Five-fold increase in Arctic has Inuit worried about greater hunting competition for food

James Gordon

The Ottawa Citizen

Saturday, February 17 2007


Scientists say rapidly-melting sea ice is partially to blame for a five-fold increase in killer whale sightings in some parts of the Canadian Arctic.

Jeff Higdon, a researcher with a joint University of Manitoba and Fisheries and Oceans Canada monitoring project, said the trend concerns Inuit hunters who fear increased competition for food.

He explained there were only six killer whale sightings reported in western Hudson Bay in the 1980s, and six more in the 1990s. Since the year 2000, however, there have already been more than 30. In areas that never saw a killer whale before the 1940s, orca visits are an annual occurrence.

While several factors -- including better monitoring and the end of commercial whaling in the early 1970s -- could be affecting the numbers, Mr. Higdon said there is a strong correlation between declining sea ice and increased spottings.

"There is a relationship there, in that it seems with ice melting sooner and more open water ... killer whales are able to penetrate a little further west in the Artic," he said.

According to a NASA study released last year, the past two winters have seen a dramatic reduction of Artic winter ice cover. While it had been declining on average about 1.5 per cent per decade since 1979, there was a six-per-cent drop in each of 2005 and 2006. Summer ice continues to drop at a rate of 10 per cent per decade.

Mr. Higdon's "Orcas in the Canadian Arctic" project was launched in 2005, due to Inuit concerns over how an increase in killer whales would affect their livelihood.

More killer whales mean less of their prey, including the beluga, bowhead and narwhal whales that are nutritionally and culturally significant to the Inuit.

"That's their biggest concern," said Winnipeg-based Mr. Higdon, who has compiled a large database of sighting reports. "It's competition, basically, for some of their very important species.

Project leader and Fisheries and Oceans Canada researcher Steven Ferguson said some hunters actually welcome the orca boost.

"We get different reports from the hunters who are out on the water," said Mr. Ferguson, who is also a professor in the University of Manitoba's zoology department. "Some of them are glad the killer whales are there, because the prey response to killer whale activity is to hug the shoreline."

As a result, the prey becomes much easier for humans to catch.

Mr. Ferguson said research is under way to try and determine if that activity will have any long-term effects for species such as the beluga and narwhal.

"That's our big concern," he said.

In the case of the bowhead, his researchers have started a photo identification project to identify whales that have rake marks suggestive of killer whale attacks. Attacks on calves will also be monitored.

In addition, the group has placed underwater listening devices near Repulse Bay, Nunavut, to track killer whale activity. While orcas are silent when they hunt, evidence on the West Coast suggests they "celebrate" after a successful kill.

"That's when they make a lot of noise," Mr. Ferguson said. "If we can record some of these instances, then we might have a record of possible predation events."

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