-16 Final 316(b) Demonstration 

March 1,2000 
P.30 

5.0 Results 

Red Sea Urchins (Strongylocentrotus franciscanus) 

t 

HI 

1.77 

1.6-

1.57 

1.4 -

1.3 -

1.2 

1.1 

1.0 

0.9 

o.s 

0.7 

0.6 -

os

~ 

0.4 -

0.3 -

0.2~ 

0.1 -

0.0 - T? 

Ml III I III 11II Ml III IIIIII I Hill 111 1 • 1111111111 T 111 1111111111 1 111 

DJFMAM J 

Survey Date 

• Ctosignatessurveywithdensity=0 

Purple Sea Urchins (Strongylocentrotus purpuratus) 

1= 

UJ 

I 

CO 

c 

C9 O 

c 

& 

IS 

1 4 -

1 3 -

1 2 -

11 ~ 

1 0 -

9 -

8 — 

7 -

6 -

5 -

4 -

3 -

2 " 

1 -

0 - i iL 

IIIIIIIIIIIIIIIIIIIIIIIIIIIIIII|II I 

IJFMAMJJ A 

fi'ininnfifrinfir» 

11111 HI 111 

.lisi Ilia. J 

11 IIIIIII I 111 nil 

N I D I J I F | 

II IIII IIIIIII 

M A M 

11 IIIIII IIII I 

J J A 

11111111111111 

S O N 

IIIIIIIIIIIIIIIIIIIIIIMII 

J F M A I M | J 

Survey Date 

• designalessurveywrthdensity=0 

Figure 5.1-1. Weekly mean larval density (#/m3 + 1 S.E.) at the DCPP intake. Y-axis 

scale varies between graphs. 

TENERA E9-055.0 5-17 Final 316(b) Demonstration 

March 1,2000 
P.31 

«~ 5 

I 

U- 3 

« 

o ° 1 o

 1 

.>. 

"5 

D n 

5.0 Results 

DCPP Unit 1 Flow During Weekly Impingemen t Samplin g 1985-1986 

Feb Mar , Apr May Jun Jul Aug Sep Oct Nov Dec Jan Fab 

1985 1986 

Number of Unit 1 Traveling Screens Operating During Weekly Impingement Sampling 1985-1986 

w 8 

* * 

E « 

3 2 i Fab Mv Apr May Jun Jul Aug Sep Oct Nov Oae Jan Fab 

1985 1986 

Zr « 

i o 

£ i 

_c 

•5 

o u 

"(5 

o 

2 

DCPP Unit 2 Flow During Weekly Impingement Sampling 1985-1986 

Feb Mar Apr May Jun Jul Aug Sep Oo \ov Oec Jen Feb 

1985 1986 

Number of Unit 2 Traveling Screens Operating During Weekly Impingement Sampling 1985-1986 

0) 6 

5 2 

Feb Mar Apr May Jun Jul Aug Sep Oct Nov Oec Jan Feb Mar 

1985 1986 

Figure 5.1-2. DCPP intake operational status: cooling water pump (CWP) daily water flow and 

number of traveling screens operating on impingement sampling days. Bold bars indicate days 

when all pumps and traveling screens operated concurrently. Each unit has two pumps and seven 

traveling screens (six for the CWP and one for the auxiliary seawater system). 

TENERA E9-055.0 5-18 Final 316(b) Demonstration 

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P.32 

5.0 Results 

UNITI 

o 

_Q 

E 

3 

30 

20 

10 

Unit 1 Fishes (n) 

No samples 

24 Mar to 

29 Apr""" 

11 shiner 

surfperch No. samples 

on 2 Dec 

/—T^'V K^v^TV 

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Jan Feb Mar Apr 

~ 3000 

2000 

1985 1986 

1000 

Unit 1 Weight (g) 

^A^^ZyJ\ P^" ** vJWV.A 

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Oec Jan Feb Mar Apr 

E 

a 

o 

> 

a 

• c 

2 

E 

_c 

Ol 

1 

250 

200 4-

150 

100 -

50 ... _•>_ 

^rm* 3* 

1 1 -H— - 1 1 1 

. .« / .. • 

J 1 1 1 «4—« 1 1 ! 1 

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Jan Feb Mar Apr 

UNTT2 

30 

20 

10 

Unit 2 Fishes (n) 

14 juvenile 10thombackrays 

--rockfish j7 .t'g'twa 

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Jan Feb Mar Apr 

a 3000 

2000 

1985 1986 

1000 

Unit 2 Weight (g) 10tnombackrays 

5 thomback rays 

No Unit 2 Impingement 

. Sam pling 24 Apr to 30 Jul. \s\ 

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Jan Feb Mar Apr 

o 

> 

a o 

a 

250 

200 

150 

100 

50 

Unit 2 Debris (gal) 

- * • '» > . 

•"••.-•• • 

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Jan Feb Mar Apr 

Figure 5.1-3 Comparison of fish abundance (n) and weight (g), and seaweed debris yolume 

(gallons) collected in DCPP Unit 1 and 2 impingement samples. 

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P.33 

Blank Page 
P.34 

5.2.1 Cancer Crabs 

5.2 Assessment of Effects on Target Taxa 

The effects of larval entrainment mortality caused by the DCPP cooling water intake system were 

assessed for 16 target taxa. In the following sections, life history and distribution information 

describing the adult and early life stages of these taxa were summarized to give context to the 

subsequent estimates of entrainment effects. The data generated from the various sampling 

programs were then used to estimate effects of larval entrainment mortality using demographic 

data for hindcasting (FH) or prediction (AEL) of adult losses, or were translated directly into 

proportional annual losses to the local larval population (PM). 

5.2.1 Assessment of Target Taxa in the Crab Genus Cancer 

Crabs ofthe genus Cancer are widely distributed in coastal waters ofthe west coast of North 

America (Nations 1975). They occur in intertidal and shallow subtidal habitats on both rock and 

sand substrate. Ofthe nine species known to occur in the northeast Pacific, four species 

contribute to economically significant fisheries. Dungeness crab (Cancer magister) has the 

highest economic value among these, and three species of rock crabs (C. anthonyi, C. 

antennarius, and C. productus) comprise the remainder ofthe catches. Seven species of Cancer 

larvae have been collected in the DCPP entrainment study and are listed here (in order of relative 

abundance): 

Common name Scientific Name 

Brown rock crab C. antennarius 

Slender crab C. gracilis 

Hairy rock crab C. jordani 

Red rock crab C. productus 

Yellow crab C. anthonyi 

Dungeness crab C. magister 

unknown sp. A Cancer spp. 

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P.35 

5.2.1 Cancer Crabs 

The two most abundant species (brown rock crab and slender crab) were selected for a detailed 

impact assessment in this report. The other five species were not consistently abundant enough in 

the study to be analyzed. 

All species of Cancer crabs share certain fundamental life history traits. Eggs are extruded from 

the ovaries through an oviduct and are carried in a sponge-like mass beneath the abdominal flap 

ofthe adult female. After a development period of several weeks, the eggs hatch and a pre-zoea 

larva emerges, beginning the planktonic life history phase. As in all crustaceans, growth 

progresses through a series of molts. The planktonic larvae advance through six stages of 

successive increases in size: five zoea (not including the brief pre-zoea stage) and one megalopal. 

After several weeks as planktonic larvae, the crabs metamorphose into the first crab stage (first 

instar) and settle out to begin their benthic life history phase. Maturity is generally attained within 

1-2 yr. Mature females mate while in the soft shell molt condition and extrude fertilized eggs 

onto the abdominal pleopods. Females generally produce one or two batches per yr, typically in 

winter. Fecundity per batch increases significantly with female body size (Hines 1991). 

Each species in the genus has characteristic differences in distribution, preferred habitat, growth 

rates, and demographic parameters. For example, brown rock crab is a relatively large species 

(carapace width >200 mm) that lives primarily on sand and mud substrates in estuarine and 

coastal shelf areas. Slender crab is a smaller species (carapace width >130 mm) associated with 

mixed rock-sand substrates in shallow outer coast habitats. Maximum clutch sizes in Cancer 

crabs can range from as many as 5,000,000 eggs in C. anthonyi to approximately 50,000 in C. 

oregonensis, one ofthe smaller species (Hines 1991). These types of differences imply that 

specific information on life history parameters cannot readily be generalized among Cancer 

species. 

Rock crabs are fished along the entire California coast (Leet et al. 1992). Three species are 

harvested commercially: brown rock crab, red rock crab, and yellow crab. There is no 

commercial fishery for the slender crab. The rock crab fishery is most important in southem 

California (from Morro Bay south), which produces a majority ofthe landings, and of lesser 

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P.36 

I 5.2.1 Cancer Crabs 

importance in northern areas of California where a fishery for the more desirable Dungeness crab 

takes place. Recreational crabbing is popular in many areas and is often conducted in conjunction 

with other fishing activities. The commercial harvest has been difficult to assess on a species-byspecies basis because the fishery statistics are combined into the general "rock crab" category. 

Rock crab landings in California in 1990 were 818 MT, including the landings of crab claws only 

that were converted to whole weight (Leet et al. 1992). Rock crab landings from five ports near 

the Monterey Bay National Marine Sanctuary averaged 92 MT/yr from 1980-1995 (Starr et al. 

1998). 

5.2.1.1 Brown rock crab (Cancer antennarius) 

Cancer antennarius Stimpson 1856; brown rock crab; carapace width to 15.5 

cm (6.1 in); Queen Charlotte Sound, British Columbia to Cabo San Lucas, 

Baja California; intertidal to >100 m (328 ft); mottled dark brown dorsally 

with red spotting over a white background ventrally (Jensen 1995; Carroll 

and Winn 1989). 

The brown rock crab primarily inhabits rocky shores and rocky subtidal reefs but may bury in 

coarse to silty sands adjacent to preferred habitat. Ovigerous brown rock crabs have been 

observed buried in sand at the base of rocks in shallow water and are found more commonly in 

water less than 18 m (59 ft) deep in southern California. Brown rock crab females can extrude 

between approximately 156,000 and 5 million eggs per batch (Hines 1991; Table 5.2.1-1). 

Females on average produce a single batch per year; however, due to occasional multiple 

spawnings, the average number of batches per year may be greater than one (Carroll 1982). 

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5.2.1 Cancer Crabs 

Eggs require a development time of approximately 7-8 wk from extrusion to hatching (Carroll 

1982). Larval development in the brown rock crab was described by Roesijadi (1976). Eggs 

hatch into pre-zoea larvae that molt to first stage zoea in less than l h. Average larval 

development time (from hatching through completion ofthe fifth stage) was 36 d at 13.8 °C. 

Although some crabs molted to the megalops stage, none molted to the first crab instar stage, so 

the actual duration ofthe megalops stage is unknown. A reasonable estimate can be derived from 

studies of slender'crab by Ally (1975), who found an average duration of megalops stage of 

14.6 d. Therefore, the estimated length of time from hatching to settling for brown rock crab is 

approximately 50 d.-

During their planktonic existence, crab larvae can become widely distributed in nearshore waters. 

In a study in Monterey Bay, Graham (1989) found that brown rock crab stage 1 zoeae are most 

abundant close to shore and that subsequent zoea stages tend to remain within a few kilometers of 

the coastline. The adult population primarily resides in relatively shallow rocky areas, and the 

nearshore retention of larvae in Graham's study (1989) was related to the formation of an 

oceanographic frontal zone in northern Monterey Bay that prevented substantial offshore 

transport during upwelling periods. 

The nearshore distribution of crab larvae depends upon developmental stage. Shanks (1985) 

presented evidence that early stage larvae of rock crabs (probably yellow crab in his southern 

California study) generally occur near the bottom, in depths up to 80 m; late stage larvae, 

however, were more abundant near the surface. He suggested that a combination of physical 

factors (primarily including wind-generated surface currents and tidally forced internal waves) 

caused megalopae to be transported shoreward. Late stage larvae (megalops) generally begin to 

recruit to the nearshore habitat in spring (Winn 1985). 

There are no published estimates of brown rock crab larval mortality. However, data from the 

abundance of zoea and megalops in the DCPP entrainment subsamples (Appendix I) can be used 

to estimate mortality between stages. First stage zoea ofthe taxa Cancer antennarius, C. 

anthonyi, and C. gracilis (combined because of uncertainties in identification) were substantially 

TENERA E9-055.0 5-23 Final 316(b) Demonstration 

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P.38 

5.2.1 Cancer Crabs 

more abundant, on average, than all other stages combined. The proportions of each species of 

zoea stage 1 were derived by using the proportions of each species in zoea stage 2 that could be 

identified to species. Larval mortality of brown rock crab was estimated from the entrainment 

data by comparing adjusted abundances of zoea stage 1 to abundance of megalops. Intermediate 

stages 2, 3,4, and 5 were not used in the estimate because they were significantly affected by 

offshore transport out ofthe study grid and would, therefore, be under-represented in the 

subsamples (Paul Reilly, California Department of Fish and Game, pers. comm.). Megalops of all 

species were more abundant than zoea stage 5 in the entrainment subsamples, indicating that 

many ofthe developing megalops were being transported back toward shore. 

An instantaneous larval mortality of 0.158/d was estimated by fitting an exponential curve to the 

estimated numbers of entrained zoea stage 1 (December 1996 through June 1998) and megalops 

(mid January 1997 through mid August 1998) and using 38 d as the time between stages (i.e., 5 d 

and 43.3 d, respectively). This procedure is fully described in the following section concerning 

fecundity hindcasting. Because brown rock crab megalops were more abundant close to shore 

than slender crab (Graham 1989), the mortality rate developed for brown rock crab is also 

applied to slender crab larvae (Section 5.2.1.2) that also have a duration of 38 d between zoea 

and megalops stages. 

Estimated weight at age was used in interpreting adult equivalent losses to the population. Brown 

rock crabs mature at an age of about 18 mo post-settlement with a size of approximately 60 mm 

carapace width and a weight of 73 g (Carroll 1982). Faster growth rates may occur in highly 

productive environments such as on the supporting members of offshore oil platforms (Dan 

Dugan, Tenera Environmental, pers. comm.). A growth curve for brown rock crab was estimated 

based on asymptotic carapace width and weight (155 mm and 1,050 g for males, 145 mm and 

683 g for females), and a growth rate between instars from tag recovery data (ranging from 7-

26 % with smaller crabs growing at the highest rate), for a maximum of 12-13 post-larval instars. 

Brown rock crabs can probably live to a maximum age of about 6 yr. Size at recruitment to the 

fishery is approximately 125 mm carapace width at age 4 yr for males and 4.5 yr for females. 

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March 1,2000 
5.2.1 Cancer Crabs 

Summary of Field Collections 

Brown rock crab zoeae were removed from subsamples collected at the DCPP intake structure 

from December 1996 through June 1998 while megalopae were removed for the period October 

1996 through June 1999. Zoeae were removed from only some ofthe subsamples collected 

during two grid surveys in 1998. Megalopae were removed from subsamples from the study grid 

from July 1997 until June 1999. Estimated density (numbers per volume of water filtered) of 

zoeae and megalopae from the processed subsamples are presented in Appendix H. The 

estimated weekly number of zoeae and megalopae entrained (Appendix I) was calculated by 

multiplying the estimated larval density by the volume of water drawn through the CWS. 

