sabato 24 settembre 2011

Whales Mingle Across the Arctic

The loss of Arctic sea ice is predicted to open up the Northwest Passage (the vast northern sea lanes above Canada presently choked off by ice), shortening shipping routes and facilitating the exchange of marine organisms between the Atlantic and the Pacific oceans. Skeletons, DNA samples and harpoon heads have all suggested that bowhead populations living on each side of the continent did meet and mingle in the past. Previous satellite tracking has demonstrated that bowhead whales from West Greenland and Alaska enter the ice-infested channels of the Canadian High Arctic during summer. In August 2010, two bowhead whales from West Greenland and Alaska entered the Northwest Passage from opposite directions and spent approximately 10 days in the same area, documenting overlap between the two populations.

The bowhead whale is a baleen whale of the right whale family. A stocky dark-colored whale without a dorsal fin, it can grow to 66 feet in length. This thick-bodied species can weigh 75 tons to 100 tons. It lives entirely in fertile Arctic and sub-Arctic waters, unlike other whales that migrate to feed or reproduce.
The new research published in the journal Biology Letters has used satellite tags to provide confirmation that these whales cross and mingle through the northwest passage region of upper Canada.
Also intriguing lies in the human societies such as the Inupiat that historically depended on such whales as part of their society and diet. The culture originated in Alaska and spread to Greenland in the last 1000 years which suggests that they followed the bowhead whale in their migratory path across the Arctic.

Full article: here

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