Sunday, September 4, 2011

Offshore Killer Whales Chowing Down on Sharks (Globe and Mail)


The whale-watching season in B.C. kicked off April 1 and runs until October. - The whale-watching season in B.C. kicked off April 1 and runs until October. | iStockphoto
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IN THE WILD

Killer whales found feasting on sharks off B.C. coast

VANCOUVER— The Canadian Press
It was the kind of feeding frenzy John Ford had never seen before.
Mr. Ford, a research scientist with the Department of Fisheries and Oceans, was aboard a boat north of Haida Gwaii but just south of Alaska, studying the feeding habits of a little-known group of offshore killer whales.
The mammals were hyperventilating, arching their backs and diving deep.

On the hydrophone, Mr. Ford could hear their excited songs.
Minutes passed and then a chunk of tissue – about 250 grams in size and later proven to be part of a liver – floated to the surface, coming to rest in a slick of oil.
More and more tissue and oil soon appeared, covering an area of ocean in a sheen hundreds of metres in size and flattening the water’s ripples.
Mr. Ford and a colleague collected samples, which were later analyzed at DFO’s Pacific Biological Station in Nanaimo, British Columbia.
The tests confirmed Mr. Ford’s long-held hypothesis: the offshore orcas weren’t eating salmon or sea lions. They were chowing down on sharks, specifically sleeper sharks.

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