Holocene productivity changes off Adélie Land (East Antarctica)

International audienceThis study presents the first high-resolution multiproxy investigation of primary productivity (PP) during the Holocene from the Antarctic continental margins. Micropaleontological and geochemical data from the sediment core MD03-2601, associated to sea ice model outputs, give unprecedented insights into the biological pump of the Antarctic coastal area off Adélie Land in response to climatic changes. Plurimillennial and millennial changes of PP are observed in the study area in response to changes in nutrient availability, stratification, and growing season duration, which are linked to sea ice, upwelling, wind, and glacier dynamics. The precessional cycle seems to be responsible in the PP long-term variations, while forcing factors involved at the millennial timescale remain more enigmatic. Our results emphasize enhanced biological pump during warmer and windier Holocene phases because of a longer growing season and greater nutrient input. Antarctic coastal and continental shelf zones may therefore represent a more intense carbon sink in the future