While wild oysters were an important part of an Indigenous diet in what is now Maine, by the 1900s they had all but disappeared. Most people considered them functionally extinct, in fact, until this spring, when researchers from the University of Maine published a study confirming their return, often in close proximity to the oyster farms that have populated the waterfront over the last few decades.
“When we think about the emergence of wild oysters, it’s bringing back a part of the ecosystem that has been a part of who we are as people in this place, part of Indigenous people’s connections to this place,” says Heather Leslie, a marine conservation scientist who took part in the study. “It foregrounds the question of not just restoring the non-human parts of the ecosystem but also enabling the Native people to reconnect with coastal ecosystems.”
“When we think about the emergence of wild oysters, it’s bringing back a part of the ecosystem that has been a part of who we are as people in this place.”
Oysters sequester carbon and help filter sea water, making them one of nature’s most beneficial bivalves. Their appearance may be a boon for the ecosystem of the Damariscotta River and the local economy. But the rediscovery isn’t all good news: It is also a sign of warming waters that can imperil other species.
As filter feeders, oysters help to remove natural and unnatural contaminants, such as algae and pollutants, from the water. The state of Maine has encouraged oyster farming as a way to maintain clean waterways, which are at higher risk of harmful algal blooms as waters warm.
Those warming waters are not only more prone to contaminants, they are also becoming too hot for Maine’s most iconic harvest, the lobster, whose migration north will likely upset a longstanding way of life on the Maine coast.
A Comeback Story
Oyster industry experts have proposed many reasons for the disappearance of Maine’s wild oysters. One hypothesis is that the Gulf Stream—a warm current in the North Atlantic that operates like a river within an ocean—shifted gradually in the late 1800s, causing the Gulf of Maine to cool. The change killed off oysters, which prefer slightly warmer temperatures.
Additionally, in the late 1800s, oysters had a heyday of popularity among European settlers—not unlike the booming appetite for them today. The craze for oysters subsided when the bivalve population was severely depleted.
The owner of Maine’s Pemaquid Oyster Company and local historian, Smokey McKeen, has farmed oysters in the Damariscotta River since the 1980s. (Photo credit: Kayli McKeen)
Another leading cause of oyster decline was the rise of the New England state’s sawmills.
“The upper Damariscotta River had 20 shipyards,” explains Smokey McKeen, local historian and co-founder of the Pemaquid Oyster Company. “What were they going to do with the sawdust? Well, why not just dump it in the river?”
Oysters feed on ambient algae, plankton, and bacteria as they draw in the water around them. They can help keep estuaries clear and healthy by filtering out bacteria, but too much sediment, such as sawdust, can kill them.
In the mid 1980s, long after the sawdust had settled, three oyster farms opened in relatively quick succession in the Damariscotta River, bringing oysters back to Maine’s mid-coast waters. One of these was the Pemaquid Oyster Company, which McKeen established with partners Carter Newell and Dave Barry. The company still grows and sells oysters today.
While a few oyster farmers grow their oysters on the flats of tidal seabeds, most raise the bivalves in submerged cages that have holes to allow water, which contains everything an oyster needs to eat, to flow in and out.
Wild oysters grow on rocks at the tide line on Maine’s coast. (Photo credit: Sarah Risley / University of Maine Darling Center)
Until that point, most oyster farms in Maine had used Belon oysters (Ostrea edulis), a popular French type with a metallic taste that McKeen describes as “like sucking on a pocket full of coins.” The three new Damariscotta River farms were inspired by Herb Hidju, a college professor at the University of Maine, who suggested farming with Eastern oysters (Crassostrea virginica), which were once native in the region and have the sweet, rich and briny taste that oyster lovers go crazy for.
At the fledgling Pemaquid Oyster Company, the Eastern species thrived in the nutrient-rich waters of the Damariscotta River. “All the oysters grew,” remembers McKeen, “and it turned out everybody liked them, and we thought, ‘Huh, well, maybe this is more than just something to do on a Saturday morning.’ It became a thing, and it really ballooned.”
