The humpback whales that summer off the coast of Maine are no longer at grave risk of extinction, so the federal government has officially removed them from its list of endangered species.

In fact, the National Oceanic and Atmospheric Administration announced earlier this month that it has taken all North Atlantic humpbacks, plus those in eight other of their species’ 14 population segments around the globe, off the list.

“It certainly is a cause of celebration,” said Sean Todd, marine sciences professor at the College of the Atlantic in Bar Harbor.

Todd said the humpbacks’ population rebound, which triggered the status change, is likewise worthy of celebrating.

Centuries of whaling followed by ship strikes and fishing-gear entanglement pushed whale populations to the brink. Four decades ago, the western North Atlantic was home to fewer than 2,000 humpbacks. Now, between 10,000 and 13,500 swim in those waters, according to the International Whaling Commision.

Patrice McCarron, executive director of the Maine Lobstermen’s Association, hailed the recovery recognized by the de-listing of the humpbacks as “great news.”

“Maine lobstermen have made significant changes in how they rig their gear over the last 20 years in an effort to aid in the recovery of large whales,” McCarron said. “The [Maine Lobstermen’s Association] is proud of all the work our lobstermen have done to protect whales. And it’s nice to see those efforts pay off.”

All whale species remain protected under the Marine Mammal Protection Act, which prohibits interfering with them in any way and limits how closely sightseeing boats may approach. The International Whaling Commission’s ban on commercial whaling, which has been in place since the 1980s, is honored by most nations. Japan, Norway and Iceland still kill whales.

Four humpback groups continue to be listed by NOAA under the Endangered Species Act as “endangered.” A fifth had its status changed to the less severe category of “threatened.”

On Sept. 6, all seven humpback populations in the Southern Hemisphere were designated by NOAA as “not at risk,” after having been listed as endangered in 1970. In the Northern Hemisphere, NOAA Fisheries gave the same designation to humpback whale populations that winter off Hawaii and the West Indies in the Caribbean, the latter of which is estimated to have a population growth rate of more than 3 percent per year.

It is the West Indies humpbacks that can be found in summertime feeding areas in the western North Atlantic, including along Maine’s coast.

Estimates of the humpback’s worldwide population range very wide — from 30,000 to about 90,000.

Four Northern Hemisphere population groups — those found along the Pacific coast of Central America, around the Cape Verde Islands, in the Arabian Sea and in the western Pacific — remain endangered. The humpbacks that winter off the Baja Peninsula of Mexico are the group ranked as threatened.

Eileen Sobeck, assistant NOAA administrator for fisheries, said in a prepared statement that the continuing recovery of most humpback whale populations is an ecological success story. She added that “separately managing humpback whale populations that are largely independent of each other allows us to tailor conservation approaches for each population.”

Todd, director of his college’s Allied Whale research program, said his organization’s studies suggest that the population groups may not be as distinct as the NOAA contends.

College of the Atlantic has long kept track of humpback whales in the North Atlantic, serving as curator of the North Atlantic Humpback Whale Catalog, which helps researchers follow the health of both individual whales and of the species’ overall population in region.

“We have some data that there is a lot more fluidity [between populations] than what they’re suggesting,” Todd said.

The marine sciences professor said he does not fear that taking so many humpbacks off the Endangered Species list will put them in jeopardy because other protections are already in place under the Marine Mammal Protection Act, which also covers dolphins, porpoises, seals, sea lions, walruses, manatees, sea otters and polar bears.

Todd noted that many whale species remain endangered. North Atlantic right whales, for example, are estimated to have a population of only about 500, up from about 300 in the mid-1990s but still critically low.

Todd also pointed out that there are still many urgent challenges when it comes to marine health and conservation. In addition to continuing threats from fishing gear and ship strikes, broader issues such as plastic pollution and rising sea temperatures linked to climate change also pose serious hazards.

“I would not want to see us relaxing our conservation practices,” Todd said. “We have adopted better human behavior that we should continue to pursue.”

A news reporter in coastal Maine for more than 20 years, Bill Trotter writes about how the Atlantic Ocean and the state's iconic coastline help to shape the lives of coastal Maine residents and visitors....