In this 2008 photo, a North Atlantic right whale dives in Cape Cod Bay near Provincetown, Massachusetts. (AP Photo/Stephan Savoia, File)

By Kristine Phillips and Amy B Wang / The Washington Post

The United States is temporarily halting efforts to rescue large whales trapped in fishing gear after the death of a Canadian fisherman this week.

Joe Howlett, founder of the Campobello Whale Rescue Team, was killed Monday after freeing a trapped North Atlantic right whale off the coast of New Brunswick, a Canadian province next to Maine. Details about how he was killed were slim, but Mackie Greene, captain of the whale rescue group, told the Canadian Press that the whale “made a big flip” after it was freed and somehow struck Howlett.

It’s unknown how long the suspension will stay in place.

The National Oceanic and Atmospheric Administration is “suspending all large whale entanglement response activities nationally until further notice, in order to review our own emergency response protocols in light of this event,” Kate Brogan, spokeswoman for the NOAA fisheries division, said in a statement.

Howlett, described as “one of the few certified whale disentanglement experts in Canada,” founded a volunteer group that responds to dozens of reports of whales trapped in fishing gear off the coast of New Brunswick. He had been on a “fast response vessel” belonging to Fisheries and Oceans Canada when the incident occurred, according to a statement from the agency.

What the suspension means for nonprofit entities authorized by the United States and Canada to rescue trapped whales is unclear.

One such group is the Massachusetts-based Center for Coastal Studies, a marine research nonprofit that worked with Howlett on rescue efforts. Spokeswoman Cathrine Macort told the Bangor Daily News that Howlett is the first such person killed since the 1970s, when the United States and Canada started a network of governmental and nonprofit groups from both countries that respond to whale entanglements.

How the suspension might affect North Atlantic right whales is also unclear.

Hunted heavily by commercial whalers in the 1900s, the animals are considered among the world’s most endangered large whale species, according to the Marine Mammal Commission. Today, they’re killed or injured primarily because of entanglements in fishing nets and strikes by vessels.

Only about 500 of the animals are left in the world, according to Fisheries and Oceans Canada. North Atlantic right whales can live at least 75 years and grow up to 59 feet long. They migrate between the coasts of Florida and Georgia in winter and the Atlantic Canadian waters – especially the Bay of Fundy and southwestern Nova Scotia – in the summer.

This summer, seven North Atlantic right whales have been found dead in the Gulf of St. Lawrence near New Brunswick and Prince Edward Island, alarming conservationists.

“This situation is very concerning,” Fisheries and Oceans Canada said in a statement June 24, after a fifth whale carcass sighting had been confirmed in the Gulf of St. Lawrence. “The cause of death is unknown at this time and DFO is committed to finding out what happened to these animals and to protecting this species.”

Members of the marine community describe Howlett, a 59-year-old lobster fisherman, as a longtime advocate who dedicated his life to saving the endangered whales.

“Joe’s dedication to saving entangled whales was as deep as his love for fishing. He was truly a hero whose passion for the ocean transcended diverse groups of people and opinions,” Scott Kraus, head of the New England Aquarium’s right whale research program, told the Associated Press.

NOAA will continue to respond to other reports of stranded marine mammals, Brogan said. Members of the public who see an animal in distress should contact the agency’s hotline at 866-755-6622.