DEEP-SEA CORALS · Deep-Sea Coral Geochemistry and Climate: a Focus on the History of the Southern Ocean

The Southern Ocean plays a crucial role in modulating global climate, and exhibits a sensitive response to perturbations. Today, some of the most obvious symptoms of changing climate, such as ice shelf melting and ocean temperature rise, are being observed in the Southern Ocean and coastal Antarctica. Leading hypotheses for the cause of the low atmospheric CO2 levels at the last glacial maximum include Southern Ocean processes such as enhanced biological productivity or stronger vertical stratification. Constraining the rates and amplitude of environmental change (on both millennial and decadal timescales) in the Southern Ocean is, therefore an important goal of climate science. This sensitivity of the Southern Ocean to climate perturbation means that the fauna that live there are likely to experience large changes in their environments. Carbonate organisms are at risk from ocean acidification, with deep-sea corals being a group that is likely to be particularly vulnerable. However, our understanding of how climate change may affect the distribution and health of cold-water corals is inadequate and improving this understanding is a pressing concern for conservation efforts. This project seeks to combine existing and novel geochemical approaches to optimize the use of deep-sea coral skeletons as archives of past Southern Ocean climate. The records produced during the reintegration period will provide data suited to testing hypotheses linking Southern Ocean circulation to global climate on timescales from decades to millennia and will provide unique insights into the history of deep-sea coral population dynamics.