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FISH FOOD HABITS STUDIES
1ST PACIFIC NORTHWEST TECHNICAL WORKSHOP
WORKSHOP PROCEEDINGS ASTORIA, OREGON OCTOBER 13-15, 1976 WSMWO 77-2
WashingtonSea Grani Divisionof MarineResooroes EDITORS: CHARLES A. SIMENSTAD AND SANDY J. LIPOVSKY Universityot WashingtonttG-30 Seattle9tt195 WASHINGTON SEA GRANT Division ot Marine Resources WSG WO 77-2 ss.oo UniversityOf Washington HG 30, Seattle,Washington 98195 CONTENTS
ACigfceLEIXNEMS, vl I FOREIIORD. lx INTRODUCTORYADDRE'SS, . xI I I Afonso2'. Proter
SESSIONI: PURPOSEAND SAMPLING DESIGN fJJ~ xSavaralApproaches tothe Feeding Ecology ofFishes.. CraqorIf. CoiHiat Narltlc ReefFish Ccewunitles Soae Problems and a PossibleSolution. Ia ffioftotvfC. Stainer C~ A Studyof Fish FoodHab I ts as Relatedto the Biological Enrichmentof an Area, 19 JofstS. Stephens,Jr, ard JohnP. STffson SamplingCopslderatlops In the Analysis of FoodHeb Relationships. 25 corti a. a ith InteractionsBetveen Juvenile Salmon and Benthic InvertebratesIn the Skaglt Salt lasrsh, 51 COSPONSORSOF I IIE-WOFIKSIIOP Jomaaf Cangfatonand lama@ a. Sivith FishrnesResearch liisiiiuli, Elniversily ofWashington WashingtonSea Orant. Univrrsily of Washinglon Discussion:Session I . Purposeand Sampling Design... NaliOnaiMarine f iaherieaSeiviCD hiorlhwealand Ala ka I ishenesCenlei Edilcra.Charlea A Simenatad andSandy J Lipcvaky SupporllorIhis workshop aiiripublicalicn olIhe Proceediiigs wasprovided in partby giantnurnbera D4S-158-48 arid 04-T-f58 44021 frOm Ihe Nahonal Oceanisand Atrnoapherio Adminislralion lo the Washington Sca Grani PrO- gram SESSION?: PREDATORANDPREY COLLECTION FrequencyDistributions of FoodItem Counts In Individual I lsh Stomarhs., 167 AnEva! uat lan of Ueritlilt; Irivurfebrate Samvllng Devlees for Investigat ing FeedingHabits af Fish, Sibert and., Obrebeki Jack f?. soref DS Nivaluat Ion of Standirig5loi'I s of Ma Inn Re,niircrs I laid MethodsIor Sarrpllrvi DcnersafFish In the EasternBer ing Saa: Uslng a Statir- lrnphir I'oculit for» andOb ierv lng Their llehavfar NumerfcnlBulk BiomassModel BEM. ?e.James Allen 56 T. Eaevaatuand F. Favorite P~v AStorage Rel!!eval/ProeasingSystem for Stomach Snipl ing Inter+I dul caI t 'Jursh Macrabanthos... I '19 JamesE..onif h 63 Analysisand Other Fish Data. Charles4. Simanetadand Sarrk E. Dales Fuseing Habits and SrI e t I v i' y cl P feuronactI dc c!n itic 'J ' Discussion: Session4: DataMcnlpulotlon aed I'!osantntion.. .. I SO JtrvI ~ ShelI: 6 6 rriary cf I!as!aii h In Pioui ess,, .. 6 VenJg f,. 0!truss ioii: Sessi!n ? ',.vipI liiI af Benihi!. Predatorand Prni': SESSION5; INTERPREIATIONA?ID RESIILTS line OcI? It farsr t Su !pie!4 arI "nriplI iq Tech!Iques Al ti r niir Dlet OverlapsIn Compot iiiig F I sh Papii!ation. Impressfons of tlie Beiit'ius'? 69 In the IJanalac River Est»sry.. ,139 StevenDbrabaki and John Sihart. SESSlctf I; IAuORATDIIVPRJi.f IXIRE' AIJD I OFIJTIF ICATION A Bug s Eye y lcmof Fish Predation ,147 A LaLioia?art MethodI oi !Iie Aiiaftees of f lsh Stomachr'!intent Cy r fr lsvtriae andD le»u Ne»erlebKiiak and 'Pi.' I "she't 'prosentedby TonyPhillips! - Prellrrlnary Observationson Interactions BetuaenTwa Bottam-FeedingRays and a Cosmunltyof Potential Prey MethodsUsed In studying ! aodHabits af oregan's , .153 EstuarineFI'lies...... ,...... ,...... ,...... I ~ a cublil.tonal SandHabitat In SouthernCalifornia... JohnJ<,hnaan !.l ennA. V !rifiLari stem? TheP ey of Deep-.ea Macr»aridI IshesOif Oregon.. - Prey Organismsand Prey Camsu!il ty Composition of 163 Julie Ar.!1mb Ter' 82 Juvenile Sales!oldsIn HoodCanal, Washington...,,. CharlesA. Simenst Iv ACKNOW L EDGMENT S This workshopwould