Abundance of both zoea and megalops was greatest in the spring although zoea 1 began to appear 

in winter months (Figure 5.2.1-1). 

Larval densities were estimated from bongo net subsamples collected at the DCPP intake 

structure between October 1996 and June 1999; for a daily sampling event there were generally 

32 to 64 subsamples processed for estimating megalops densities and 8 subsamples processed for 

estimating zoea densities. Of a possible 5,524 entrainment subsamples processed for megalopae, 

665 (12%) were positive for brown rock crab. Megalops densities in entrainment subsamples 

were highest during 1997 and lowest in 1999 (Figure 5.2.1-1). Of 636 subsamples processed for 

zoea, the percentages of subsamples by stage were: 83% zoea stage 1,26% zoea 2, 14% zoea 3, 6 

% zoea 4 and 2% zoea 5. 

Megalops densities in the DCPP study grid were highest in May and June of 1998 and 1999, but 

much higher in 1998 than in 1999 (Figure 5.2.1-2). Of 3,168 bongo net subsamples collected in 

the grid, 13% contained brown rock crab megalopae. 

Estimating Total Annual Entrainment 

Estimates of annual entrainment (ET ) ofthe five zoea and one megalops stages of brown rock 

crab during the two analysis periods (December 1, 1996-November 30, 1997 and July 1, 1997— 

June 30, 1998) are presented in Table 5.2.1-2. The date ofthe first analysis period for zoea was 

adjusted from October 1996 through September 1997 to December 1996 through November 1997 

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5.2.1 Cancer Crabs 

because the entrainment subsamples collected during October and November 1996 were not 

processed for zoea. Generally there were fewer individuals of each older stage. Although 

estimates of zoea stages 1-4 abundances were approximately equal between the two analysis 

periods, the greater abundance of zoea stage 5 during 1998 for Analysis Period 3 (ET = 

111,000,000) did not result in an increased megalops abundances for that period. Estimated 

megalops abundance was actually greater during 1997, Analysis Period 1 (ET = 56,500,000) than 

during 1998, Analysis Period 3 (ET - 24,500,000). The estimates of annually-entrained brown 

rock crab were not adjusted to a long-term average because crab larvae were not enumerated in 

the Intake Cove surface plankton tow samples. 

Fecundity Hindcasting (FHj 

The FH method requires age-specific mortality and fecundity to assess entrainment effects. A 

single value for instantaneous mortality, Z, was estimated for the two analysis periods by fitting 

an exponential curve to the zoea 1 and megalops entrainment estimates. The survival rate to 43.3 

d post hatching was estimated for all larval stages using an exponential survival model: 

N,=N0ez('-h) 

where the estimated entrainment of zoea stage 1 (NQ at time tQ =5) and megalops (Nt at time 

t=43.3) stages were used to estimate the rate Z. Zoea 1 abundance was estimated as the fraction 

of brown rock crab stage 2 larvae times the number ofthe unidentified zoea 1. The instantaneous 

mortality rate, Z, can then be solved from the two larval stage abundances (zoea 1, December 

1996 through June 1998 and megalops, mid January 1997 through mid August 1998) as 

f 34,600,000,000 "| 

_

 n[ 80,100,000 J . , „ . Z=— — = 0.158 per day . 

43.3-5 

An estimated survival through larval stages can then be calculated as Slanai. = e<_0158)', where / is 

reported in Table 5.2.1-3 as mean cumulative duration. Cumulative survival estimates to stage 

midpoint were 

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5.2.1 Cancer Crabs 

1) 

2) 

3) 

4) 

5) 

zoea 1 

zoea 2 

zoea 3 

zoea 4 

zoea 5 

0.454 

0.128 

0.0497 

0.0193 

0.00637 

6) megalops 0.00107. 

The FH approach combines larval entrainment losses with survival and adult fecundity to 

hindcast the numbers of adult females effectively removed from the reproductively active 

population. An estimate of mean annual fecundity is 1,756,450 eggs. The number of reproductive 

years was estimated by halving the range between age of maturity of 1.5 yr and longevity of 4 yr. 

A longevity of 4 yr was chosen because of low abundance of older animals found in a trapping 

study (Jay Carroll, Tenera, pers. comm.). Coefficients of variation of survival, fecundity, and 

ages of maturation and longevity are not well known and are therefore reasonably assumed to be 

100% with a lognormal error structure. 

The number of female brown rock crabs estimated to produce the entrained larvae was calculated 

for the five zoea and one megalops stage for the two. All larval stages were hindcast and the 

estimated numbers of females and variances of estimates were added to compute an estimate of 

total number of brown crab females and the variance ofthe estimate. 

The estimated FH values for zoea and megalops stages for the period December 1, 1996 through 

November 30, 1997 from Table 5.2.1-2 were 

FHi =17,500 females with SE(FH, )= 39,000 

FHi = 16,300 females with SE(FH2)= 38,100 

FH3 = 43,300 females with SE(FH,) = 104,000 

FH, = 15,700 females with SE(FHr)= 37,400 

FH, = 239 females with SE(FH,)= 626 

FHMegs = 24,100 females with SE(FHMegs) = 53,400 

The total estimated number of breeding females needed to produce the total number of larvae 

entrained during the period was calculated by summing the FH, over all stages: 

TENERA E9-055.0 5-27 Final 316(b) Demonstration 

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5.2.1 Cancer Crabs 

FH = 117,000 females 

I 6 2 

with SE(FH)=S^SE, (FH, J = 134,000. An approximate 90% confidence interval for FH, 

V 1=1 

based on a lognormal error structure, is estimated as 17,700 to 773,000 females. 

The estimated FH values for zoea and megalops stages for the period July 1, 1997 through June 

30, 1998 from Table 5.2.1-2 were 

FH, = 18,600 females with SE(FHt) = 41,700 

FHz = 13,400 females with SE(FHz) = 30,500 

FH, = 22,100 females with SE(FH,) = 51,700 

FHr= 18,500 females with SE(FH4) = 46,300 

FHs = 7,950 females with SE(FHs )= 20,100 

FHuegs = 10,400 females with SE(FHMegs) = 23,100 

The total estimated number of breeding females needed to produce the total number of larvae 

entrained during this period was calculated by summing the stage specific estimates as 

FH = 91,000 females 

. I 6 2 

with SE(FH)= jY1SEi (FHA = 91,800. An approximate 90% confidence interval for FH, 

based on a lognormal error structure, is estimated as 17,300 to 478,000 females. 

Sensitivity Analysis 

In addition to calculating a confidence interval, a sensitivity analysis (Table 5.2.1-2) for all larval 

stages was perfonned in which FH was recomputed by varying the input parameter of estimated 

annual entrainment, ET , by ± 1.645 SEI £7- j and survival, S, by using a multiplicative enor 

structure (i.e. Se ''') and using CVl S\ = 1.0 . The range of survival estimates for all stages 

produced the same relative changes in FH as expected based upon a constant multiplier. 

However, FH was less sensitive to entrainment than survival variation. This difference was 

greatest for the megalops stage and can be explained by the use of sampling variance for 

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5.2.1 Cancer Crabs 

estimating entrainment variability for all stages with CTs of close to or less than 100%. 

Therefore, improvement in the precision of FH can result from improved estimates ofthe larval 

stages' survival. 

Females that reach reproductive size are not subject to fishery capture due to their small size. 

Therefore, the FH should be extrapolated to fishery size because it will provide more 

meaningful results for subsequent comparisons. Adult survival can be estimated for brown rock 

crab as 0.088 yr 1 (based on data in Carroll 1982). Hankin et al. (1989) estimated adult survival 

for dungeness crab exceeding 155 mm as 0.11 yr^. Therefore, the estimates of FH(l 17,000 and 

90,900 female crabs) can be reasonably extended to full fishery recruitment from the 

representative female age of 2.3 yr (one third between 1.5 and 4 yr) by applying a survival of 0.1 

for an additional year. This would result in a population-wide loss of 11,700 and 9,100 as the two 

yearly estimates of fishery recruit-size females lost due to entrainment. 

Adult Equivalent Loss (AELJ 

The AEL approach uses estimates ofthe abundance of entrained organisms to project the loss of 

equivalent numbers of adults based on mortality schedules and age at recruitment. Survival rates 

from entrainment of megalopae to recruitment into fishery are not available. However, assuming 

a 50:50 sex ratio, AEL and FH can be compared as AEL = 2FH = 234,000 and 182,000 adults, 

with an associated standard error of SE(AEl) = 2SE(FH) = 269,000 and 184,000. 

To reiterate, females that reach reproductive size are not subject to fishery capture due to their 

small size. Therefore, the AEL also should be extrapolated to fishery size. Adult survival can be 

estimated for brown rock crab as 0.088 yr 1 (Carroll 1982). Hankin et al. (1989) estimated adult 

survival for dungeness crab exceeding 155 mm as 0.11 yr 1. Therefore, the estimate of AEL 

(234,000 and 182,000 crabs) can be reasonably extended to full fishery recruitment from the 

representative female age of 2.3 yr (one third between 1.5 and 4 yr) by applying a survival of 0.1 

for an additional year. This would result in a population-wide loss of 23,400 and 18,200 as the 

two yearly estimates of fishery recruits lost due to entrainment. 

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5.2.1 Cancer Crabs 

Empirical Transport Model (ETMy 

The ETM assessment requires estimates of larval stage duration and larval density in entrainment 

and grid subsamples. The crab data were collected for only the megalops larval stage in the grid 

subsamples and will be compared to megalops stage larvae in the entrainment subsamples. 

Two entrainment mortality estimates are presented: for July l, 1997 through June 30, 1998 and 

for July• 1, 1998 through June 30, 1999. Brown rock crab larvae may be susceptible to 

entrainment by the plant for approximately 43 d, the average age of a megalop. Although the 

duration is more than one month, each monthly survey period will be assumed to represent 

discrete groups of larvae, permitting two independent weighted estimates of total entrainment 

mortality from 24 subsamples. Total annual entrainment mortality (PM) is estimated from the 

values of PE, and / for each survey period (Table 5.2.1-4), based on larval densities from 

entrainment (Figure 5.2.1-1) and grid surveys (Figure 5.2.1-2). 

The proportion ofthe population within the nearshore study grid was based on a linear 

extrapolation of densities in the grid in the offshore direction and displacement in the alongshore 

direction. Table 5.2.1-4 shows monthly estimates of entrainment proportions, of survey period to 

survey grid abundance (PE,; based upon paired surveys) and of survey period to yearly 

entrainment (ft; based upon weekly subsamples), for brown rock crab. PE, from the two years 

sampled ranged from a minimum of zero to a maximum of 0.0254±0.0219 (±]SE(PE,)) in 

October 1997. Because estimated per period survival is weighted to form an annual mortality 

estimate, the largest values of f, (and of associated PE, ) have the largest effects on the estimate 

(July and June 1998). No larvae were collected at either the DCPP intake or the study grid when 

both PE, and the annual proportion of larvae hatched (ff) in the rth survey period were equal to 

zero (September 1998, February 1999, and March 1999). When PE, =0 and ^>0, larvae were 

collected at the DCPP intake during the survey period but not during the entrainment survey 

paired with the 72-hr study grid survey. Low values of fi indicate periods ofthe year when 

brown rock crab megalops are least abundant in weekly entrainment subsamples. While June and 

July 1998 entrainment fractions were highest overall, May and June 1998 densities were highest 

in the study grid (Figure 5.2.1-2). 

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5.2.1 Cancer Crabs 

Total annual entrainment mortality from the ETM is estimated as PK1 = 0.0000186 for the period 

July l, 1997 through June 30, 1998 and TM = 0.000146 for the period July l, 1998 through June 

30, 1999 with associated standard errors of SE(PM)= 0.2327 and 0.0325, respectively (Figure 

5.2.1-3). The sensitivity analysis considers the effect of varying values of Ps on the outcome of 

the ETM calculations shown in Figure 5.2.1-3 for the two periods. The values of PM resulting 

from calculations using only the alongshore displacement were higher (0.00563 and 0.00652) 

than those reported for the offshore extrapolated densities (0.0000186 and 0.000146). Values of 

p] ranged from 0.000386 to 0.00239 for TM extrapolated offshore and ranged from 0.11 to 0.13 

for alongshore only. 

Interpretation of Assessment Results 

The ETM estimate of entrainment mortality of megalopae can be assumed to apply to all stages of 

larval mortality at DCPP and, by extension, can be applied to the adult crab population or to 

harvest assuming no compensation. Estimates of stock size and density that could be used to 

convert PM into an estimate of adult equivalent loss (assuming no compensatory mortality) are 

not available. Although PM was estimated using both alongshore current displacement and 

density extrapolation offshore, the estimate using alongshore currents was used in assessing 

fishery value because it was more representative ofthe areas actively fished for rock crab. The 

rock crab fishery does not extend into the offshore areas included in the extrapolation. 

Brown rock crabs have both commercial and recreational fishery value. An area that contains the 

population at risk, predicted by using the average alongshore displacements of 140 km to 160 km 

(Figure 5.2.1-3), is limited to the region where crabs are landed at the ports of Morro Bay and 

Avila. From 1975 to 1998 an average of 135,200 kg of rock crabs were landed at Morro_Bay and 

Avila (Figure 5.2.1-4). An ex-vessel price of $2.32 per kg and average weight of 0.34 and 0.45 

kg for females and males, respectively, is reported for the Morro Bay area catch (Deborah 

Johnston, California Department of Fish and Game, pers. comm.). The estimated mortality rates 

from the ETM using alongshore extension (PM = 0.00563 and 0.00652) are applied to the 

average landings. Assuming that the proportional effect of entrainment mortality on the larval 

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5.2.1 Cancer Crabs 

population also acts on the adult population, then the average yearly historical Mono Bay area 

catch is affected by the same proportion, which equates to 760 and 880 kg of crabs for the two 

years, respectively. In terms of monetary value, the yearly valuation would be $1,760 and $2,040 

for the two years. 

The AEL model estimates are assigned to population-wide losses but can be compared to the 

fishery using the ex-vessel price and average weight of 0.4 kg. Crabs that reach reproductive size 

are not subject to fishery capture due to their small size. Therefore, the number of estimated 

adults lost to the population is extrapolated to fishery size, and the resulting two yearly estimates 

of 23,400 and 18,200 crabs lost to the population per yr represent $21,700 and $16,900, 7% and 

5% of individuals in an average annual catch (based on an average annual catch of 135,200 kg 

and 0.4 kg per crab). These values overestimate fishery losses since proportional reductions of 

numbers due to catchability, trapping selectivity, and fishing effort are not considered. In an 

experimental trapping study by Carroll (1982), tag returns on over 9,000 brown rock crab along 

the Diablo Canyon coastline averaged 6.3%. Further, fewer than 0.1% ofthe tagged crabs were 

recovered in the local commercial fishery over the course ofthe 5-year study. Although there 

were no data available on commercial fishing effort during that period, a conservative estimate 

that 10% ofthe fishery-sized crabs in the population were actually landed per year would reduce 

the valuation ofthe FH and AEL losses by one order of magnitude. 

