PHIPPSBURG — In a quiet tidal cove a few miles from Popham Beach, a team of biologists and fishermen are working to improve water quality and habitat by helping a popular delicacy gain a literal foothold in the muddy bottom.

The late-July sun was baking the air and mudflats as a team of workers dropped what looked like miniature, concrete castles into the receding waters of “The Basin” area of the New Meadows River. Although nearly impossible to see with the naked eye, untold thousands of oyster larvae were tucked into the nooks and crannies of the concrete contraptions, waiting for transplant into their new tidal home.

Oyster farming is booming in the state as restaurants from Boothbay to Los Angeles put shellfish grown in the cold, clean waters of coastal Maine on the menu. But this experimental 400-square-foot plot in The Basin isn’t aimed at the commercial market, at least not directly. Instead, The Nature Conservancy and its partners are exploring ways to help restore or build up oyster populations growing on the bottom – rather than in floating cages or bags used by oyster aquaculturalists – in hopes of encouraging more natural spawning in the future.

“This is different in that it is meant to be more permanent on the bottom,” said Jeremy Bell, aquatic habitat restoration manager with the Maine chapter of The Nature Conservancy, pointing to the heavy concrete “tiles” slated for The Basin floor. “And hopefully, as we learn the technique, you will get oyster populations growing and you’ll get the habitat protection that comes with that reef.”

The Nature Conservancy worked with the Phippsburg Shellfish Commission, the Maine Department of Environmental Protection and the Maine Department of Marine Resources (DMR) to line up the project. Located just offshore from a 10,000-acre Conservancy property known as the Basin Preserve, the plot is situated in a sheltered cove that has long drawn both commercial and recreational shellfish harvesters looking for oysters, clams and other edibles.

Eagles, osprey and gulls flew above on a recent afternoon as boaters – in small aluminum boats and high-priced cruisers – drifted through the cove roughly halfway down the peninsula best known for Popham Beach State Park. On the shoreline, about a half-dozen people worked to prepare the concrete “tiles” of oyster larvae while divers scouted out the best placement spots in the calm waters.

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Dean Doyle, a fisherman who serves on the Phippsburg Shellfish Commission, said you can still find nice, native American oysters in parts of The Basin along with the non-native European oyster commonly found in Maine. But much of the basin’s clams were lost to worm diggers a few years ago, a long-running competition that periodically erupts into tense waterfront exchanges and municipal meetings among those midcoast Mainers who work the mudflats.

Doyle said the Phippsburg Shellfish Commission supported The Nature Conservancy’s proposal.

“I think it’s a good idea,” Doyle, who also volunteers with DMR’s water-quality monitoring program. “This is the perfect area to put them. We used to have a lot here . . . Hopefully, it will work, and these will spawn and settle in the area. It can’t hurt to try.”

Oysters have long been a dietary staple of Maine residents, perhaps best illustrated by the massive shell middens left behind by Native American communities in places such as Damariscotta. And while oysters have always been popular elsewhere among some segments of the population, the bivalves are undergoing a renaissance in restaurants across the country, whether served raw on the half-shell or in some other fashion.

Maine’s oyster aquaculture industry is capitalizing on their growing popularity.

Maine DMR reported that oyster farmers hauled in a record $5 million worth of oysters – or roughly 2.1 million pounds – in 2016. That is a fraction of the value of Maine’s roughly $500 million lobster industry but represents a growing segment of a fishing industry that many fishermen and observers say has become too dependent on the official state crustacean. Oyster landings in Maine have increased 254 percent, and the harvest’s value has grown about 300 percent since 2011, according to state records.

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And while the Damariscotta River and other parts of the midcoast have long been known for their quality oysters, new oyster aquaculture leases are going out from southern Maine to Down East.

Bell said The Nature Conservancy doesn’t ever plan to commercially harvest the oysters that he hopes will soon be populating that corner of The Basin, even though they are using the genetic strain of American oyster commonly used in aquaculture. If the population grew large enough years down the line, Bell said he would be comfortable with locals harvesting some of the oysters on a sustainable basis.

But the real goal is a self-sustaining oyster population that can help improve the ecological health of The Basin and, perhaps, serve as a model for other areas around Maine.

Because oysters are filter-feeders, they are often regarded as a natural ally in the fight to improve water quality as they suck up microorganisms, sediments, nitrogen and nutrients from the water. Those activities help reduce sedimentation in the water column and encourage growth of other aquatic plants, such as eel grass. In turn, these provide food and shelter to other aquatic organisms, thereby helping with ecological diversity.

At The Basin, the team is deploying the roughly 2-foot-square tiles that look like something you might find in a tropical fish aquarium. Before arriving in Phippsburg, the tiles had been in a large tank filled with 500,000 oyster larvae. The idea is the concrete-and-rebar structures – in addition to providing a platform for baby oysters – will act like a coral reef, helping to rebuild the complex bottom habitat that provides shelter to smaller fish and other organisms that, in turn, feed larger predators. But Bell acknowledges that is just an idea.

“They tested very well down in Virginia in the Chesapeake Bay,” Bell said. “We don’t know how they are going to work in Maine.”

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The team also plans to test other methods of oyster cultivation in the hopes that one, or several, will prove successful at establishing a larger, self-sustaining oyster population and, in the process, improving water quality and habitat.

The larvae-laden tiles weren’t even in the waters, however, before the group came face-to-tiny face with one of the major challenges facing bottom-dwelling oysters, clams and other shellfish in southern Maine.

Almost on cue, small green crabs not much larger than a silver dollar began emerging from seemingly nowhere (but actually from the mud or waters) and side-stepping their ways toward the larvae tiles and piles of oyster shells. The invasive green crab has become a menace in recent years to clam and mollusk harvesters who are scrambling to find ways to stop, or at least slow, their spread because of their capacity to kill shellfish larvae.

Amanda Moeser, an oyster farmer who also leads The Nature Conservancy’s oyster conservation programs in Maine and New Hampshire, and others devised a plan to enclose the tiles in plastic cages with mesh small enough to keep many green crabs at bay. Those caged tiles were later placed in waters in The Basin deep enough for them to stay full submerged and avoid entanglements with passing boats even at low tide.

Bell said the project will have to weather the winter ice-scraping and other challenges, but he was optimistic about the tiny oyster plot.

“We could potentially do this in other places,” Bell said. “Hopefully, other groups or towns might get interested and try it.”

Kevin Miller can be contacted at 791-6312 or at:

kmiller@mainetoday.com

Twitter: KevinMillerPPH


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