not haverun smoothly, I f at a II, without the help of several people and agencies. First, our thanksgo to personnelof the WaslilngtonSea Orant Program at the University ot Washington,who prepared work hop ftyer- and o'lher materIals arid served as the channel for oiir f lnances. Staff of the co-sponsors,the UnIverslty of Washington'sFisheries Ifesearch Insritutu and the National Marine Fisheries Service northwest and Alaska FI-li ri"; Center,are to be thankedfor assistingwith the piannlnqand programrnlnq. SpecI a I thanksgo to WashingtonSea Br aiit CommunI catIons who coo r dI naii."I the productionof these proceedings,Joseph T. Durkin of the Hammond Laboratory,and National MarineFisheries Service for coopi,ratingwit'i the co-chairmenIn plannlnq and providlnq muchof the audio-visual equip- ment, MaryLee Brownof the samelaboratory provided invaluable assis- tance with registration, last minute details, and these proceedings. Also, HerbJenlcke, National MarineFisheries Service at AukeBay, kindly loanedus his tapiis, whichwe,"- nxccpf iona l ly better than niir own, of the discussion sess'lons. Mostof all, wewish to thank the participants for provldlnq excellent presentations and stimulating d'IscussIona. FOREWORD Ideasfor a workshopon Food Habits and Trophic Relationships of Pacific Northwestfish hadbeen kicked around for severalyears. They coulcsc< I duringa professlona!meeting in March1976, where reglona! food habits studieswere addressed superf'Ic !ally. Our'Ingthat meotirrg,and durinrj subsequenttelephone conversations, wediscussed the need for a workshop coveringthe presentstate of fish foodhabits studies, Asa result,the f Irst Pacif I cN<>rthwesf F shI Food Habits Studies Workshrrp wasdesigned to assemble West Coast biologists currently siudy lng fish foodhabits for Informa!discussions onsampling deslqn and techniques, analysisprocedures, andcurrent research. This type of researchIs sometimesnebulous each investigator doing things just a little differ- entlyy from everyone else. However,lf seemed to us that the time bar! cometo comparenotes, to discussthc meritsof varioustechniques, and 'Ina forumfor researcherswith problems, to get the advice of reglr>naf experts In the field. Flyerswore sent to peoplewho we ihouglrt might be In! erestod insuch a get-together,Originally we hoped to hold it at Harmond,Oreqon, where the NationalMarine Fisheries ServIce maintains a field stationin arr old CoastGuard building. Fromthe numberof responses,it soonbecame evidentthat the field stationcould not comfortablyhold the group, the orirrinaiexpectation was to hostabout 25-30, but registration eventuallyreached 50 people. So the workshop was expanded to 3 days andwas moved to theThunderbird Motel in Astorla,Oregon, where confer- ence,room, and restaurant facilities wereava!Iable. Despite Its remoteness,weconsidered Astorla an appropriate setting both because of Its scenicquality and because attendees would be Ies- likely to wanderoff to moreurban temptations as usually happens at meetingsin bigcltles. Weall cametogether' with a surprisingmin Imurn of late arrivals and no-shows,on October15-17, 1976. Onegotofto the knowrrrost each importantother and resulfseach other'sof thework. workshop Conversations was that rr.soarcirersextended into coffeeand meal breaks and well Into thenight. Thiswas the k'Indof Ix 'I s it appearsthat this workshopwas e I f I f h,d I I 11 o k h interaction we had hoped for, and apparently achieved. success and In the future. Severalp eo p le suggosf ed c hanqes an in format and new rs ex ressed the op lnlan ia wor ni Other than a general I lmlt on length ~ there was no