Seal captured near Yakutat found to have hair loss and skin sore disease
Juneau, AK — Marine mammal scientists last Wednesday received a curious report: fishermen near Yakutat had observed what appeared to be a ringed seal pup hauled out at the shoreline.
Because the seal was reported to be fairly bald, sickly-looking, and lethargic, NOAA Fisheries scientists quickly advised that the animal be captured and transferred to Anchorage for examination by a pathologist and wildlife veterinarians from the Alaska SeaLife Center, Bridge Veterinary Services, UAF Marine Advisory Program and ringed seal experts from the North Slope Borough Department of Wildlife Management.
When the seal pup arrived in Anchorage, it was found to be so ill it had to be euthanized.
Alaska Veterinary Pathology Services veterinary pathologist Kathy Burek-Huntington led the necropsy on the animal. Findings indicated that the seal exhibited similar symptoms to those in the declared 2011 Northern Pinniped Unusual Mortality Event (UME) which has been affecting ice seals and walruses in the Arctic and Bering Strait regions of Alaska since last summer.
“The seal, determined to be a yearling, exhibited almost total hair loss and nodular, ulcerated scabbed skin sores,” said Burek-Huntington, the lead pathologist in an international working group of experts working to find out what is causing the disease. “These sores are consistent with the disease process we have been seeing in the ice seals in the North Slope and Bering Strait areas.”
Blubber thickness indicates the animal was in good body condition. Given that most of the distinctly-patterned fur was missing from the animal, a sample of the seal’s DNA is being sent to NOAA Fisheries Southwest Fisheries Science Center to confirm species identity. If indeed it is a ringed seal, it will be the first known ringed seal reported in the Gulf of Alaska, outside the ice seal’s normal habitat range.
It is not unheard of, however, for species of ice seal to venture south into the Gulf of Alaska or beyond. Past sightings of ribbon seals have occurred near Anchorage and in Tracy Arm Fiord in Southeast Alaska. Earlier this year, a healthy ribbon seal was found hauled out in Central Puget Sound, Washington.
Since last July, more than 60 dead and 75 diseased seals, most of them ringed seals, have been reported in Alaska. Scientists with the U.S. Fish and Wildlife Service have also discovered the disease in walruses at the Point Lay haul-out.
Although scientists still don’t know the underlying cause of the disease, they have ruled out numerous bacteria and viruses known to affect marine mammals. Last month, preliminary radiation testing results were announced which indicate radiation exposure is likely not a factor in the illness. Further quantitative radionuclide testing is occurring this spring. Results will be made publicly available as soon as the analyses are completed.
Since this is the first UME involving subsistence species, both NOAA Fisheries and the U.S. Fish and Wildlife Service continue to prioritize concerns about the food safety dimensions of this outbreak. The agencies have been working closely with the State of Alaska Division of Public Health to distribute general precautionary guidelines around handling and consumption in the absence of a known pathogen. Throughout this event, hunters have been encouraged to use traditional and customary practices when dealing with healthy and/ or sick seals. At present, there is no evidence that consuming animals involved in this disease event has caused any human illness.
If you find a marine mammal which appears diseased or distressed, please call NOAA Fisheries Stranding Hotline at 1-877-925-7773.
Information on the UME assessment progress and findings can be found at:
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