Seasonal Phenology of Zooplankton Composition in the SE ...
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Acknowledgements We thank A. Andrews, K. Cieciel, J. Duffy Anderson, E. Farley, N. Ferm, J. Napp, K. Siwicke, W. Strasburger, and the many scientific cruise participants and crews of the research vessels: Dyson, Healy, Knorr and Thompson. Funds provided by North Pacific Research Board, National Science Foundation, and NOAA/NMFS/Alaska Fisheries ScienceCenter. Reference Sigler, M., Stabeno, S., Eisner, L., Napp, J., Mueter, F. 2013. Spring and fall phytoplankton blooms in a productive subarctic ecosystem the eastern Bering Sea during 1995-2011. Deep Sea Res II 109:71-83. • Stations (above) sampled by Bering Sea Project (spring, summer), EcoFOCI (spring, red ovals and 70 m isobath), BASIS (early fall) • Zooplankton vertical tows, near bottom to surface • 150 µm mesh (primarily), 335 and 505 µm mesh (large taxa, EcoFOCI) • Concurrent CTD (temperature, salinity) data • Concurrent Ichthyoplankton /juvenile fish data Data Analysis • Bray-Curtis similarity of 4 th root transformed abundance (No. m -3 ) • Cluster analysis of taxa/stages for zooplankton and ichthyoplankton (Primer –E) • nMDS and ANOSIM to evaluate differences among seasons (Primer-E) • Bar plots to show variations of taxa and copepod stages from April –August for 2008, 2009 and 2010 Methods Zooplankton Collection Results Seasonal Differences Objectives • Evaluate differences in zooplankton communities (taxa/stage) during cold/ high ice years • Seasonal v Spring, Summer, early Fall • Interannual v 2008, 2009, 2010 • Evaluate environmental drivers v Ice retreat and spring phytoplankton bloom timing, temperature • Compare zooplankton and ichthyoplankton What taxa/stages typified communities? Seasonal differences in community structure All years combined (excluding spring EcoFOCI) Groups R statistic Sig. level Spr, Sum 0.42 0.001 Sum, Fall 0.35 0.001 Spr, Fall 0.50 0.001 0 5 10 15 Apr May Jun Jul Aug Sep Neocalanus cristatus 0 1000 2000 3000 Apr May Jun Jul Aug Sep Pseudocalanus spp. 2008 2009 2010 mean 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 Copepod abundance (No. m -3 ), common taxa All stages combined Middle Shelf Outer Shelf Abstract The availability of large crustacean zooplankton prey is critical to the condition and survival of forage fish (e.g., age-0 Walleye Pollock), sea birds, and marine mammals in the eastern Bering Sea. Zooplankton community composition and abundances of large lipid-rich copepods (e.g., Calanus spp.) have been evaluated for single seasons, but few studies have investigated seasonal variations in this region. Here, we investigate seasonal changes in taxa (community structure) and stage composition (where appropriate) from spring through late summer/early fall over three consecutive cold years in the SE Bering Sea (south of 60 °N). Zooplankton phenology is compared to changes in ichthyoplankton composition to investigate common environmental drivers and potential overlap of fish predators and zooplankton prey. Conclusions 1) The large seasonal differences in zooplankton communities are due to variations in taxonomy and stage structure of copepods. 2) Interannual differences are greatest in spring, primarily due to variations in stage structure of copepods, and are related to differences in spring bloom timing and seasonal temperature progression. 