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Radiation investigated as possible cause of Alaska ringed-seal deaths

Alex DeMarban
Photo courtesy North Slope Borough Department of Wildlife Management

The University of Alaska Fairbanks' Institute of Marine Sciences is launching an investigation into whether radiation, including possibly from the Fukoshima Daiichi nuclear power-plant disaster in Japan, has harmed or killed more than 100 ringed seals off Alaska's coasts.

More than 60 dead and 75 diseased seals have shown up mostly on Alaska's Arctic beaches since this July, with symptoms that include oozing skin sores, patchy hair loss and damaged organs, prompting a wide-ranging investigation into the mysterious cause of their illness.

Scientists are considering several possible causes. But much of the effort has been geared toward finding the bacteria or virus that's causing the apparently unprecedented symptoms, with labs nationally and in other countries examining tissue from ringed seals and Alaska walrus, which appear to be suffering the same affliction.

The National Oceanic and Atmospheric Administration recently declared the ringed-seal deaths an unusual mortality event, a decision that should free up federal funds and more expertise to help with the analysis.  

It's not unusual for investigations into wildlife-deaths to continue for this long without an answer, said Terri Rowles, coordinator for National Marine Mammal Health and Stranding Response Program.

The work so far has yielded at least one important clue: "Tests indicate a virus is not the cause," said a recent press release from NOAA and the U.S. Fish and Wildlife Service.

Some wonder if radiation could be causing the skin sores and related problems, including ulcers on internal organs and abnormal growths on brains.

John Kelley, with the Institute of Marine Sciences at UAF, said he's just received a large batch of tissue from afflicted ringed seals and will soon begin the university's hunt for radiation as a possible cause.

"The tissues just came down from Barrow," he said on Friday. "They sent a large quantity through (state) public health in Anchorage. It's quite a job. We have to freeze dry it, grind it, analyze it. This will take some time."

The work will begin over the holidays, he said.

He believes it's unlikely that Fukoshima had anything to do with the seals' deaths, given that levels of detected radiation are quite low around Alaska, both in the air and water.

Is it possible that the ringed seals traveled to a contaminated area? They do, after all, have quite a range. Experts could not be reached the Friday before Christmas to explain migratory routes for Alaska's estimated stock of 250,000 ringed seals.

Or did they eat prey contaminated by radiation? If there is a link to Fukoshima, the lab will find it, said Kelley.

They'll be testing for radionuclide Cs-134 and Cs-137.

"This will give us or not give us a fingerprint that is out there," he said. "If Fukoshima is there, this should give us some indication."

Contact Alex DeMarban at alex(at)alaskadispatch.com