The Canadian Arctic as a Source of Trace Metals to the Atlantic Ocean: Distributions and Fluxes through Nares Strait, Lancaster Sound and Baffin Bay

The Canadian Arctic Archipelago (CAA) is a shallow conduit conveying Pacific- and Atlantic-derived waters to Baffin Bay via Lancaster Sound, Jones Sound, and Nares Strait. At the southern edge of Baffin Bay, Davis Strait is a key gateway for exchange of Arctic modified water masses with the Labrador Sea and Atlantic Ocean. We estimated trace metal sources, sinks and fluxes through major water transport pathyways by sampling of these exchange points in 2019, 2021, 2022, and 2024 for iron (Fe), manganese (Mn), cobalt (Co), nickel (Ni), copper (Cu), zinc (Zn), cadmium (Cd), and lead (Pb). A linear mixing model was applied to provide information on the relative contribution of water masses in Baffin Bay. Ultimately, the Arctic waters which have transited the CAA are a source of Co, Ni, Cu, Zn, Cd, Pb, Ba and V to the Atlantic, while there is no net flux of Fe and Mn across Davis Strait. We propose that rapid warming in the Arctic due to ongoing climate change, and the more frequent failure of the Kane Basin ice arch in Nares Strait will increase the southward flux of Co, Ni, Cu and Cd, but diminish the flux of Mn and Fe. Our results suggest potential changes to micronutrient availability in highly productive regions of the Arctic and in source waters feeding into the North Atlantic.