SGER: Science-of-Opportunity Aboard Icebreaker Oden: Bioactive trace metals in the Amundsen and Ross Seas

The research objective is (1) to determine the distributions and dynamics of a full suite of bioactive trace metals in dissolved and suspended particulate forms, along sampling transects of the Amundsen and Ross Seas. And (2) to test the sensitivity of overall cellular metal stoichiometry (metal/carbon ratios) to natural gradients in species assemblage and Fe availability. Our earlier findings from a single Ross Sea station and from a Drake Passage crossing suggest that Fe-limited phytoplankton cells are unusually enriched in Zn, Cu and Cd relative to biomass carbon, with strong implications for the biogeochemical cycling of these elements relative to carbon fluxes in the Southern Ocean.

In collaboration with other researchers on the cruise, we will also measure metal stoichiometry of cells exposed to predicted 2010 temperature and carbon dioxide levels in shipboard incubation studies, as a window into possible effects of climate change on metals biogeochemistry in these regions. This proposal will support close international collaborations and lasting infrastructure development as US and Swedish scientists, and more importantly, their students, work toward shared the shared goal of understanding a region that is experiencing one of the fastest rates of climate change on the globe. Trace metal micro-nutrients are a key control on the productivity of Antarctic marine ecosystems. Our results will be made widely available through research publications and internet-available databases, and public outreach through COSEE at Rutgers University.