The ETM-based loss assessments of $1,760 to $2,040 use a more appropriate valuation method 

because it considers catch as a proportion ofthe population and is also conservative because it is 

calculated using the larger values of PM (i.e., based on an alongshore-only translation ofthe 

survey grid numbers). Because ofthe low estimated population mortality by power plant 

entrainment (alongshore and offshore-based PM = 0.0000186 and 0.000146), effects on the 

brown rock crab population are probably low. 

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5.2.1 Cancer Crabs 

5.2.1.2 Slender crab (Cancer gracilis) 

Cancer gracilis Dana 1852; slender crab; carapace width to 11.5 cm (4.5 in); 

Prince William Sound, Alaska to Bahia Playa Maria, Mexico; low intertidal 

to 143 m (470 ft); carapace purple with white edging; claws with white tips, 

legs purple (Jensen 1995). 

The slender crab is commonly found on mud flats and in beds of eelgrass although it is usually 

not found intertidal ly south of central California (Morris et al. 1980). Although seasonally found 

in bays, the slender crab does not tolerate brackish conditions. Slender crabs can extrude between 

approximately 143,000 and 1,000,000 eggs per batch (Hines 1991; Table 5.2.1-5). Females, on 

average, produce a single batch per yr. Total lifetime spawning occurs over a maximum of three 

seasons and more commonly only two (Orensanz and Gallucci 1988). In Elkhorn Slough, mating 

is common in November, and ovigerous females were noted in July and August (Morris et al. 

1980). Farther north, in Puget Sound, animals held in the laboratory bore eggs from December to 

April, and a few females produced a small second batch. Graham (1989) recorded both spring 

and fall spawning periods in Monterey Bay. 

Larval development in the slender crab was described by Ally (1975). Eggs hatch into pre-zoea 

larvae, which quickly molt to first stage zoea. Average larval development time (from hatching 

through completion ofthe megalops stage) was 48.9 d at 17 °C, with most stages lasting 

approximately one week (Table 5.2.1-6). 

During their planktonic existence, crab larvae can become widely distributed in nearshore waters. 

In a study in Monterey Bay, Graham (1989) found that slender crab stage 1 zoeae were very 

abundant close to shore (within 6 km) during March and April. During an autumn spawning 

period in August, he found stage 1 zoeae concentrated approximately 11 km from shore. Later 

TENERA E9-055.0 5-33 Final 316(b) Demonstration 

March 1,2000 
5.2.1 Cancer Crabs 

stage larvae, including megalopae, were found further from shore during all times ofthe year. 

This offshore larval distribution, compared to the nearshore distribution of brown rock crab, 

reflects the fact that adult slender crabs are widely distributed in coastal shelf areas, further 

offshore than brown rock crabs. The megalops larvae and juvenile crabs are frequently found 

crawling unharmed on and under the bells, and even in the stomachs, of larger jellyfishes, 

especially Pelagia colorata (Monis et al. 1980). 

There are no published estimates of larval mortality in slender crab, except for in laboratory 

culture (Ally 1975). From December 1996 until July 1997, megalopae of C. gracilis were more 

abundant than all zoea stages 2-5 in the entrainment subsamples, indicating that many ofthe 

developing megalopae were being transported back toward shore. However, slender crab 

megalopae are less abundant close to shore than brown rock crab (Graham 1989). As a result, it is 

difficult to estimate slender crab larval survival from entrainment sampling. Therefore, data from 

the abundance of stage 1 zoeae and of megalopae for brown rock crab in the DCPP entrainment 

were used to estimate the larval mortality of slender crab. An instantaneous larval mortality of 

0.158/d, estimated for another species, the brown rock crab, and described in Section 5.2.1.1, 

was applied for estimating the number of females that produced the entrained slender crab. 

Based on field growth studies, it was estimated that slender crabs matured at an age of about 10 

months post-settlement to a size of approximately 60 mm carapace width (Orensanz and Gallucci 

1988). Growth occurs through 11-12 instars, with crabs attaining an estimated maximum age of 

4 yr post-settlement. 

Summary of Field Collections 

Cancer gracilis zoea were removed from subsamples collected at the DCPP intake structure from 

December 1996 through June 1998, while megalops were removed for the period October 1996 

through June 1999. Zoea were removed only from some ofthe subsamples collected during two 

grid surveys in 1998. Megalops were removed from subsamples from the study grid from July 

1997 until June 1999. Estimated density (numbers per volume of water filtered) of zoea and 

megalops from the processed subsamples are presented in Appendix H. The estimated weekly 

TENERA E9-055.0 5-34 , Final 316(b) Demonstration 

March 1,2000 
P.49 

5.2.1 Cancer Crabs 

number of zoea and megalops entrained (Appendix I) was calculated by multiplying the 

estimated larval density by the volume of water drawn through the CWS. Zoea abundance was 

greatest in the spring although zoea 1 began to appear in the entrainment subsamples during the 

winter months (Figure 5.2.1-5). Megalops were found throughout the entire year, with peak 

abundances in winter 1996-97, fall 1998, and spring 1999. 

Larval densities were estimated from bongo net subsamples collected at the DCPP intake 

structure between October 1996 and June 1999. For a daily sampling event there generally were 

32 to 64 subsamples processed for estimating megalops densities and eight subsamples processed 

for counting zoea. Of a possible 5,524 subsamples processed for megalopae, slender crab were 

found in 590 (11%). Megalops densities appear relatively constant with peaks in late fall and 

winter (Figure 5.2.1-5). Of 636 subsamples processed for zoea, the frequencies of subsamples by 

stage were 83% zoea 1,6% zoea 2,3% zoea 3, 1% zoea 4, and no zoea 5. 

Megalops densities in the DCPP offshore study grid were highest in May and June 1998 and 

frequently encountered at all other times, especially July 1997, April 1998, August 1998, 

September 1998, March 1999, and May 1999 (Figure 5.2.1-6). There were 3,168 bongo net 

subsamples processed for megalops, of which 15% contained slender crab megalops. 

Estimating Total Annual Entrainment 

As previously mentioned, estimates of entrainment of zoea 1 ofthe taxa brown rock crab, yellow 

crab, and slender crab were combined because of uncertainties in identification. The proportions 

of slender crab zoea stage 1 were derived by using the proportions of slender crab in zoea stage 2 

that could be identified to species. 

Estimates of annual entrainment (ET ) ofthe five zoea and one megalops stages of brown rock 

crab during the two analysis periods (December 1, 1996-November 30, 1997 and July 1, 1997-

June 30, 1998) are presented in Table 5.2.1-7. The date ofthe first analysis period for zoea was 

adjusted from October 1996 through September 1997 to December 1996 through November 1997 

because the entrainment subsamples collected during October and November 1996 were not 

TENERA E9-055.0 5-35 Final 316(b) Demonstration 

March 1,2000 
P.50 

5.2.1 Cancer Crabs 

processed for zoea. Generally there were fewer individuals of each older zoea stage, although no 

zoea stage 4 were collected during 1997 in Analysis Period 1, and no zoea stage 5 were collected 

in either period. Although zoea abundance overall was estimated to be less in 1997 during 

Analysis Period 1, the estimate of megalops abundance (ET = 20,300,000) was greater than 1998 

during Analysis Period 3 (ET = 4,870,000). The estimates of annually-entrained slender rock 

crab were not adjusted to a long-term average because crab larvae were not enumerated in the 

Intake Cove surface plankton tow samples. 

Fecundity Hindcasting (FHj 

An instantaneous daily mortality rate, -0.158, calculated for brown rock crab is used for slender 

crab. Estimated survival through larval stages can then be calculated as Slarmt =e(~

0l58)', where / 

is reported in Table 5.2.1-6 as mean cumulative duration. Survival estimates to stage midpoint 

were 

1) 

2) 

3) 

4) 

5) 

zoea 1 

zoea 2 

zoea 3 

zoea 4 

zoea 5 

0.584 

0.375 

0.063 

0.0222 

0.0077 

6) megalops 0.0014. 

The FH approach combines larval entrainment losses with survival and adult fecundity to 

hindcast the numbers of adult females effectively removed from the reproductively active 

population. Mean annual fecundity, using data through age three (Table 5.2.1-5), was estimated 

as 555,583 eggs. The number of reproductive years was estimated by halving the range between 

age of maturity of 1 yr and assumed effective longevity of 3 yr (supported by linear survivorship 

model for adults). Coefficients of variation of survival, fecundity, and ages of maturation and 

longevity are not well known and are, therefore, reasonably assumed to be 100% with a 

lognormal enor structure. 

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P.51 

5.2.1 Cancer Crabs 

The number of female slender crabs estimated to produce the entrained larvae was calculated for 

the five zoea and one megalops stage for the two periods. All larval stages were hindcast, and the 

estimated numbers of females and variances of estimates were added to compute an estimate of 

total number of slender crab females and the variance ofthe estimate. The estimated FH for 

zoea and megalops stages for the period December 1, 1996 through November 30,1997 from 

Table 5.2.1-7 were 

FHl = 538 females with SE(FHi ) = 1,150 

FHi = 220 females with SE(FH2) = 563 

FH3 = 221 females with SE(FH*) = 528 

FH< = 143 females with SE(FHr) = 392 

FHMegs = 26,200 females with fk(FHMegs)= 55,500 

No slender crab zoea stage 5 were collected during this period. The total estimated number of 

breeding females needed to produce, the total number of larvae entrained was calculated by 

summing the FH overall stages: 

FH = 27,300 females, 

. . I 3 _ , _ - 2 

with SE(FH)= l^SE, [FH,) = 55,500. An approximate 90% confidence interval for FH, 

based on a lognormal error structure, is estimated as 959 to 776,000 females. 

The estimated FH for slender crab zoea and megalops stages for the period July 1, 1997 through 

June 30, 1998 from Table 5.2.1-7 were 

FH> =1,480 females with SE(FHx ) = 3,180 

FHz = 469 females with SE(FH2) = 1,050 

FH3 = 729 females with SE(FHi)= 1,670 

FHMegs = 6,270 females with SE(FHMegs)= 13,300 

No slender crab zoea stage 4 or 5 were collected during this period. The total estimated number 

of breeding females needed to produce the total number of larvae entrained during this period 

was calculated by summing the stage specific estimates as 

TENERA E9-055.0 5-37 Final 316(b) Demonstration 

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P.52 

5.2.1 Cancer Crabs 

FH = 8,950 females 

with SE(FH)=JfcsEi (FH, )* = 1-3,800. An approximate 90% confidence interval for FH, 

Y i"\ 

based on a lognormal error structure, is estimated as 703 to 114,000 females. 

Sensitivity Analysis 

In addition to calculating a confidence interval, a sensitivity analysis (Table 5.2.1-7) for all larval 

stages was perfonned, in which FH was recomputed by varying the input parameter of 

estimated annual entrainment, ET , by ±1.645S£l£7. J and survival, S, by using a multiplicative 

error structure (i.e. Se ' ' ') and using CKI.S) = 1.0 . The range of survival estimates for all 

stages produced the same relative changes in FH, as expected based upon a constant multiplier. 

However, FH was less sensitive to entrainment than survival variation. This difference was 

especially pronounced for the zoea 1 and megalops stages and can be explained by the use of 

sampling variance for estimating entrainment variability, with CVs of less than 100%. Therefore, 

improvement in the precision of FH can result from improved estimates ofthe larval stages' 

survival. 

Adult Equivalent Loss (AELj 

The AEL approach uses estimates ofthe abundance of entrained organisms to project the loss of 

equivalent numbers of adults based on mortality schedules and age at recruitment. Survival rates 

from entrainment of megalopae to recruitment into fishery are not available. However, assuming 

a 50:50 sex ratio, AEL and FH can be compared as AEL = 2FH = 54,600 and 17,900 adults, 

with an associated standard enor of SE(AEl) = 2SE(FH) = 111,000 and 27,700. 

5.2.1.2e Empirical Transport Model (ETM; 

The ETM assessment requires estimates of larval stage duration and larval density in entrainment 

and grid subsamples. The crab data were collected for only the megalops larval stage in the grid 

subsamples and will be compared to megalops stage larvae in the entrainment subsamples. 

TENERA E9-055.0 5-38 Final 316(b) Demonstration 

March 1,2000 
P.53 

5.2.1 Cancer Crabs 

Two entrainment mortality estimates are presented: for July I, 1997 through June 30, 1998 and 

for July 1, 1998 through June 30, 1999. Slender crab megalops larvae may be susceptible to 

entrainment by the power plant for approximately 42 d, based on the average estimated larval 

duration (Ally 1975). Almough the duration is more than one month, each monthly survey period 

will be assumed to represent discrete groups of larvae, permitting two independent weighted 

estimates of total entrainment mortality from 24 subsamples. Total annual entrainment mortality 

(PM) is estimated from the values of PE, and / for each survey period (Table 5.2.1-8), based 

on larval densities from entrainment (Figure 5.2.1-5) and grid surveys (Figure 5.2.1-6). 

The proportion ofthe population within the nearshore study grid was based on a linear 

extrapolation of densities in the grid in the offshore direction and displacement in the alongshore 

direction. Monthly estimates of proportional entrainment (PE,) for slender crab in each rth 

survey from the two years sampled ranged from a minimum of zero to a maximum of 

0.859±0.911 (±1 SE(PE,}) in August 1997 (Table 5.2.1-8). Periods when both PE, and the 

annual proportion of larvae hatched in the rth survey period (ft) were equal to zero (December 

1997 and January 1998) indicate that no larvae were collected at either the DCPP intake or the 

study grid. When PE, =0 and ft>0, larvae were collected at the DCPP intake during the survey 

period but not during the entrainment survey paired with the 72-hour study grid survey. Low 

values of f. indicate periods ofthe year when slender crab megalops are least abundant in 

weekly entrainment subsamples. June 1998 and October 1998 were highest for the two annual 

periods. May and June 1998 densities were highest in the study grid during the first period, and 

August and September 1998 were highest in the second period (Figure 5.2.1-6). 

Total annual entrainment mortality from the ETM is estimated as PM = 0.0107 for the period July 

1, 1997 through June 30, 1998 and P^ = 0.000784 for the period July 1, 1998 through June 30, 

1999 with associated standard errors of SE(PM) 0.0515 and 0.0373, respectively (Figure 5.2.1-

7). The sensitivity analysis, which considers the effect of varying values of Ps on the outcome of 

the ETM calculations, is shown in Figure 5.2.1-7. The values of PM resulting from calculations 

using only the alongshore displacement were higher (both years/^ = 0.09) than those reported 

TENERA E9-055.0 5-39 Final 316(b) Demonstration 

March 1,2000 
5.2.1 Cancer Crabs 

for the offshore extrapolated densities (0.0107 and 0.000784). Values of Ps ranged from 0.00422 

to 0.00875 for PM extrapolated offshore and 0.125 for both years using alongshore only. ! 

