Just as marine commerce could soon exploit the opening of the fabled north-west or north-east passages between the two great oceans, so could at least 80 species of fish.
Mary Wisz, an ecologist now with the Danish DHI group, but formerly at the Arctic Research Centre of Aarhus University in Denmark, reports with colleagues in Nature Climate Change that as sea temperatures increase, and food sources begin to flourish at the highest latitudes, shoals of fish from the Atlantic could reach the Pacific along once almost impassable seaways north of Arctic Canada and Siberia.
Northerly species
The last such large-scale transfer was nearly three million years ago, with the opening of the Bering Strait. But climate conditions that were once harsh have begun to open migration opportunities for the northerly species in both oceans, the researchers say.
Such changes have happened before. Since the opening of the Suez Canal in 1869, the Mediterranean has been invaded by 55 Red Sea species, with a “drastic impact” on commercial fisheries.
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By 2050, the scientists believe, trans-Arctic traffic will accelerate, and by 2100, 41 Atlantic species − among them cod and herring − could reach the Pacific, while 44 species could get into the Atlantic.
They warn: “This exchange of fish species may trigger changes in the North Atlantic and the North Pacific, with ecological and economic consequences to ecosystems that at present contribute 39% to global marine fish landings.”
Read more at Climate Change Triggers Threats to Marine Ecosystems
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