Marine scientists had an unexpected sighting earlier this week — a large number North Atlantic right whales near Jeffreys Ledge off the southern Maine and New Hampshire coasts.
Research scientist Orla O'Brien, who leads aerial surveys for the New England Aquarium, said observers spotted at least 75 whales over the course of a two-day survey.
"[And that] is a huge number, not just for this area, but really for anywhere," she said. "It's about one-fifth of the population."
It is unusual to see so many right whales off the Maine coast, especially this time of year, O'Brien said. But she notes that large aggregations have been spotted in several unexpected places over the last 12 months, including a large group seen south of Long Island this summer.
The unexpected aggregations are likely a response to a changing currents and a warming Gulf of Maine, O'Brien added.
"What we have been seeing is that things are dynamic, and the whales will pop up, basically, wherever's there's food," she said. "And we need to figure out a way to be able to be better prepared for that."
O'Brien said most whales were feeding and taking long dives below the surface for food. Photos from the survey showed some individuals with mud on their jaws, a sign that right whales were feeding near the sea floor.
Jeffreys Ledge is a heavily fished area. And federal officials have asked mariners traveling through over the next two weeks to slow their speeds to 10 knots to avoid entangling or colliding with the whales as they feed.
The voluntary warning from the National Oceanic and Atmospheric Administration came on the same day that the Biden administration announced it will drop an effort to require seasonal speed limits in specific circumstances.
Vessel strikes and entanglement with fishing gear are the leading causes of death and injury to right whales.