Interpretation of Assessment Results 

Interpretation of assessment results for slender crabs is limited by the absence of any information 

on population size. The ETM estimates of 1.07% and 0. 0784% probably represent low 

population impacts. Values of Ps that were calculated based on extrapolation offshore were also 

larger than for brown crabs. As a result (comparing \IPS ), the population of slender crab at risk 

proportional to the study grid was estimated to be approximately 5-10 times smaller than the 

population of brown rock crabs relative to the study grid. However, values of \IPS are nearly the 

same for both slender and brown rock crabs, from the calculation using alongshore currents only. 

There is no fishery value for the estimates of slender crab adult equivalent loss (54,600 and 

17,900 crabs). 

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P.55 

5.2.1 Cancer Crabs 

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

antennarius; from Carroll 1982 and Hines 1991). 

Age (yr postsettlement) 

1.5 

2 • 

3 

4 

5 

6 

Estimated 

carapace width 

(mm) 

62 

83 

105 

123 

135 

143 

Estimated 

no. eggs per batch 

156,400 

513,100 

1,401,800 

2,664,700 

3,994,600 

5,004,000 

Number of 

Batches 

1.0 

1.5 

1.5 

1.5 

1.5 

1.5 

TENERA E9-055.0 5-41 Final 316(b) Demonstration 

March 1,2000 
5.2.1 Cancer Crabs 

Table 5.2.1-2. Brown rock crab (Cancer antennarius): Annual estimated number of zoeae and 

megalopae entrained, estimated FH, and sensitivity of zoea- and megalops-based FH estimates 

for two analysis periods. Sensitivity estimates recalculated for model parameters (9) of 

entrainment (^±1.645-5£(^)), and survival (^e ±1645rn *

)where CK(^ ) = 1.0). TT =estimated 

annual # crab larvae entrained (by stage), FH= number of adult female crabs, and S= finite 

survivorship. 

a) Analysis Period 1 (date adjusted): December 1, 1996-November 30, 1997 

Sensitivity Analysis Parameters of 

Recalculated FH 

— ' _,— . ET ET S 

Stage

 T J y ' +1.645S£(0) -\.MSSE(8) x" 

LafVal

 % TE(tT) FH TE[FH) +|JMJ L - _ _.,MJfl,„ _.,«„.,,„ 

Zoeal 17,400,000,000 3.940,000,000 17,500 39,000 24,000 

Zoea 2 4,580,000,000 3,410,000,000 16,300 38,100 36,200 

Zoea 3 4,720.000,000 4,370,000,000 43,300 104,000 109.000 

Zoea 4 665,000,000 572.000.000 15,700 37,400 38,000 

Zoea 5 3,480,000 4,140,000 249 626 735 

Megalops 56,500,000 4.480,000 24,100 53,400 27,200 

11,000 

0 

0 

0 

0 

20.900 

3.370 

3,140 

8,350 

3,040 

48 

4,650 

90,600 

84,400 

224,000 

81,500 

1,290 

125,000 

TOTAL ] 1, V)i-\ C: \ C ,-.- - 117,000 

b) Analysis Period 3: July 1, 1997-June 30, 1998 

Sensitivity Analysis Parameters of 

Recalculated FH 

LatvalStage % £(£} FH ffl(ffi) ^ £ ^ ^J^ J ^ 

K(6) -1.645 SE(0) *e 

Zoea 1 18.500,000,000 6.260.000,000 18,600 41,700 28,900 8.270 3.590 96.400 

Zoea 2 3,770.000,000 1,900.000.000 13,400 30,500 24.500 2,310 2.590 69,400 

Zoea 3 2.420.000.000 1.760.000,000 22,100 51,700 48,700 0 4.280 115.000 

Zoea 4 781.000.000 910.000,000 18,500 46.300 53,900 0 3,570 95.700 

Zoea 5 111.000.000 135.000.000 7,950 20,100 23.800 0 1.530 41.200 

Megalops 24.500.000 2.200.000 10.400 23,100 12.000 8,880 2,010 54.000 

TOTAL ? 5//t? f r 4t» ;( y p 91.000 

TENERA E9-055.0 5-42 Final 316(b) Demonstration 

March 1,2000 

'____.! 
P.57 

5.2.1 Cancer Crabs 

Table 5.2.1-3. Duration of laboratory-reared zoea stages (@ 13.8°C) of. 

brown rock crab (Cancer antennarius; Roesijadi 1976) and megalops 

stage duration from. Ally (1975). Mean cumulative duration is 

cumulative duration minus half of the stage duration. 

Stage Mean 

Duration Cumulative Cumulative 

Larval Stage (d) duration duration 

Zoea 1 

Zoea 2 

Zoea 3 

Zoea 4 

Zoea 5 

Megalops 

Total 

10 

6 

6 

6 

8 

14.6 

50.6 

10 

16 

22 

28 

36 

50.6 

5 

13 

19 

25 

32 

43.3 

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5.2.1 Cancer Crabs 

Table 5.2.1-4. Brown rock crab (Cancer antennarius): Monthly estimates of proportional 

entrainment (PE,) and annual proportion of larvae hatched in the /th survey period (ft) 

and associated standard enors (SE) used in estimating entrainment mortality for two 

analysis periods, 

a) Analysis Period 3: July 1, 1997-June 30, .1998 

Survey Start Date 

Jul 21, 

Aug 25, 

Sep 29, 

Oct 20, 

Nov 17, 

Dec 10, 

Jan 22, 

Feb 26, 

Mar 18, 

Apr 15, 

May 18, 

Jun 8, 

1997 

1997 

1997 

1997 

1997 

1997 

1998 

1998 

1998 

1998 

1998 

1998 

PE, 

0 

0 

0 

0.0254 

0.0224 

0 

0 

0 

0 

0.00248 

0.000260 

0.000890 

b) Analysis Period 4: July 1, 1998-

Survey Start Date 

Jul 21, 

Aug 26, 

Sep 16, 

Oct 6, 

Nov 11, 

Dec 9, 

Jan 12, 

Feb 3, 

Mar 17, 

Apr 14, 

May 24, 

Jun 23, 

1998 

1998 

1998 

1998 

1998 

1998 

1999 

1999 

1999 

1999 

1999 

1999 

PE, 

0.00114 

0 

0 

0.00807 

0.00644 

0.0108 

0 

0 

0 

0 

0 

0.000820 

SE(PE,) 

0 

0 

0 

0.0219 

0.0313 

0 

0 

0 

0 

0.00146 

0.0000700 

0.000390 

-June 30, 1999 

SE(PE,) 

0.00117 

0 

0 

0.00903 

0.00723 

0.00917 

0 

0 

0 

0 

0 

0.000520 

0.00600 

0.00586 

0.00169 

0.0127 

0.00163 

0.00106 

0.00370 

0.00201 

0.00251 

0.0528 

0.289 

0.621 

fi 

0.650 

0.0132 

0 

0.0302 

0.0156 

0.0274 

0.0179 

0 

0 

0.0212 

0.171 

0.0532 

SE(f,) 

0.00134 

0.00167 

0.000640 

0.00206 

0.000620 

0.000470 

0.00103 

0.000660 

0.000830 

0.00504 

0.0157 

0.0162 

SE(fi) 

.0.0232 

0.00384 

0 

0.00637 

0.00435 

0.00582 

0.00483 

0 

0 

0.00535 

0.0164 

0.00963 

TENERA E9-055.0 5-44 Final 316(b) Demonstration 

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5.2.1 Cancer Crabs 

Table 5.2.1-5. Schedule of estimated fecundity by age for slender crab (Cancer 

gracilis) (from Orensanz and Gallucci 1988; Hines 1991). 

Age (yr postsettlement) 

1.5 

2 

3 

4 

Estimated carapace 

width (mm) 

47 

62 

77 

86 

Estimated 

no. eggs per batch 

143,800 

342,400 

672,900 

953,400 

Number of 

Batches 

1.0 

1.5 

1.5 

1.0 

Table 5.2.1-6. Duration of planktonic zoea and megalops stages of slender crab 

(Cancer gracilis) reared in the laboratory (Ally 1975). 

Mean Lower Upper Mean 

Larval Stage duration limit (d) limit (d) Cumulative Cumulative 

(d) duration duration 

Zoea 1 

Zoea 2 

Zoea 3 

Zoea 4 

Zoea 5 

Megalops 

Total 

6.8 

7.2 

7.0 

6.2 

7.1 

14.6 

48.9 

5 

5 

5 

5 

6 

12 

38 

11 

12 

10 

8 

8 

17 

66 

6.8 

14.0 

21.0 

27.2 

43.3 

48.9 

3.4 

6.2 

17.5 

24.1 

30.8 

41.6 

TENERA E9-055.0 5-45 Final 316(b) Demonstration 

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5.2.1 Cancer Crabs 

Table 5.2.1-7. Slender crab (Cancer gracilis): Annual estimated number of zoeae and megalopae 

entrained, estimated FH, and sensitivity of zoea- and megalops-based FH estimates for two 

analysis periods. Sensitivity estimates recalculated for model parameters (0) of entrainment 

(^± 1.645-5£(t9)), and survival (t9e±1645cM) where Cv(o} = \.0). E~T = estimated # crab larvae 

entrained (by stage), FH= number of adult female crabs, and S = finite survivorship. 

a) Analysis Period 1 (date adjusted): December 1, 1996-November30, 1997 

Larval Stage 

Zoea 1 

Zoea 2 

Zoea 3 

Zoea 4 

Zoea 5 

Megalops 

TOTAL 

% 

175,000.000 

46,000.000 

7,740,000 

1,770,000 

0 

20,300,000 

iso.^H 

SE(E7) 

39,600,000 

65,600,000 

8,510,000 

3,040,000 

0 

1,140,000 

FH 

538 

220 

221 

143 

0 

26,200 

27.300 

SE(FH) 

1,150 

563 

528 

392 

55,500 

Sensitivity Analysis Parameters of 

Recalculated fi. 

+I.645S£(0) 

739 

737 

621 

549 

0 

28,600 

-\ .64$ SK(9) 

338 

0 

0 

0 

0 

23,700 

5 

104 

43 

43 

28 

0 

5.050 

S 

-i.Msn-|»i 

2,790 

1,140 

1,150 

742 

0 

136.000 

b) Analysis Period 3: July 1, 1997-June 30, 1998 

Larval Stage 

Zoea 1 

Zoea 2 

Zoea 3 

Zoea 4 

Zoea 5 

Megalops 

TOTAL 

ET 

480.000.000 

97.700,000 

25,500,000 

0 

0 

4.870.000 

tt><A '0*7 

SE(l%) 

162,000,000 

67,200.000 

21,800.000 

0 

0 

633.000 

FH 

1,480 

469 

729 

0 

. 0 

6.270 

8.950 

SE(FH) 

3.180 

1,050 

1,670 

13,300 

Sensitivity Analysis Parameters of 

Recalculated fv 

% 

+1.645££(6) 

2.300 

999 

1,760 

0 

0 

7.610 

ET S 

~ - „.t.645(V.<i> 

-\M5SK(0) ** 

658 

0 

0 

1 

2 

4.930 

286 

90 

141 

0 

0 

1.210 

S 

7.670 

2.430 

3,780 

0 

0 

32.500 

TENERA E9-055.0 5-46 Final 316(b) Demonstration 

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5.2.1 Cancer Crabs 

Table 5.2.1-8. Slender crab (Cancer gracilis): Monthly estimates of proportional 

entrainment (PE,) and annual proportion of larvae hatched in the rth survey period (fj) 

and associated standard errors (SE) used in estimating entrainment mortality for two 

analysis periods, 

a) Analysis Period 3: July 1,1997-June 30, 1998 

Survey Start Date 

Jul 21, 

Aug 25, 

Sep 29, 

Oct 20, 

Nov 17, 

Dec 10, 

Jan 22, 

Feb 26, 

Mar 18, 

Apr 15, 

May 18, 

Jun 8, 

b) Analysis 

1997 

1997 

1997 

1997 

1997 

1997 

1998 

1998 

1998 

1998 

1998 

1998 

PE, 

0 

0.859 

0 

0.0230 

0.00102 

0 

0 

. 0 

0 

0.000860 

0.000350 

0.000190 

SE(PE,) 

0 

0.911 

0 

0.0137 

0.00105-

0 

0 

0 

0 

0.000890 

0.000130 

0.000140 

Period 4: July 1, 1998-June 30,1999 

Survey Start Date 

Jul 21, 

Aug 26, 

Sep 16, 

Oct 6, 

Nov 11, 

Dec 9, 

Jan 12, 

Feb 3, 

Mar 17, 

Apr 14, 

May 24, 

Jun 23, 

1998 

1998 

1998 

1998 

1998 

1998 

1999 

1999 

1999 

1999 

1999 

1999 

PE, 

0 

0.000310 

0.000910 

0.00439 

0.000900 

0.00432 

0.00490 

0 

0.000670 

0 

0.00106 

0.00278 

SE(PE,) 

0 

0.000310 

0.000670 

0.00288 

0.000910 

0.00334 

0.00557 

0 

0.000490 

0 

0.000770 

0.00153 

/ 

0.0602 

0.0726 

0.0754 

0.0961 

0.0644 

0 

0 

0.000680 

0.00422 

0.144 

0.151 

0.332 

0.0442 

0.0508 

0.0267 

0.302 

0.242 

0.0535 

0.0226 

0.00923 

0.0434 

0.0869 

0.0859 

0.0325 

SE(f,) 

0.00969 

0.0131 

0.0158 

0.0114 

0.00974 

0 

0 

0.000680 

0.00173 

0.0152 

0.0160 

0.0259 

SE(f.) 

0.00675 

0.00591 

0.00471 

. 0.0231 

0.0193 

0.00609 

0.00433 

0.00261 

0.00567 

0.0141 

0.0083 

0.00488 

TENERA E9-055.0 5-47 Final 316(b) Demonstration 

March 1,2000 
P.62 

5.2.1 Cancer Crabs 

*•"•»» 

UJ 

CO 

T— 

+ 

r> 

E 

% 

Of 

</ C ) 

OJ 

O 

c 

ra <i) 

2 

110 -

100 -

9 0 -

8 0 -

7 0 " 

6 0 -

-

5 0 -

4 0 -

3 0 -

-

2 0 

i o -

oJ.I: 

Brown rock crab (C. antennarius) - Zoea I 

UL... 

in IIIIIIIIMIIII I in ii IIIIIIII|NII|I I IIII I III I ll iiii|iiii)iiii II I MI 1111 IIIIII I III mi III I 11 IIIIII i III I III I III 1111111 

| O I N | D | J FMAM J I J ASOND J FMAM J J ASO N 

llllllll|lll| 

D J F M | A 

1999 

III III IIIII 

M J 

• designates survey with density - 0 

Survey Date 

g0mm^ 

UJ 

CO 

,— 

+ 

F 

% >rrr' 

>. 