Ital t lcular format seful. Sflii oth rs Indi f d ti, I prescribed for workshop presenfaf lons. Thus, these proceedings represent than formarmal p resentatlons wouldd bethat useful. the next one slivuld be extended 'to' o a varIety of subjects, rather loosely organized around the tive session this wor ksho p was too short andt I ha 'I at e lorine waswei I received, the topics: 4 or 5 days. Although the Astor a oca or fl for the next meetinq. consensus was f oto move another scenic lai a on or Purpose and sampl Ing design Becauseth'Is type of researcrch i prog ro ressrss lowly,new Informal Inn i s niif Sampl1ng of benthic predators and prey: ilaw different =ampler generated fast as enau gh to warrant an annua mee ng. ere that we shou I d mee f ever y other year, whicii pii and sarnpl ing techniques alter our Impressions of the benthos respondentsIndicated t a f fhe f I rst meet liig, the next workshop ln fai a 1 1978. As co-chairnen ar e Laboratory procedures and Identlf Ication or anIze the 1978session. However, we hope that by we have agreedu wi fo I orga~I be welI enougheslubl lshed fliat ia the chairmanship fhen the group w n the v*r ious countr ies and state,. Data manI pul ation and present at lon andeditorship can be rotatedamong the v*r ous hi S WarkSha r eaui I ed f rOmthe peep1 ewhO Interpretation and resu!fs f I nai i y, the success of t » p f r their work end had par I Ic Ipaf ed. The ey s shared a a special enthusiasmor e r Although they cover the present at lons, the papers assembled here vary a wI II 'Ingnessto I istento newand d'Iff ercn 'I techniques. It wa this In length, format, and overal I organization. Hopeful ly, future pro- t madethis workshopso prof It- ceedings papers wl I I be more uni forni 'In format. The discussions half ardentparticipation by eachperson tha mae of each session! proved to be so meaty and worthwhile that we have able, transcribed these from tape recordings and have Included them here pretty much In their entIrety. Charles A Slmenstad Because this was the first "gathering of the minds", we planned to spend Sandy 0 L I povsky a great deal of time discussing methodology--and Indeed we did, Un fa- rfunafel, even though flic rnerlfs and disadvantages of various techniques were discussed at length, a standardized method < If there ls one! was nat derived. We st I I I iieed to def Irie the prey dlmens1ons and weigiits, June l971 efc.--their pros and cons, and the appropriateness of each relal lve ta the questions being asked, Therefore we strongly bel leva thai ore outcome of the next workshop should be a handbook on methadol oqy of f lsh stomach analys'is, Widespread use at such a handbook could mean that results of studies a'ang the I'aclfl~ Coast of Canada and the United States, or anywhere else, miglif be more eas'Ily compared. Another area that received much at tention, but that could nat be suf f 1- clenfly covered involved the statist ics used In testing the s igni f lcance oi dl f ferer t prey composlf lors. Several of the best sfal' Istical analysts In th1 f laid af fended and answered many questions; however, many more quest lons were posed In the process. The next meet lng should 'Inc liide at I east one entire session on the use of stat 1st I cs as appl led I'a f Ish pr ey compositions. Again, in Impsirtani byproduct could be a han A th'Ird Item for inclusion in such a handLeok should bo a list of useful sources, key, etc., categorized by faxonomIc groups, used lii Identifying prey organisms, Alii i Ihe workshop a urvey,hen! wa, mal leiI to sl tendai' qurryliiq them abiiii lhelr oplriions of t1ie workstiz>p and their desires for