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The strengthening East Australian Current, its eddies and biological effects - an introduction and overview
Citation
Suthers, IM and Young, JW and Baird, ME and Roughan, M and Everett, JD and Brassington, GB and Byrne, M and Condie, SA and Hartog, JR and Hassler, CS and Hobday, AJ and Holbrook, NJ and Malcolm, HA and Oke, PR and Thompson, PA and Ridgway, K, The strengthening East Australian Current, its eddies and biological effects - an introduction and overview, Deep-Sea Research II, 58, (5) pp. 538-546. ISSN 0967-0645 (2011) [Refereed Article]
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The definitive version is available at http://www.sciencedirect.com
DOI: doi:10.1016/j.dsr2.2010.09.029
Abstract
The polewardflowingEastAustralianCurrent(EAC)ischaracterisedbyitsseparationfromthecoast,
100–200nauticalmilesnorthofSydney,toformtheeastwardflowingTasmanFrontandasouthward
flowingeddyfield.Theseparationzonegreatlyinfluencescoastalecosystemsfortherelativelynarrow
continentalshelf(only15–50kmwide),particularlybetween32–341S. Inthisregionthecontinental
shelfhasamarkedshiftintheseasonaltemperature-salinityrelationshipandelevatedsurfacenitrate
concentrations.ThiscurrentparallelstheportionofthecoastwhereAustralia’spopulationis
concentratedandhasalonghistoryofscientificresearch.However,understandingofphysicaland
biologicalprocessesdrivenbytheEAC,particularlyinlinkingcirculationtoecosystems,islimited.In
this specialissueof16papersontheEAC,weexaminetheeffectsofclimaticwind-stressforcedocean
dynamicsonEACtransportvariabilityandcoastalsealevel,fromENSOtomulti-decadaltimescales;
eddy formationandstructure;finescaleconnectivityandlarvalretention.Comparisonswiththe
poleward-flowingLeeuwinCurrentonAustralia’swestcoastshowdifferencesinecosystem
productivitythatcanbeattributedtotheunderlyingphysicsineachregion.Onaveragethereis
double thechlorophyll a concentrationontheeastcoastthanthewest.IncomparisontotheLeeuwin,
the EACmayhavelesslocalretentionoflarvaeandactasapartialbarriertoonshoretransport,which
may alsoberelatedtothelocalspawningandearlylifehistoryofsmallpelagicfishoneachcoast.Inter-
annualvariationsintheEACtransportproduceadetectablesea-levelsignalinSydneyHarbour,which
could provideausefulfisheriesindexasdoestheFremantlesealevelandLeeuwinCurrentrelationship.
The EAC’seddystructureandformationbytheEACareexamined.Aparticularcold-coreeddyisshown
to havea‘‘tilt’’towardsthecoast,andthatduringarotationtheflowofparticlesmayriseuptothe
euphoticzoneandthendownbeneath.Inawarm-coreeddy,surfacefloodingisshowntoproducea
new shallowersurfacemixedlayerandpromotealgalgrowth.Anassessmentofplanktondatafrom
1938–1942showedthatthelocal,synopticconditionshadtobeincorporatedbeforeanycomparison
with thepresent.ThereareusefulrelationshipsofwatermasscharacteristicsintheTasmanSeaand
separationzonewithlarvalfishdiversityandabundance,aswellaswithlong-linefisheries.These
fisheries-pelagichabitatrelationshipsareinvaluableforfisheriesmanagement,aswellasforclimate
changeassessments.
There isfurtherneedtoexaminetheEACinfluenceonrainfall,stormactivity,dustdeposition,and
on themovementsbyfish,sharksandwhales.TheAustralianIntegratedMarineObservingSystem
(IMOS)hasprovidednewinfrastructuretodeterminethechangingbehaviouroftheEACandits
bio-physicalinteractionwiththecoastsandestuaries.Theforecastingandhindcastingcapability
developedundertheBluelinkprojecthasprovidedanewtoolfordatasynthesisanddynamical
analysis.TheimpactofastrengtheningEACandhowitinfluencesthelivelihoodsofoverhalfthe
Australianpopulation,fromBrisbanetoSydney,HobartandMelbourne,isjustbeingrealised.
Item Details
| Item Type: | Refereed Article |
|---|---|
| Keywords: | East Australian Current, Leewin Current, Separation zone, Tasman Front, Eddy, Climatology, Bluelink |
| Research Division: | Earth Sciences |
| Research Group: | Oceanography |
| Research Field: | Physical oceanography |
| Objective Division: | Environmental Management |
| Objective Group: | Terrestrial systems and management |
| Objective Field: | Assessment and management of terrestrial ecosystems |
| UTAS Author: | Holbrook, NJ (Professor Neil Holbrook) |
| ID Code: | 69634 |
| Year Published: | 2011 |
| Web of Science® Times Cited: | 193 |
| Deposited By: | Geography and Environmental Studies |
| Deposited On: | 2011-05-09 |
| Last Modified: | 2017-12-07 |
| Downloads: | 7 View Download Statistics |
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