(NaturalNews) A federal investigation into the mysterious and ongoing deaths of marine mammals all along the Pacific coast has ended, with investigators still dumbfounded as to the cause of this disturbing phenomenon. Throughout the past several years, seals and walruses have reportedly been turning up with skin lesions, breathing problems, extreme fatigue, hair loss, and various other symptoms for which experts say there is no identifiable cause.

The investigation began back in 2011, not long after the Fukushima disaster occurred in Japan. Record numbers of sick animals, many of which ended up dying, were showing up in California and as far north as Alaska, prompting an inquiry into the cause. Scientists from the National Oceanic and Atmospheric Association (NOAA) and the U.S. Fish and Wildlife Service (FWS) began studying the animals to look for clues that might point to a culprit.

At the time, more than 100 animals were found to be afflicted with the mystery disease, having mostly been discovered off Alaska's northern and western coasts. Ringed seals were among the most common creature identified, along with ice seals and others. Concentrated primarily in Alaska, the sick animals continued to turn up in waves for several years, with an estimated 200 to 300 seals found to have suffered from the condition.

"Part of the problem is we don't have a diagnostic test," stated Joel Garlich-Miller, a walrus biologist with FWS, to ADN.com. "We can't say, 'OK, this animal has the disease.'"

Sick animals still emerging along Pacific coast

With enough time, the sick animals would probably just stop appearing, some had hoped. But identifiable cases of the disease are still being observed today, though less frequently. And Pacific walruses, according to KNOM Radio Mission, have officially been removed from the unusual mortality event, which has yet to be explained.

"They could never identify what caused the lesions," claims Andrea Medeiros, an FWS spokesperson based out of anchorage.

According to the NOAA, the mystery disease is marked by unusual changes to the animals' internal organs, including accumulation of bloody fluid in the lungs and an enlarged heart. Many of the afflicted creatures also had damaged livers that crumbled easily and discharged blood. Other symptoms include systemic inflammation, enlarged lymph nodes, and tissue congestion.

Since massive plumes of radiation are believed to have passed over the area where the walruses and seals were living at the time of the Fukushima disaster, some are convinced that these and other symptoms clearly point to radiation poisoning. The timing and intensity of the phenomenon when it was discovered also point to Fukushima as the likely cause.

Both seals and walruses eat ocean fish as part of their diet, which further supports the notion that these animals may have consumed sea creatures tainted with Fukushima radiation, or perhaps come into direct contact with Fukushima radiation themselves. This would make sense, as radioactive fish have been detected on multiple occasions off the coast of California and elsewhere.

"It's not 'mysterious' to those who have been following Japan's nuclear crisis ... (and) can see the link between nuclear radiation and the illnesses seen in Pacific sea life," wrote one commenter at KNOM Radio Mission.

Sources for this article include:

http://alaskafisheries.noaa.gov

http://www.adn.com

http://www.knom.org

http://enenews.com

http://www.huffingtonpost.com