At the public boat ramp to Quonochontaug Pond in Charlestown, a dozen volunteers wearing rubber boots and work gloves loaded thousands of pounds of clam and oyster shells into black plastic fish totes, then rolled them along a 50-foot conveyor and onto a small maroon barge. From there, the empty shells were transported to the eastern and western edges of the pond and carefully dropped over the side.
After a week of work in mid-May to ensure that the proper quantity of shell was placed in the proper locations, construction was complete on nine oyster reefs to provide habitat for juvenile fish. It will take a year or more to determine if the effort is a success, but biologists from The Nature Conservancy and the Rhode Island Department of Environmental Management are
confident that the new reefs will soon be home to juvenile
striped bass, tautog, black sea bass, scup, and summer and winter flounder.
|Oyster shells are delivered to site of new reef. Photo by Mike Derr|
“Shellfish reefs are an important habitat for juvenile fish, but the amount of shellfish reef in Rhode Island is greatly reduced compared to what we historically had,” said Eric Schneider, DEM’s principal marine fisheries biologist.
“The idea is that there are certain areas in the ponds that don’t have good structure – reefs, rocks, something that gives fish somewhere to hide – but if we build some structure, the fish will come,” added The Nature Conservancy’s Scott Comings.
The biologists said that about 95 percent of the state’s oyster population has disappeared since the mid-1900s, largely due to over-harvesting, poor water quality and diseases. In the mid-Atlantic states, researchers found that juvenile fish move right in to man-made reef habitat in areas where it no longer exists. So the Conservancy and DEM decided to give it a try.
The project got started at Ninigret Pond, where 130 tons of shell were used to construct eight reefs in 2015. Each began with a base layer of clam shells that was then covered with a thick layer of oyster shells piled up to about two feet below the waterline at low tide.
“After it’s spent some time in the water, you start to get a host of species like crabs and snails and starfish colonizing the area,” Comings explained. “It becomes a little hub of life, a mound of shell that moves and changes just as nature would intend.”
Monthly surveys of each reef using fish traps, video cameras and other techniques found that many of the expected marine species have moved in and taken up residence, including several of the targeted fish.
Where do all those empty shells come from? Local restaurants, of course. Most originate with diners at Matunuck Oyster Bar, but other restaurants occasionally participate as well. The 20,000 oysters consumed at last year’s Newport Oyster Festival are also being used in the reefs.
“This project offers me something to do with the byproduct of our oysters without sending it to the landfill,” said Perry Raso, owner of Matunuck Oyster Bar. “It’s important that we incorporate sustainability into our business model, and while it might not be easy to see the benefits of going through all this effort, we’re happy to do something that’s good for the environment.”
After the shells are collected from the restaurants, they are stored in massive piles for “seasoning” at the Great Swamp Management Area in South Kingstown, where they are turned over several times during a six-month period, just as one would turn a compost pile for better decomposition. The turning ensures that all of the shells are exposed to the air so any leftover flesh decomposes. The shells are certified by the Coastal Resources Management Council as restoration material before they are deployed in the ponds.
After the reefs are constructed, they are “seeded” with year-old live oysters – wild strains from Green Hill Pond and the Narrow River, as well as the variety used at aquaculture farms – in hopes that the empty shells will eventually be covered with living oysters. The biologists also hope that larval oysters drifting with the currents from nearby oyster farms will settle on the new reefs.
“Oysters need something to set on, so without the reef they have nowhere to go,” Comings said. “But while we hope the oysters thrive, this project is really about benefiting juvenile fish.”
Next year, DEM and the Conservancy will build one more series of reefs in another coastal pond before shifting to sites in Narragansett Bay.
This article first appeared in South County Life magazine on August 1, 2017.