In August 2011 a large herd of Pacific walruses (Odobenus rosmarus divergens) hauled out onto a barrier island near the coastal community of Point Lay, Alaska. Some of the walruses at the haulout site were reported to have bleeding skin lesions, and a ground-based survey confirmed the presence of ulcerative skin lesions on several walrus carcasses and some of the live animals.
Alaska Marine Science Symposium poster (January 2012)
The cause(s) and significance of the skin lesions are currently unknown. Most walruses exhibiting skin lesions appeared to be otherwise healthy. One hypothesis under investigation is that the skin lesions observed in walruses at the Point Lay site might be associated with a suspected disease agent which appears to be affecting other seal species in the region.
Specifically, in July 2011, subsistence hunters from Barrow, Alaska began reporting a number of ringed seals (Phoca hispida) either hauling out on land or washing up dead across the North Slope of Alaska. Live seals appeared weak, lethargic, often had labored breathing, and typically lacked a normal flight response when approached. Other reported symptoms included alopecia (patchy to extensive hair loss), sloughing of skin at the base of the tail, and ulcerated skin lesions on the face, flippers and scattered across their body. Since these early observations similar symptoms have been reported in ringed seals, spotted seals (Phoca largha) and bearded seals (Erignathus barbatus), in the Bering Strait region of Alaska and Chukotka (only ringed seals). Clinical and pathological investigation of potential disease agents in sampled seals and walruses from the region is ongoing. Preliminary diagnostics indicate a virus is probably not the primary cause of the observed symptoms. Testing continues for a wide range of possible factors that may be responsible for the animals’ condition.
Additional questions answered: Walrus Disease Q&A
In December 2011 the Working Group on Marine Mammal Unusual Mortality Events (WGMMUME) determined that an “Unusual Mortality Event” (UME) involving multiple species of pinnipeds is occurring in the Arctic. A UME is defined as: "a stranding that is unexpected; involves a significant die-off of any marine mammal population; and demands immediate response." News Release
The primary species involved in the mortality event has been ringed seals (Phoca hispida); however other species of arctic pinnipeds, including walrus have exhibited similar symptoms. As part of the UME investigation process, The U.S. Fish and Wildlife Service will be working with the WGMMUME and an Inter-agency response team to investigate factors contributing to the observed symptoms.
Reports from hunters are crucial to the research effort into this event. Federal, state, and local governments, as well as many partner organizations working on this effort are encouraging hunters and anyone who sees a marine mammal that has skin sores, appears ill, or is dead, to report the animal to your closest wildlife management area:
North Slope area
North Slope Borough Department of Wildlife Management (907) 852-0350
Nome and Bering Strait region
Eskimo Walrus Commission (877) 277-4392
Sea Grant Marine Advisory Program (800) 478-2202 or (907) 443-2397
Elsewhere in Alaska
NOAA Fisheries Alaska Marine Mammal at (877) 925-7773
U.S. Fish and Wildlife Service Marine Mammals office at (800) 362-5148
Unusual Mortality Event Q&A (June 25, 2012)
April 2012 update
Preliminary Assessment of Radionuclide Exposure (2/17/2012)
February 1, 2012 update
Diseased Ice Seals
Marine Mammal Unusual Mortality Events
October 10, 2012 update
April 2013 update
Public Health Guidance
Radiation and Wild Foods Safety
Proceedings of the Arctic Pinniped Disease Investigation Workshop (2012)