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Fur loss, oozing sores observed in Arctic Alaska polar bears

Jill Burke
USGS photo

Alaska polar bears, protected under the Endangered Species Act, have joined the list of Far North species afflicted with a mystery illness. An iconic animal that has become a symbol for global awareness of a melting arctic, polar bears are beginning to show up with hair loss and lesions.

Polar bear researchers with the U.S. Geological Survey are only halfway into their annual survey in Alaska and they’ve already come across nine bears – six in Barrow and 3 in Kaktovik – with signs of alopecia and skin lesions. The muzzle, face, eyes, ears and neck appear most affected, according to a bulletin published Friday by the agency.

“We are seeing it in bears across the Southern Beaufort Sea in Alaska,” said Tony DeGange, a biologist with the USGS in Anchorage.

Researchers say they aren't alarmed because the bears seem healthy otherwise. But their curiosity is piqued. They want to know what the condition means, if anything, to the animals’ long-term health and whether there’s any connection to the illnesses recently discovered in other animals that share the same waters.

Large numbers of sick and dying seals were found along Alaska's Arctic coast last summer, followed by a similar but less-severe condition found in Pacific Walrus in the same region during the fall.  The combination led to a declaration by the National Oceanic and Atmospheric Administration in December of an Unusual Mortality Event. That brought together agencies and researchers seeking answers about what was happening and why.

Both animals suffered skin lesions. The seals also had hair loss. It's not known what is causing the afflictions or whether all the species suffer from the same disease.

Polar bears feed on seals. Whether they are feeding on the sick seals, or whether the sick seals have the potential to make the bears ill, isn't known. DeGange calls it "the million dollar question."

Hair loss is not uncommon in polar bears – it happens both to bears in the wild and in captivity. The Association of Zoos and Aquariums lists allergies, mites, self-inflicted wounds from rubbing in stressed bears, water quality issues and hormone imbalances as leading suspects for the cause of the problem.

The USGS has collected data on polar bears in Alaska every year since 1984. About 13 years ago, during the 1998-99 season, its researchers witnessed a similar spike in hair loss, with 10 of 48 bears captured that year showing signs of hair loss. The cause was never found. In most other years, the condition shows up with much less frequency. 

Federal scientists have collected blood and tissue samples from the afflicted bears “to investigate the cause of the symptoms and determine whether there is any relationship between the symptoms observed in polar bears and those reported for arctic pinnipeds from the same geographical region earlier this year,” according to a prepared announcement about the findings.

Polar bear observations will wrap up near Prudhoe Bay in early May.

Hunters are advised not to eat sickly animals and to thoroughly cook any meat they plan to eat. A hotline has also been set up for anyone who sees or harvests a polar bear with fur loss or skin sores. That number is (907) 786-7034.

Contact Jill Burke at jill(at)alaskadispatch.com