PORTLAND – Scientists and federal agencies are starting a process of modifying commercial fishing practices that threaten large whales in the Gulf of Maine.

Perhaps only 300 endangered right whales are believed to be alive, and evidence indicates that 72 percent of them have been entangled at some time during their lives, according to Bob Bowman, who operates a whale rescue service in Maine.

Starting today, a panel from the National Marine Fisheries Service will hold two meetings in Maine to gather information that will help shape the new rules governing where fishermen can work and what gear they can use.

The sessions are scheduled for 6 p.m. Monday at the Holiday Inn by the Bay in Portland, and 6 p.m. Tuesday at the Holiday Inn in Ellsworth.

Mack Green was leading a whale watch tour Wednesday off Campobello Island when he saw a right whale with fishing gear around its tail stalk.

Green, who has been trained in disentangling techniques, took the group to port and then went back to look for the entangled marine mammal. He found it two miles east of Head Harbor in the Bay of Fundy.

“He pulled up right alongside it and managed to get all the gear off it,” Bob Bowman, who operates a whale rescue service in Maine, said.

Right whales are usually very difficult and extremely strong, Bowman said. The fact that this one let Green get so close could be an indication that it had been weakened by dragging the gear.

Bowman said experts believe that only about 8 to 10 percent of entangled right whales are ever reported, and the reporting rate for humpback whales is even lower.

Seven humpbacks have been reported as newly entangled this year, he said, but that’s just a small fraction of the estimated 150-200 humpback entanglements in the Gulf of Maine annually.

Humpback whales are more plentiful than right whales, although both species are on the endangered species list.

The whale entanglements are not all bad news, said Teri Frady, spokeswoman for the Northeastern regional office of the fisheries service in Gloucester, Mass.

People are spotting the entanglement, reporting what they see, and in most cases the whales are being released, she said.

“We are not seeing a rash of entanglements,” Frady said. “It is a rash of disentanglements.”

The meetings this week are the first step in a long process to revise the practices of fishing operations that threaten whales. Current rules are primarily focused on lobster traps and sink gill net fisheries.

Among the changes to be considered are gear modifications, such as banning floating line and demanding the use of breakaway connections between traps and buoys.

The new rules are expected to be in place in early 2005.