The mystery disease that killed or sickened at least 135 seals in the Arctic has been discovered for the first time in a yearling seal that traveled far from its range to Southeast Alaska.
A fisherman there found a "fairly bald, sickly-looking, and lethargic" seal hauled out on the shore near Yakutat last week, the National Oceanic and Atmospheric Administration reported.
After hearing about the seal, thought to be a ringed seal, officials recommended it be sent to Anchorage for analysis. The animal was so sick it had to be euthanized, the agency said in a press release.
A necropsy determined the seal's symptoms were similar to those that led NOAA late last year to declare the deaths an unusual mortality event, a decision that frees up more resources to pinpoint the cause of the disease, the agency said.
The seal "exhibited almost total hair loss and ulcerated scabbed skin sores," said Kathy Burek-Huntington, the lead veterinary pathologist in the international inquiry.
Baffled scientists have ruled out several bacteria and viruses known to affect marine mammals. Radiation is also not suspected. "Last month, preliminary radiation testing results were announced which indicate radiation exposure is likely not a factor," Burek-Huntington said. "Further … testing is occurring this spring. Results will be made publicly available as soon as the analyses are completed."
The sickness was observed primarily in ringed seals and a few walrus last summer in the Arctic and the Bering Strait region near Alaska. This is the first time a seal with the disease has been found so far outside its range, Speegle said. Most of the sick seals have been found on off western or northern Alaska, more than 1,000 coastal miles from Yakutat.
In the last two months, the agency has received a handful of additional reports from those who sighted sick ice seals but has not confirmed them, Speegel said. The number of sightings could grow, now that spring seal hunting by Alaska Natives is on the verge of starting.
The agency cautioned that seals have been known to venture well outside their range, though rarely. In fact, a healthy ribbon seal -- which are normally found in the Arctic and north Pacific waters -- caused a stir when it showed up in Seattle earlier this year.
The ringed seal found near Yakutat appeared to be in good body condition, based on its blubber thickness. To confirm it was a ringed seal -- the hair loss caused some uncertainty -- the animal's DNA is being tested.
If the animal is a ringed seal, it will be the first one reported in the Gulf of Alaska, the agency said.
Hunters who find a marine mammal that is diseased or distressed should call NOAA Fisheries Stranding Hotline at 877-925-7773.