A pair of North Atlantic right whales interact in Cape Cod Bay off Massachusetts in March. Robert F. Bukaty/Associated Press

The decline of the North Atlantic right whale could be slowing based on a new population estimate, but scientists warn that a leveling off of the whales’ overall number does not mean this critically endangered species is rebounding.

The 2022 population estimate released Monday at the North Atlantic Right Whale Consortium in Halifax, Nova Scotia, puts the number of right whales at 356. That is eight fewer than the year before, but within the overall margin of error for the count and the same as the 2020 estimate.

Scientists consider the three-year stabilization to be a flattening out of the population.

“They seem to be hovering around that 350-ish number,” said Heather Pettis, a research scientist at New England Aquarium’s Anderson Cabot Center for Ocean Life. “The decline appears to be settling out. That’s better than a free-fall decline, but it’s still not a good picture for right whales.”

The trajectory of such a small population can change very quickly, Pettis said. It only takes one year of high mortality or low calving – such as occurred in 2018, when the population declined by almost 10% – to put the species on the fast track to functional extinction, Pettis said.

Last year’s count could be off by as many as 10 whales due to the improbability of cataloging every whale in any given year, scientists say. Past estimates are recalculated each year to factor in uncataloged calves or the reappearance of whales that had previously been marked dead.

For example, last year the consortium estimated the 2021 population to be about 340. Now, after cataloging all of the 18 calves born last year, consortium scientists have recalculated the 2021 count to be about 364. The annual estimate can change significantly in the first two years after the count is made.

The count was unveiled Monday by the North Atlantic Right Whale Consortium at the start of its three-day annual meeting. The estimates are a collaboration between the New England Aquarium and the National Oceanic and Atmospheric Administration.

Nearly 500 people are registered to attend the consortium meeting, where scientists and regulators report on right whale deaths, entanglements and vessel strikes, as well as advances in ropeless fishing gear. In early 2024, the consortium will issue a comprehensive report on the species’ status.

In the past, the consortium has called on the U.S. and Canada to take steps to limit whale deaths and injuries from vessel strikes and fishing gear entanglement by enacting and enforcing marine speed limits and reducing surface-to-seabed fishing ropes in places where whales gather.

Representatives of the shipping and fishing industries had not yet seen the report to comment on the apparent population stabilization, and what that might mean for NOAA’s pending vessel speed limits or consideration of fishing gear restrictions and seasonal fishing bans.

According to consortium data, two right whales are known to have died in 2023, including a 20-year-old male killed by a ship strike and an orphaned newborn calf. Those are the known whale deaths, but scientists note that about two-thirds of right whale deaths go undetected.

Consortium records show the population has lost an average of 12 whales a year over the last decade. But numbers can vary widely from year to year, from as few as four in 2014 to as many as 42 in 2018, when right whales abandoned the Bay of Fundy feeding grounds for the Gulf of St. Lawrence.

Ship strikes and fishing gear entanglements also caused 32 human-caused injuries that could eventually lead to a whale’s death or leave them in a condition that is unfit for reproducing, said Philip Hamilton, a senior scientist at the Anderson Cabot Center.

According to the 2023 data, vessel strikes injured two whales, and fishing gear caused 30 entanglement injuries. Only six of the whales injured by entanglement still had gear attached. Of those, five trace back to Canadian lobster or crab fisheries.

The sixth, a 4-year-old female, hasn’t been spotted since January, Pettis said, when an aerial team from the Clearwater Marine Aquarium saw it off the coast of North Carolina severely entangled in an unidentifiable kind of fishing gear.

“This is an important piece of the right whale puzzle,” said Hamilton, who runs the consortium’s whale identification database. “We can’t just focus on (detected) bodies. We must also reduce all injuries that harm this species if they are to turn the corner.”

LOBSTER INDUSTRY ENCOURAGED

The Maine fishing industry, especially the state’s $1.5 billion lobster powerhouse, has asserted that it already has taken significant steps over the last 20 years to modify fishing methods to protect right whales. No right whale death has ever been linked to Maine lobstering gear.

“The (Maine Lobsterman’s Association) is encouraged by the right whale population numbers, which are consistent with our position that worst-case analyses do not paint an accurate picture of either the status of the population or the nature and magnitude of the potential threats to right whales, said Patrice McCarron, the association’s policy director. “We need good, objective science for effective management of both the right whale population and the lobster fishery.”

Scientists note that no rope is found on most whales killed or injured by fishing gear entanglement.

The federal government had devised a 10-year plan to reduce the risk of fishing gear entanglement, but a federal circuit court judge ruled in June that NOAA’s whale protection plan and the rules put in place to achieve it were based on “pessimistic assumptions.”

The ruling was a victory for the state’s lobster industry and a disappointment to whale advocates.

The industry is now facing new fishing restrictions not because of the right whale, but because new surveys are showing a 39% decline in the population of young lobsters in the Gulf of Maine and Georges Bank, some of the most critical fishing waters off New England.

Pettis applauded the lobster industry’s willingness to implement gear modifications in the past and acknowledged that ropeless fishing gear still has a long way to go before it can be adopted across the region. But entanglement remains a leading cause of death for this species, she said.

ADDITIONAL MEASURES NEEDED, WHALE RESEARCHERS SAY

Additional measures are needed to prevent the entanglements and vessel strikes that still threaten the survival of the species, including vessel speed restrictions and financial support and training for fishermen to adopt ropeless fishing as it becomes available, the consortium said.

“While the absolute population numbers are important, other indicators are discouraging,” consortium Chairman Scott Kraus said. “Until we implement strategies that eliminate injuries and deaths, and promote right whale health, this species will continue to struggle.”

Calving numbers continue to be lower than in past years. Only 11 calves were born during the past calving season, which runs from December through March, compared to 18 in 2021 and 15 in 2022. The average annual birth rate in the 2000s averaged around 24, Hamilton said.

Scientists are especially worried about whales not calving; there was only one new mother in the last calving season. In the past, the average age of a first-time mother was 10 years old. Data now shows that 77% of female right whales under the age of 20 have never calved at all.