BRUNSWICK

Thunderstorms clung to the edge of the horizon as volunteers hurried Saturday afternoon to seed half a million baby soft-shell clams across the intertidal flats of Brunswick and Harpswell.

The seeding project — the first in Harpswell in more than a decade and the first in living memory to be jointly undertaken by the towns — was carried out in an effort to rebound the soft-shell clam population which have suffered from green crab predation and ocean acidification.

More than 20 clam harvesters from Brunswick and Harpswell participated in the seeding effort — pooling resources from the Harpswell and Brunswick Marine Resources committees — and laid more than 25 nets over clam beds, despite internal debate about netting’s efficacy.

Brunswick Marine Resource Officer Dan Devereaux instructed harvesters on how to cut the net, in 25-foot-long increments, and zip tie buoys in three rows of three at the front, back and center of the nets.

“This is the kind of thing they would be doing if they were doing aquaculture,” said Devereaux. “So they can each cut a net and learn the skill.”

Roughly one-third of Brunswick’s flats are under conservation closures, said Devereaux, which ban any type of harvesting that disturbs the mud. Buttermilk Cove and Woodward Cove — locally called the Big Bull Pen — are part of a pilot project. Last week, the Thomas Point Beach flats were also closed for harvesting, he said, as 70 percent of the clams there are at a sublegal size.

Overall, a higher percentage of Brunswick is closed for harvesting now than in the past eight years.

“We’re really trying to get a grip on developing the best methods to deploy to keep the crabs in check in these two areas,” said Devereaux of Buttermilk and Woodward coves.

Placing netting over seeded clam beds protects the baby clams — or spat — from predation, particularly of the invasive European green crabs. However, the netting is costly and placing it over the beds is laborintensive. Additionally, the netting has to be buoyed and kept free of debris to maintain a healthy environment for clam growth.

“I’d say in Harpswell they’re split 70-30 on the netting and reseeding,” said Deputy George Lee Bradbury, of the Cumberland County Sheriff Department Marine Patrol, noting that 70 percent were not in favor of the concept.

“It certainly works,” said Darcie Couture, the Harpswell Marine Resource Coordinator and principal of Resource Access International.

“This stuff is expensive though,” she added of the netting. “Just one roll of this netting is about $700.”

A roll is 300-feet long, by 12-feet wide, said Couture, enough for approximately 12 nets.

“I cut as much as I could out of my roll — the town didn’t have to buy that,” said Couture, who brought 10 nets to be laid on Harpswell’s flats. “I’m carrying that cost and, in theory at least, they’re recoverable and I can use them for other projects.

“We’ll be netting some seed and leaving some seed unprotected,” said Couture. “Just because it’s so expensive, it’s not practical for us to plan to net our whole town. If we can have comparable survivability without it, that would be nice.”

At their Aug. 26 meeting, the Harpswell Marine Resources Committee agreed to partner with Brunswick on the project and purchased half of Brunswick’s order of 500,000 spat from the Downeast Institute hatchery.

Harpswell’s portion, 250,000 spat, cost approximately $4,000, said Couture, which will issue from the Marine Resources Committee’s budget.

Nets also have to be cleared of debris, said Devereaux, and have to be secured with buoys so they lift when the tide comes in and clear sediment from the surface.

“Anything that you put in the water that catches algae and plankton — it fouls and gets heavy,” said Devereaux. “We put a lot of buoys on ours. People that don’t buoy and just net, what that does is smothers it so the clams can’t get up through the blanket of algae and they end up essentially suffocating.”

Before netting is laid, the volunteers roughed rows of mud up with rakes and broadcast clam seed into the furrows, “just like seeding your garden,” said Couture.

In Strawberry Creek, a conservation area in Harpswell unanimously approved by the Board of Selectmen in June, Evan Patierno and Jason Viggiano, marine biologists with Resource Access International, planted two beds, laid one net and broadcast additional seed.

“The goal was to get it done by dead low so they had time to settle in and weren’t pulled out by the tide,” said Viggiano of seeding the beds. “We want to get them in as quickly as possible — they’ve already been in refrigeration for two days and we really don’t want to keep them out longer than that.”

“We’ve done a bunch of ocean acidification testing, so we test sediment for pH levels and test the water for salinity levels,” said Patierno. “Everything we do is geared toward helping people who are actually working — it’s not just research — we are here to help out the industry.”

Couture said they will return regularly to check on the netted and seeded areas. “I think everybody is going to be curious to see how it goes,” she said. “This is a big event.”

“The real question is, how will things look next summer?” said Couture. “Will they live, will we have good growth, will they be able to get in there and dig all those bushels out? We’ll see.”