Right whale population rebounded in recent years, but was tested by tough 2024

Endangered North Atlantic right whales, such as the one pictured here with her calf in the documentary 'Last of the Right Whales,' have become somewhat more numerous over the last few years.  (Last of the Right Whales - image credit)
Endangered North Atlantic right whales, such as the one pictured here with her calf in the documentary 'Last of the Right Whales,' have become somewhat more numerous over the last few years. (Last of the Right Whales - image credit)

The estimated population of North Atlantic right whales is gradually growing, biologists say, but this year proved deadly for some members of the endangered species.

"After about seven years of free fall, numbers declining, that [growth] is really good news," said Philip Hamilton, a senior scientist at the New England Aquarium.

Because the population was quite small to begin with, the increase represents "just a few animals," Hamilton told CBC's Island Morning.

In 2020, the number of right whales hit an all-time low of 358. Last year, 372 whales were counted.

"It's tenuous. It's tentative," Hamilton said. "The really good news is that it's not a free fall."

He said it's too early to tell whether the recent growth represents a trend, but his optimism has been tempered by a "really, really bad" year for the whales in 2024.

In this Wednesday March 28, 2018 photo, a North Atlantic right whale feeds on the surface of Cape Cod Bay off the coast of Plymouth, Mass. A study of vessel speeds in the Cabot Strait shows that two-thirds are not complying with a voluntary speed restriction meant to protect critically endangered North Atlantic right whales that migrate through the area.

In this photo from March 2018, a North Atlantic right whale feeds off the coast of Plymouth, Mass. (Michael Dwyer/The Canadian Press/The Associated Press)

Although more calves than usual were born this year, Hamilton said nine whale mortalities and at least 13 human-caused injuries could reverse some of the recent gains.

"It really has been a roller-coaster ride," Hamilton said.

To have 20 calves born was really exciting. To see them slowly, one after another, die... It's hard to witness. — Philip Hamilton, New England Aquarium

"To have 20 calves born was really exciting. To see them slowly, one after another, die… It's hard to witness."

Most of the mortality took place in the Atlantic Ocean off the United States, Hamilton said. Just one whale carcass was found in Canadian waters.

Despite that, he said he'd like to see stronger preventive measures — such as vessel speed restrictions and more fishing regulations — on both sides of the border.

"It's not pointing fingers. I just look at the whales," he said. "In the Gulf of St. Lawrence, there are lots of protective measures, but eight whales were detected entangled there."

Federal protocols require P.E.I. fishing crews to move their gear out of all but the shallowest water in the event of a right whale sighting in an area.

A free Halifax-based gear-lending program called CanFish is one option P.E.I. fishers have turned to in order to switch from traditional traps to "ropeless gear" following a whale sighting.

Ropeless gear eliminates the vertical buoy line in the water column that can entangle whales, allowing harvesters to keep fishing when a closure is announced.

Hamilton considers ropeless gear to be a promising technology, but said a lot more has to fall into place before it and other interventions can be truly effective.

"You just have to look at the whales to say, sadly, it's not enough," he said.