Abstract: The research will examine the relative importance of the physical and chemical controls on phytoplankton dynamics and carbon flux in continental margin regions of the Southern Ocean, and elucidate mechanisms by which plankton populations and carbon export might be altered by climate change. We specifically will address (1) how the phytoplankton on the continental margins of the southern Ocean respond to spatial and temporal changes in temperature, light, iron supply, and carbon dioxide levels, (2) how these factors initiate changes in phytoplankton assemblage structure, and (3) how carbon export and the efficiency of the biological pump are impacted by the biomass and composition of the phytoplankton. Two regions of study (the Amundsen and Ross Seas) will be investigated, one well studied (Ross Sea) and one poorly described (Amundsen Sea). It is hypothesized that each region will have markedly different physical forcing, giving rise to distinct chemical conditions and therefore biological responses. As such, the comparison of the two may give us insights into the mechanisms of how Antarctic continental margins will respond under changing environmental conditions. Broader impacts include participation by an international graduate student from Brazil, outreach via seminars to the general public, collaboration with the teachers-in-residence on the cruise, development of a cruise web site and interactive email exchanges with local middle school students while at sea.