An endangered North Atlantic right whale entangled in fishing rope is sighted on Dec. 2, 2021, with a newborn calf in waters near Cumberland Island, Ga. Georgia Department of Natural Resources/NOAA Permit via Associated Press

The number of whales entangled in fishing gear has declined recently, but the entanglements remain a critical threat to rare species, the federal government said in a report released Tuesday.

There were 53 confirmed cases of large whales entangled in gear in the U.S. in 2020, the National Oceanic and Atmospheric Administration said Tuesday. That was a 25 percent decline from the previous year and a lower figure than the 13-year average, the agency said.

Entanglement in fishing gear is one of the two biggest threats to declining species of whales, particularly endangered North Atlantic right whales, which number less than 340 in the world. The other threat is collisions with ships.

More than half the entangled whales counted in the NOAA report were humpback whales, which are popular with whale watchers and have a relatively stable worldwide population. However, four of the whales were North Atlantic right whales, which are in the midst of population decline due to recent years of high mortality and poor reproduction.

Every coastal region except Alaska saw a decrease in whale entanglements, NOAA said. The agency said it will take more research to determine the cause of the decline in entanglements, and it’s possible that the COVID-19 pandemic’s disruption of both fishing activities and data reporting could have played a role.

It’s also possible that factors unrelated to the pandemic could have played a role, as “some regions have reported large-scale environmental changes, like marine heat waves, that may also be affecting large whale entanglement rates and reporting,” the agency said in the report.

Maine fishermen had mixed feelings about the report’s assessment of reduced whale entanglements.

“It’s good news, but it doesn’t change anything about what NOAA is trying to do to us,” said Kristan Porter, a Cutler lobsterman and scalloper who is president of the Maine Lobstermen’s Association.

Maine lobstermen are concerned about the latest round of federal fishing gear regulations, which are the first phase of a 10-year plan to reduce the risk of whale entanglements by 98 percent. The newest regulations took effect May 1, but their enforcement has been delayed until supply chain issues for some required gear are resolved.

The regulations require lobstermen to splice NOAA-approved weak rope or weak plastic links into the lines they use to connect buoys to traps on the ocean floor. But the approved gear has been in short supply as manufacturers struggle to produce enough to outfit the Northeast lobster and Jonah crab fishing fleets. The regulations are intended to prevent whales from becoming entangled in fishing gear, which can result in injuries and death.

The association is suing the federal government, claiming the new regulations are based on flawed science and will not help the whales. It argues that right whales are not using the area of the Gulf of Maine where lobstermen fish and would be better protected by addressing their other threats. Regulators counter that the whales continue to travel through Maine waters and that the changes are necessary to protect the species from extinction.

Dustin Delano, a Friendship lobsterman who is the association’s second vice president, said it has been challenging, costly and time consuming to redesign fishing gear each year to meet NOAA’s changing regulations. Weak rope he has spliced into his lines hasn’t worked well, he said, but a newly approved version has shown promise.

“We’re trying our hardest to comply, but it’s going to take time,” Delano said.

There are fewer than 340 North Atlantic right whales today.

The right whales give birth off Florida and Georgia and migrate north to the waters off New England and Canada to feed. Scientists and conservationists have sounded alarms in recent years that warming waters seem to be causing the whales to stray from protected areas of ocean in search of food.

The current level of entanglements is more than whales can stand, said Kristen Monsell, an attorney with the Center for Biological Diversity, a conservation group. The group and others have pushed for tighter restrictions on commercial fishing to prevent the whales from entanglement.

“These reports show far too many endangered whales are caught in fishing gear, particularly because reported entanglements are just the tip of the iceberg,” Monsell said.

Staff Writer Kelley Bouchard contributed to this report.