The federal government is weighing whether to shut down the cod fishery in the Gulf of Maine, citing scientific projections of decline that the fishermen themselves don't believe.

The New England Fishery Management Council will decide next year, after an independent review of studies on the cod population, if new restrictions, including outright closure of the fishery, should be imposed. The basis for that decision, The New York Times reports, will be wildly divergent estimates on how much progress has been made in rebuilding the population of an iconic staple of the New England economy and diet.

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 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.”

The money is big, and the potential effect on the region's fishing culture is equally great. (Coastal Maine is already a good place to spot bumpers protesting federal management of fish populations. "NATIONAL MARINE FISHERIES SERVICE: DESTROYING FISHERMEN AND THEIR COMMUNITIES SINCE 1976," is a popular one.) The scientists are trying to keep the cod stock from dying out completely, and the issue is straining political leaders in Massachusetts and around New England.

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, Mr. 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.

The new data are coming at a time of extraordinarily high tension between New England fishermen and federal regulators. The industry is still adjusting to a new management system, started last year, that divided fishermen into groups, called sectors, that share an allotted catch of each species. Though the allotments were intended to provide fishermen with steadier income, many have complained that they were set too low and that small boats, in particular, were being pushed out.