In this March 28, 2018, file photo, a North Atlantic right whale feeds on the surface of Cape Cod bay off the coast of Plymouth, Mass. Six of the endangered right whales died in the Gulf of St. Lawrence in June 2019, prompting scientists and conservationists to call for a swift response to protect the endangered species. Credit: Michael Dwyer | AP

For the past several years, including this one, endangered North Atlantic right whales appear to have been bypassing traditional feeding grounds off Maine’s coast, congregating instead off Canada in the Gulf of St. Lawrence, where some are dying.

Scientists are working hard to understand that shift, while lobstermen here in Maine say it shows the whales’ risk of entanglement in their gear is overblown.

For decades, the North Atlantic right whales’ annual migration took them from the Florida coast up past Maine and into the mouth of the Bay of Fundy, where, from midsummer to fall, they would feast together on massive plumes of tiny crustaceans.

But these days, the whales are showing up far from their usual haunts.

“It was only in 2014 that we began to hear stories that they were showing up there and that prompted us to do more surveillance up there and have found quite an aggregation up there,” said Amy Knowlton, a scientist with the New England Aquarium, just back from an 18-day cruise in Canada’s Gulf of St. Lawrence, among the right whales and the food they eat. “We documented 72 right whales. We had four mother-calf pairs, which was great. But we also had three entangled whales, which was very discouraging to the team. The whales were feeding and socializing and doing what right whales do.”

Eight whales have been found dead off Canada this summer, some from ship strikes or gear entanglement, and others of undetermined causes. Knowlton says this batch looks mostly quite healthy.

It could be thanks to the local abundance of their favorite crustacean cuisine, a fat-rich zooplankton called Calanus. Knowlton’s colleague on the trip, University of New Brunswick scientist Kimberley Davies, said that became clear when she dipped her sample net next to the whales.

“Calanus has kind of an orangey hue to it. And we’ll bring it on deck and we’ll put it through a sieve, and we’ll immediately be able to see all these orange grains of rice they look like,” she said.

It is not clear why it’s only in the past several years that so many whales have been observed feeding in the area, hundreds of miles away from traditional grounds in the Gulf of Maine, Davies said.

“Is the resource here particularly good, or is it just that there’s no food anywhere else? Certainly the evidence is suggesting there’s no food anywhere else,” she said.

Recently, more than a dozen scientists joined forces for a big data crunch on the question. They found that rapid spikes in deep-water temperatures and changing currents are disrupting the historic abundance of the whale’s staple food in the Gulf of Maine.

“We’ve lost these really regular year-to-year patterns that we had based a lot of our management on,” said Nick Record, a data analyst at Bigelow Labs who led the project.

Record said climate change is sending the forage species into a steep decline in some years.

“It’s almost like this back-and-forth between good years and bad years, and we’ve just had a lot of bad years recently. And it just makes it harder to know where and when whales might show up,” he said.

Some lobstermen and their political allies, though, are concluding that the research shows the whales just are not swimming near Maine any more.

“We’ve all talked about it,” said Rocky Alley, a Jonesport lobsterman and president of the Maine Lobstermen’s Union.

Alley spoke at a recent rally in Stonington, where hundreds of lobstermen signed a petition attesting that they had never seen a right whale. And he had joined members of the state’s congressional delegation for a private briefing on the latest whale-and-forage data, which they said bolstered their case against the federal proposal’s most onerous gear restrictions.

“We’ve all seen it, that the whales aren’t in Maine waters, and it’s because of food source. So I’m glad that [it was] described and shown to our delegation. They understand, now, the issue,” Alley said.

But Record says the advocacy is getting ahead of the data.

“Our politicians have been sort of using this research to say there’s no risk anymore, and we should leave the Maine coastal fishery out of that. And that’s not what the paper is actually saying,” he said.

Record cautions that climate change isn’t smooth. It can push ecosystems abruptly into new states — shifts that may just as quickly revert to the historical norm or make a fast jump to an even more novel situation.

And even if the whales make some sort of lasting move to feeding grounds farther from Maine’s coast, with a species that’s so close to the point of no return, it still may not matter.

“The risk of a right whale coming into the inshore waters of Maine is very, very low,” said Carla Guenther, senior scientist at the Maine Center for Coastal Studies.

But she adds that once in the underwater forest of rope lines rising from Maine’s lobster traps, one wandering whale’s risk of injury is still very, very high.

“That one whale’s chance of … getting entangled is 100 percent. So with a population of 400, can you risk that one errant whale that’s hungry, trying to adapt to its new context coming into where there’s such a density of gear,” she said.

This fall, federal, state and independent scientists plan to get better data on whale activity near Maine — they will sink a set of eight acoustic monitors up and down the state’s coast, listening for the calls of the roughly 400 endangered North Atlantic right whales left on the planet.

This article appears through a media partnership with Maine Public.