Killer whales are migrating farther north as the Arctic Ocean's ice cover melts, threatening the livelihood of the native Inuit who traditionally depend on fishing for their food, Canadian researchers have said.

"We found a really direct correlation with decreasing ice in the Arctic and more observations of killer whales so we think they are moving further into the Arctic because of less ice," Steven Ferguson, a scientist at the arctic division of the Canadian fishing ministry, told AFP.

Ferguson's team last year was notified of spottings of the black and white orca, (Orcinus orca, popularly called killer whales) by scientists, tour operators and Inuit fishermen who criss-cross Hudson Bay, a North Canadian inland sea bigger than France.

In the 1980s, experts counted between five and 10 summer spottings of orca each year in the same area. That number jumped to about 30 last year, the Canadian researchers said.

During the same period, the ice cover in the Arctic has sharply declined. By 2040 the ice could be completely gone during the summer, according to a study by Canadian and US researchers recently published in the journal Geophysical Research Letters.

Ferguson's team was unable to identify where the orca seen in Hudson Bay were coming from, but they said it was probably from the northern Atlantic Ocean, near Iceland or Nova Scotia.
 

The researchers also were unsure what was on the menu for the giant creatures, which are not true whales but instead the largest members of the dolphin family.

"We don't know for sure what the killer whales are eating. Some killer whales eat fish but we don't think there is that much good fish food for them in the Arctic. So we are working on the assumption that they are probably eating belugas, narwhals, bowhead and maybe seals as well," Ferguson said.

Their migration is worrying fishermen of the Inuit, the indigenous Eskimo people of the region, he said in discussions of the research led in cooperation with the University of Manitoba.

"It's a real concern for the hunters. They think it is competition for their food (because) the whales that they would be shooting and eating would be attacked by the killer whales," he said.
 

Source http://physorg.com/news88610812.html