BRUNSWICK, Maine — Marine resource experts who discussed how to begin regional efforts to conserve the softshell clam said green crabs and nitrogen are the No. 1 enemies.

Harvesters from Scarborough to Wiscasset attended the meeting the Casco Bay Marine Resource Summit on March 7 at the Brunswick Municipal Meeting Room.

“Local problems are regional problems,” said Brunswick Marine Patrol Officer Dan Devereaux. “If Brunswick has them, Freeport probably has them, Harpswell probably has them.”

Among the speakers who addressed the group was Brian Beal, director of research for the Downeast Institute in Beals.

“We have to remember that your flats are in part of a bigger picture of the gulf of Maine and along the coast of Maine,” Beal said.

With this in mind, he suggested two approaches to regional shellfish management: closing flats for one to two weeks during peak spawning times, and implementing a ban on large clams because they produce more offspring.

Casco Baykeeper Joe Payne, of Portland, said ocean acidification and coastal acidification are two major factors in the decline of softshell clam.

Where ocean acidification happens as a result of burning fossil fuels, causing carbon dioxide to go into the water, Payne said, coastal acidification happens because of nitrogen runoff from fertilizer, sewage, pesticide and other manmade pollutants.

“Nitrogen pollution is the problem because it exacerbates acidification,” Payne said, adding that conservation techniques may not make a difference if coastal acidification isn’t mitigated. “… If the pH level on that flat is low enough, [clams] are going to dissolve, so it may be the worst predator of them all.”

Payne suggested communities consider purchasing certified pH meters to screen the acidity in mudflats and record the data.

“The stakes are going to get higher, and it’s been my experience that when the stakes get higher, you need really good data,” Payne said. “It’s inevitable that we need people to go out and do screening.”

State biologist Denis Knault, of the Maine Department of Marine Resources, raised concerns about Payne’s proposal because he said the most reliable pH meters are too costly for many communities. He said they need more workable solutions.

“Look at the resource and the value to those families,” Payne responded.

Chad Coffin, president of the Maine Clammers Association, spoke of another enemy to the softshell clam: the predatory green crab.

“This is enemy No. 1 in the state of Maine,” Coffin said. “… As a clammer, I can tell you we’re really confident this little thing is destroying every marine organism on the coast of Maine.”

Coffin said education, volunteer trapping, regional conservation efforts, and research and development can go a long way in fighting the expanding green crab population.

Knault said the town of Penobscot is planning to have a green crab derby, where the town will award a prize to the person who catches the most green crabs.

“Now if we get a lot of communities looking at doing that, now we might have something,” Knault said.

James Campbell, an urchin and worm harvester from Bath, said he knows the green crab problem first-hand, but accused the DMR of repeatedly refusing proposals to manage the crab population.

“We have come up with multiple plans to harvest these things, and every single plan we come up with, the DMR shuts us down,” Campbell said.

Coffin defended the DMR and said it is amenable to proposals, suggesting that may not have been the case under previous administrations.

Knault said the problem is that green crabs have no value on the market.

Devereaux said another regional shellfish meeting will likely happen within the next two months.