Annual report 2005-06.indd - Antarctic Climate and Ecosystems ...

antarctic marine ecosystemsProgram LeaderDr Andrew ConstableAustralian Antarctic DivisionThe Southern Ocean, in particular thecoastal region around Antarctica, hostsa vast and complex marine ecosystemthat supports the fisheries of Australiaand several other nations. This importantregion is internationally acknowledged asregion of great ecological importance, butit remains relatively under-sampled andpoorly understood.The ACE CRC Antarctic MarineEcosystems Program is exploringrelationships among the biologicalpatterns and processes of the marineecosystem around East Antarctica andrelating them to physical oceanographicprocesses. This knowledge will help guideAustralian government and industrydecision-makers in the formulation ofpolicy and management strategies inresponse to harvest of some resourcesand to future climate change.Program Objectives• To identify how biological productivityis affected by sea ice extent andproperties, and by ocean circulation.Productivity in the Southern Ocean hasbeen linked to the winter sea ice cover andto large-scale ocean circulation patterns,both of which are sensitive to climatechange. ACE CRC researchers are combiningoceanographic data, satellite data and ship-based observations with historical data fromice and sediment cores, penguin rookeriesand operational records. They will use thisdata to test the hypothesis that reduced seaice extent due to climate warming or otherfactors will lead to a smaller sea ice algalcommunity and to explore what impactssuch changes would have further up the foodchain.• To quantify and describe processes thatlink sea ice, and primary and secondaryproductivity. The linkage between thephysical environment and the Antarcticmarine food web is poorly understood atpresent. ACE CRC research will result inmodels of the small scale processes linkingthe physical and biological components ofthe system. The models will be used as thebasis for predicting the impacts of physical orbiological changes on the overall function ofthe Antarctic marine ecosystem.• To project the effects of long-termchange on Antarctic ecosystems. TheAntarctic environment is highly variable inspace and time. We need to account for thisvariation in ecosystem processes in order todevelop accurate predictive models for theSouthern Ocean. We also need improvedmodels to predict how local changes causedby climate change and fisheries might impactthe greater ecosystem. ACE CRC scientistsare using remote sensing of ocean colourand water movements, as well as field-basedoceanographic and biological measurements,to improve our abilities to accurately modelthe effects of ocean circulation and sea ice onbiological productivity.• To translate predictions of the effectsof climate change on SouthernOcean ecosystems into sustainablemanagement models. A combination36 Antarctic Climate & Ecosystems CRC - Annual Report 2005-06