Canada, U.S. join forces to save gulf porpoises

HALIFAX, Nova Scotia — A joint Canadian-American effort to save herring-chasing harbor porpoises from snagging themselves in gill nets — primarily in the Bay of Fundy and the Gulf of Maine — is starting to pay off.

The two countries have been working for the last year on a joint initiative to help prevent the hundreds of entanglements that occur every year.

Accidental entanglements are already down, thanks to the joint effort, said Neil Bellefontaine, regional director for Canada’s Department of Fisheries and Oceans.

“We think we’ve been successful in reducing mortalities by the gillnetters,” said Bellefontaine. “They have been much more vigilant in how to set their gear.”

The dark-gray harbor porpoises are a quiet species that swim alone or in small groups. They don’t call attention to themselves as their rollicking cousins the bottlenose dolphins do by leaping, frolicking around boats and traveling in packs of up to 50.

Two years ago, about 800 harbor porpoises were snagged in gill nets set on the ocean bottom off the Fundy and Maine coasts, Bellefontaine said.

Last year, the number dropped by half.

Acoustical devices that scare porpoises away from nets, and relocation of nets to deeper water have helped cut the fatalities. The acoustic deterrents sound like motorboats or sirens.

The countries have also limited the number of nets and how long they may be left in the water.

Porpoises get caught when pursuing herring and other bait fish into the nets, Bellefontaine said.

Scientists have estimated between 3,500 and 15,000 porpoises live in the Fundy-Maine area. Some environmentalists have estimated that the deaths in past years were much higher than the official figures — up to 2,500 a year off Maine alone and 300 in the Bay of Fundy.

Environmentalists have been concerned because porpoises have a limited reproduction cycle. Females can give birth only once a year and can’t have more than three pups in a lifetime.

Scientists say the porpoises can’t see the nets until they’re only about a yard away, and by then it’s too late.