Foraging habitats of southern elephant seals, Mirounga leonina , from the Northern Antarctic Peninsula
ElephantIsland(EI)isuniquelyplacedtoprovidesouthernelephantseals(SES)breedingtherewithpotentialaccesstoforaginggroundsintheWeddellSea,thefrontalzonesoftheSouthAtlanticOcean,the PatagonianshelfandtheWesternAntarcticPeninsula(WAP).QuantifyingwheresealsfromEI foragethereforeprovidesinsightsintothetypes...
Published in: | Deep Sea Research Part II: Topical Studies in Oceanography |
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Main Authors: | , , , |
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
Pergamon-Elsevier Science Ltd
2013
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Subjects: | |
Online Access: | https://doi.org/10.1016/j.dsr2.2012.07.009 http://ecite.utas.edu.au/89056 |
Summary: | ElephantIsland(EI)isuniquelyplacedtoprovidesouthernelephantseals(SES)breedingtherewithpotentialaccesstoforaginggroundsintheWeddellSea,thefrontalzonesoftheSouthAtlanticOcean,the PatagonianshelfandtheWesternAntarcticPeninsula(WAP).QuantifyingwheresealsfromEI foragethereforeprovidesinsightsintothetypesofimportanthabitatsavailable,andwhichareofparticularimportancetoelephantseals.TwentynineSES(5sub-adultmalesSAM and24adultfemalesAF) wereequippedwithSMRUCTD-SLDRsduringthepost-breeding(PB2008,2009)andpost-moulting(PM2007,2008,2009,2010)tripstosea.Therewerestrikingintra-annualandinter-sexdifferencesinforagingareas,withmostofthePBfemalesremainingwithin150kmofEI.OnePBAFtravelleddowntheWAPasdid16outofthe20PMfemalesandforagednearthewinterice-edge.MostPM sub-adultmalesremainedclosetoEI,inareassimilartothoseusedbyadultfemalesseveralmonthsearlier, althoughoneSAMspenttheearlypartofthewinterforagingonthePatagonianShelf.ThewatersoftheNorthernAntarcticPeninsula(NAP)containabundantresourcestosupportthemajorityof theIslandsSESforthesummerandearlywinter,suchthattheanimalsfromthispopulationhaveshortermigrationsthanthosefrommostotherpopulations.Sub-adultmalesandPBfemalesarecertainlytakingadvantageoftheseresources.However,PMfemalesdidnotremainthereoverthewintermonths,insteadtheyusedthesamewatersattheice-edgeinthesouthernWAPthatfemalesfrom bothKingGeorgeIslandandSouthGeorgiaused.Femalesmademorebenthicdivesthansub-adultmalesagain thiscontrastswithothersiteswhereSAMsdomorebenthicdiving.Unlikemostother populationsstudiedtodateEIisarelativelysoutherlybreedingcolonylocatedontheAntarcticcontinentalshelf.EIsealsareusingshelfhabitatsmorethanotherSESpopulationsbutsomeindividualsstill employopenwaterforagingstrategies.Sea-icewasalsoveryinfluentialforPMfemaleswithmoreforagingoccurringinheavierpack-ice.Largerfemalesusedareaswithheavierice-concentrationthansmallerfemales.Thestudydemonstratestheimportanceofshelfandslopehabitattoelephantseals,but alsohighlightedtheinfluenceofsea-iceandfine-scalebathymetryandlocaloceanconditionindeterminingforaginghabitat. |
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