Seal numbers in Narragansett Bay reached a record high in March when an informal survey conducted by volunteers from Save the Bay, the Environmental Protection Agency and the Narragansett BayNational Estuarine Research Reserve tallied 603 seals at 26 sites. The previous record of 569 seals was set in 2011.
Seals were observed in all parts of the bay, including a single animal hauled out on a rock just off Fields Point in Providence and 101 seals counted at Brenton Point in Newport. Participants also counted large numbers of seals at Rome Point, Coddington Cove, Prudence Island and Hope Island, each of which had more than three dozen seals in the vicinity.“High numbers of observed seals in the water are a strong indicator of a hospitable environment and a healthy ecosystem that provides sufficient food and other needs for marine life,” said Eric Pfirrmann, the captain of the boat used by Save the Bay to count seals. “We can attribute a strong seal population here to both a healthier bay and the Marine Mammal Protection Act of 1972, which made it illegal to kill, take or harass marine mammals.”
The seal survey has been conducted annually since 1994, though ice and poor weather forced the cancellation of last year’s survey. Almost all of the animals counted were harbor seals, which have been proposed to be designated as the state marine mammal of Rhode Island. A small number of gray seals were also seen.
Pfirrmann said that despite the record number of seals in the bay this year, seal numbers have remained somewhat consistent in recent years.
“Seal populations fluctuate from year to year, just as environmental conditions fluctuate,” said Pfirrmann. “I feel the seal population has been relatively stable for some time now, and that the bay is probably at carrying capacity for harbor seals.”
According to Robert Kenney, a marine mammal expert at the University of Rhode Island’s Graduate School of Oceanography, harbor seals begin to arrive in Narragansett Bay in September, reach a peak in March, and depart by the end of April. They all migrate north to the coast of Maine and the Canadian Maritimes to breed, though a small number give birth on the Isles of Shoals in New Hampshire and in Manomet, Massachusetts.
Despite the record number of seals observed in Narragansett Bay this year, Kenney said scientists suspect that the New England harbor seal population may be declining.
“Stock assessment surveys hint that numbers are down from their peak, maybe because they’re being pushed around by the larger gray seals, which are growing like crazy,” Kenney said. Large numbers of gray seals breed at Monomoy National Wildlife Refuge on Cape Cod.
Seals were quite rare in Rhode Island waters prior to passage of the Marine Mammal Protection Act. The peak number of seals observed at any one place in Narragansett Bay in the 1960s was 12 at Rome Point. At that time, Massachusetts and Maine paid a bounty of $5 for every seal killed, because the animals were thought to be negatively affecting the region’s commercial fishing industry.
“I remember hearing stories of people who would go out on motorboats to shoot seals for fun,” said Kenney.
Despite the seemingly healthy population of seals in Narragansett Bay today, little is known about their ecology during the six months they spend in Rhode Island waters. Kenney said it is unknown what they eat while they are in the state, so it’s impossible to determine whether there is enough food to sustain them or whether the population can continue to grow.
One thing is certain, however. The harbor seal population that winters in southern New England has been spreading out in recent years, Kenney said. Rather than being confined to Narragansett Bay, eastern Long Island and eastern Connecticut, they are now found as far south as New Jersey.
“We really don’t know what component of the population comes down this far,” Kenney said. “There has always been some suspicion that harbor seals in our area tend to be younger animals. Maybe the younger ones have a harder time coping with the really cold water to the north.”
People interested in observing seals should be careful not to disturb them.
“Anything that’s going to spook them off the rocks is harmful to the seals because it makes them waste precious energy,” said July Lewis, the volunteer manager at Save the Bay who organized the seal survey. “So be careful not to let dogs bark at them. And if you’re approaching them in a kayak or other boat, go parallel to the rocks so it doesn’t look like you’re going straight at them, which they interpret as an attack.”
“Even if you think you’re at a safe distance,” she added, “if you see them stretching their necks or moving around, you’re too close.”
This article first appeared on EcoRI.org on April 6, 2016.