The paper, entitled ‘Will the declining sea ice extent in the Arctic cause a reversal of net benthic-pelagic exchange directions?’ – suggests that these changes will go on to disrupt the natural movement of matter between the seabed and the water column – a key process for cycling carbon and nutrients. This movement depends on physical mixing, animal activity, and other drivers, and it can work in two directions – particles and dissolved matter moving down, or being stirred back up.
This study is part of the Changing Arctic Ocean Seafloor project (or ChAOS), which focused on the Barents Sea – a shallow shelf sea in the Arctic Ocean. Much of this work hs been carried out by Plymouth Marine Lab’s Dr Saskia Rühl.
Through in-situ sampling and experiments, Rühl and her team have examined how matter moves between the seabed and water under different ice conditions.
The study found that in the southern Barents Sea – which has more of an Atlantic influence – dissolved substances mostly move down into the seafloor while particles move up into the water. In the northern barents Sea, however – with more of an Arctic influence – the opposite happens. This makes the northern area more of what the scientists call ‘a depositional zone’ – where material settles and supports productivity near the sediment surface.
All of these findings offer insight into how a warming Arctic could reshape these vital processes in the future. As the Polar Front is pushed further North, the Northern regions are likely to become more similar to today’s Southern conditions, leading to a larger area in which particles are not deposited reliably, and seafloors are more prone to disturbances.
“Our findings highlight the need for broad, multidisciplinary monitoring of the Arctic’s changing ecosystems,” said Dr Rühl. “Understanding how particulate and dissolved fluxes respond to climate and human pressures is critical for predicting impacts on biodiversity, fisheries, and the Arctic’s role in storing carbon.
“This research provides a vital foundation for future studies and for refining ecosystem models in one of the world’s most climate-sensitive seas.”
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