BOSTON – Lobstermen in southern New England face a five-year fishing ban because biologists have told regulators that the drastic step is needed to save the depleted stock.

The Lobster Technical Committee of the Atlantic States Marine Fisheries Commission acknowledged such a moratorium’s “catastrophic effects” on lobstermen, but said it is needed to rebuild the lobster population and secure the industry’s long-term health.

Bill McElroy, a lobsterman in Rhode Island, said there will be no industry in southern New England if the recommendation is adopted.

“The infrastructure would collapse, the markets would be swept up. There just wouldn’t be any way to come back from it,” said McElroy, 63. “So it’s essentially a death sentence, if they were to follow through on that.”

The recommendation to the commission’s American Lobster Management Board is a long way from reality. The board will meet in July to discuss a range of options being devised to revive the lobster stock, including far less severe alternatives, such as no changes at all.

Dennis Abbott, a New Hampshire state representative and a member of the lobster board, said the committee’s recommendation, although extreme, must be considered seriously, given the stock’s persistent weakness and the rigorous science behind the advice.

“They didn’t wake up in the morning and just pull this out of the air,” he said. “At some point, some drastic action seems to be necessary.

“But it becomes a dilemma of trying to protect the lobstermen in their occupations versus protecting the resource and ensuring there is a resource,” Abbott said.

The vast majority of lobsters caught in the Northeast are trapped from north of Cape Cod to Maine. The area accounts for about 93 percent of the catch and has recently had the opposite problem — a glut of lobsters on the market.

The southern region includes areas south of Cape Cod down to North Carolina, with most of the inshore lobster catch between Massachusetts and Long Island Sound.

The area once accounted for as much as a quarter of the Northeast’s total catch, but it’s just 5 to 7 percent today. The population peaked in the late 1990s at an estimated 35 million lobsters, but the stock plummeted to around 13 million by 2003. Scientists have never pinpointed a cause, but possible culprits include overfishing, an oil spill in Rhode Island in 1996, a disfiguring shell disease, and pesticide-polluted runoff.

Since 2003, recovery has been slow, with about 15 million lobsters now estimated in southern New England, well below the 25 million target and a sliver of the 116 million estimated to live in the Gulf of Maine.

The committee report offers some explanations for why the stock hasn’t rebounded, including water temperatures that more frequently exceed 68 degrees, a temperature that can retard a lobster’s growth and spawning. It can also force lobsters into deeper, colder waters, where they are more susceptible to predators and their larvae are less likely to settle in suitable spots to grow.

The report also cited fishing pressure, although it said lobstermen aren’t overfishing the area. The report said the catch hasn’t declined as steeply as the lobster population.

McElroy questioned how getting lobstermen off the water would solve anything if everyone acknowledges that they aren’t overfishing. He noted that southern New England’s estimated lobster population was even lower in the early 1980s than it is now, and a boom followed.

He advocated keeping the status quo, saying lobsters already have tough protections, such as trap and size limits. There’s no guarantee that banning fishing would have any impact on what could be a cyclical downturn, he said.

“It’s pretty obvious to most fishermen that it’s a host of environmental problems that are creating this trouble,” McElroy said. “If you’re not the problem, how can you be the solution?”