If) 

c OJ 

Q 

c 

ra 0) 

5 

120 -

110 -

100 -

9 0 ~ 

8 0 -

7 0 " 

6 0 -

so4 0 -

3 0 -

20" 

10" 

o- 1t ,, ' •!-* 

Brown rock crab (C. antennarius) - Zoea II 

.I.J 

I I 11 I I 1111111 IM 11111111111 I I 11 in 1111111 I I 11 I I 1111111 iu 11111111111 ia 11111111111 NI 11 I I 1111111 NI 1111111 I I 11 MI 111 u n 

Io I NI D | j |F|M|A|M|J[ J A|S|O|N|D| J I FIMI A I M | J | J | A I S| O | N 

iiiiiiiiinii 

D J F | 

11 nil i ill nil-ill 

M | A | M | J 

I 19S6 J 

Survey Date 

T designates survey with density - 0 

Figure 5.2.1-1. Weekly mean zoeae and megalops larval density (#/m3 + 1 S.E.) at the DCPP 

intake. Y-axis scale varies between graphs. Zoea not sorted from July 1998 through June 1999 

samples. 

TENERA E9-055.0 5-48 Final 316(b) Demonstration 

March 1,2000 
P.63 

5.2.1 Cancer Crabs 

UJ 

co 

E 

CO 

c 

OJ 

Q 

c 

ra 

OJ 

140 

1 3 0 

120 -

1 1 0 

100 -

9 0 -

80 

7 0 -

6 0 ~ 

50 

40 

3 0 " 

20 

10 

0 

Brown rock crab (C. antennarius) - Zoea III 

f""""i»"*""i"nfifmiiinfnif?mnfi? i mi f 

O N D J 

|III|UIIIMI|IIII|MI|I 

FMAM J 

i J y 

I III 1111111 1 < 1 1 III 11111111111IJI11 1 > 1111J1 1 III 11 1 

jIAISOND J F M A| M J J 

IIIII11 III 11II 

A S O 

llllllllllllllllllll l 

M A M J 

• designates survey with density «• 0 

Survey Date 

3 0 " 

UJ 

CO 

^ » 

+ 20 " 

E 

CO 

c 

OJ 

D 

c 

ra 

OJ 

2 

Brown rock crab (C. antennarius) - Zoea IV 

nmmmim tmrnrmiifimmfmrmmmiMn i mnrn rtt' 

• i III P II I [ II I IIIIII I ••ifiiiwiriTTii i iiit i II I IIBJ I i|i IIIII I it i II I fi i IIIII I i|i i >• II I uitiip i i >Ti irjiiiiiai i •_•••! IIII I riiifaiiiTVJi • |i>i •• >>ijriiii i irai 11 III 

|o | N | D | J | FIM|A|M|jIj |A|S|O|N|D| J | F|MI AIM| J |J I A | S j O | N|D| J |F|M|A|M|J | 

• designates survey with density ~ o 

Survey Date 

Figure 5.2.1-1 (continued). Weekly mean zoeae and megalops larval density (#/m3 + 1 S.E.) 

at the DCPP intake. Y-axis scale varies between graphs. Zoea not sorted from July 1998 through 

June 1999 samples. 

TENERA E9-055.0 5-49 Final 316(b) Demonstration 

March 1,2000 
,£,64 

5.2.1 Cancer Crabs 

4 — 

**~r. 

UJ 

CO

 3

~ 

V 

+ 

E. 

& Dens 

c 

ra , -

OJ

 1 

0 -

T 

0.8 -

0.7 -

^ - K 

UJ 

CO 0.6 -

^ 

+ 

n O.S -

E 

c 

0) 0.3-

Q 

I 0.2-

2 

0.1 -

0.0 -

Brown rock crab (C. antennarius) - Zoea V 

miitiiiiimi11*iiim*iiiiitiiwiiiiiiiiiintiitimrMTi1 mrmi 1 rt m 

I 0 | N |0| J |F|M|A|M|J|J|A|S|O|N|O|J|F|M|A[M|J|J|A|S|O|N|D|J|F|M|A|M|J | 

| 1996 | 1997 | 1998 | 1999 | 

Survey Date 

designates survey with density = 0 

..L.ul.il.tll....il 

Brown rock crab (C. antennarius) - Megalops 

| ll ll 1 

''Wv.S.mn-Wn'mSt'm'm.J"' 

1,1, lill 

i 

ll —"ft ni'i" I'II 'm Amtmn'mii' t 

|0|N|o!j[F|MlA|M|jlj|A|s!o|N|D|j|F|M|A|M|j|j|A|s|o|N|D|j|F|M|AiM|j | 

| 1996 ; 1997 | '998 j 1999 | 

Survey Date 

V designates survey with density = 0 

Figure 5.2.1-1 (continued). Weekly mean zoeae and megalops larval density (#/m3 + 1 S.E.) at 

the DCPP intake. Y-axis scale varies between graphs. Zoea not sorted from July 1998 through 

June 1999 samples. 

TENERA E9-055.0 5-50 Final 316(b) Demonstration 

March 1, 2000 
m 

z 

m 

m 

CO 

6 

Ol 

Ol 

cn 

i 

tn 

-n 

5' 

92. 

co 

.____. 

a. 

02) ° (D 

il 

-7 tfl 

IO Oi 

o = 

o o 

O 3 

Brown rock crab megalops (Cancer antennarius) 

CO 

E 

2.1 

1.8 

1.5 

1.2 

0.9 

0.6 

0.3 

0.0 

Depth Contours 

20 meters 

^ — 40 meters 

• ^ — 60 meters 

Point Buchon 

DCPP Intake 

Point San Luis 

Jul. 21, 97 Aug. 25,'97 Sep. 29,'97 Oct. 20,'97 Nov. 17,'97 Dec. 10,'97 

St Figure 5.2.1 -2a. Mean larval density (#/m3) collected in the DCPP study grid cells and at the entrainment sampling location. 
m 

z 

m 

£ 

m 

CO 

I 

o 

tn 

cn 

tn 

• tn io 

CJ 

o> 

2 O 

3 " O 

3 

CO 

K> Q) 

o cr. 

o o 

O 3 

Brown rock crab megalops (Cancer antennarius) 

CO 

E 

2.1 

1.8 

1.5 

1.2 

0.9 

0.6 

0.3 

0.0 

Depth Contours 

—»•=- 20 meters 

— — 40 meters 

^^— 60 meters 

Point Buchon 

DCPP Intake 

Point San Luis 

Jan. 22, '98 Feb. 26, '98 Mar. 18, '98 Apr. 15, '98 May 18, "98 Jun. 8, "98 

Figure 5.2.1-2b (continued). Mean larval density (#/m3) collected in the DCPP study grid cells and at the entrainment sampling location. 
m 

z 

m 

m 

s 

tn tn 

tn 

• tn 

w 

3 

0) 

OJ 

.____. 

O) 

2

 a 

si 

_**> N > i B 

o =r. 

o o 

o 3 

Brown rock crab megalops (Cancer antennarius) 

CO 

E 

2.1 

1.8 

1.5 

1.2 

0.9 

0.6 

0.3 

0.0 

Depth Contours 

.i 20 meters 

^ — 40 meters 

••• • 60 meters 

Point Buchon 

DCPP Intake 

Point San Luis 

Jul. 20,'98 Aug. 25,'98 Sep. 15,'98 Oct. 5,'98 Nov 10, *98 Dec. 8, '98 

Figure 5.2.1-2c (continued). Mean larval density (tf/m1) collected in the DCPP study grid cells and at the entrainment sampling location. 

Ul 

ro 

i7 

3 

O 

CB 

-1 

O 

2 

CO 

O) 

^1 
m 

z 

m 

£ 

m 

CO 

o 

tn 

tn 

<___> 

tn 

s 

91 

to 

___ 

O) 

2 ° 

il 

- * tf) 

- ^* 

M 3 

o a-, 

o o 

o 3 

0) 

Brown rock crab megalops (Cancer antennarius) 

CO 

E 

2.1 

1.8 

1.5 

1.2 

0.9 

0.6 

0.3 

0.0 

Depth Contours 

— « — 20 meters 

— — • 40 meters 

^ ^ TM 60 meters 

Point Buchon 

DCPP Intake 

Point San Luis 

Jan. 11, '99 Feb. 2. '99 Mar. 16, '99 Apr. 13, "99 May 23, '99 Jun 22, '99 

Figure 5.2.1-2d (continued). Mean larval density (fl/m1) collected in the DCPP study grid cells and at the entrainment sampling location. 

u 

V) 

•J 
P.69 

5.2.1 Cancer Crabs 

Brown rock crab (Cancer antennarius) - duration to megalops stage 

Ps alongahore 

Analysis Period 3: Jul 1997-Jun 1998 

Density Extrapolated Ps off scale 

VPs = 2,591 

Pu- 0.0000186 ± 0.0384 

Estimate 

90% Cl. 

Ox 

O km 

Sx 10x lOx 20x 2Sx 30x 3Sx 40x 

B7 km 174 km 26 1 Km 347 km 43 4 km B21 km 60S km SSS km 

Siz e of Population Relativ e to Study Oli d 

Eq.ulvala_.nt Distanc e Alongshor v 

Brown rock crab (Cancer antennarius) - duration to megalops stage 

Analysis Period 4: Jul 1998-Jun 1999 

Density Extrapolated Ps off scale 

1/Ps = 418 

Pu = 0.000146 ± 0.0535 

Estimate 

—i—i—i—i—i—i—i—i—i—i—i—i—i—i—i—i—i—i—i—i—i—i—i—i—i—i—i—.—i—i— r 

Ox Sx 10x ISx 20x 2Sx SOx 3Sx 40x 

O km 8 7 k m 174 km 281 km 347 km 43 4 km S21 km SOS Km 60S Km 

Siz a of Population Relative to Study Ortd 

Equivalent Distanc e Alongshor e 

Figure 5.2.1-3. Total annual entrainment mortality (Pu) and 90% confidence interval (CI.) as 

a function ofthe reciprocal ofthe fraction ofthe population at risk and contained in the study grid 

(Ps) used to approximate the alongshore extent ofthe study grid population expanded on me 

basis of alongshore current movements and the offshore extrapolation of study grid abundance 

extended alongshore using both onshore and alongshore current movements with 90% C.I.'s 

indicated. 

TENERA E9-055.0 5-65 Final 316(b) Demonstration 

March 1.2000 
P.70 

5.2.1 Cancer Crabs 

250 

u-><or^<so)OT-tNco3tfttor*-eoo > r^^^^^floconcococDCDaoflO " 

at Clo U> O) O. <ft CT> C- <J) O) CT> Oi Qi <7i 01010>0)>OiO)0>0>0>0 ) 

Figure 5.2.1-4. Rock crab (Cancer spp.) landings (MT) at Morro Bay and Port San Luis between 

the years 1975-1998 (source: CDF&G database). 

TENERA E9-055.0 5-56 Final 316(b) Demonstration 

March 1,2000 
P.71 

5.2.1 Cancer Crabs 

^ 

ui 

CO 

T -

+ 

n 

E 

$ ,

*-"* & 

CO 

c CV 

O 

c 

CO 

CD 

5 

"•—* 

ui 

CO 

•^ 

+ 

IO 

E 

% '^rr 

_>. 

'55 

c 

CD 

Q 

c 

CTJ 

CD 

2 

3

-

-

2 ~ 

1 ~ 

O

-

Slender crab (C. gracilis) - Zoea I 

jJilli l l ii,.._xJU i i 

|O|N|0|J|F|M|A|M|J|J|A|S|O|N|D|J|F|M|A|M|j|j|A|S|O|N|0| J 

| 1996 | 1997 | 1998 | 

Survev Date 

• designates survey with density « 0 

1.4" 

1.3" 

1.2" 

1.1 " 

1.0-

0.9 -

0.8" 

0.7 -

0.6" 

0.5 -

0.4-

0.3~ 

0.2 -

0.1 -

0.0" 

• 

II'IIIIIIIII'I 

Slender crab (C. gracilis)-Zoea II 

' i HI ni i iiiiimmimnn'iniii'iii i mimi ,,!• 

I II M|M 1 II 1 1 III 1 III Ni l II 1 IIIIIIII H 1 III III Ml HI III I IN 1 1 II M III I IIIIIIII Mi l 1 IHN Mil II 1 M UIIH 1 III I III II III II Mil l II 1 M 

|O|N|D|J|F|M|A|M|J|J|A|S|O|N|D|J|F|M|A|M|J|J|A|S|O|N| O 

| 1996 | 1997 | 1998 

Survey Date 

• designates survey with density = 0 

|F|M|A|M]j | 

1999 | 

III III III IIIIII III ll III nil] J|F|MIA|M|J | 

1999 

Figure 5.2.1-5. Weekly mean zoeae and megalops larval density (#/m3 + 1 S.E.) at the DCPP 

intake. Y-axis scale varies between graphs. Zoea not sorted from July 1998 through June 1999 

samples. 

TENERA E9-O55.0 5-57 Final 316(b) Demonstration 

March 1,2000 
P.72 

r-tft - y 

5.2.1 Cancer Crabs 

UJ 

CO 

*-

+ 

7, 

h 

* 

>» 

CO 

r CD 

O 

c 

CCO D 

> 

0.3B 

0.36 

0.34 

0.32 

0.30 

0.28 

0.26 

0.24 

0.22 

0.20 

0.18 

0.16 

0.14 

0.12 

0.10 

0.08 

0.06 

0.04 

0.02 

0.00 

Slender crab (C. gracilis) - Zoea I 

minimum nm 

..ll 

lllll|MMIIII|llll|lll|MIBIII||| | 

|O|N|0 | J |F|M|A|M | 

nt mmmiimiiinnnimitin i mimi rii n III Mill 111 M11 

8 O ••• ' 

Mini 

D | J F |M 

IIMIIIIIfMM|IMI|i|llll|IIMM] 

|M|J|J|A|S|O | 

IIIIIIMIIIMIH.I I I ! II 

I D | J I F IM | A I 

• designates survey with density = 0 

Survey Date 

ui 

co 

T -

+ 

E Density Mean 

0.10 

0.09 

O.OS 

0.07 

0.06 

0.05 

0.04 

0.03 

0.02 

0.01 

0.00 

Slender crab (C. gracilis) -Zoea IV 

miiimimm mm nmiiimiiiimmnnniiniiiii i mini nmtiti 

vrv. 

.11 MI|.M,U,li,ll.,lllll L M|l l IIIIIIII! 

O | N I D j J j F ! M j A I M [ J ! j A !SiO!N|D ! J F IM | A iM | J J !A|S:O!N|DI J |F | 

i 1996 1997 | 1998 \ 

M i A | M | J I 

1999 I 

V designates survey with density - 0 

Survey Date 

Figure 5.2.1-5 (continued). Weekly mean zoeae and megalops larval density (#/m' + 1 S.E.) at 

the DCPP intake. Y-axis scale varies between graphs. Zoea not sorted from July 1998 through 

June 1999 samples. 

