Scientists Investigate Spike in New England Seal Pup Deaths

The appearance of more than five dozen dead harbor seal pups along the New England coastline in the past two weeks has sent scientists into labs across the country to determine what is causing the sudden increase in mortality. As of the morning of October 7, the bodies of sixty-six juvenile harbor seals had washed up on the shore between Yarmouth, Maine, and Plymouth, Massachusetts.

Necropsies performed by the New England Aquarium in Boston determined that the seals had not died of starvation and had no signs of trauma, said Allison McHale, a spokesperson for the National Oceanic and Atmospheric Administration’s Northeast Regional Office in Gloucester, Massachusetts. McHale said that the aquarium’s scientists have sent carcasses to laboratories for toxicology tests to help determine what is causing the spike in seal pup deaths.

“A 30 percent mortality rate is normal on juveniles, so this is definitely an unusual event,” McHale said. “There was one adult, but all the rest have been juvenile harbor seal pups.” She said fishermen, beach-walkers, and others — including McHale’s own husband — have been discovering the seal carcasses over the past two weeks. “Once people find them, we’re telling them to call the reporting hotline at the New England Aquarium,” she said.

The Marine Mammal Stranding Agency hotline is 617-973-5247.

McHale said no connection had been made between the seal deaths and the body of a tuna that washed up in Hampton, New Hampshire, on October 4. Officials did not send the body of that fish, an eight-foot-long Bluefin with no obvious signs of trauma, out for a necropsy, McHale said. “It’s not that unusual,” she said. “Last year we had a large porbeagle wash up here near Gloucester, so it does happen in the large pelagic group.”