ARROWSIC

A fter briefly surveying this year’s batch of green crabs, Arrowsic

Shellfish Commission committee member Paul Burgess noted “(they’re) bigger — I don’t know by how much” during a trapping assessment that was conducted on Thursday.

This is Arrowsic’s second green crab assessment. The event was first organized last year to help estimate the number of green crabs on Arrowsic’s coast and to see how far they were traveling. Thursday’s assessment will continue to build on last year’s data to see if there are variations in crab number or location since the previous year.

On Thursday morning, about 10 traps were set up at various points along the coast of Arrowsic near clam beds, including North Squirrel Island, Crow Island and Fisher Eddy. Several hours later, committee members and volunteers collected the crabs and classified them according to location, size and sex.

Last year, a total of 630 crabs were trapped and collected for data, with the highest number of crabs — 237 — found near North Squirrel Island. Only two crabs were found at Fisher Eddy.

This year, the Fisher Eddy trap captured four crabs, and the largest number of crabs were found at South Squirrel Island. All together, several hundred crabs were caught on Thursday.

Ruth Indrick, project manager at the Kennebec Estuary Land Trust, said green crab research began when clammers had seen an increase in crabs and a decrease in the clam population in 2013.

“Many clammers across the state identified that they had seen really huge decreases in clam populations and young clams on the flats,” she said. “Most towns hadn’t been aware that green crabs were an issue to think about and they needed to find out how many crabs there actually were.”

According to KELT’s website, green crabs are not only associated with a decrease in clam population, but also contribute to salt marsh erosion and a loss of eelgrass.

Through a grant awarded by the Maine Outdoor Heritage Fund, KELT purchased traps and hip waders to conduct more research about the green crab population. The traps were also made available for local towns to borrow for crab assessment.

Indrick, who helped compile Arrowsic’s crab data for both years, noted that the green crabs especially varied in number and sex ratio based on each site.

“Trapping last year shows there is a lot of variation, and different habitats appeal to different characteristics of crabs,” she said.

However, the good news is that there appears to be an overall decrease in the green crab population since last year.

“Anecdotally, from what fishermen see out and about in their daily business, the numbers are down from what they were two years ago,” said Pete Thayer, an area biologist from the Department of Marine Resources. He also noted that there were a decent number of “seed sets” or baby clams in the area this year.

“All it takes is one good dose of natural seed, as along as it survives the winter and predators,” he added.

Shellfish warden Jon Hentz, who participated in Thursday’s event, said the data will be helpful for future use. “Over the long haul, it’s going to help us better manage our shellfish,” he said.

Although there are differing speculations regarding the increase in green crab population, Hentz suspected that harsh winters and temperature may help to scatter them.

“As we watch temperatures, 42 (degrees) is a magic temperature it seems where the crabs just stop or start,” he said. “And I think we can say a cold, nasty winter with a lot of subzero is going to kill off a lot of crabs. And so the next year, you’re going to find fewer crabs, and in most cases, a thriving bivalve industry, or better than it was.”

For Maine’s local shellfish industry, many hope that will be the case.