Stray grey whale navigates the North-West Passage

Earth 11 May 2010

New Scientist Default Image

Coast to the left, coast to the left…

(Image: IMMRAC)

Conventional wisdom has it that grey whales have been extinct in the Atlantic Ocean for more than 200 years, and the species survives only in the north Pacific. That was the case until last weekend, when a 13-metre-long grey whale was spotted cruising off the coast of Israel.

“This is sensational,” said Phillip Clapham of the US government’s National Marine Mammal Laboratory in Seattle after hearing the news from marine biologists in Israel. “The most plausible explanation is that it came across an ice-free North-West Passage from the Pacific Ocean, and is now wondering where the hell it is.”

The North-West Passage, which runs through the Canadian Arctic, has been open in summer in recent years, partly because of rising global temperatures.


Although they are known for their long migrations, grey whales do not normally stray from their regular routes. “Were I to speculate wildly, I’d say it found Europe and remembered its mother telling it to keep the coast to its left going south, then it hit the strait of Gibraltar and entered the Mediterranean,” said Clapham.

The Arctic route makes most sense, agrees Giuseppe Notarbartolo di Sciara, an expert on Mediterranean cetaceans who advises several international conservation bodies. He points to reports that grey whales have been seen getting farther north than usual into the Arctic, probably helped by the low-ice conditions.

“Probably this one went so far east that when the time came to go south it had the Atlantic rather than the Pacific in front of its rostrum,” says di Sciara. “Then, hugging the eastern side of the ocean as any good Pacific grey whale would do, it went into the first big warmish ‘lagoon’ it could find: the Mediterranean.”

Incredible but inescapable

The finding was announced last Saturday by Aviad Scheinin, chairman of the Israel Marine Mammal Research and Assistance Center, who had followed the whale at sea for 2 hours. He at first thought it was a sperm whale, but checked the markings back on land and reached the “incredible but inescapable conclusion that it was a grey whale”. Clapham told New Scientist that the identification had now been confirmed.

There are two distinct populations of grey whales in the northern Pacific Ocean, one on the Asian side and one on the American. A third population inhabited the Atlantic shores of North America and Europe until the 18th century, when it seems to have been hunted to extinction by American and European whalers. Archaeologists have found fossil remains in the Mediterranean, where the whales probably calved.

The discovery of a Pacific grey whale so far from home may revive calls to reintroduce the species to European waters. In 2005, Owen Nevin and Andrew Ramsey of the University of Central Lancashire in Preston, UK, proposed airlifting grey whales from the population in the eastern Pacific to the Irish Sea (PDF).

Conservationists at the time questioned whether the animals would survive in the Atlantic. That question, at least, seems to have been answered.

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