PORTLAND — Maine lobster and gill net fishermen and their families can breathe a big sigh of relief. Their protests over federal draft rules to protect the endangered right whale have produced an interim plan that will cost them a lot less than originally expected.

Federal officials Tuesday unveiled a four-year plan designed to protect four species of whales, including the rare northern right whale, from being entangled in lobster and gill net gear off the New England coast. Gear modifications take effect next January.

Dr. Andy Rosenberg, Northeast regional administrator for the National Marine Fisheries Service, called the 95-page plan the first stage of a long-range conservation program to ensure the safe passage of migrating whales along the Eastern Seaboard. His agency will take public comments until Oct. 15, before a final version is published.

Rosenberg said at a press conference in Portland he believes his agency’s plan protects whales, including minke, finback and humpbacks. It also protects fishermen from losing their livelihoods, he said.

He estimated the rules will cost “a couple of million” dollars to implement — a far cry from the original $50 million price tag. Compliance will cost individual fishermen at most a few hundred dollars.

Asked whether the public uproar over NMFS’ initial plan had forced the agency to do an about-face, he said, “I don’t think they are watered down. I believe they are more workable.”

Under the plan, Maine lobstermen who fish only in bays and coves along the coast will be exempt from any changes except a rule requiring a two-color gear marking scheme showing the area where they fish and their gear type.

In waters extending eight to 12 miles out, Maine lobstermen and gill netters must choose one option from a menu of gear modifications having to do with buoy lines to reduce the chance of whales becoming entangled in their gear.

Those working offshore beyond the 8- to 12-mile line must pick one of the options as well.

Both the fishermen working in waters 8 to 12 miles out and those further offshore have to obey two rules prohibiting floating line and requiring them to tend their gear at least once every 30 days. Both groups also have to mark their gear in different ways.

Robin Alden, commissioner of the Maine Department of Marine Resources, hailed the plan as the dawning of a new era of cooperation between state and federal authorities and the fishing industry to protect whales.

“Ever since April, everywhere I go, I have been asked, `Robin, is everything going to be all right?”‘ she said. “This is a great day for the more than 7,000 fishermen and their families who would have been impacted by the rule.”

Last month, DMR submitted an alternative whale protection plan to the feds. Many of its elements are reflected in the new federal rules. The state called for NMFS to draw up rules distinguishing among different fishing areas where right whales are more or less likely to swim. The state plan also recommended an entangled-whale response program involving fishermen.

“I am happy to say, the fundamental principles that we put forth in our proposal were embraced by federal authorities,” Alden said.

While he has yet to study the document closely, Patten White, executive director of the Maine Lobstermen’s Association, said he was confident the rules will not harm Maine’s most lucrative fishery, which landed $107 million in revenue last year. He represents 1,200 men and women who fish for lobster.

A lobsterman from York, White praised the hundreds of Mainers — from Sen. Olympia Snowe, who spearheaded the congressional delegation’s efforts, to the Midcoast Fishermen’s Wives Association — for getting to message across to NMFS that its draft plan was unacceptable.

“It has been a wonderful reflection on the people of the state of Maine,” he said, estimating that the cost of compliance for a fisherman could range from $10 to several hundred dollars.

Only 300 northern right whales exist. Since 1991, six of the endangered creatures have either been killed or seriously injured by fishing gear. None of those cases occurred in the Gulf of Maine. Only one right whale is known to have been entangled in Maine waters, and it was released unharmed.

NMFS, mandated by the federal Marine Mammal Protection Act, has been working since last year to draft a whale protection plan. The federal government is under a court order to enforce the plan.

Aired at a series of public hearings in Maine last spring, NMFS’ draft plan came under fire from lobstermen and gill netters who charged the rules were impractical and would cost tens of millions of dollars to implement.

Max Strahan, a Massachusetts right whale activist, won a lawsuit last year against the state of Massachusetts for issuing permits to a fishing industry that he charged threatened right whales. Strahan has threatened to sue again if the federal plan is not tough enough. He could not be reached for comment Tuesday through his Boston lawyer.

Jennifer Atkinson, an attorney specializing in marine fisheries at the Conservation Law Foundation’s Rockland office, said NMFS’ interim plan sounds adequate to protect right whales and the fishing industry.

“It sounds very reasonable. It has chosen gear modifications over closures, which is very good. We are very impressed with how the federal government and fishing industry have worked together.”

Maine’s lobster and gill net fishermen will have a large role to play in the federal plan, which calls for a voluntary network of people trained to disentangle right whales. NMFS’ gear advisory group, including four Maine fishermen, also has been charged with continuing to develop whale-proof fishing gear. The agency also plans to hold outreach and educational workshops for fishermen.

Little Cranberry Island lobsterman Jack Merrill has served on the Maine Lobstermen’s Association’s board of directors for a decade. A member of NMFS’ gear advisory group, he was among the fishermen who spent two intensive days in Massachusetts meeting with the federal agency’s fisheries scientists after the stormy public hearings.

Reached by phone at home Tuesday, he acknowledged the plan differs substantially from the original one, but he said he was uncomfortable endorsing it. “In a sense, it would be an admission there is a problem in the Gulf of Maine, and I don’t think there is,” he said. “I think in some respects government has created and set out to solve a problem that doesn’t exist.”

Nevertheless, Merrill says he and other Maine lobstermen are prepared to cooperate with federal authorities to protect the right whale.

“As fishermen, we will do everything we can to prevent a right whale from being killed or injured in the Gulf of Maine,” he pledged.

Ever since the initial plan’s release, members of Maine’s congressional delegation have played a key role in forging a dialogue between fishermen and federal authorities.

Sen. Snowe, chairwoman of the Senate’s Ocean and Fisheries subcommittee, has kept in constant touch with NMFS as the interim plan has been developed. She called the plan a “victory for Maine” Tuesday.

“The consequences of the original rule would have been devastating,” she said by phone from Washington, D.C. “Maine’s lobster and gill net industries have done an incredible job drawing attention to the problem and making their case.”

Sen. Susan Collins called the interim plan thoughtful and reasonable. She added the rules should reaffirm Mainers’ faith in the federal government.

“Embedded in the regulations is the fact this agency listened to the public,” she said.