MaoDcC I'lo : Eq*7) 11- TECHNICAL REPORT TO THE CALIFORNIA COASTALCOMMISSION D. Adult-EquivalentLoss MARINE REVIEW COMMITTEE. INC. William W. Murdoch.Chairman Universityof California ByronJ. Mechalas SouthernCalifornia Edison Company Rimmon C. Fav PacificBio-Marine L;ibs, Inc. Preparedby: Keith Parker EdwardDeMartini ContributineStaff: BonnieM. WiJliamson October1989 I I TABLE OF CONTENTS I SUMMARY ............. v 1.0 INTRODUCTION.... 1 I 4 Estimation of reducedrecruitment of new adultsdue to I entrainmentof immature stages 2.1 Basicmethod for estimatingadult-equivalent loss........... 5 2.l.L Compensationignore?..... 6 2.1,.2Loss to the adult standingstock 6 I 2.2 Estimation of entrapmentprobabilities 7 2.3 Estimation of entrapmentiates 8 2.3.1 Entrapmentrate for plankton... 9 I 2.3.2 Entra-pmentrate for iuveniles... 13 2.3.3 Duration of the stagds. 15 I 3.0 RESULTS T7 3.1 Ta:<awhose juvenile stages are entrapped 18 Q.23.2 \u<awhoseTaxawhose juvenile stalesstages are not enirapeirirapped 24 I 3.3 Potentiallosses to the a[ult standingstoili.... 3L 4.0 DISCUSSION 34 I 4.1 Magnitude of effects 34 4.1.1 Taxawhose juveniles are entrapped............ 35 4.1.2 Taxawhosejuveniles are not entrapped 37 I 4.2 Potentiallosses to the adult standingstoCk 37 I 5.0 REFERENCES.......... 39 6.0 TABLES and FIGURES.......... 43 I APPENDICES I APPENDIXA: EstimatingEntrapment Rate For PlanktonicStages A-1 APPENDIX B: EstimatingAdult StockSi2e........... B-1 I APPENDIX C: EstimatingThe EntrapmentRate of Young Adults c-1 APPENDIX D: EstimatingJuvenile Entrapment Rate... D-1 I APPENDIX E: EstimatingDuration At Rick For PlanktonicStages E-1 I I I TABLE OF CONTENTS- APPENDICES APPENDIXA: EstimatingEntrapment Rate For planktonic stages 4.1, Data collection A-1 A.2 Intake1oss............. A-2 4.2.1, Intake lossfor taxanot affectedbv SONGS. A-2 A.2.2 Intakeloss for taxaaffected by SONGS....... A-3 A.3 Standingstock in the bight.......... A-4 +.1.1 Standingstock foi taxanot affectedby SONGS........................A-5 +.3_.?Standing stock for taxaaffected by SONGS A-6 A.3.3 Standingstock of northern anchoi'y. A-7 A.4 EntrapmentRate.......... .. A-7 A.5 Major a_ssumptionsin estimating entrapment rate........... A-8 A.5.1 Usingimpact and control-datafor taxanot affected................A-8 4.5.2 Interpretingand estimatins SONGS'effect........ A-9 A.5.3 Usingimpalt datafor affeited taxa........... A-lz A.5.4 Meansover time A-13 A.5.5 No standingstock bevond E,Block.... A-14 A.!.q Ioss is profortionateacross all depthstrata........ A-15 A.5.7 Equal effeit acrossall stases ,4'-16 A.5.8 Pri:cisionof adult-equivalEnt1oss........... ,4.-16 REFERENCES - APPENDIX A A-L7 TABLES A.1 - A.3.. A-19 APPENDIX B: EstimatingAdult StockSize 8.1 Introduction... B-1 8.2 Queenfishand white croaker: eggabundance and production......... B-3 8.2.1 F;ggabundance ..................:.: B-3 8.2.2 Daily eggproduction ........... B-4 B.3 Queenfishand croaker: Batchfecundity.. B-5 8.4 Queenfishand croaker: Spawningfraction..... B-6 B.5 Queenfishand croaker: Femalefraction B-6 8.6 Northernanchow stockestimation B-7 8.7 Estimatesof adult stocksize B-7 8.7.1 Northernanchow B-7 8.7.2 Queenfish...........:. B-8 B.7.3 White croaker B-8 B.8 Potentialinaccuracies: Factors affecting stock estimates B-8 REFERENCES - APPENDIX B B-10 TABLES 8.1 - B.7 B-15 APPENDIX C: EstimatingThe EntrapmentRate of young Adults C.1 Introduction......... c-1 C.2 Inplant lossand bight-wideabundance of youngadults c-1 C.3 Taxaaccount: Discussion of problemdata and assumptionviolations ................... c-4 C.3.1Northern anchovy.... c-4 C.3.2 Queenfish...........:....... c-4 C.3.3 White Croaker c-5 C.3.4 Taxawith inplantlosses estimable for old iuveniles c-6 C.3.5Taxa with inillantlosses inestimable for juieniIes.....................c-7 C.3.6 Generalpatterns for all taxa..... c-7 REFERENCES- APPENDIX C........... c-9 TABLESC.1 - C.5 c-l1 APPENDIX D: EstimatingJuvenile Entrapment Rate... D.1 Outlineof methods.............. D-1 D.2 Minimum and maximumlength, availability and vulnerability for queenfishand white croa-ker.... D-3 D.3 The shapeof availabilityand vulnerability functions................. D-7 D.4 Summary............. D-12 REFERENCES. APPENDIX D.......... D-1,4 TABLE D.1 D-17 lll APPENDIX E: EstimatingDuration At Rick For planktonic Stages E.1 Estimatingrange in bodylength of a stage E-1 E.2 Growthrate........ E-2 E.3 Durationin time at stage......... E-2 REFERENCES- APPENDIX E........... F-4 TABLESE.I.E.2 E-9 lv I I SUMMARY I In this report we estimatethe loss of adult-equivalentfish due to entrapmentby I SONGS'Units 2 and3. We definean adult equivalentas a fish that would haverecruited to the adult stock had it not been entrapped as an egg, larva, or juvenile. We estimate I adult-equivalentloss in terms of 1) percent of new recruits and?) numbersand biomassof the standingstock. The first estimate,percent of new recruits,is an annual rate. This we I estimatefor2'l' ta,ra.The second,lossto the standingstock, is for all year classescombined I and requiresthe accumulatedeffect of plant operationover the number of yearsequal to the oldestfish in the stock. I I Percent of New Recruits I The percent of new recruits lost is highest for those taxa with the highest proportionsof planktonicand juvenile stagesfound in watersnear the depth of SONGS' I intakerisers. Of the 2J.tw<a studied, three haveestimated losses in excessof 5Vo,1l.have 'J.Vo. estimated lossesbetween 1.Voand 5Vo, and seven have estimated lossesless than I Queenfish,white croaker and giant kelp fish have the highest estimated losses, 12.7Vo, 7.5Voand 6.5Vo,respectively. Northern anchory, Pacific mackerel and California halibut, I whoseplanktonic and juvenile stagesare not at great risk to entrapment,have the lowest I estimatedloss, all lessthan 0.2Vo. I Numbersand Biomass T We estimateloss to the standingstocks of adults for three taxa, those for which we could estimate adult abundance. Lossesare 551 MT (18,000,000fish) and 394 MT I (4,100,000fish) for queenfishand white croaker,respectively. Estimated loss of northern I I anchovyis 1,340MT (89,000,000fish). Thesethree taxaaccount for approximately70Vo of all entrainedlarvae and togethersum to total lossof over2,290MT. t I 1.0 INTRODUCTION I SONGS' Units 2 and 3 draw in approximately6.8 million cubic meters of I water per day. This equalsthe volume of a seawatertank with a basethe size of a football field and a height of over one-half mile. Entrapped with thesewaters are I adult and juvenile fish, larvae, and eggs. Some entrapped adults and juveniles (sexuallyimmature fish) are impinged or otherwisekilled. The fish return system I may allow a significantportion of older juveniles and adultsto survive(DeMartini er I al. t987;l-ove et al.1987). All entrappedlarvae and eggsare killed (Barnett 1987). I In this report we evaluate the potential effects of SONGS' entrapment of eggs,larvae, and juveniles on stocksof adult fish living in the California Bight, the I body of water extending from Cabo Colnet, Baja California, Mexico to Point I Conception. We call this estimate"relative adult-equivalentloss," or simply "adult- equivalentloss." We define an adult-equivalentas a fish that would have recruited I to the adult stock"had it not been entrappedand killed as an egg,larva, or juvenile. We estimate adult-equivalent loss for 2l tu<a: those with the highest risk to I entrapmentandf or thoseof sport/commercialinterest. We do not estimatelosses for taxa where only the juvenile stage is entrapped becauseof insufficient data. I However,we do discussthe relative magnitudeof lossof thesetaxa. t We report adult-equivalent loss in two ways. First, we report adult- I equivalentloss as a percent of new recruits to the adult stock (annual cohort). This estimate is an annual rate. Second,for select taxa, we estimate the numbers and I biomassof adult equivalentslost to the standingstock. I I I I T To compute relative loss,our primary task, we use proceduresdeveloped by MacCall et al. (1983). While we discussthese proceduresin METHODS, we ! mention at this point the main advantageof using this technique: estimates of natural mortality for eggs,larvae, and juveniles are not required. This is fortunate, I since the natural mortality rates of theselifestages are unknown. (In fact, natural I mortality rates for the adults of most entrappedtaxa have never been estimated.) Other methodsmake a lessdirect comparison. Goodyear (1978) extended a method I proposedby Horst (1975) for treating entrainedlarvae in terms of adult-equivalent losses. Additional methods of assessmentinclude more complex models using I Irslie matrices (Vaughan and Saila 1976;Horst 1977;Vaughan 1.981),differential equations(Hackney et al.1980),or stock-progeny-recruitmodels (Christensenet al. I 1977). All of thesemethods, including those usedin the Hudson River Study (see I Barnthouseet aL.1984),require life historyparameters (i.e., fecundity, survivorship) which are unknown for the taxa analyzedin this report. The proceduresof MacCall I et al. rcquire only 1.)estimates of the ratio of numbersentrapped to numbersin the sourcewater (the Bight), and2) duration of risk to entrapment. I I We estimate the potential loss in numbers and biomass of adult fish by multiplying relative adult-equivalentloss (an annual rate) times the abundanceof I adults (all year classes)in the Bight. In effect, we compute loss by reducing each year classin the adult stock by the relative loss it would have experiencedduring its I first year (as an egg, lawae or juvenile) due to SONGS' operation. Thus, we essentiallyaccumulate loss over the number of yearsrepresented in the adult stock. I We estimateadult abundanceand, consequently,losses in numbersand biomassfor I only three taxa (queenfish,white croaker,and northern anchory). Thesethree ta:ra togetheraccount for approximately70Vo of all entrappedeggs and larvae. I I I We use cornmon nameswhen discussingtaxa. Table 1 lists common and correspondingscientific names.