Scientists in Alaska are investigating whether local seals are being sickened by radiation from Japan's crippled Fukushima nuclear plant.
Scores of ring seals have washed up on Alaska's Arctic coastline since July, suffering or killed by a mysterious disease marked by bleeding lesions on the hind flippers, irritated skin and fur loss.
Biologists at first thought the seals were suffering from a virus, but they have so far been unable to identify one, and tests are now underway to find out if radiation is a factor.
Water tests have not picked up any evidence of elevated radiation in U.S. Pacific waters since the March earthquake and tsunami in Japan, which caused multiple fuel meltdowns at the Fukushima plant and forced tens of thousands of people to evacuate the surrounding area.
Scientists from the National Oceanic and Atmospheric Administration and the U.S. Fish and Wildlife Service have been seeking the cause of the diseased seals for weeks, but have so far found no answers.