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AcknowledgementsWethankA.Andrews,K.Cieciel,J.DuffyAnderson,E.Farley,N.Ferm,J.Napp,K.Siwicke,W.Strasburger,andthemanyscientificcruiseparticipantsandcrewsoftheresearchvessels:Dyson,Healy,KnorrandThompson.
FundsprovidedbyNorthPacificResearchBoard,NationalScienceFoundation,andNOAA/NMFS/AlaskaFisheriesScienceCenter.
ReferenceSigler,M.,Stabeno,S.,Eisner,L.,Napp,J.,Mueter,F.2013.SpringandfallphytoplanktonbloomsinaproductivesubarcticecosystemtheeasternBeringSeaduring1995-2011.DeepSeaResII109:71-83.
• Stations(above)sampledbyBeringSeaProject(spring,summer),EcoFOCI (spring,redovalsand70misobath),BASIS(earlyfall)
• Zooplanktonverticaltows,nearbottomtosurface• 150µmmesh(primarily),335and505µmmesh(largetaxa,EcoFOCI)
• ConcurrentCTD(temperature,salinity)data• Concurrent Ichthyoplankton /juvenilefishdata
Data Analysis • Bray-Curtissimilarityof4th roottransformedabundance
(No.m-3)• Clusteranalysisoftaxa/stagesforzooplanktonand
ichthyoplankton (Primer–E)• nMDS andANOSIMtoevaluatedifferencesamongseasons
(Primer-E)• Barplotstoshowvariationsoftaxaandcopepodstages
fromApril–Augustfor2008,2009and2010
MethodsZooplankton Collection
ResultsSeasonal Differences
Objectives• Evaluatedifferencesinzooplankton
communities(taxa/stage)duringcold/highiceyears
• Seasonalv Spring,Summer,earlyFall
• Interannualv 2008,2009,2010
• Evaluateenvironmentaldriversv Iceretreatandspringphytoplankton
bloomtiming,temperature• Comparezooplanktonandichthyoplankton
Whattaxa/stagestypifiedcommunities?
SeasonaldifferencesincommunitystructureAllyearscombined(excludingspringEcoFOCI)
Groups Rstatistic Sig.levelSpr,Sum 0.42 0.001Sum,Fall 0.35 0.001Spr,Fall 0.50 0.001
0
5
10
15
Apr May Jun Jul Aug Sep
Neocalanuscristatus
0
1000
2000
3000
Apr May Jun Jul Aug Sep
Pseudocalanus spp.
200820092010mean
0
500
1000
1500
Apr May Jun Jul Aug Sep
Calanus spp.
0
500
1000
1500
Apr May Jun Jul Aug Sep
Metridia pacifica
0
100
200
Apr May Jun Jul Aug Sep
Eucalanus bungii
Copepodabundance(No.m-3),commontaxaAllstagescombined
MiddleShelf OuterShelf
AbstractTheavailabilityoflargecrustaceanzooplanktonpreyiscriticaltotheconditionandsurvivalofforagefish(e.g.,age-0WalleyePollock),seabirds,andmarinemammalsintheeasternBeringSea.Zooplanktoncommunitycompositionandabundancesoflargelipid-richcopepods(e.g.,Calanus spp.)havebeenevaluatedforsingleseasons,butfewstudieshaveinvestigatedseasonalvariationsinthisregion.Here,weinvestigateseasonalchangesintaxa(communitystructure)andstagecomposition(whereappropriate)fromspringthroughlatesummer/earlyfalloverthreeconsecutivecoldyearsintheSEBeringSea(southof60°N).Zooplanktonphenologyiscomparedtochangesinichthyoplankton compositiontoinvestigatecommonenvironmentaldriversandpotentialoverlapoffishpredatorsandzooplanktonprey.
Conclusions1) Thelargeseasonaldifferencesin
zooplanktoncommunitiesareduetovariationsintaxonomyandstagestructureofcopepods.
2) Interannual differencesaregreatestinspring,primarilyduetovariationsinstagestructureofcopepods,andarerelatedtodifferencesinspringbloomtimingandseasonaltemperatureprogression.
3) Zooplanktonandichthyoplanktoncommunitiesmayco-vary(e.g.bothcommunitiesweredifferentinspring2009comparedto2008and2010).