3) Zooplankton and ichthyoplankton communities may co-vary (e.g. both communities were different in spring 2009 compared to 2008 and 2010). Interannual Differences 0% 20% 40% 60% 80% 100% -2 -1 0 1 2 3 4 5 6 7 8 Calanus CIV+CV Water Column Mean Temperature (° C) 2008 2009 2010 Calanus spp. CIV + CV (late stages) in relation to temperature on middle shelf There was an increase in % late stages from 0 to 3 °C. As the season progresses and temperature increases ~ all are stage CV. These copepods will increase lipid content until overwintering (as CV). Timing of peak abundance varies by taxa. For example, highest numbers were seen in spring for N. cristatus , summer for Calanus spp. (C. marshallae + C. glacialis ) and fall for Pseudocalanus spp. Seasonal differences were primarily due to changes in taxonomic composition and stage of copepods (see boxes). For example, Calanus was in highest abundance in summer and Acartia was highest in fall. Copepodites (particularly CI- CIV) were less abundant in spring than in summer or fall. Zooplankton and ichthyoplankton cluster groups for spring 2008, 2009, 2010 (EcoFOCI stations only) Cluster groups were different in 2009 compared to 2008 and 2010 for both communities. Copepod stage structure drove changes in zooplankton (as described for Calanus spp.), while changes in dominant taxa were important for ichthyoplankton (e.g. near the Alaska Peninsula (oval), pollock were dominant in 2008 and 2010, while sandlance were dominant in 2009. (Note, 2008 turned out to be a strong year class for pollock). 2010 2009 2008 Zooplankton Ichthyoplankton Sandlance dominant (Blue in oval) Pollock dominant (Greenin oval) Pollock dominant (Greenin oval) 0 5 10 15 ACARTIA SPP. AF AM CI CII CIII CIV CV BIVALVIA LARVAE CALANOIDA NAUPLII CALANUS SPP. AF CI CII CIII CIV CV OITHONA SIMILIS AF AM CI-CV POLYCHAETA LARVAE PSEUDOCAL. SPP. AF AM CI CII CIII CIV CV SAGITTA ELEGANS 4 th root abundance (no. m -3 ) Fall Summer Spring ANOSIM Pairwise comparisons nMDS Community composition varied significantly by season; largest differences for Spr, Fall and smallest for Sum, Fall month 0 0.2 0.4 0.6 0.8 1 Fraction 0 0.2 0.4 0.6 0.8 1 14 16 18 20 22 24 26 28 30 32 34 36 38 Fraction week CV CIV CIII CII AM AF 0 0.2 0.4 0.6 0.8 1 Fraction A M J J A S Calanus spp. stages by week and year (middle shelf) spring bloom max (M2) ice retreat (M2) 2008 2009 2010 In these three cold years, stages progress from adults (males (AM) and females (AF)) to early copepodite stages (CI (not shown), CII, CIII) in spring, with early and late stages in mid summer to almost entirely CV by Aug-Sep. However, interannual variations were observed. In 2009 stage progression was delayed likely due to delay in the spring bloom (food for reproduction). In 2008, there were higher ratios of late stages (CIV+CV) in June-July likely due to higher water temperatures (see below). PMEL Mooring 2 (M2) ice retreat and spring bloom timing from Sigler et al. (2014). X axis flipped The recommendations and general content presented in this poster do not necessarily represent the views or official position of the Department of Commerce, the National Oceanic and Atmospheric Administration, or the National Marine Fisheries Service. Poster ME14E-0657 Seasonal phenology of zooplankton composition in the SE Bering Sea, 2008-2010 Lisa Eisner 1 , Alexei Pinchuk 2 , Colleen Harpold 1 , Elizabeth Siddon 3 , and Kathy Mier 1 1 Alaska Fisheries Science Center, National Marine Fisheries Service, NOAA, 7600 Sand Point Way N.E., Seattle, Washington 98115, USA. [email protected], [email protected], [email protected] 2 University of Alaska Fairbanks, School of Fisheries and Ocean Sciences,17101 Pt. Lena Loop Rd., Juneau, Alaska 99801, USA. [email protected] 3 Alaska Fisheries Science Center, National Marine Fisheries Service, NOAA,17109 Pt. Lena Loop Rd., Juneau, Alaska 99801, USA. [email protected]
Transcript of Seasonal Phenology of Zooplankton Composition in the SE ...
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. [email protected], [email protected], [email protected] University of Alaska Fairbanks, School of Fisheries and Ocean Sciences,17101 Pt. Lena Loop Rd., Juneau, Alaska 99801, USA. [email protected] Alaska Fisheries Science Center, National Marine Fisheries Service, NOAA,17109 Pt. Lena Loop Rd., Juneau, Alaska 99801, USA. [email protected]