TENERA E9-055.0 5-58 Final 316(b) Demonstration 

March 1.2000 
5.2.1 Cancer Crabs 

UJ 

CO 

E 

CO c 

CD 

a 

c 

ro 

(D 

5 

Slender crab (C. gracilis) - Zoea V 

o - mnnnmiimnnmmmnmmiimmmmiimnii i mimi wnimi 

11 Mill ll | I II III I' lllll j I IIIII I III III I lllllllllll l II I I III IIIIII I Illlllllll Mil |H | III I 1111111111111 I I III II , r- i r •'.' i • i M|lll|MIIFIII| !

ll|MMIIIM|lll|MM!i 

ioiNID I J I F|M|A| M j j| j |A|S|O|N|O| J | F|M|A|M| J [ J |A|S|O|N|D| J |F|M|AJM|J | 

| 1996 j 1997 j 1998 j 1999 I 

• designates survey with density - 0 Survey Date 

0.09 

0.07 

0.06 

111 

CO 

+ 

E 

• = 0.04 

c 

CD 

o 

c 

CD 

CD 

0.03 

0.02 

0.01 

Slender crab (C. gracilis) - Megalops 

Jt 

II Mil'I I IIIIII. l'l|l!llllll|MM|lll|||:,i[i.'|'i,|ll...! | | ,i | ll.l Ul III] llfll ITI|llllV!IIIIITIIll11llliail llfTL^I] III •! II ISl II (III I' 11 Mil. 

io , N j D I J ( FIM!AIMI j | j IAISIO!NID; J |FIM|A|M| J | J |A|S|O{N|0| J FIM | A 

Survey Date 

• designates survey with density = 0 

Figure 5.2.1-5 (continued). Weekly mean zoeae and megalops larval density (#/m3 + 1 S.E.) at 

the DCPP intake. Y-axis scale varies between graphs. Zoea not sorted from July 1998 through 

June 1999 samples. 

X! 

TENERA E9-055.0 5-59 Final 316(b) Demonstration 

March 1,2000 
m 

z 

m 

m 

CO 

i o 

yi Ol 

b 

CJl 

i a. o 

3 

SL 

w 

.____. 

.2 15 

_£ C3 

§1 

r* co 

ro 5 o s-. o o 

o 3 

Slender crab megalops (Cancer gracilis) 

CO 

E 

0.63 

0.54 

0.45 

0.36 

0.27 

0.18 

0.09 

0.00 

Depth Contours 

m •" 20 meters 

ttemmm. 40 meters 

^ — 60 meters 

Point Buchon 

DCPP Intake 

Point San Luis 

Jul. 21,'97 Aug. 25,'97 Sep. 29,'97 Oct. 20,'97 Nov. 17,'97 Dec. 10,'97 

Figure 5.2.1-6a. Mean larval density (#/W) collected in the DCPP study grid cells and at the entrainment sampling location. 
m 

z 

m 

£ 

m 

CD i 

o 

Ol 

Ol 

Ol 

I O) 

3 

92. 

W 

a> 

"ex 

2 ° 

§ | 

- k (0 

M 3 

o A o o 

O 3 

Slender crab megalops (Cancer gracilis) 

CO 

0.63 

0.54 

0.45 

0.36 

0.27 

0.18 

0.09 

0.00 

Depth Contours 

••— - 20 meters 

— — 40 meters 

••"•• 60 meters 

Point Buchon 

DCPP Intake 

Point San Luis 

Jan. 22, '98 Feb. 26, '98 Mar. 18, '98 Apr. 15, '98 May 18, '98 Jun. 8, '98 

Figure 5.2.1-6b (continued). Mean larval density (#/m5) collected in the DCPP study grid cells and at the entrainment sampling location. 

u 

cr 

vt 
m 

z 

m 

m 

co 

6 

Ol 

Ol 

b 

01 

i 

CD 

ro 

3 

!!__. 

w 

.___. 

at 

,cr 

§1 

r o 55 

O CT. 

O O 

O 3 

Slender crab megalops (Cancer gracilis) 

CO 

E 

0.63 

0.54 

0.45 

0.36 

0.27 

0.18 

0.09 

0.00 

Depth Contours 

—— 20 meters 

— » 40 meters 

— ^ 60 meters 

Point Buchon 

DCPP Intake 

Point San Luis 

Jul. 20,'98 Aug. 25,'98 Sep. 15,'98 Oct. 5,'98 Nov 10,'98 Dec 8, 98 

Figure 5.2.1-6c (continued). Mean larval density (#/m3) collected in the DCPP study grid cells and at the entrainment sampling location. 01 

cr 
m 

z 

m 

m 

CD 

• o 

Ol 

Ol 

Ol 

I 

0> 

3 

82. 

co 

.«* 

a> 

"ex 

2 O 

•_* tn u# r. §- 1 7 ! 3 

- i W 

IS) 01 

O Sf 

O O 

O 3 

Slender crab megalops (Cancer gracilis) 

CO 

E 

0.63 

0.54 

0.45 

0.36 

0.27 

0.18 

0.09 

0.00 

Depth Contours 

' 20 meters 

40 meters 

• — • 60 meters 

Point Buchon 

DCPP Intake 

Point San Luis 

Jan. 11,'99 Feb. 2, '99 Mar. 16,'99 Apr. 13,'99 May 23,'99 Jun 22,'99 

i» Figure 5.2.1 -6d (continued). Mean larval density (#/m1) collected in the DCPP study grid cells and at the entrainment sampling location. 0) 

cr. 

to 
5.2.1 CancerCrabs 

Slender crab (Cancergracilis) - duration to megalops stage 

0.320 -

0.288 -

0.268 -

0.224 — 

0.102 -

£ O.IOO 

\ 

R B alonoshoie 

Analysis Period 3: Jul 1997-Jun 1998 

Density Extrapolated Ps off scale 

1/Ps = 237 

Pu-- 0.0107 ±0.0843 

Ox Sx 10x iex 20X 2Sx SOx 3Sx 40x 

O km 8 7 km 174 km 261k m 347 km 43 4 km 621 km BOB km 68 6 km 

Siz e of Population Rotative to Study Orld 

Equivalent Distance Alongahora 

Slender crab (Cancer gracilis) - duration to megalops stage 

Analysis Period 4: Jul 1998-Jun 1999 

Density Extrapolated Ps off scale 

MPs = 114 

Pu-- 0.000784 ±0.0621 

Estimate 

90% Cl. 

Ox Sx lOx 16x 20x 26x SOx 3Sx 4 Ox 

O km 8 7 km 174 km 261 km 347 km 43 4 km S21 km SOS km 69 6 km 

Siz e of Population Relative to Study Orld 

Equivalent Distance Alongahora 

Figure 5.2.1-7. Total annual entrainment mortality (PM) and 90% confidence interval (CI.) as 

a function ofthe reciprocal ofthe fraction ofthe population at risk and contained in the study grid 

(P,) used to approximate the alongshore extent ofthe study grid population expanded on the 

basis of alongshore current movements and the offshore extrapolation of study grid abundance 

extended alongshore using both onshore and alongshore current movements with 90% CI.'s 

indicated. 

TENERA E9-055.0 5-64 Final 316(b) Demonstration 

March 1.2000 
P.79 

Blank Page 
P.80 

r . F - T 

5.2.2 Pacific Sardine 

5.2.2 Assessment of Pacific Sardine (Sardinops sagax) 

Sardinops sagax (Jenyns 1842); Pacific sardine; length to 41 cm but usually less 

than 30 cm; Kamchatka, Russia to southeast Alaska and Guaymas, Mexico to 

Peru and Chile; schools over continental shelf, often near shore (Eschmeyer 

et al. 1983). Blue-green above, white below, series of black spots on back 

(Miller and Lea 1972). 

Pacific sardine is a member ofthe family Clupeidae (herrings), which is also represented in the 

waters around Diablo Canyon by American shad (Alosa sapidissima), Pacific herring (Clupea 

pallasi), threadfin shad (Dorosoma pelenense), and round herring (Etrumeus teres). The sharp 

decline ofthe Pacific sardine population in the mid-1940's led to the demise ofthe world's 

largest commercial fishery and to the establishment ofthe California Cooperative Oceanic 

Fisheries Investigations (CalCOFI) program (originally named the Cooperative Sardine Research 

Program) in 1947 (Moser 1996). Recently, the California Department of Fish and Game 

(CDF&G) issued a press release (January 15,1999) indicating that the Pacific sardine resource 

has now fully recovered. Their most recent stock assessment indicated the catch quota be 

increased from the 1998 quota of 43,574 metric tons (MT) to a 1999 harvest of 120,556 MT (Hill 

et al. in press). Pacific sardine larvae were not among the ten most abundant larval fish taxa 

collected in the DCPP study, but are a species of interest because of their recovery status, their 

recent inclusion in the Fishery Management Plan for Coastal Pelagic Species (PFMC 1998), and 

their potentially growing fishery. 

Pacific sardine spawn pelagic eggs and larvae year round with a fall/winter minimum and a 

spring/summer maximum (Moser 1996) primarily south of Point Conception to the south of San 

Diego (Hart 1973). Reproduction is temperature dependent, and the spawning biomass may move 

north during El Nino years. Age at maturity also may be temperature dependent, with 50% of 

females maturing at about 16 cm standard length (SL) in southern California (Macewicz et al. 

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5.2.2 Pacific Sardine 

1996) and 50% ofthe females maturing at about 13 cm off Ensenada, Baja California Norte, 

Mexico in 1958 during an El Nino year (Ahlstrom 1960). Relatively large proportions offish at 

age class 0-yr have reached maturity in both the Southern California Bight and Monterey Bay 

(Table 5.2.2-1; Deriso et al. 1996). 

Estimates from previous studies of sardine fecundity range widely. Hart (1973) estimated 

30,000-65,000 eggs/batch with large individuals producing 200,000 eggs/yr. Fitch and 

Lavenberg (1971) reported an estimate of sardine fecundity of 90,000-200,000 eggs/yr. Lo et al. 

(1996) estimated an average batch fecundity of 24,282 (CV=11%). The highest estimates of 

annual fecundity from Butler et al. (1993) indicate that Pacific sardine fecundity ranged from 

146,754 eggs/two-yr-old female to as many as 2,156,600 eggs for ten-yr and older females 

(Table 5.2.2-2). Fitch and Lavenberg (1971) indicated that Pacific sardine can live to 25 yr, but 

longevity is more likely about 13 yr according to Butler et al. (1993); however, Leet et al. (1992) 

indicated that Pacific sardine older than five years were seldom encountered in the fishery; this 

was supported by data on catch-at-age presented in Hill et al. (in press). 

Each year sardines migrate northward early in summer and return south in fall, migrating farther 

with each year of life. The timing and extent of these migrations are complex and may be 

affected by oceanographic conditions. Age stratification ofthe adult population does appear to 

occur over a latitudinal gradient, with the larger, older fish occurring farther north (Hart 1973). 

The adult population off the central coast of California generally consists of young adults (2-

4 yr) that have migrated from the primary spawning grounds in southern California to feeding 

grounds in the waters near Diablo Canyon (PFMC 1998). 

Age and growth characteristics of Pacific sardine at all life stages have been well described. 

Larval growth estimated from otoliths has been measured in several temperature regimes (Miller 

1952), from which we are able to derive an approximate growth rate for larvae collected in the 

DCPP study. Growth ofthe adults has been described with a von Bertalanffy growth function 

(VBGF: L„=205.4 mm ± 1.6 mm SE, k=1.19 ± 0.04 SE, to = 0) by Butler et al. (1996). 

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5.2.2 Pacific Sardine 

Pacific sardine are among the few fishes with age- and stage-specific mortality estimates from the 

egg stage through later life stages reported in the scientific literature. Instantaneous egg mortality 

has been estimated as 0.13/d off of Oregon with a CV=243% (Barnes et al. 1992). Lo et al. 

(1996) produced a similar estimate of embryonic (yolk-sac) mortality of 0.12/d, but with a 

CV=97%. Butler et al. (1993) modeled the demography of Pacific sardine from the egg stage 

through the late adult stages with estimates of instantaneous daily natural mortality, the estimated 

duration of each stage, and daily fecundity. Deriso et al. (1996) modeled the annual fishing 

mortality of Pacific sardine for the years 1983-1995 (Table 5.2.2-3).The natural adult mortality 

rate in fished populations has been assumed to be 0.4/yr (Murphy 1966; MacCall 1979). 

A recent stock assessment of Pacific sardine incorporated fishery harvest statistics collected 

through 1998 (Hill et al. in press). They indicate that in 1998 the ex-vessel revenue ofthe 

commercia] sardine fishery (i.e., wetfish) in the state of California totaled $3.5 million, which is 

down from the $4.1 million generated in 1997. Directed fishery harvests in southern and central 

California are mostly canned for human consumption and sold overseas, with a small proportion 

sold fresh for human consumption or animal food (PFMC 1998). The ex-vessel price for sardines 

in the wetfish fishery ranged from $55-91 per MT, averaging $73.70/MT for January through 

September of 1998. In addition to the wetfish fishery, a small live bait fishery exists that usually 

takes <4,540 MT/yr. The overall revenue generated by the live bait fishery exceeds that ofthe 

directed fishery because ofthe higher dollar value for live bait, averaging $817/MT in 1998. 

5.2.2.1 Summary of Field Collections 

Pacific sardine larvae were present intermittently in the entrainment subsamples during the years 

1997-1999 (Appendix H), with their greatest abundance occurring during March-May, 1998 

(Figure 5.2.2-1). There was a total of 2,191 larval Pacific sardines in 230 bongo net subsamples 

collected at the DCPP intake structure between October 1996 and June 1999, representing 5% of 

the subsamples collected and processed from the sampling locations in front ofthe DCPP intake 

structure. An El Nino event began during the spring of 1997, influencing oceanographic 

conditions along the California coast in the fall/winter season of 1997-98 (Lynn et al. 1998; 

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5.2.2 Pacific Sardine 

NOAA 1999), and corresponds with die observed peak in larval Pacific sardine abundance in 

DCPP subsamples collected in 1998. The spread of warm water during the El Nino may have 

shifted the sardine spawning biomass north of their primary spawning grounds from south of 

Point Conception in the Southern California Bight (Hart 1973; Hill et al. in press) to the vicinity 

of Diablo Canyon. 

Larval Pacific sardine occurred in the DCPP study grid during February-July 1998, in December 

1998, and again during April-June 1999 (Appendix H), with the highest abundance occurring in 

March and April of 1998 (Figure 5.2.2-2). The patterns observed in the study grid further 

support the supposition that the 1997-98 El Nino may have displaced the Pacific sardine 

spawning biomass center further north than its distribution in a cooler water year. There was 

5,122 larval Pacific sardines identified from 368 bongo net subsamples, representing 12% ofthe 

study grid subsamples collected and processed from July 1997-June 1999. 