unafher one, xl INTRODUCTORYADDRESS AlonzoT. Pruter, DeputyDIrector National hfarlneI'Isher-les Servf»e Northwest Frsher'les Center Seattle, WA I wouldlike to welcomeyouto thefirsl PacificNorthwest Fish Food HabitsStudies Workshop. I th'Ink we obviously owe a realvote of tharlks to theco-chairmen, Sandy I.ipovsky and S ISlmenstad. It looksa. If theydeveloped a rea I yIr»ter est lng, and useful agenda and g ~ther»»»I»r»I>'od p fpart I cI pants.I understandthat you ' ve come a I I theway f r»rrrr SanDiego to Fairbanks;youcould actual ly renamethis workshop pacific Coastinstead of paclflc Northwestwith no problem. They even managed to producesome beautiful weather down here. I noticethat Sl and Sandyhave such a busyschedule outlined for youthat you are not goingto havemuch time to takeadvantage of the nice weather and lookaround. That's a shamefor those of youwho haven't been to Astoria beforebecause this city andthe surroundings have a lot of Interestirur thingsto offer. This'Is the site of someImportant commerc'laI fisheri» s, rn the ColumbiaRiver and nearbyocean waters. TheColumbia River has been used In manyways over the years; to produce flshl to producesand and gravel for buildings;and as a depositfor pollutants,The expression "unique" Is overworked today but I think I ~many ways, Astoria Is uniqueand has some important lessons for everyoneIf theywill lookai the situationclosely. I'maiways happy to returnto Astoria.As SI mentioned, I slarted my careerout here about 26 years ago with the Oregon Fish Commission; In fact,some of your agenda top'Ics bring back memories. I guess my flrsl errppsureto food studies was while work'Ing for theOregon Fish Comm- issionln Astorlaand I learneda fewlessons. I recallthat one of thethings we were doing In thosedays was studying the distribution andlife historyof theblack cod. I routinelyused to ridea lot of the commerciaI t raw lers out of Astor'lathat were fish Ing for PacificOcean perch;in thosedays the depth for Irawilngfor fhernwas generally fromIDO to about150 fathoms. The black cod were quite prevalent al thesame depths and over the same substrafe as the Pacific Ocean perch sothe trawlers caught a lot of themwith the'Irperch catches, I usedto lookat andcollect scales for aqcstudies and examine a Iol of stomachsso I thoughtI had a prettygood conception nf the feedin»j xi i I andConservation Act by the U.S.Congress a coupleof monthsago. As habttsof blackcod. Ilowever,a fewyears iater a groupof us returned youundoubtedly know, this extendsthe fishing liinlt of theUnited States with a different organization,oii a contractwith the AtomicEnergy ovt to 200miles off thecoast. T'he effecttve date of Implementation Cainmlssionto da some deep-wafer trawling off themouth of the Columbia of that 200m'Ile limit Is March1st of 1977and to complywith terms of RIverfn the ColumbiaRiver canyon,We found b'lack cod c mviionfydown that Act ft Is necessaryto developmanagement plans to governall of to depthsof 400to b00fathoms. Looking at the StcmachSfram black tlie foreignfisheries that w!Ii booccurring with'In 200 mlles of theU.S. codat thosedepths showed an eiit truly differentfssdfng sltuatlon-- after MarshI of 1977.Although the Actestablishes regional councils cannlbalfsm among other things being quite common, In the deepwater aroundthe countryto devetapmanagement plans there was not enoughtime onehad a greatsimp! if icatlonof the demsrsalcommunity of black cod for thesecouncils to be formedand develop the necessarydetailed andSebastolobus alascanus, scorpaenidrattal I s beIngthe dominant planson such a shorttime frame so the Departmentof Commerce was forins, 'I