Séminaire
Arctic marine ecosystems are characterized by strong seasonality of the sea-ice cover, light and food availability. Climate change effects are enhanced in the Arctic and these changes are expected to have repercussions on the entire ecosystem functioning. While benthic-pelagic coupling over much of the Arctic ice-covered shelves is thought to be particularly tight, climate-induced changes in ice cover are expected to lead to shifts in productivity regimes and carbon fluxes. It is particularly unclear how benthic organisms will respond to these variations in food sources and environmental conditions in such environments.
Ice-contrasted ecosystems were studied during the CASES, Cabanera, Marine Night and ECOTAB projects (Beaufort Sea and Rijpfjorden, with a seasonal ice-cover, Kongsfjorden, with a reduced ice cover). Results show that the benthos of Kongsfjorden may not rely on seasonal inputs of organic matter such as in other Arctic shelves with more important ice covers. This suggests that a decrease in ice cover may lead to a weakening on the pelagic-benthic coupling, having repercussion on ecosystems functioning and carbon cycling.