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