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 around the nose and eyes and patchy hair loss on the animals' fur coats.
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.
"We recently received samples of seal tissue from diseased animals captured near St Lawrence Island with a request to examine the material for radioactivity," said John Kelley, Professor Emeritus at the Institute of Marine Science at the University of Alaska Fairbanks.
"There is concern expressed by some members of the local communities that there may be some relationship to the Fukushima nuclear reactor's damage," he said.
The results of the tests would not be available for "several weeks," Kelley said.
Water tests have not picked up any evidence of elevated radiation in US 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 US Fish and Wildlife Service have been seeking the cause of the diseased seals for weeks, but have so far found no answers.