GLOUCESTER, Mass. » Federal regulators are considering the unthinkable in New England:B severely restricting — maybe even shutting down — cod fishing in the Gulf of Maine, from north of Cape Cod clear up to Canada. New data suggests that the status of the humble fish that has sustained the region for centuries is much worse than previously thought.

Fishermen insist that there are plenty of cod and that the real problem is fuzzy science. They say the data are grossly inconsistent, pointing to a 2008 federal report that concluded that Gulf of Maine cod, though historically overfished, was well on the way to recovery.

The news is causing high anxiety in Massachusetts, where a wooden "Sacred Cod" has hung in the State House for more than 200 years and the fishing industry, though struggling, still figures prominently in the state’s identity.

"I can’t think of another fishery shutdown that would have the economic consequences of this," said Steven Cadrin, a scientist at the University of Massachusetts, Dartmouth, who helped with the assessment.

From May 2010 to April 2011, commercial fishermen caught about nine million pounds of Gulf of Maine cod, according to the New England Fishery Management Council, earning more than $2 per pound on average.

The National Oceanic and Atmospheric Administration set a deadline in 2004 to rebuild the cod species by 2014, and the 2008 survey suggested that goal was within reach. But researchers now say the survey might have sharply overestimated the number of young cod; the new data suggest that the spawning population is at only about 20 percent of the rebuilding target. The estimates are based on a mathematical model that uses data from a number of sources, including catch records and research trawlers that fish in the gulf several times a year.

"It’s just mind-boggling," said Maggie Raymond, executive director of Associated Fisheries of Maine, a trade group, and the owner of two fishing boats. "Some years you get better news, some years you get worse. But to have two such totally opposite conclusions is really hard to wrap your head around."

Some fishermen say they are seeing more cod in the Gulf of Maine than they have in years. Many in Gloucester have already reached their quota for the fishing year that started in May and are looking to buy the rights to catch more from others who have not yet reached their federal limit. Recreational fishermen, who land more than 30 percent of the total Gulf of Maine cod catch, are reporting similar observations.

"I’m telling you, it’s out there," said Russell Sherman, who started fishing for cod in 1971 and has just about reached his annual allocation of 25,000 pounds. "We’ve had no problems locating codfish."

But scientists take more into account than what fishermen see.

"Fishermen will almost always tell you that, and it’s not that they’re lying," said Mark Kurlansky, whose 1997 book, "Cod: A Biography of the Fish That Changed the World," documented how Canada’s once-abundant Atlantic cod were fished almost to extinction. "Landing a lot of fish can mean the fish are very plentiful, or it can mean the fishermen are extremely efficient in scooping up every last one of them."

Independent scientists conducting a peer review of the data are expected to make recommendations in January to the New England Fishery Management Council, which sets regional fishing policy. The council will then decide what new cod restrictions should be imposed in the Gulf of Maine, the starkest of which would be a first-ever shutdown of the fishery. Any new restrictions would most likely start in May.

Even though the data have not been finalized, NOAA has taken the unusual step of convening a team to meet with fishermen and discuss options. Eric Schwaab, assistant administrator for the NOAA Fisheries Service, said it was "too early to speculate" on the likelihood of closing the fishery.

"We think we have a lot of tools yet in our toolbox before we would get to that kind of place," he said.

At a meeting with fishermen on Friday in Portsmouth, N.H., regulators said that even without closing the fishery, the catch might have to be reduced by as much as 90 percent. Under that scenario, they said, groundfish revenues would drop by 90 percent in New Hampshire, 54 percent in Maine and 21 percent in Massachusetts, with Gloucester seeing a 60 percent decline.

A separate stock, Georges Bank cod, which is found south and east of Cape Cod, would probably not face new restrictions next year. But most of the small day-boat fishermen who focus on Gulf of Maine cod could not fish for it, partly because it requires longer trips to more distant fishing grounds and larger boats.

One possibility is extending the deadline for rebuilding the fishery, although even then, "you would still have to cut back tremendously," said Peter Shelley, senior counsel at the Conservation Law Foundation, an advocacy group in Boston. Other possibilities might be requiring different gear or closing sections of the Gulf of Maine, he said.

Shutting down the fishery, or even sharply curtailing the allowable catch, "would be devastating," said Joe Orlando, a fourth-generation Gloucester fisherman who landed 160,000 pounds of cod last year, about 80 percent of his total catch. "It would cut the legs right off of us."

Such restrictions would make it hard to fish for other species, Orlando and others said, because it is nearly impossible to trawl for any other groundfish — those that live near the sea bottom, like flounder and haddock — without bringing up cod.

He and other fishermen said they expected that the public would blame them for the bleak new numbers, assuming that they had heedlessly overfished, when in fact they had been sticking to the limits regulators set in light of the rosy 2008 population estimate.

"It’s not fishermen who’ve caused this problem," said Raymond from the Maine trade group. "But that’s the interpretation the public gets, when what they should be understanding is that this is a very imprecise science."

Sen. Scott Brown, R-Mass., has been a vocal critic of NOAA over the last year and has even called for the firing of Jane Lubchenco, the agency’s leader. Brown said he had never seen an agency "that is so distrusted by the folks it’s supposed to regulate."

"This just adds fuel to the fire of that lack of trust," Brown said.

Sen. John Kerry, D-Mass., said his staff was already putting together a proposal for federal disaster assistance "to tide people over" should cod fishing be curtailed or shut down. But he added that the new data should be taken seriously.

"We have to be very sober in our assessment of this thing," he said. "The important thing is this fishery be saved and exist for centuries to come."

© 2011 The New York Times Company