September 22, 2011
Bowhead Whales Use Northwest Passage To Migrate
According to research published in the journal Biology Letters, bowhead whales are using the Northwest Passage to move across the top of the Americas.
Scientists analyzed skeletons, DNA samples and harpoon heads and found these giants of the Arctic living on each side of the continent did meet and mingle.
Mads Peter Heide-Jorgensen from the Greenland Institute of Natural Resources and colleagues satellite-tagged over 100 bowheads over the last decade.
The researchers found that one whale from the Greenland side and one from the Alaskan side had arrived in essentially the same area.
The team spent 10 days circling the same patch of water before heading back to their respective home ranges.
Bowhead skeletons are found on elevated beaches through the Canadian archipelago. Whales were also caught containing tips of harpoons that had been thrown by whalers in the Atlantic in the 19th Century Alaska.
Scientists believe traveling through the Northwest Passage may have been easier in the past four summers than previous decades because the Arctic ice has shrunk to a smaller size.
"I'm pretty sure that the low sea ice in the summer has triggered this migration through this area," Dr Heide-Jorgensen told BBC News.
"I'm pretty sure that when it occurred in the past, when we got all these skulls on the beach, that was during a warm period.
"During any climatic period, there could have been years with less ice in the Northwest Passage; and I'm pretty sure the bowheads can find cracks [in the ice] that are too small to show up on satellite images."
Scientists also found more evidence for the migration pattern through human societies who may have depended on the creatures to survive.
Thule people ate meat and blubber from the bowhead, built houses using their bones and burned their oil.
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