suppose,because of that greatsimplification of community assignedthe taskand lt filtered downto the NationalMarine Fisheriss structure,the feedinghabfts af blackcod were entirely different at Service--onlyfor the foreignfisheries aspect. So iiow at the Northwest those depths than In shallow water. andAlaska Flsherles Center In Seattlewe' ve beenvery busily engaged In Evenafter this episode,ln the mid-fgbU's,we did soniwof thefirst mld- developingthese plans covering nine different fisheries extending all watertrawl tng with largemid-water trawls for hakeoff Astorla,Oregon theway from the Bering Sea down to CalIfornia,including s wideverlafy andWashington, snd we learned another lesson. Tlie stomach contents of speciessuch as groundflsh, shrimp, tanner crab, king crab, snails of the hakewere qul te dl f fsreritwhen they weretaken on tlie bottomor becauseJ apanhas a smallsnail fishery in the BeringSea!, and high whenthey were taken In thewai.sr column; hake undergo dlurna I migration, seas salmon. A researcherneeds to havecomplete geographic coverage iii his samples Theksy thing that wehave to determineIn relationto eachof these to really beable to generalizeabout the speciesIn quest'lon.Other- plansIs themaximum sustainable y'laid for eachspecies and the wise,one had better conftne his Interpretationto the limited part of equilibriumyield at currentpopulations' densities, and levels. How the range with which he is dealing. In doingthis--because of the lack of data--wehad to lookat eachof Therewas another exciting discoveryIn termsof goodstudies, so con- thesespecies and fisheries as lf It existedin a vacuumandas If it troversial at the time that manypeople would not acceptlt. In the wasnot a memberof a communityof organisms that Interrelateto each early 1950's,Or. Fukvhara,with our laboratoryin Seattle,was the other,competing for foodand preying on each other, Webaslcalty Ignored f'Irst Americanscientist, to myknowledge, ta go out with the Japanese thesefactors, not ovt of Ignorancebvt for a lackof understandingof mothershipfishery ln the NorthPacific, Gulf of Alaskaarea. This the 'Interrelatlansh'Ips,arid that's notgood. The result of that ls to ls a gitlnetfishery, as many of youknow, and Dr. Fukuhara looked at realize less foodpotential fromthe particular systemyou' re looking a lot of sackeyesalmon stomachs and fovnd that theywere feeding at thanyou could realize If youunderstood the relatfonshipsbetween predom'Inantlyonfish andsquid, Many people wouldn't believe that thedifferent animals and organisms In ths system,So, to me,that Is becausesockeye salmon were known to beplankton eaters. ButIt was oneof the veryrelevant aspects of whichyou are going to bs talking true that ln that part of the Gulf of Alaskasockeys salmon do feed the rest of this week.The things you are do'lng now and in the future extensivelyonfish, smelt,myctophlds, andsquid. Again the lessonIs makeyav ail potentiallyextremely valuable contributors to the~hole prettyclear, either qual'Ify your remarks in terms of thegeographic management area. coverageof ths animal or besure that you cover the entire range of Weneed ta knowmare that Justwhat a particularspecies is eatingat the animal, a particulartfme of pointIn space.We need to knowthe food habits at differentsizes and ages, particularly at the larval stages,which Thesame sorts of tessonsemerge wlien one thinks aboutthe sampling probablyare the crftical stagesfor determiningyear class strength. gearItself. Youobviously need to knowthe selective characteristics Oneof the keyfeatures of goodmanagement ts the ability to predlct-- of the gearyou are using in orderto