Seal Strandings in Maine Linked to Bird Flu

Four stranded pinnipeds tested positive for the avian influenza H5N1

Seals sitting on a rock
Seals in Bar Harbor, Maine Paolo Picciotto / REDA&CO / Universal Images Group via Getty Images

The National Oceanic and Atmospheric Administration (NOAA) has connected an elevated number of seal strandings this summer in Maine to the avian flu, per a statement from the administration. 

Ninety-two seals were reported stranded in Maine from May 10 to July 4, and the rate of dead seals from strandings is three times what’s normally seen by this point in the year, per NOAA. 

"While marine mammal strandings frequently occur, there are some cases, such as this one, where an unusually high number of live or dead animals may come ashore in a short period of time in the same geographic area," says Ainsley Smith, regional marine mammal stranding coordinator with NOAA Fisheries, per Sean Stackhouse from News Center Maine.

Samples from eight seals were sent to Tufts University for testing, and four tested positive for H5N1, the avian influenza currently circulating in wild and domestic birds. The flu has also infected foxes, bobcats, skunks, otters and other mammals, including two humans. 

“The seal is the first marine mammal that we’ve seen on the spillover end,” Dr. Julianna Lenoch, a national wildlife disease program coordinator for the U.S. Department of Agriculture, said at a news briefing on Wednesday, per the New York TimesEmily Anthes. “But this is not unexpected to have bird flu move into mammalian species on occasion.”

Bird flus in the past have tended to die out in the summer and return in the fall, per the Times, but whether this strain will do the same is unknown. 

“This particular avian influenza is acting a little bit different, so we’re going to remain on high alert,” Lenoch tells the newspaper. 

Meanwhile, millions of birds in the U.S. have either died or been culled because of the disease. Zoos across the country have moved their birds indoors to prevent contact with wild birds. Seabird deaths in the U.K. have risen so high that several parks have closed to visitors . 

"This is substantially different than the outbreak we experienced in 2015, with more species, bigger numbers, more substantial mortality and this tremendously larger geographic footprint," Bryan Richards from the USGS National Wildlife Health Center tells Patty Wight of Maine Public. "So essentially, there's a lot more virus out there in the environment this time around."

NOAA states that the risk to the general public remains low, but recommends both humans and pets stay at least 150 feet away from live and dead seals. 

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