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Brunswick looks to quahogs to buoy shellfish future

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Brunswick looks to quahogs to buoy shellfish future

BRUNSWICK — It’s a windy, grey morning at Wharton’s Point, and Dan Devereaux is sorting a mud-caked plastic bin a quarter full of quahogs – hard-shell clams – just seized from the bottom of Maquoit Bay.

Using a small metal gauge, Devereaux quickly measures a couple of the hardy bivalves; the smallest is about half the one-inch legal limit, others more than twice that size.

For his purposes, however, the size doesn't matter; the 367 quahogs pulled out of the mud aren't headed into a chowder. They're headed back into the 100-square-foot patch of mud Devereaux's research team just spent an hour and a half excavating.

Monday's dig was the first phase of a long-term research project to map Brunswick's quahog population, with the hope of opening up a new resource for commercial shellfish operators hit hard by the sudden decline in the soft-shell clam population.

While soft-shell clams have become more scarce, harvesters have reported an explosion in the number of quahogs found in the town’s clam flats, said Devereaux, Brunswick’s marine resources officer.

Anecdotes are not enough, however, to convince town officials to open the intertidal zone to more clammers. The town needs hard evidence to prove there is a sustainable population large enough to support increased harvesting.

“We need to know what’s out there before we can implement a management program, ” Devereaux said.

Although quahogs fetch a lower market price than soft-shell clams, town officials think the new resource might allow it to issue more commercial harvesting licenses, after years of cutting down to protect clam stocks. 

But before it determines how many quahogs can be harvested, the town must know how fast they are growing.

To that end, a team of researchers led by local marine biologists Darcie Couture and Chris Heinig are targeting two areas in Maquoit and Middle bays to scour for quahogs. 

The two bays were selected for the project because of the historically large quahog population in the area, Devereaux said. Photos from the 1950s show flats so full of the clams, harvesters were able to pull them up with pitchforks, he said.  

The hundreds of quahogs collected by the team are marked, measured, scored, and then returned to the excavated area, which will be covered with netting to prevent accidental harvesting for the next six months, which is the clams' prime growing season. 

In November, researchers will return, dig up the clams, and measure them again to get a rough growth-rate estimate. 

Pairing that data with a general survey of the quahog population will give town officials a clearer picture of the size and sustainability of resource, Couture said.

“This experiment will help us understand how quickly quahogs in different size ranges grow,” she explained.

“So when you go out and survey the population, and you're trying to estimate how many bushels of quahogs you're going to have ready to harvest in two years from now or three years from now, you'll be able to figure that out,” she continued. “You need to know how big they're going to get how quickly.”

With that knowledge, officials can start developing guidelines for increased quahog harvesting and eventually integrate the resource into the town's shellfish management program.

“If our waters prove to good growing waters, we could ultimately enhance the natural resource with hatchery stock,” Devereaux said.

Although researchers have conducted similar projects in other New England states, those findings aren't applicable to the unique ecosystems and growing conditions on Brunswick's coast, Heinig said.

If results show the quahog population is sustainable, the population could be included in the town's marine resource strategy as early as next spring, Devereaux estimated.

Peter L. McGuire can be reached at 781-3661 or pmcguire@theforecaster.net. Follow him on Twitter @mcguiremidcoast.