Quahogs Sittin’ in the Bags in the Bays

I will eat almost any food pulled from the ocean, but since I live on Quahog Lane, eating hard-shell clams is requisite.

Pronounced CO-HOGS, these bivalves typically grow in fragrant, muddy sediment along the Eastern seaboard from Canada to Florida. When they mature to be littlenecks, cherrystones, topnecks, and chowder clams in the cooler Maine climate, their taste is buttery and sweet. They are often overlooked in these parts, though, in favor of their softer-shelled cousins, the darlings of the fried-clam set. But interest in quahogs in Maine is rising. Cultivating larger populations of quahogs can improve water quality and provide a supplemental income source to commercial clammers as soft-shell clam populations decline due to warming waters and invading European green crabs. These crabs have no natural predators in Maine, can survive freezing temperatures, and have ravenous appetites for soft-shell clams. Quahogs have thicker purple and gray–lined shells through which the green crabs can’t always permeate. As chair of the Brunswick Marine Resource Committee (MRC), I have an inside line on how my town is working on ways to grow more quahogs to market size. “Supplementing wild stocks with hatchery-reared shellfish is critical to maintaining quality food production along the shores of Casco Bay as the climate changes,” says Dan Devereaux, co-owner of Mere Point Oyster Company and Brunswick’s coastal resource manager. In early 2020, the town won a $19,000 grant from the Maine Shellfish Restoration and Resilience Fund to purchase quahog seed and cover the cost of scientific consulting and project coordination help. The towns of Georgetown and Phippsburg and the environmental research non-profit Manomet, Inc. are also running test programs geared toward rearing quahogs in Midcoast Maine.

Three-quarters of a million baby quahogs purchased from the Downeast Institute in Beals and Muscongus Bay Aquaculture in Edgecomb are spending their youth floating inside bags in the salty water at three locations around Maquoit an Middle Bays. When the tiny seed clams were planted in June and early July, they were only a couple of millimeters big. But, by summer’s end, they’d grown to the size of M&Ms. It’s not the speediest of processes, but the research team hopes that by late next summer, after two growing seasons, the quahogs will be close to 15 millimeters and hardy enough to be planted in the mud in hospitable places along the shores of the bay. There, they’ll need one or two more growing seasons before reach harvestable size. “If these quahogs survive, it will create a more sustainable resource and provide steady income for commercial harvesters,” says shellfish harvester and MRC member Cody Gillis. Other growers in Massachusetts and Rhode Island have had success nursing baby quahogs in systems called upwellers. That process, though, requires specialized, pricy equipment. The Brunswick crew, comprising five shellfish harvesters and farmers plus members of the town and state marine resource departments, is trying out a lower-tech solution. It relies on the natural movement of the tide to provide nutrients for these tiny filter feeders. They are nestled into mesh bags that are placed inside wire cages attached to floats on the surface of the water.

A logistical complication to this approach is that stuff naturally grows on all surfaces in the ocean. Colonies of colorful, gelatinous creatures called tunicates envelop the gear. Squishy, balloon-like sea squirts attach to the cages, weighing them down and curtailing water flow to the young quahogs. So, town staff frequently buzz out in airboats over the soft mud to clear off this biofouling and help the quahogs thrive. Staff also repeatedly measure and sort the quahogs, monitoring their progress and tracking data about environmental factors—water temperature, salinity, and oxygen levels. The team will correlate the factors that play into healthy quahog growth.

“I see real entrepreneurship in the face of rapidly changing and unpredictable conditions in the ocean,”

says Matt Nixon, project coordinator and owner of Muddy River Farm Aquaponics in Topsham. “Business as usual is simply no longer an option. This is a real-world example of a public/private partnership making change happen on the ground (or in the water).” To help these quahogs make it through the winter, the research team will sink most of their cages to the muddy bottoms of Maquoit and Middle Bays. About 150,000 will travel back to the Downeast Institute to overwinter in a more controlled environment. Come spring, the crew will pull them all of them to the surface and see how their survival rates may play into Maine’s future hard-shell clam supply.