Benthic phosphorus cycling within the Eurasian marginal sea ice zone
The Arctic Ocean region is currently undergoing dramatic changes, which will likely alter the nutrient cycles that underpin Arctic marine ecosystems. Phosphate is a key limiting nutrient for marine life but gaps in our understanding of the Arctic phosphorus (P) cycle persist. In this study, we investigate the benthic burial and recycling of phosphorus using sediments and porewaters from the Eurasian Arctic margin, including the Barents Sea slope and the Yermak Plateau. Our results highlight that P is generally lost from sediments with depth during organic matter respiration. On the Yermak Plateau, remobilization of P results in a diffusive flux of P to the seafloor of between 96 and 261 μmol m-2 yr-1. On the Barents Sea slope, diffusive fluxes of P are much larger (1736 to 2449 μmol m-2 yr-1) but these fluxes are into near surface sediments rather than to the bottom waters. The difference in cycling on the Barents Sea slope is controlled by higher fluxes of fresh organic matter and active iron cycling. As changes in primary productivity, ocean circulation, and glacial melt continue, benthic P cycling is likely to be altered with implications for P imported into the Arctic Ocean Basin.
AWI Organizations > Biosciences > Polar Biological Oceanography
Helmholtz Research Programs > PACES II (2014-2020) > TOPIC 3: The earth system from a polar perspective > WP 3.2: Earth system on tectonic time scales: From greenhouse to icehouse world