The Arctic is heating up faster than any other region of the planet. As a result, once-distinct boundaries between the frigid polar ocean and the warmer, neighboring Atlantic and Pacific Oceans are blurring, opening the way for the southern waters to enter the polar regions. The volume of Pacific Ocean water flowing into the Arctic Ocean through the Bering Strait has increased by 70% over the past decade. The Arctic Ocean’s cold layering system that blocks Atlantic inflows is breaking down.
These growing intrusions of the warmer oceans are driving heat, nutrients, and temperate species to new polar latitudes, having profound impacts on Arctic Ocean dynamics, marine food webs, and longstanding predator-prey relationships.
Humpback whales, a sub-Arctic species, are now being observed as far north as the North Slope of Alaska. Salmon are now venturing much further north along the coast of western Canada. The northward spread of Atlantic phytoplankton is likely to drastically change the Arctic marine ecosystem because they are not nearly as rich food sources as specialized Arctic species.
Indigenous Arctic seabirds are now being supplanted by species from the south, and prey species are being swept north through the Bering Strait and causing an overall decline in seabird numbers. Killer whales are appearing with increasing regularity in the Canadian Arctic. Formerly a rare event, these visitations pose a threat to narwhals, Beluga, and bowhead whales.
All signs are that the Atlantification and Pacification of the Arctic Ocean will only intensify in the coming decades as the world warms and the Arctic becomes increasingly ice-free. The unique and sensitive polar ecosystem may essentially cease to exist in the years to come.
Photo, posted December 20, 2012, courtesy of NOAA via Flickr.