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

ocean control of carbon dioxideOutput / Milestone Date ProgressComparison of the model to observationsof export to deep sediment traps in theSouthern Ocean south of AustraliaDetermination of the role of iron limitationin biological carbon export to the deep seaExamination of the links between ironsupply and export in an area of natural ironinputsQuantification of the response of SouthernOcean ecosystems to persistent natural ironfertilisationDetermination of the role of elevated CO 2levels on phytoplankton communities2010 Progress towards milestone slowed by twomaternity leaves in 2006-07, but alternatestaffing plans under development andmilestone should be achieved on time.Deep sediment trap samples successfullyobtained and currently being analysedusing newly developed methods forparticulate carbonates and silicates.Field study in 2005 of the naturally ironfertilised waters over the Kerguelenplateau by ACE CO2 program researchersduring the French-led KEOPS programsuggested that the additional iron supplyin these waters produces a very efficientcarbon export to depth – at least 10 timeshigher than that observed in artificial ironfertilisation experiments. Currently inreview for publication in Nature.2003-05 Program delayed 1.5 years by internationalpartner shipping schedule change.KEOPS field program completed in 2005.Analyses ongoing in 2006, first papers inreview (Blain et al., Ebersbach and Trull),additional publications expected in 2007.2006-07and 2009;efficacy& riskassessed2006 &2010Strong but delayed progress (see abovemilestone) with completion of KEOPSfield program in 2005, first researchpapers in review in 2006, and additionalpapers expected in 2007. Assessment ofefficacy expected in 2007, but evaluationof risk requires further conceptual andexperimental advances.2007 Initial results achieved ahead of time withpublication of paper on expected changesin ocean acidification (Orr et al., 2005).Major field program SAZ-SENSE to addressphytoplankton community responsesscheduled for early 2007 but analysis andpublication likely to be delayed until 2008.Additional study of this problem scheduledfor 2007 with supplementary funding fromAGO.Laboratory experiments under elevated CO 22007 Large tanks are currently being modified toallow work under elevated CO 2levels, withthe first experiments to be carried out inJanuary 2007 during the SAZ-SENSE fieldprogram.Antarctic Climate & Ecosystems CRC - Annual Report 2005-06 35