Standard lengths of all Pacific sardine larvae collected at the DCPP intake structure between 

October 1996 and June 1999 ranged from a minimum of 1.5 mm to a maximum of 25 mm, with 

corresponding age estimates ranging from 0-94 d (Figure 5.2.2-3). The growth rate of larval 

Pacific sardine (0.24 mm/d; Miller 1952) was used to estimate ages of entrained larvae. The 

central 98% of this length-frequency distribution resulted in minimum and maximum lengths 

used for the analyses of 2.4 mm and 19.1 mm, respectively. We assumed that larvae shorter than 

the minimum length ofthe central 98% ofthe distribution were just hatched and, therefore, age 0 

d, and we calculated estimated ages from this point. However, reported hatching size for this 

species ranges from 3.5-3.8 mm (Moser 1996), indicating that the smallest larvae observed 

represent either natural variation in hatch lengths within the population or the phenomenon of 

shrinkage following preservation (Theilacker 1980). The possibility remains that all larvae from 

the observed minimum length of 1.5 mm to the greatest reported hatching length of 3.8 mm 

(Moser 1996) could have just hatched, leading to gross overestimation of ages for all larvae <3.8 

mm. The mean larval length in this distribution was 5.5 mm and approximately 13 d of age based 

on a minimum length of 2.4 mm. 

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5.2.2 Pacific Sardine 

Mean lengths of Pacific sardine larvae sampled at the DCPP intake structure and from the study 

grid (Figure 5.2.2-4) were not different (Mest: p=0.185), but the Kolmogorov-Smirnov goodness 

of fit test detected a significant difference between the distributions ofthe two collections 

(p=0.003). Since mean lengths were not significantly different between the two locations, it was 

determined that the estimated mean ages were not significantly different either (about 14 d). The 

length-frequency distributions of Pacific sardine larvae were based on 155 larvae from the intake 

and 2,882 larvae from the study grid mirroring their adult distribution. It was concluded from 

these data that the Pacific sardine larvae entrained came from the same population available in 

the study grid, but that there was a greater proportion of small individuals present in the study 

grid subsamples as compared with the entrainment subsamples. 

5.2.2.2 Estimating Total Annual Entrainment 

Annual estimated numbers of Pacific sardine larvae entrained at DCPP increased by greater than 

three orders of magnitude between Analysis Period 1 (October 1996-September 1997; 

£> = 368,000) and Analysis Period 2 (October 1997-September 1998; % = 104,000,000: 

Table 5.2.2-4). Estimates for Analysis Periods 2 and 3 (July 1997-June 1998) were the same 

because they included the same period of 1998 when peak abundance of Pacific sardine larvae 

occurred. Most ofthe spawning biomass of Pacific sardine is located south of Point Conception 

in the Southem California Bight (Hill et al. in press) during non-El Nino years. However, during 

El Nino events (e.g., fall and winter of 1997-98), warm water moves up the California coast from 

the south (NOAA 1999), probably carrying southern California spawning stocks north with it. 

This appeared to be indicated in the waters near Diablo Canyon by the increase in larval Pacific 

sardine abundance in 1997 and 1998 during Analysis Period 2. 

The estimates of annually entrained Pacific sardine larvae were adjusted (Table 5.2.2-5) to the 

long-term average Intake Cove surface plankton tow index (III,) calculated as the ratio between 

the 9 yr average (I) of Intake Cove sampling (Figure 5.2.2-5) and the average annual index 

estimated from these same tows during the year being adjusted (/,). The average indices for 

Analysis Period 1 and Analysis Periods 2 and 3 were O.001 and 0.070 larvae/m^, respectively, 

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5.2.2 Pacific Sardine 

and the long-term average index for 1990-98 was 0.0152 larvae/m^. Thus, the ratios used to 

adjust the Analysis Period 1 and Analysis Period 2 estimates of larvae entrained were 23.0 and 

0.217, respectively. The same trends in overall abundance as noted for unadjusted entrainment 

values are apparent in the adjusted values: larval Pacific sardine were less abundant in Analysis 

Period 1 (EAdj_T = 8,470,000) than in Analysis Periods 2 and 3 (EAJj_T = 22,600,000). However, 

the adjustment to the long-term average had the effect of reducing the difference in abundance 

between years from three orders of magnitude to less than one. The adjusted CV ranged from 

28% in Analysis Period 1, reflecting the low and patchy abundance during the period, to 7% in 

Analysis Periods 2 and 3 when the larvae were found in greater abundance and were more evenly 

distributed. 

5.2.2.3 Fecundity Hindcasting (FH) 

Fecundity hindcasting requires age-specific fecundity (Mx) and mortality (Lx) to assess 

entrainment effects. Butler et al. (1993) modeled egg and larval survivorship of Pacific sardine 

for several life stages (Table 5.2.2-2). Their 'best' estimate is derived by fitting the range of 

field-estimated mortalities to the assumption of a stable and stationary population. Instantaneous 

mortality rates from Butler et al. (1993) were used to describe survivorship of egg (0.720), yolksac (0.670), and early larval stages (0.242) of Pacific sardine. Applying these rates over their 

respective average stage durations (Butler et al. 1993), they can then be used to estimate finite 

survivorship for each developmental stage: 0.165 (egg), 0.125 (yolk-sac), and 0.077 (early 

larvae). The survival rate from egg stage to entrainment (0.002) was then calculated from an 

average age at entrainment of 16 d, estimated using a growth rate of 0.24 mm/d (Miller 1952), 

and an average and smallest size at entrainment of 5.5 mm and 1.5 mm, respectively. 

The FH approach combines larval entrainment losses and adult fecundity to hindcast the numbers 

of adult females effectively removed from the reproductively active population. For Pacific 

sardine, there is substantial regional variation in size-at-age, and ages generally increase from 

north to south (Phillips 1948). Size and age at maturity may decline with a decrease in biomass, 

but latitude and temperature are also important (Butler 1987). At low biomass levels, MacCall 

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5.2.2 Pacific Sardine 

(1979) reports that all 1 yr old sardines appear to be reproductively mature, whereas at high 

biomass levels some 2 yr old fish have yet to reach maturity. Butler et al. (1993) also developed 

models using age at first maturity as 2 yr. Geographic distribution, however, influenced maturity 

as Deriso et al. (1996) estimated that 58% of age 0 sardines (<1 yr) were mature in Monterey Bay 

and 65% mature in the Southern California Bight in 1995 (Table 5.2.2-1). In subsequent 

calculations, we will assume that age at first maturity is 2 yr as modeled in Butler et al. (1993). 

Pacific sardines may live as long as 13 yr (Butler et al. 1993; Love 1996), but Deriso et al. (1996) 

and Hill et al. (in press) report that the oldest fish in their samples from off the California coast 

were aged 9 yr. Leet et al. (1992) reports that fish older than 5 yr are seldom caught in the 

fishery, and this is supported by the catch-at-age data reported in Hill et al. (in press) that extends 

through June 1998. 

Since both longevity and age at maturation are biomass dependent (Hart 1973) and likely 

changing in this recovering population (Hill et al. in press), we will use what appears to be the 

fishery longevity (i.e., 5 yr; Leet et al. 1992; Hill et al. in press) to calculate total lifetime 

fecundity (TLF). If 5 yr is an underestimate ofthe actual reproductive life span of this fish, then it 

represents an assumption that reduces the total lifetime fecundity and thus may overestimate the 

impact of entrainment losses on adult females. The average fecundity from age-2 to age-5 

modeled by Butler et al. (1993) is 496,018 eggs per female per year. This fecundity is multiplied 

by one half the difference between the fishery-modified longevity and age at maturation yielding 

7ZF = 496,018-( — j = 744,027 . 

The adjusted total larval entrainment for Pacific sardine (EAdj_T) was used to estimate the number 

of breeding females needed to produce the number of larvae entrained (Table 5.2.2-5). The 

estimated number of breeding females (FH) whose fecundity equals the estimated total loss of 

entrained larvae is calculated assuming age of maturation is 2 yr and longevity in the fishery is 5 

yr (Table 5.2.2-6). The number of adult females hindcast from the larvae entrained at DCPP 

during Analysis Period 1 (FH = 3,170) was less than one-half of the adult females hindcast 

during Analysis Periods 2 and 3 (FH = 8,460). 

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5.2.2 Pacific Sardine 

Sensitivity Analysis 

Two parameters, survivorship and fecundity, had the greatest leverage on recalculated values of 

FH (Table 5.2.2-7). Varying either of these two parameters in the model resulted in an FH 

range of 613-43,800 adult females for Analysis Period 1 and Analysis Periods 2 and 3, compared 

to the original estimate of 3,170-8,460 adult females. Maturation and longevity had the next 

greatest amount of leverage on recalculated FH. 

5.2.2.5 Adult Equivalent Loss (AEL) 

Similar to the FH results, estimates of adult equivalents lost (AEL) due to larval entrainment 

were smaller during Analysis Period 1 (2,630) .than during Analysis Periods 2 and 3 (7,000) 

(Table 5.2.2-8). The AEL of 2,630 adults predicted from EAdj.T at DCPP during Analysis Period 

1 reflects the low abundance of Pacific sardine larvae during this period. As indicated from the 

long term Intake Cove surface tows, these low abundance estimates represent a more typical year 

relative to the following years that appeared to be influenced by El Nino conditions. AEL values 

were almost three times higher during Analysis Periods 2 and 3 (i.e., 7,000 adult equivalents) 

when spawning stocks generally found south of Point Conception were likely displaced 

northward as warm El Nino waters spread up the Califomia coast. 

Sensitivity Analysis 

Late larval survivorship had the greatest leverage on recalculated values oi AEL (Table 5.2.2-9). 

Varying this parameter in the model resulted in an AEL ranges of 507-36,300 adult equivalents 

for Analysis Period 1 and Analysis Periods 2 and 3, compared to the original estimate of 2,630-

7,000 adult equivalents. Early juvenile survivorship had the next greatest leverage on AEL, while 

varying the estimate of entrainment did not substantially change the original estimate of AEL. 

5.2.2.6 Empirical Transport Model (ETM) 

Monthly estimates of proportional entrainment (PE,) in each rth survey from the two years 

sampled ranged from a minimum of zero to a maximum of 0.859±0.911 (±ISE(PE, I) in January 

1999 (Table 5.2.2-10). When both PE, and the annual proportion of larvae hatched in the rth 

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5.2.2 Pacific Sardine 

survey period (fj) were equal to zero, no larvae were collected at either the DCPP intake nor 

from the study grid. When PE, =0 and f>0, larvae were collected at the DCPP intake during the 

survey period but not during the entrainment survey paired with the 72-hr study grid survey. For 

Pacific sardine, the relatively large PE, for January 1999 was accompanied by an / = 1 since 

this was the only month in which Pacific sardine were collected during Analysis Period 4. In 

addition, there were no Pacific sardine larvae collected in the study grid during the paired 72-

hour sampling period. A PE was calculated for the survey period because the larval density from 

the weekly entrainment sample (Appendix H) was used to estimate the densities in the 

unsampled volume inshore ofthe two cells nearest the intake (Dl and El). As a result no 

estimates of larval mortality due to entrainment (PM) were calculated for Analysis Period 4. 

By varying the estimated proportion ofthe sardine population in the study grid (Ps) over the 

mean and maximum larval durations, estimates ofPM ranged over nearly an order of magnitude 

during Analysis Period 3 (Figure 5.2.2-6). The differences in PM resulted from longer larval 

duration and consequently greater alongshore and onshore transport during the period which 

decreased Ps, although it increased time the larvae were susceptible to entrainment. The PM 

values calculated from offshore extrapolated abundance extended alongshore were small 

regardless ofthe larval duration used (i.e., 0.0000669 and 0.000284 for the maximum and mean 

durations, respectively). The extrapolations developed in this analysis indicated that sardine 

larvae were at risk over an area ranging from 938 km^ to 14,800 km^ (based on 1997-1998 data 

of current velocities, gradients in larval distribution, and durations at risk for mean and maximum 

larval sizes entrained, respectively). These areas represent 0.6-9.1%, respectively, ofthe total 

area ofthe 1998 spawning population of Pacific sardine extending from San Francisco Bay to 

Ensenada, Mexico (based on values reported by Hill et al. [in press] and the PSMFC database; 

Figure 5.2.2-7). 

5.2.2.7 Interpretation of Assessment Results 

Estimates of entrainment losses using AEL estimates can be used to estimate effects on local 

harvest of Pacific sardine. An estimated annual average equivalent loss of approximately 5,000 

adult sardines (AEL) at DCPP translates into 0.625 MT/yr using an average weight of 125 g for 

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5.2.2 Pacific Sardine 

two year old sardines (Hill et al. in press). Assuming, conservatively, that all of these sardines 

were vulnerable to the fishery, approximately 10% of this biomass would be directed to the live 

bait fishery (average value of $817/MT) and the remainder would be directed to the wetfish' 

fishery (average value of $74/MT). These amounts translate into $51/yr from the live bait fishery 

and $42/yr from the wetfish fishery. 

Alternatively, the estimates of annual entrainment mortality probability (PM ranges from 

0.0000669-0.000284) can be applied to the proportion ofthe recent stock size estimates at risk to 

entrainment assuming no compensation. Hill et al. (in press) report that approximately 337,596 

MT of Pacific sardine were present in the area from Monterey Bay to San Diego. The proportion 

of this amount to which PM would be applied would be 16,900 MT, which is approximately 5% 

(the average area ofthe spawning population potentially affected by entrainment, based on the 

two estimates using maximum and mean larval durations) ofthe total biomass within the area 

from San Diego to Monterey. Using the larger more conservative PM estimate yields a potential 

loss of 4.8 MT of Pacific sardine as a result of entrainment. By apportioning the valuation of 

catches as in the AEL loss estimates, 4.8 MT represents direct annual dollar value losses of $390 

to the live bait fish^i^nd_$32^tothe wetfish fishery. 

These estimates indicate that DCPP entrainment effects represent minimal risk to local or 

regional populations of Pacific sardine. During the period of power plant operations that began in 

1985, adult stocks of Pacific sardine have fully recovered (Hill et al. in press) from their 

population crash in the late 1940's and early 1950's (PFMC 1998), and commercial catches have 

steadily increased (Starr et al. 1998). Pacific sardine larvae occurred episodically in plankton 

samples collected at DCPP during the present study and in data sets spanning a larger time frame. 

There is little possibility that any additional larval mortality due to entrainment of this species at 

DCPP is affecting the adult stocks when one considers the uncommon occurrence of Pacific 

sardine larvae in plankton tows near DCPP combined with the trends of increasing abundance 

and catch. 

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5.2.2 Pacific Sardine 

Table 5.2.2-1. Percent maturity of female Pacific sardines (Sardinops sagax) in 

the Southern California Bight and in Monterey Bay (Deriso et al. 1996). 

