BOSTON — The ocean waters off southern New England continue to see high North Atlantic right whale activity, with the New England Aquarium documenting over a quarter of the population in the last six weeks.
Scientists in the aquarium’s Anderson Cabot Center for Ocean Life regularly conduct aerial surveys south of Martha’s Vineyard and Nantucket to collect data on whales, dolphins, turtles, and other marine species. The team flew six surveys in this area between Feb. 5 and March 18 and photographed over 115 unique right whales during that period, collaborating with another aerial survey team at the NOAA Northeast Fisheries Science Center to document the aggregation.
Right whales can be individually identified through unique markings on their heads called callosities, which are visible in the photographs researchers capture and match to images in the North Atlantic Right Whale Catalog.
On the March 2 survey flight alone, observers sighted over 70 right whales, marking the highest number of individual right whales the New England Aquarium has photographed in a single day since it began survey flights here in 2011. The scientists noted that the whales were likely feeding deep below the surface, which indicates that food may be abundant south of Massachusetts, especially in the Nantucket Shoals area.
“Seeing this many right whales in one area has been incredibly exciting for our team and marks one of the busiest seasons we’ve ever had,” said Katherine McKenna, an associate scientist on the aerial survey team. “Our recent surveys highlight the Nantucket Shoals as an important habitat for a significant portion of the population.”
Most of the documented right whales are adults, which is typical for this time of year in southern New England. Of the 31 adult females seen, 17 are known to be calving females. Among them was Calvin, a 34-year-old female who the aquarium sighted last year in the same survey area. Calvin illustrates the resiliency of this critically endangered species: She was orphaned as an 8-month-old calf, has endured eight entanglements in fishing gear, and has given birth to four calves of her own.
Another notable whale seen this past month is “the Irish whale” who made headlines in 2025. This right whale, who hasn’t yet been entered into the North Atlantic Right Whale Catalog, was first sighted in Ireland in 2024 and then again in Cape Cod Bay last year. The most recent sighting marks just one of the few times researchers have ever documented it.
The winter/spring season is the peak time of year for right whale sightings in southern New England waters.
“We have seen right whales in southern New England waters year after year, and they are extremely vulnerable to fishing gear entanglements and vessel strikes,” said Orla O’Brien, research scientist in the aquarium’s Anderson Cabot Center who leads the aerial surveys. “This area has seasonal fishing restrictions in place, yet right whales still face risks from vessel strikes without mandatory speed restrictions to protect them.”
The aquarium’s February aerial surveys triggered a dynamic management area (DMA) or voluntary slow zone, which urges mariners to slow down to 10 knots or less to prevent collisions with whales, and repeated sightings have extended the DMA. The latest DMA is in effect until March 27, one of several active voluntary slow zones from Massachusetts to Maryland due to right whale sightings. Alongside entanglement in fishing gear, vessel strikes are one of the leading causes of injuries and deaths for this species, which numbers about 380 individuals, making it critical that vessels slow down to the recommended speed.