Deadly skin-lesion disease hits Alaska’s seals

Investigation into cause of outbreak

October 2011: The US National Oceanic and Atmospheric Administration (NOAA) Fisheries is working with a group of international wildlife researchers to find out what is causing a disease outbreak in Arctic seals, primarily in ringed seals. The disease is most visible as skin lesions.

Since July, the North Slope Borough Department of Wildlife Management has responded to at least 107 cases of stranded ringed seals, mainly between Barrow and Wainwright. About 100 of those ringed seals appeared to have skin lesions, and nearly half of the animals were dead when found, or died shortly after.

More signs of serious illness
Similar cases have been reported in Russia and Canada, and in walruses along the Arctic coast of Alaska. In October, European scientists documented similar cases in harp seals around Greenland. At this point it is not known if multiple species are affected by the same agent or whether these are all independent events.

Although abnormal hair loss has been under investigation in ringed seals for several years, this summer hunters and researchers started seeing more severe signs of illness as well as dead seals. Diseased ringed seals have exhibited hair loss, delayed molting, and skin ulcers. Some of the live diseased seals have exhibited lethargy and labored breathing. Findings from dead seals have shown significant lesions in the skin, respiratory system, liver, lymphoid system, heart, and brain.

Laboratory findings have been inconclusive to date, and scientists have not yet pinpointed a single cause of this disease. A group of international wildlife researchers continue to test for a wide range of possible factors, including: bacterial, viral, fungal, or toxic agents that may be responsible for the animals' condition.