Researchers have found four seal pups born earlier than normal during the first comprehensive count of the seal population in a decade.
Three of the seals found during the capture and tagging program off Penobscot Bay in Maine and Chatham Harbor and Jeremy Point in Massachusetts that began last month appeared to be small, prematurely born pups, while one appeared to a healthy, full-term pup that was born early.
Harbor seals spend the winter in Long Island Sound and travel back to northern New England to mate and birth in May and June.
The reason for the early births is unclear, said Gordon Waring, head of the seal research program at the Woods Hole Laboratory of the National Oceanic and Atmospheric Administration’s Northeast Fisheries Science center.
In a telephone news conference Tuesday, Waring said he and a team of researchers have thus far radio-tagged 12 seals in Maine and 17 in Massachusetts. Before release, the animals also are measured, weighed and samples of blood, fur and other body fluids taken for genetic testing and health assessments. Up to 60 animals will be tagged.
The radio tags will help the team locate the seals when they begin aerial and photographic surveys in May. The tagging work will help researchers develop more accurate estimates of population and distribution, Waring said.
“We don’t know how many harbor seals there are in New England because most seal surveys focus on one specific area or location, but we do know that seal populations have grown in size during the last few decades,” he said.
A count conducted in 2001 estimated the New England population at 100,000, but that is no longer considered accurate.
Both harbor seals and gray seals — the two most common types in New England — will be counted by researchers.
Waring could not provide an estimate for the winter population in Long Island Sound, where seals can sometimes be seen hauled out on offshore rocky islands or beaches. Seals from northern New England migrate to offshore areas of New Jersey, New York, Rhode Island and Connecticut during the colder months.
“It’s one population that disperses over late autumn and winter,” he said.
The survey work is also important in light of the seal strandings and approximately 150 seal deaths that took place in Maine, New Hampshire and Massachusetts last fall, said Mendy Garron, marine mammal stranding coordinator for NOAA. Research into that phenomenon is ongoing, she said.
© 2012 The Day
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