properlyInterpret what you see. andwe can't dothat verywell now. It seemsto methat foodstudies I seeby your agenda that these kinds of topilcsare Included and It 'Is aimedat critical life stages,such as the larva'Istages, could help us extremelyfitting for a workshopof thils sort. I noticealso that your understandthe inechanlsmsbehind year classes. In add'Itfonto year agendaIncludes a discussion of food cha'In dynamics or troph Ic classstrength, I think wsneed to knowa lot moreabout rates of trans- relationships,or eco-systemstud les or whateveryou want to call 'lt. fer of energybetween trophlc levels. Weneed to knowthe effect of This,to me,Is extreme'lyimportant and gives the neededperspective to se'lectlvefishing, ar targetingon a particular specieswithin a commvn- food habit studies. fty, onthe growth and survival of thenon-targeted species, the com- I mustconfess that I probablyfeel this wayso strongly right now petitorsand predators in thatsystem. We need to knowthe effects becauseof a personalexperience In whichI' ve recentlybeen Involved, of the physicalenvironment itself onthe growthand survival of the andam still, that hssto dow'Ith passage of the FisheryManagement elementsin the canrnunilty.When one begins to addup a'll the thingswe XV x lv needknowledgeto know Isthroughit becomes a prettyreaI mui obvioust I-disc i thatpiinary the approach,only way tocoordlncrt achieve lngthatthe SESSlON t efforts of manyresear chers. It 's anawesome taskbut It canbe dorre and'Ithink we have the tools with which todo It. Oneofthe biggest heps is the field of eco-system dynamicsand modeling thatIs Just PURPOSE gettingpofendlalstarted.by being Iable think tothat's help us--fair Into the say. area Thisof food field studies,has a forgreat example--toIdentify some ofthe crltIcal species orelements Inthe AND SAMPLING differentsystems. I think enough is known about modeling al-the present DESIGN timeto at leastpoint us In directions thatw'Ill save usa lotof time elementsbyfilling of lncormnunitles the gaps ofthat knowledgeappear fortohave those theparticular greatest speciesImpact orordriving forcewithin the systems. I'm glad to seeyou are going to havesome discussionof this in your workshop, Soagain I certainly commend aI Iof you for coming tothis workshop. I knowdiscussed.that when Youyoumay Inot eave gohere away you allw'I agreeingI I behappy tow'Ithuse thethe samethings Identicalyou methodsbodyeisain is your doing studies upand butdown I bettheyoucoast will and go theiraway rationaleknowing whatandevery- lt seemstome with that kind of startit's oniya matteroftime until youcome tocommon agreement ontechniques andmethods, maktng the resultsup and down the coast comparable to each other, PARTICIPAIVTS SESSION LEADER: Gregor M, Cailliet Howard Horton Richard G. Stainer John S Stephens Jr xv I Gary Smith James L. Congleton James E Smith SEVERALAPPROACHES TOTHE FEEDING ECOLOGY OFFISHES Gregor M. Cailliet MossLanding Marine Laboratories MossLanding, CA TheInvestigation of f ishfood habl ts is becomingvery popular amongresearchers in such fle I dsas ecology, Ichthyology, andf sherl I es biology.It Is notthe Intention of thisshort paper to reviewthis rapidlygrowing field, but rather to brief iy presentseveral approache- to studyingfish feeding ecology that we have utilized In studying fishesfrom three dist'Inct habltats: the deep-sea bas'Ins off Santa B b,Clif I, I hihth ~ Idt f1 I ~hl *tllbl lf I ly~ thyI g Id I d Pt I hi ~l. It fly llyt phld ~I werestudied Ca i I I let 1972a,b!,the Monterey Submarine Canyon, where we hp I tlg t dt ~ bf fl h fh~lfl b I I Pp I tl *" lt relatedto theloca'I trap f ishery