BOSTON — The Northeast’s fisheries chief announced Wednesday that he’ll delay the shutdown of local fishing grounds after fishermen warned that the closure, intended to protect harbor porpoises, would devastate a segment of the fleet.

John Bullard said the Gulf of Maine will be closed for two months to fishermen who use stationary nets called gillnets starting Feb. 1, instead of Oct. 1.

Bullard said he made shift after considering the most recent data, which indicates porpoises are more frequently entangled in fishermen’s nets between February and March.

“Adjusting the closure to begin in February should result in fewer harbor porpoise entanglements in commercial gillnet gear, if fishing behavior is consistent with recent years,” said Bullard, who made the announcement at the New England Fishery Management Council meeting in Plymouth.

Bullard initially had refused to change the closure, even after being lobbied by lawmakers, various fishermen and the Northeast Seafood Coalition, an industry group. But he agreed to reconsider after meeting with coalition leadership in Gloucester last week.

The coalition estimated a fall closure would mean a $10 million loss for the industry, including the Maine, New Hampshire and Gloucester-based gillnetters most affected.

Fishermen still expect to take a hit with a winter closure, but Gloucester gillnetter John Montgomery said it won’t be as severe. A fall closure would have taken away some of his best fishing months, when there’s warm weather and plenty of pollock, he said.

“I haven’t slept in a couple of weeks just thinking about this totally, every day,” said Montgomery, 54. “(Now) we know that we can get a chance to make a few bucks and salt them away for the winter.”

But Sharon Young of The Humane Society of the United States said Bullard caved to pressure from a small segment of the industry.

Young said the shutdown was no surprise, since the penalty was agreed to by fishermen, environmentalists, scientists and regulators during lengthy negotiations over the rules to protect the porpoises. With his decision, Bullard undermined that process and rewarded the fishermen who didn’t follow the rules, she said.

“This was done behind closed doors at the behest of a small section of the industry,” Young said. “It’s bad for porpoises and it’s bad for policy.”

The harbor porpoise isn’t endangered, with a population estimated at about 60,000. But federal law currently allows only about 550 porpoises to be accidentally caught and killed annually — saying any more will jeopardize the population. Regulators are charged with reducing the annual deaths to about 70.

Gulf of Maine gillnetters have been criticized by regulators for failing to install working “pingers” on their nets to prevent porpoise deaths.

The devices emit a sound that drives the porpoises away if they head for the nets, each about 100 yards long and strung together. If even one pinger on a string isn’t working, a porpoise might think it’s an open gap, swim for it, and get caught and drown.

Regulators said local fishermen had only a roughly 40 percent compliance rate.

But fishermen argued they’ve actually been far more compliant, and equipment that tests if their pingers are working often doesn’t work itself. They add it’s difficult to tell when the pingers break down because they’re tough to hear.

In shifting the closure, Bullard is requesting that gillnetters install pingers on all their nets starting Oct. 1, a month earlier than usual. It’s proven that when fishermen focus on using pingers properly, fewer porpoises die in fishing nets, he said.

“We need that same amount of focused attention to reduce harbor porpoise entanglements now,” Bullard said.