WEST BOOTHBAY HARBOR, Maine — Marine scientists and lobster harvesters in Maine’s largest fishery say some fishermen may be abandoning a key conservation method practiced for nearly 100 years at a time of growing fears that a run of record hauls is coming to an end.
The mandatory practice, called v-notching, requires lobstermen to mark the tail of any egg-bearing lobster they catch and let it go. The notch lasts two to three years and alerts other lobstermen that that lobster is off-limits.
State officials say that about 66 percent of the egg-bearing females surveyed in 2013 were v-notched, down from nearly 80 percent in 2008.
The decline comes at a time when the state’s lobster catch has boomed, growing from 70 million pounds in 2008 to more than 125 million pounds in 2013. State officials and some lobstermen said the lower percentage of v-notching could indicate waning participating in the conservation program, or it could mean that fishermen are having trouble keeping up with notching so many lobsters.
Carl Wilson, the state’s lobster biologist, said the downward trend bears monitoring.
‘‘You could have a decline in participation. You could have an underlying biological change,’’ he said.
V-notching has existed for nearly 100 years as a way to preserve the species.
The declining v-notch percentage has motivated state officials to draw more attention to their enforcement efforts against violators. The Maine Marine Patrol aggressively publicized its case against Stonington lobsterman Theodore Gray, who is accused of illegally harvesting hundreds of undersize and breeding lobsters and who had his license suspended for three years. His case, which the patrol calls the most egregious of its kind in 25 years, is pending, and he could face jail time or a fine.
Still, cases brought for violations of v-notch rules are uncommon. The state issued 14 violation notices from 2006 to 2013, said Jeff Nichols, spokesman for the Department of Marine Resources. The Marine Patrol conducts about 17,000 boat checks for v-notch violations and other offenses yearly.
Maine imposes a fine of $500 for possession of v-notched lobsters, plus an additional $100 fine for the first five lobsters involved, and $400 for each lobster after that.
David Cousins, a South Thomaston lobsterman and president of the Maine Lobstermen’s Association, said lobstermen are aware that v-notching ‘‘is dipping a bit.’’ Some new lobstermen don’t have the same level of commitment to the practice as older harvesters, who took it as an article of faith that v-notching would preserve the fishery, he said.
Part of the generational rift could be that newer lobstermen have grown up with huge catches of lobster.
‘‘We’re working really hard in the Maine Lobstermen’s Association to get the younger generation into it,’’ Cousins said. ‘‘It’s what’s kept us going for 100 years, and if we keep doing it, it’ll keep us going.’’
The v-notch percentage decline is dovetailing with other challenges to the fishery’s sustainability, including a worrisome decline in baby lobsters, state officials said. The number of young lobsters found in 2013 was less than half what was found in 2007, according to a University of Maine survey of 11 Gulf of Maine locations.
Other metrics are more hopeful. The percentage of adult females discarded because of eggs or a v-notch was 40 percent in 2013, down from 43 percent in 2010 and 2011, but up from 30 percent in 1998.
Belfast lobsterman Mike Dassatt said he is confident v-notching is still widespread. He said the state’s concern over v-notching might just reflect the time and place of state surveys, not the fishery as a whole.