Loss of sea-ice, ice shelves and retreat of coastal glaciers around the Antarctic Peninsula in the last few years has exposed new open water, allowing large blooms of phytoplankton to flourish in the newly exposed coastal areas. This new productivity has important consequences as the phytoplankton die and sink to the sea-bed where the carbon is sequestered for thousands of years. This carbon sink acts as a negative feedback to climate change, with an estimated 2.9 million tonnes of carbon drawdown per year on the West Antarctic continental shelf.
Carbon accumulation differs significantly between regions based on specimens collected from the continental shelves of South Georgia, the South Orkney Islands and Bellingshausen, Amundsen and Weddell Seas. The South Orkney Islands are the most productive region per km2 but, at only 4x104 km2, the greatest overall gains are for the larger continental shelves.