Undeterred by the rain whipping over the water at Todd’s Landing in Georgetown on a recent morning, seventh grade students at Bath Middle School pulled on their waders and tossed baited green crab traps into Robinhood Cove.

The trapping effort is part of a two-year-long study carried out by students and teachers at BMS in collaboration with the Kennebec Estuary Land Trust. The study aims to shed light on the number and the habits of the invasive green crab species that is endangering soft-shell clam populations.

“It’s something that is happening right in their backyards,” said BMS teacher Jennifer Galasso, “and there is a benefit to getting the kids outside to do real scientific work.

“A lot of our students have ties to the fishing industry and the clamming industry specifically — we have a couple of clamming families,” she added. “This directly impacts their family life because this is their livelihood.”

According to the Downeast Institute, Maine’s soft-shell clam industry is worth roughly $15.6 mil- lion, and during the past 30 years has ranked second or third among the state’s fisheries in commercial value.

An increase in the green crab population is thought to be associated with warming ocean temperatures. Various studies are being carried out across the state, by municipal and nonprofit entities, to determine methods for saving clams from green crab predation.

The Maine Department of Marine Resources has also issued Green Crab Exemption permits to municipalities that engage in trapping studies, allowing green crab trapping and removal to occur without requiring individual permits.

“What we’re doing is called a mark recapture study,” said Ruth Indrick, KELT’s project manager working with BMS on the field study. “Students are visiting three sites, two in Woolwich and one in Georgetown.

“They measure and sex the crabs they’ve caught in the traps, and paint a mark on their shell,” she added. “The second time they set traps, they see how many crabs they recapture with painted shells,” which helps calculate a population estimate.

“We’ve been finding a lot of large females in red phase, which they started to see that at this time of year last year,” said Galasso. “Green crabs typically have green underbellies, but they can have red underbellies as well.

“There’s a lot of hypotheses out there in the scientific community as to why — is it part of their moult? Does it have something to do with nutrition?” she said. “There could be a lot of reasons, but no one’s really sure why yet.”

Students will be presenting their findings to the Bath City Council at 6:30 p.m. Nov. 24, said Galasso. The public is invited to attend the presentation.

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