Age (yr) 

0 

1 

2 

3 

4 

5+ 

% Mature (Southern % Mature (Monterey, 

Califomia Bight) California) 

65 

87 

96 

99 

100 

100 

58 

79 

91 

97 

99 

100 

Table 5.2.2-2. Life table for Pacific sardine (Sardinops sagax): a) Age-specific fecundity 

schedule (Mx=natality rate; Lx=survivorship) and b) stage-specific survivorship schedule 

(Z=instantaneous daily mortality; S=finite survival rate) modified from Butler et al. (1993). 

a) Age-specific fecundity 

(continued) 

TENERA E9-055.0 

Age (yr) 

1 

2 

3 

4 

5 

6 

7 

8 

9 

10 

11 

12 

13 

Mx 

0 

146,754 

388,188 

599,640 

849,490 

1,167,457 

1,487,528 

1,617,450 

1,887,025 

2,156,600 

2,156,600 

2,156,600 

2,156,600 

5-75 

Lx 

1,000 

670 

449 

301 

202 

135 

91 

61 

41 

27 

18 

12 

8 

MXLX 

0 

98,325,180 

174,296,412 

180,491,640 

171,596,980 

157,606,695 

135,365,048 

98,664,450 

77,368,025 

58,228,200 

38,818,800 

25,879,200 

17,252,800 

Final 316(b) Demonstration 

March 1,2000 
P.91 

5.2.2 Pacific Sardine 

Table 5.2.2-2. (continued) 

b) Stage-specific survivorship 

•Duration Duration 

Stage Zmin Z^, Zm„ (d) Cumulative (d) Sm„ SbesI Smin CVbest 

Egg 0.3100 0.7200 2.1200 

Yolk-sac 0.3940 0.6698 0.9710 

larva 

Early larva 0.1423 0.2417 0.3502 

Early larva 0.1423 0.2417 0.3502 

Late larva 0.0570 0.0964 0.1390 

Early 

juvenile 0.0290 0.0560 0.0810 

Juvenile I 0.0116 0.0197 0.0285 

Juvenile II 0.0023 0.0040 0.0058 

Juvenile III 0.0016 0.0028 0.0040 

Juvenile IV 0.0012 0.0022 0.0032 

Pre-recruit 0.0006 0.0011 0.0015 

Survivorship from entrainment to recruitment: 0.0003 

Table 5.2.2-3. Estimated fishing mortality rates (F) on Pacific sardine 

(Sardinops sagax) from 1983-1995. Data from Deriso et al. (1996). 

Age (yr) Estimated F Range 

0 0.00-0.04 

1 0.01-0.30 

2 0.04-0.71 

3 0.04-1.08 

4 0.03-1.05 

5 0.03-0.96 

3 

3 

11 

orshi 

11 

35 

25 

50 

no 

146 

170 

175 

6 

17 

p from egg 

17 

52 

77 

127 

237 

383 

553 

728 

3 0.4607 

3 0.2948 

7.26 0.356 

to entrainment: 

3.74 0.587 

35 0.1360 

25 0.4843 

50 0.5599 

110 0.7765 

146 0.7917 

170 0.8155 

175 0.9003 

0.1653 

0.1254 

0.173 

0.0036 

0.4047 

0.0343 

0.2466 

0.3734 

0.6440 

0.6644 

0.6880 

0.8249 

0.0050 

0.0493 

0.0788 

0.270 

0.0077 

0.1320 

0.2405 

0.5283 

0.5577 

0.5804 

0.7691 

0.4595 

0.3264 

0.267 

0.131 

0.6243 

0.2381 

0.1425 

0.0642 

0.0587 

0.0569 

0.0265 

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5.2.2 Pacific Sardine 

Table 5.2.2-4. Estimated total annual entrainment (£, ) and standard error 

(SE(ET)) for Pacific sardine (Sardinops sagax) larvae from the three analysis 

periods. 

Analysis Period Er SE(ET) 

1) Oct 23, 1996-Sep30, 1997 

2) Octl,1997-Sep30, 1998 

3) Jul 1, 1997-Jun30, 1998 

368,000 

104,000,000 

104,000,000 

103,000 

7,430,000 

7,430,000 

Table 5.2.2-5. Estimated total annual adjusted entrainment (EAdj_T) and 

standard error (SE(EMJ_T)) for Pacific sardine (Sardinops sagax) larvae from 

the three analysis periods. 

Analysis Period EAdj.T SE(EAdj_r) 

1) Oct 23, 1996-Sep30, 1997 

2) Octl, 1997-Sep30, 1998 

3) Jul 1, 1997-Jun 30, 1998 

8,470,000 

22,600,000 

22,600,000 

2,360,000 

1,610,000 

1,610,000 

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5.2.2 Pacific Sardine 

Table 5.2.2-6. Estimated number of Pacific sardine (Sardinops sagax) adult females 

(FH) whose reproductive output was equivalent to the adjusted number of larvae 

entrained per year (EAdj_T) at Diablo Canyon Power Plant including the standard error 

ofthe estimate (SE(FH)) and 90% confidence limits (C.L.). 

Analysis Period FH 

Upper Lower 

SE(FH) 90% CL. 90% CL. 

1) Oct 23, 1996-Sep30, 1997 3,170 12,100 1,690,000 6 

2) Octl, 1997-Sep30, 1998 8,460 32,300 4,490,000 16 

3) Jull,1997-Jun30, 1998 8,460 32,300 4,490,000 16 

Table 5.2.2-7. Pacific sardine (Sardinops sagax): Sensitivity analysis for FH from the 

three analysis periods recalculated for each model input parameter (0): EAdJ_T ± 1.645 

SE(0); other parameters are 0.e±i645CK«?) wher e CV(0 ) = 1.0 or 100%. 

a) Analysis Period 1: October 1, 1996-September30, 1997 

Parameter 

FH 

F-Adj-T 

5

 egg 

S yolk-sac 

•S larvae 

# Eggs/yr 

Longevity 

Maturation 

Estimate 

= 3,170 

8,470,000 

0.165 

0.125 

0.173 

496,000 

5 

2 

Minimum 

1,720 

613 

613 

613 

613 

1,190 

2,380 

Recalculated FH 

Maximum 

4,630 

16,400 

16,400 

16,400 

16,400 

6,350 

9,520 

Range 

2,910 

15,800 

15,800 

15,800 

15,800 

5,160 

7,140 

TENERA E9-055.0 5-78 Final 316(b) Demonstration 

March 1,2000 
P.94 

5.2.2 Pacific Sardine 

Table 5.2.2-7 (continued). Pacific sardine (Sardinops sagax): Sensitivity analysis for 

FH from the three analysis periods recalculated for each model input parameter (9): 

EAdj.T ± 1 -645 SE(9); other parameters are 6e±x M5cyW where CV( 9) = 1.0 or 100%. 

b) Analysis Period 2: October 1, 1997-September 30, 1998 

Parameter 

FH 

F-Adj-T 

S

 egg 

s

 yolk-sac 

S larvae 

it Eggs/yr 

Longevity 

Maturation 

Estimate 

= 8,460 

22,600,000 

0.165 

0.125 

0.173 

496,000 

5 

2 

Minimum 

7,460 

1,630 

1,630 

1,630 

1,630 

3,170 

6,340 

Recalculated FH 

Maximum 

9,450 

43,800 

43,800 

43,800 

43,800 

16,900 

25,400 

Range 

1,990 

42,200 

42,200 

42,200 

42,200 

13,700 

19,000 

c) Analysis Period 3: July, 1997-June 30, 1998 

Parameter 

FH 

F-Adj-T • 

s

 egg 

S yolk-sac 

S larvae 

ti Eggs/yr 

Longevity 

Maturation 

Estimate 

= 8,460 

22,600,000 

0.165 

0.125 

0.173 

496,000 

5 

2 

Minimum 

7,470 

1,630 

1,630 

1,630 

1,630 

3,170 

6,350 

Recalculated FH 

Maximum 

9,450 

43,800 

43,800 

43,800 

43,800 

16,900 

25,400 

Range 

1,990 

42,200 

42,200 

42,200 

42,200 

13,700 

19,000 

TENERA E9-055.0 

i 

5-79 Final 316(b) Demonstration 

March 1,2000 
P.95 

5.2.2 Pacific Sardine 

Table 5.2.2-8. Estimated number of equivalent Pacific sardine (Sardinops sagax) adults 

(AEL) equal to the adjusted number of larvae entrained per year (EAdj_T) at Diablo 

Canyon Power Plant including the standard error ofthe estimate (SE(AEL) ) and 90% 

confidence limits (CL.). 

Analysis Period 

•Upper Lower 

AEL SE(AEL) 90% CL. 90% CL. 

1) Oct 23,1996-Sep30,1997 

2) Octl, 1997-Sep30,1998 

3) Jull,1997-Jun30,1998 

2,630 10,300 1,650,000 

7,000 27,400 4,390,000 11 

7,000 27,400 4,390,000 11 

TENERA E9-055.0 5-80 Final 316(b) Demonstration 

March 1,2000 
5.2.2 Pacific Sardine 

Table 5.2.2-9. Pacific sardine (Sardinops sagax): Sensitivity analysis for AEL from the 

three analysis periods recalculated for each model input parameter (6): EAdj_T ± 1.645 

SE(0); other parameters are 0.e

±lM5CVW where CV(0) = 1.0 or 100%. 

a) Analysis Period 1: October 1, 1996-September 30, 1997 

Parameter 

AEL = 

^Adj-T • 

S early larvae 

S late larvae 

S early juvenile 

S juv. I 

S juv. II 

S juv. Ill 

. S juv. TV 

S pre-recruit 

Estimate 

2,630 

8,470,000 

0.405 

0.0343 

. 0.247 

0.373 

0.644 

0.664 

0.688 

0.825 

Minimum 

1,420 

507 

507 

507 

507 

507 

507 

507 

507 

Recalculated AEL 

Maximum 

3,830 

6,490 

13,600 

10,700 

7,030 

4,080 

3,950 

3,820 

3,180 

Range 

2,410 

5,980 

13,100 

10,100 

6,530 

3,570 

3,450 

3,310 

2,680 

TENERA E9-055.0 5-81 Final 316(b) Demonstration 

March 1,2000 
P.97 

5.2.2 Pacific Sardine 

Table 5.2.2-9 (continued). Pacific sardine (Sardinops sagax): Sensitivity analysis for 

AEL from the three analysis periods recalculated for each model input parameter (0): 

EAdj-T ± 1-645 SE(9); other parameters are 0.e

±lM5C,'W where CV(0)= 1.0 or 100%. 

b) Analysis Period 2: October 1, 1997-September 30,1998 

Parameter 

AEL = 

E 

^Adj-T • 

S early larvae 

S late larvae 

S early juvenile 

S juv. I 

S juv. II 

S juv. Ill 

S juv. W 

S pre-recruit 

Estimate 

7,000 

22,600,000 

0.405 

0.0343 

0.247 

0.373 

0.644 

0.664 

0.688 

0.825 

Minimum 

6,180 

1,350 

' 1,350 

1,350 

1,350 

1,350 

1,350 

1,350 

1,350 

Recalculated AEL 

Maximum 

7,820 

17,300 

36,300 

28,400 

18,700 

10,900 

10,500 

10,200 

8,490 

Range 

1,650 

15,900 

34,900 

27,000 

17,400 

9,520 

9,180 

8,820 

7,130 

TENERA E9-055.0 5-82 Final 316(b) Demonstration 

March 1,2000 
j ^ 8 

^1 

5.2.2 Pacific Sardine 

Table 5.2.2-9 (continued). Pacific sardine (Sardinops sagax): Sensitivity analysis for 

AEL from the three analysis periods recalculated for each model input parameter (0): 

EAdj-T ± J -

645 SE0) \ other parameters are 0.e±iM5Cvm where CV( 0) = 1.0 or 100%. 

c) Analysis Period 3: July 1, 1997-June 30, 1998 

Parameter 

AEL = 

^Adj-T 

S early larvae 

S late larvae 

S early 

juvenile 

S juv. I 

S juv. II 

S juv. Ill 

S juv. IV 

S pre-recruit 

Estimate 

7,000 

22,600,000 

0.405 

0.0343 

0.247 

0.373 

0.644 

0.664 

0.688 

0.825 

Minimum 

6,180 

1,350 

1,350 

1,350 

1,350 

1,350 

1,350 

1,350 

1,350 

Recalculated AEL 

Maximum 

7,830 

17,300 

36,300 

28,400 

18,800 

10,900 

10,500 

10,200 

8,490 

Range 

1,650 

16,000 

34,900 

27,000 

17,400 

9,520 

9,190 

8,830 

7,140 

TENERA E9-055.0 5-83 Final 316(b) Demonstration 

March 1,2000 
P.99 

5.2.2 Pacific Sardine 

Table 5.2.2-10. Pacific sardine (Sardinops sagax): Monthly estimates of proportional 

entrainment (PE,) and annual proportion of larvae hatched in the rth survey period (£) 

within an analysis period (e.g., July 1, 1997-June 30, 1998) with associated standard errors 

(SE) used in estimating entrainment mortality for two years of paired entrainment and study 

grid surveys. 

a) Analysis Period 3: July 1, 1997-June 30, 1998 

Survey Start Date PE. ££(/>£,.) fi 

b) Analysis Period 4: July 1, 1998-June 30, 1999 

Survey Start Date PE SE(PE,) fi 

SE(f.) 

Jul 21, 1997 

Aug 25, 1997 

Sep 29, 1997 

Oct 20, 1997 

Nov 17, 1997 

Dec 10,1997 

Jan 22,1998 

Feb 26, 1998 

Mar 18, 1998 

Apr 15, 1998 

May 18, 1998 

Jun 8, 1998 

0 

0 

0 

0 

0 

0 

0 

0 

0.00092 

0.00084 

0.00096 

0.00199 

0 

0 

0 

0 

0 

0 

0 

0 

0.00011 

0.00021 

0.00032 

0.0007 

0 

0 

0.00091 

0 

0 

0 

0.00043 

0 

0.066 

0.123 

0.802 

0.00784 

0 

0 

0.00024 

0 

0 

0 

0.00015 

0 

0.00254 

0.00538 

0.00676 

0.00107 

-*(/,) 

Jul 21, 

Aug 26, 

Sep 16, 

Oct 6, 

Nov 11, 

Dec 9, 

Jan 12, 

Feb 3, 

Mar 17, 

Apr 14, 

May 24, 

Jun 23, 

1998 

1998 

1998 

1998 

1998 

1998 

1999 

1999 

1999 

1999 

1999 

1999 

"-" = no estimate of standard error 

TENERA E9-055.0 

0 

0 

0 

0 

0 

0 

0.859 

0 

0 

0 

0 

0 

because only one 

0 

0 

0 

0 

0 

0 

0.911 

0 

0 

0 

0 

0 

fish was collected during 

5-84 

0 

0 

0 

0 

0 

0 

1 

0 

0 

0 

0 

0 

this survey period 

0 

0 

0 

0 

0 

0 

-

0 

0 

0 

0 

0 

Final 316(b) Demonstration 

March 1,2000