Whales

There is considerable uncertainty as to how Arctic cetaceans will fare in a changing climate. Several species of whale occur in the Arctic, but only three are found there all year round - beluga, narwhal and bowhead. Of these, the narwhal is the most restricted in distribution and habitat and is likely to be the most vulnerable to global warming. Found only in the Atlantic sector and preferring deep or offshore waters they over-winter in areas of dense pack ice. Both belugas and narwhals are toothed whales and feed mainly on Arctic and polar cod as well as other fish including Greenland halibut and squid. Bowheads, on the other hand, are filter feeders that subsist mainly on zooplankton and it is at least a possibility that reductions in sea ice will be advantageous as more sea area becomes accessible. Bowheads were hunted almost to extinction, starting in the 16th Century, and although they have been increasing in the Western Arctic for the last thirty years but it is not yet possible to tell if this is due to a rebound from hunting pressures, a response to ice retreat, or some combination of factors. Those whales that visit the Arctic seasonally, including blue, gray, fin, humpback, minke and killer may be able to take advantage of warming by ranging further north in search of food. Gray whales are among the most flexible and adaptable visitors to the Arctic and as such can be expected to cope well with changes as can killer whales which are being much more frequently observed in sub-Arctic and Arctic waters. Any increase in killer whales could negatively impact populations of other marine mammals including bowheads, belugas, seals and walruses. Read more on Arctic wildlife and biodiversity.