Grey whale sighting in Med stuns scientists

By Tom Clarke
Updated on 11 May 2010

Scientists think the appearance of a grey whale in the Mediterranean sea may be the result of changing climate, writes Channel 4 News Science Correspondent Tom Clarke.

The sighting of a grey whale in the Mediterranean sea has left marine biologists stunned. Since the end of the 18th century the species has been confined to the Pacific ocean after it was hunted to extinction elsewhere.

Whale experts can only guess at how the 13-metre-long whale managed to get from the Pacific into the Atlantic and then down to the Mediterranean.

The whale was first spotted on Sunday by Israeli biologists a mile and a half out fromTel Aviv. Initially they thought it had to be a sperm whale, which is similar in size.

But as its discoverer, Dr Aviad Scheinin, of the Israel Marine Mammal Research & Assistance Center, explains, it soon dawned on them it was a grey whale thousands of miles from where it should have been.

"Closer inspection of the photographs back home showed quite a lot of head in front of an elevated blowhole, flukes unlike those of a sperm whale, unwrinkled and white-patched skin, all leading to the incredible but inescapable conclusion that it was indeed a grey whale," he says.

There are currently two discrete groups of grey whales. About 20,000 individuals live in the eastern Pacific, migrating between the waters of Alaska to Baja California. In the western Pacific a tiny group of western grey whales, genetically distinct from their eastern cousins, live in the Siberian sea of Okhotsk and South Korea. There are fewer than 200 of these whales and they are listed as critically endangered.

The whale sited off Tel Aviv appears to be emaciated, a sign that it is well and truly lost. Grey whales specialise in feeding on small shrimp-like crustaceans living on the sea floor.

The scientists' best guess as to how the whale got to the Mediterranean is that it is a victim of a changing climate. In recent years, particularly 2007 and 2008, the North West Passage through the Arctic Sea – normally frozen year-round - has been free of ice.

The theory is that the whale belongs to the eastern Pacific population of grey whales and swam north through the passage. It then turned south down the eastern side of the North Atlantic, as it normally would during its migration though down the Pacific.

"Instead of turning left to the Gulf of California it has turned left into the Mediterranean sea through Gibraltar straights and all the way to the eastern Mediterranean," says Dr Scheinin.

Other whale biologists, equally amazed by the discovery agree. "The most plausible explanation is that it came across an ice-free NW Passage from the Pacific and is now wondering where the hell it is," says Phillip Clapham, with the National Marine Mammal Laboratory in Seattle, Washington.

Israeli scientists hope to continue tracking the whale, which was last seen heading south past Jaffa.

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