Killer whales moving into Arctic as sea ice recedes
The climate-change driven pattern of lower-than-average ice is leading to major changes in the Arctic Ocean. In August, Pacific walruses hauled out in the thousands on Russian and Alaskan coasts. Recent research published in Nature Climate Change suggests fish in the Barents Sea are moving north at a rate of as much as 160 kilometres a decade. In the Canadian Arctic there are increasing sightings (PDF) of killer whales or orcas.
“Receding sea ice and the resulting increase of orcas in the Arctic are ecosystem impacts we are already experiencing as a result of climate change,” said Pete Ewins, WWF Arctic species specialist. “When new predators like orcas move in, they can change the entire ecosystem. In the face of these ever increasing, deeply concerning changes, we need leadership and action to reduce greenhouse gas emissions in order to protect the best interest of people, the Arctic and the entire planet.”
The orcas are not typically seen in heavily-iced waters, as they are not well-adapted to life there. Unlike Arctic whales, orcas have big dorsal fins. As sea ice covers less area than formerly, and for a shorter time, it allows the orcas longer and wider access to the Arctic. The studies of the increasing incidence of orcas in the Arctic are so far mostly confined to the Canadian Arctic. It is entirely possible that orcas are increasingly moving into other parts of the Arctic also, but the evidence there is more anecdotal.
A recent study (PDF) showed that it’s not just scientists who are concerned about the apparent northward move of the whales. Inuit are also concerned, especially because the orcas compete for the same animals that provide food to Inuit.