Interannual Differences
0%
20%
40%
60%
80%
100%
-2 -1 0 1 2 3 4 5 6 7 8
CalanusCIV+CV
WaterColumnMeanTemperature(° C)
200820092010
Calanus spp.CIV+CV(latestages)inrelationtotemperatureonmiddleshelf
Therewasanincreasein%latestagesfrom0to3°C.Astheseasonprogressesandtemperatureincreases~allarestageCV.Thesecopepodswillincreaselipidcontentuntiloverwintering(asCV).
Timingofpeakabundancevariesbytaxa.Forexample,highestnumberswereseeninspringforN.cristatus,summerforCalanus spp.(C.marshallae+C.glacialis)andfallforPseudocalanus spp.
Seasonaldifferenceswereprimarilyduetochangesintaxonomiccompositionandstageofcopepods(seeboxes).Forexample,CalanuswasinhighestabundanceinsummerandAcartiawashighestinfall.Copepodites (particularlyCI-CIV)werelessabundantinspringthaninsummerorfall.
Zooplanktonandichthyoplankton clustergroupsforspring2008,2009,2010(EcoFOCI stationsonly)
Clustergroupsweredifferentin2009comparedto2008and2010forbothcommunities.Copepodstagestructuredrovechangesinzooplankton(asdescribedforCalanus spp.),whilechangesindominanttaxawereimportantforichthyoplankton (e.g.neartheAlaskaPeninsula(oval),pollockweredominantin2008and2010,whilesandlanceweredominantin2009.(Note,2008turnedouttobeastrongyearclassforpollock).
201020092008
Zoop
lankton
Ichthyop
lankton
Sandlancedominant(Blueinoval)
Pollockdominant(Greeninoval)
Pollockdominant(Greeninoval)
0
5
10
15
ACAR
TIASPP.AF
AMCI CII
CIII
CIV CV
BIVA
LVIALAR
VAE
CALANOIDANAU
PLII
CALANUSSPP.AF CI CII
CIII
CIV CV
OITHONASIMILISAF
AMCI-CV
POLYCH
AETALAR
VAE
PSEU
DOCA
L.SPP.A
FAMCI CII
CIII
CIV CV
SAGITTAELEGAN
S
4throotabu
ndance(n
o.m
-3)
Fall
Summer
Spring
ANOSIMPairwisecomparisonsnMDS
Communitycompositionvariedsignificantlybyseason;largestdifferencesforSpr,FallandsmallestforSum,Fall
month
00.20.40.60.81
Fractio
n
00.20.40.60.81
14 16 18 20 22 24 26 28 30 32 34 36 38
Fractio
n
week
CVCIVCIIICIIAMAF
00.20.40.60.81
Fractio
n
A M J J A S
Calanus spp.stagesbyweekandyear(middleshelf)
springbloommax(M2)
iceretreat(M2)2008
2009
2010
Inthesethreecoldyears,stagesprogressfromadults(males(AM)andfemales(AF))toearlycopepodite stages(CI(notshown),CII,CIII)inspring,withearlyandlatestagesinmidsummertoalmostentirelyCVbyAug-Sep.However,interannual variationswereobserved.In2009stageprogressionwasdelayedlikelyduetodelayinthespringbloom(foodforreproduction).In2008,therewerehigherratiosoflatestages(CIV+CV)inJune-Julylikelyduetohigherwatertemperatures(seebelow).PMELMooring2(M2)iceretreatandspringbloomtimingfromSigleretal.(2014).
Xaxisflipped
Therecommendations andgeneral contentpresentedin thisposterdonotnecessarily representtheviewsorofficial positionoftheDepartment ofCommerce, theNational OceanicandAtmospheric Administration, ortheNational MarineFisheriesService.
Poster ME14E-0657
Seasonal phenology of zooplankton composition in the SE Bering Sea, 2008-2010Lisa Eisner1, Alexei Pinchuk2, Colleen Harpold1, Elizabeth Siddon3, and Kathy Mier11 Alaska Fisheries Science Center, National Marine Fisheries Service, NOAA, 7600 Sand Point Way N.E., Seattle, Washington 98115, USA. Lisa.Eisner@noaa.gov, Colleen.Haropold@noaa.gov, Kathy.Mier@noaa.gov2 University of Alaska Fairbanks, School of Fisheries and Ocean Sciences,17101 Pt. Lena Loop Rd., Juneau, Alaska 99801, USA. aipinchuk@alaska.edu3 Alaska Fisheries Science Center, National Marine Fisheries Service, NOAA,17109 Pt. Lena Loop Rd., Juneau, Alaska 99801, USA. Elizabeth.Siddon@noaa.gov