PENOBSCOT BAY, Maine — In an effort to get a better understanding of the harbor seal population in the Northeast, federal officials have started work on the first significant survey of the pinnipeds’ population since 2001.
Earlier this month, scientists with the National Oceanic and Atmospheric Administration tagged 12 harbor seals in Penobscot Bay, near Rockland. In late March, they tagged 17 harbor seals off Chatham, Mass. The data they get from tracking the tagged seals will be used to supplement data they collect from aerial surveys planned for late May and early June, officials with the agency indicated last week.
The last time a significant survey of the regional harbor seal populations was conducted, 11 years ago, scientists estimated that there were 100,000 seals living along the Northeast coast, roughly from Maine to New Jersey. No similar surveys have been conducted since, and federal scientists have made no official attempt to estimate the number of harbor seals in the region by any other means.
“Currently, we have no estimate that we report,” Gordon Waring, marine mammal biologist of NOAA’s Northeast Fisheries Science Center in Gloucester, Mass., said April 24.
But as they have been looking for seals, federal officials have found something unusual. Some female seals are giving birth earlier than normal, which has resulted in officials and researchers getting early reports of pup sightings.
Seals typically give birth in May and June, but this year some pups have been sighted in March. Scientists say they are not sure why pups are being born early.
“We do know seals can have pups early,” Waring said. “We’re not certain what contributed to that this year.”
NOAA has received three reports of early pups this year, he said — one in Plymouth, Mass., another in Gloucester, and a third in Wells, Maine. Two appeared to have been born prematurely but nonetheless were surviving, while the third appeared to be nearly full-term.
Scientists continue to look into a suspected flu outbreak last fall that killed more than 160 harbor seals along the New England coast.
Mendy Garron, Northeast stranding network coordinator for NOAA, said last week that scientists have found no links between the flu deaths last fall and the early births this spring.
“We are continuing our investigation [into the seal deaths],” Garron said. “At this time, we don’t think there is any correlation.”
As for the ongoing survey effort, Waring said the data collected from the tags will give researchers a sense of how many harbor seals might be in the water, and therefore not visible, when scientists fly along the coast and try to determine how many they can see. The tags will fall off the seals when they molt, he said, which usually happens each year by mid-July.
Rosemary Seton, marine mammal stranding coordinator for Allied Whale in Bar Harbor, said Friday that the earliest in any calendar year that the group has received a report of a stranded seal was on April 9, 2011. She said that reports of possibly abandoned seal pups typically start being made closer to late May.
“It gets busy,” Seton said. “We always joke that, as you have death and taxes, you get pups on Memorial Day weekend.”
The group has received only one call so far this winter about a seal, which turned out to be dead, according to Seton. The animal, which was on a beach on Lincolnville, was a premature pup with a fractured skull. Officials are not sure how the fracture occurred or whether it was a factor in the pup’s death, she said.
Seton said the group, which is closely affiliated with College of the Atlantic in Bar Harbor, responds to dozens of seal stranding calls each spring. Most of the calls are for pups found by themselves along the shore. She said the group helps animals that may be ill or injured or pups that have been separated too long from their mothers and need help to survive.
Seton said that, as cute and helpless as they may seem, it is important not to disturb seal pups found along the shore. Mother seals leave pups on the shore when they go out to find food and will not return to their pups if there are people nearby, she said.
Unlike whales, dolphins or porpoises, seals do not need to be wet, Seton said, and they can carry diseases harmful to humans or pets. For this reason, people should keep themselves and their pets away from seals, she said, which are federally protected animals.
“Ideally, they should be left where they are,” she said.
NOAA officials said that anyone who spots a possibly stranded seal should call NOAA’s stranding hotline at 866-755-6622. Anyone who witnesses people or pets moving or otherwise disturbing a beached seal should call the agency’s enforcement hotline at 800-853-1964.
Follow BDN reporter Bill Trotter on Twitter at @billtrotter.