Wednesday May 22, 2013


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Visiting seal offers clues in Arctic mystery

Animal's health being monitored as part of effort to find answers in large 'mortality event'
Photo by Chris Dale/Special to The Chief

This ribbon seal, which are normally native to the Bering Sea near Alaska, was spotted sunning itself on a dock in Cattermole Slough on Sunday (July 8).

A seal visiting Squamish's waterfront may hold part of the key to solving the alarming deaths of seals, walruses and polar bears in the waters off of Alaska.

On Sunday (July 8), Squamish resident Wally Fletcher saw a ribbon seal while birdwatching along Cattermole Slough. Named after its impressive white ring markings, the species is native to the cold waters of the Bering Sea — more than 2,300 kilometres away.

“I was just excited to see it,” Fletcher said.

What Fletcher happened upon was an increasingly famous seal. The male ribbon seal was first spotted near Marysville, Wash., in January. In June, it crossed the border and was tagged by the Department of Fisheries (DFO) in Steveston.

The seal has stirred hype among West Coast marine biologists. The last report of a member of its species south of Alaska took place in the '60s, Vancouver Aquarium veterinarian Martin Haulena said. More importantly, the seal's arrival coincides with an ongoing “unusual mortality event” among marine mammals in the polar regions.

“A number of animals have died due to an unknown cause,” Haulena said.

The U.S. National Oceanic and Atmospheric Administration (NOAA), along with Canadian specialists, are investigating the unexplained deaths of pinnipeds — fin-footed mammals — in Arctic regions. More recently, scientists have discovered similar symptoms in polar bears.

Cases involve hair loss and lesions, with reports noting that ringed, bearded and spotted seals have been hit the hardest. Early research shows most of the mammals die from a bacterial infection. Lung and heart abnormalities and softening liver tissue have also been reported.

No definitive cause has been identified, NOAA Fisheries Service officials stated in an April presentation to the Climate, Ecosystem and Health Working Group. Bacterial and fungal testing are underway and it's not known whether the disease can be transmitted to humans.

“Really, we don't know why these animals have died,” Haulena said.

One of the problems with tracking the mortality event, is finding a live sample that scientists can use to monitor health over time, Haulena said. That's where the visiting ribbon seal fits into the puzzle.

“To me he [the seal] presents an incredible opportunity,” he said.

Haulena was a part of a team that recently took samples from the seal. The animal had “suspicious crusty, raised lesions with hair loss that seemed similar to the lesions reported in the unknown mortality event,” Haulena noted. Scientists are awaiting results on biopsies.

The samples collected from the seal in Canada will be compared to those taken in Washington. Scientists are hunting for changes in the seal's physiology, Haulena said.

Haulena is concerned the male seal won't be able to find food or may be exposed to bacteria and parasites foreign to him. So far, specialists have decided not to take him into captivity because Alaskan regulations won't allow rehabilitated animals back into the open seas.

However, if the seal's health deteriorates, it's always an option, Haulena said, noting the aquarium rescues an average of 150 harbour seals a year.

“I do worry that he is down here due to the mortality event up north,” Haulena said.

DFO has decided not to put a tracking device on the seal as he is moulting, which could result in the equipment being lost. In 2011, the NOAA officials announced they were reviewing the status of the ribbon seal to determine whether it should be classified as an endangered species.


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