Pelagic-benthic Coupling of the Barents and Beaufort Seas, Arctic, Revealed by Sedimentary Pigments

Pelagic-benthic coupling over much of the Arctic shelves is thought to be particularly tight. The study of sedimentary pigments in the Barents and Beaufort seas showed very different pelagic-benthic coupling patterns, reflecting the important contrast of primary productivity, secondary production and hydrography between the two ecosystems. Physical parameters seemed more responsible for spatial differences. In the Barents Sea, spatial changes were highly influenced by currents while in the Beaufort Sea, spatial changes were related to depth and river influence. From a seasonal point of view, productivity regime, especially ice-algae production and the match/mismatch of zooplankton grazing, seemed important in shaping organic matter inputs to the benthos. In the spring, ice-algal production largely influenced organic matter inputs to the benthos in both the Barents and Beaufort Sea. In the summer, grazing was responsible for inputs of degraded material in both ecosystems. In addition to biological parameters, environmental factors were also important in summer and fall. In the Barents Sea during summer, the different currents lead to phytoplankton taxonomy variations, and in the Beaufort Sea during fall, riverine inputs were found to be responsible for the presence of allochtonous material in the sediment.