While researchers are still trying to figure out what is causing the illness in seals in the Bering, Chukchi and Beaufort Seas, researchers have found the cause of death for the Unusual Mortality Event declared in New England harbor seals. Just today it was announced that a type of bird flu – H3N8 – is responsible for the death of the more than 160 harbor seals on the East Coast. From September to December of last year, New England harbor seals displayed skin lesions and had severe pneumonia.
Raphaela Stimmelmayr is a research biologist for the North Slope Department of Wildlife Management and also the onsite coordinator for the Unusual Mortality Event on Ice Seals and Pacific Walrus in Alaska. She says the bird flu that killed the New England harbor seals is not what is killing seals in Alaska.
The UME seals on the Alaska side were actually tested for that early on to rule out that there was no relationship between the East Coast Unusual Mortality Event and the Alaska Unusual Mortality Event.
Stimmelmayr says she has worked closely with the investigative teams working on the New England harbor seal cases. She says while there are similarities between the illnesses – like skin lesions on the flippers – there are differences.
They did not show any of the facial lesions that we would be seeing or the lesions on the snout. These seals over there actually had fulminate pneumonia and that’s actually what we have not seen in our seals.
Stimmelmayr explains that diseased seals in Alaska did have bloody fluid in the lungs, but there was no indication of pneumonia.
So there was a clear difference between the pathological presentations, so how the organ changes are. And the only similarity that was there was that these animals also had flipper lesions on the East Coast, but did not have the type of hair loss and the other sores that we have been seeing in the ice seals.
Researchers are still trying to figure out the cause of illness in ice seals in Alaska. Stimmelmayr says they’re currently working on ruling out viruses and causes for the illness.
We don’t have a smoking gun right now. I think based on hunter observation, it is a new disease syndrome we are observing because based on traditional knowledge as well as communication from the hunters, they had never seen anything like this before.
And the researchers have NOT ruled out the radionuclide dispersed from the Fukushima nuclear accident as the cause. While a qualitative screening was done early on that told researchers that the diseased seals in Alaska were not carrying large loads of radio nuclides – it’s not enough to rule radiation out. Stimmelmayr says they are now looking at whether the diseased seals carried Cesium 134 and 137. Cesium 137 is and has been present in the environment throughout the world from nuclear testing done in the 1960s and 70s. Cesium 134 is the signature radionuclide that was released during the Fukushima accident.
We do not think at this point that it is related to that, but I think one truly has to wait until we have the quantitative numbers to be able to say ‘No, there is no trace in these animals.’ And then we can confidently can say there is no relationship.
Regarding the Unusual Mortality Event declared on Alaskan ice seals and Pacific Walrus, Stimmelmayr says they have not observed or seen new cases in Alaskan seals. As the UME onsite coordinator, she says they should be coming out with a regional update in mid August. Diseased seals in Alaska were first reported last summer.
The research for the New England UME on harbor seals was published in the journal mBio.