Scientists Are Closer To Understanding Why Maine Is Seeing Such High Numbers Of Sick and Dead Seals

Aug 24, 2018

More than 180 seals have washed onto Maine beaches this month, and most of them have died. Marine mammal rescuers have been scrambling to respond and have been testing the animals to determine the cause. Thursday, federal scientists announced possible clues that could help determine what is causing these deaths.

For nearly two weeks, rescuers have been working nearly non-stop along the shores of southern Maine. Some beaches see as many as a dozen seals in one day, others see just one or two.

On this day, it’s a male seal that was found on the rocks near Nubble Lighthouse in York.

Kat King of Marine Mammals of Maine says the seal looks emaciated, and he is missing some fur.

“He’s got a lot of really peculiar looking wounds, which we’re not quite sure where they came from,” says King. “They kind of stand out to me as – that’s more than just being battered around on a rock, possibly.”

Unlike this seal, most of the animals found dead have looked otherwise healthy. Adding to the mystery is the fact that the deaths have hit all age groups. And the problem extends beyond Maine.

A dead seal was taken from these rocks near Nubble Lighthouse in York.
Credit Patty Wight / Maine Public

“Especially in August, starting around the 12th, we’ve seen an increase in seal strandings along both the New Hampshire and the northern Mass, coast,” says Sarah Perez, a rescue assistant with the New Hampshire Seacoast Science Center.

At this time of year, Perez typically responds to about 15 seal strandings per month. So far this August, those numbers have nearly quadrupled.

"Another difference is that we're getting what we call ‘clusters,’” she says. “And so we're getting deceased seals that are washing up – a number of them – on one specific beach."

The Seacoast Science Center, like Marine Mammals of Maine, has been sending samples to labs to try to get to the bottom of what’s going on. Scientists at the National Oceanic and Atmospheric Administration (NOAA) have also been investigating, and on Thursday they announced the first clues.

"We've gotten results back that are positive for either avian influenza or what we call ‘phocine distemper virus,’" says Jennifer Goebel, a spokesperson for NOAA.

Avian flu and distemper have been linked to past seal mortality events. Goebel says it's too early to tell whether the diseases are the primary cause of this year's spike in deaths and says that testing will continue.

At the Marine Mammals of Maine triage center in Harpswell, a sick seal that was found on a beach when the spike first started is fed herring for breakfast.

At the Marine Mammals of Maine triage center in Harpswell, a sick seal that was found on a beach when the spike first started will get herring for breakfast.
Credit Patty Wight / Maine Public

Executive Director Lynda Doughty says this seal is lucky. The triage center has stopped taking in any more sick animals, to prevent spreading infections to other seals that are under the center’s care. But Doughty's team – a staff of two, a few interns and 30 volunteers – will continue to respond to reports of dead seals and gather samples to try to find answers.

"So is this one of those ways that the population regulates itself – which could well be,” says Doughty.

Even if the deaths are a normal population event, Doughty says seals are bioindicators. Understanding what's happening to them can shed light on what's happening in the ocean and its broader implications for other species.

Originally published August 24, 2018 11:13 a.m.