by Alicia Wolfram
Nantucket oysters have earned their reputation as some of the best in the world—a claim backed by diners from New York to Europe who return to the island year after year. But what many oyster lovers don’t realize is that these briny delicacies are doing more than just delighting palates.
From filtering water to protecting salt marshes from erosion to enhancing biodiversity, oysters play a vital role in coastal ecosystems. And on an island like Nantucket, where people have been living off the water for at least 3,000 years, that role is becoming increasingly important as sea levels rise and climate patterns shift.
Most people know that oysters filter water—and they do, at an extraordinary rate. According to Town of Nantucket assistant biologist Griffin Harkins, a single oyster can filter up to 50 gallons of seawater per day.
Tara Riley, Shellfish and Aquatic Resources Manager for the Town of Nantucket, noted a drop in levels of nitrogen loading in the head of the harbor, where about 60 acres of oyster farms operate.
Sean Fitzgibbon of Devil’s Creek Oysters said Wauwinet Bay, where his 10- acre lease is located, “has never been cleaner than at the peak of summer when we’ve got all the oysters up here filtering.”
But oysters do more than clean the water.
“Coastal resilience has become a big topic in the last six or seven years,” said Dr. Jen Karberg, Director of Research and Partnerships at the Nantucket Conservation Foundation. “Particularly because we’re an island, so we’re seeing the impacts of climate change so directly,” she said, “and we’re trying to figure out how we can use nature-enhanced, existing natural solutions to make Nantucket more capable of responding to change in the future.”
In 2021, the Nantucket Conservation Foundation, with support from Brant Point Hatchery, built the first intertidal oyster reef in Massachusetts, located in Polpis Harbor. Designed to protect a vulnerable salt marsh from erosion, the reef is constructed from interlocking “oyster castles”: square blocks made of a calcium-rich concrete that young oysters readily attach to. “They’re like ecologist LEGOs,” said Karberg. “So you stack them on top of each other, and those carved-out areas on the top will interlock and create a stable structure.”
After installation, the Brant Point Hatchery provided seed oysters to populate this intertidal oyster reef. Since then, it has become self-sustaining, with oysters naturally growing and stacking on top of one another.
The reef serves two purposes: the castle structure breaks up wave energy, reducing erosion and allowing the salt marsh to expand, while the oysters themselves improve water quality and increase habitat biodiversity. Karberg said the reef is already helping the marsh grow and attracting more marine life such as fish and crabs.
Even better: the reef is built to adapt.
“If sea level continues to rise, those reefs will rise with it,” Harkins said. That’s good news for homeowners along Polpis Harbor, where flooding and shoreline erosion are growing concerns. With hard infrastructure like bulkheads increasingly difficult to permit, nature-based solutions like oyster reefs offer a promising alternative.
“We’re really looking at applying shellfish to different types of restoration projects,” said Riley, who established the Brant Point Shellfish Hatchery in 2009. Today it is still one of the few municipal shellfish hatcheries in the country that focuses solely on enhancing and restoring local shellfish populations in town waters. Each season, the hatchery produces millions of bay scallop, oyster, and quahog larvae.
Beyond restoration, oysters have become a livelihood and a signature island flavor. The island is now home to five active oyster farms, though the industry’s roots here are relatively young.
It began in the early 1970s when President Richard Nixon signed the Comprehensive Employment and Training Act (CETA), which funded public service job training across the country in an effort to counteract the nationwide economic recession. Nantucket locals proposed a soon-to-be budding aquaculture industry as a way to diversify the construction-heavy local economy. According to Egan Maritime Institute, Rob Garrison and Martin Ceeley secured Nantucket’s first oyster farm lease in 1983, planting the seed for what would become a central piece of the island’s economic and cultural identity.
Today, the process starts at an off-island commercial hatchery, where adult oysters are induced to spawn in controlled tanks. The fertilized eggs grow into microscopic larvae, and once they reach about two millimeters in size—roughly the size of a pepper flake—they are sold to farms, where they will continue growing until they reach maturity about two years later.
“You get them spread into your bags and cages and, as they start to grow, it’ll take probably two years at least for a two millimeter seed to turn into a three inch adult oyster,” said Fitzgibbon, who also co-owns Hang Ten Raw Bar.
Nantucket farmers purchase the seed from hatcheries around New England, and that’s when their work begins.
After a couple of months, the oysters outgrow their initial bags and must be redistributed to give them room to grow. “They double or triple in size, so you need to separate them into more bags so they can keep growing efficiently,” said Emil Bender, owner of Pocomo Meadow Farm and the other half of the duo behind Hang Ten Raw Bar.
He learned the rhythm early on, working on his dad’s oyster farm in high school. “Every year when I came back from college for the summers I’d work for him, and then I would reinvest half my money that I made back into the farm, into buying oyster seed,” he explained. “And after four summers of doing that, I had invested so much time and thought into it, I came home and started doing that full time with my dad and trying to expand it.”
Farms use different techniques: bottom culture (on the seafloor) and off-bottom culture (in floating cages anchored to the bottom). Bender, who uses offbottom culture, says the constant tumbling from waves and wind produces a better-looking, more uniform oyster.
Despite the island’s small size, demand for Nantucket oysters is booming. “The vast majority of all the oysters farmed collectively on Nantucket are eaten on Nantucket,” said Fitzgibbon.
General Manager of Glidden’s Island Seafood, Jeffrey Long, agrees that demand is increasing: “I ordered 4,000 oysters yesterday, and I’m down to 1,200 today,” he said. He added that local oysters are what people come looking for. “I think people in particular want Nantucket oysters when they come here,” said Long. “That’s the question we get with oysters: are these local?”
Fitzgibbon attributes the distinctive flavor of a Nantucket oyster to the island’s unique geographic position 30 miles out to sea. “We’re surrounded by the most pure, flowing, open ocean, Atlantic currents that you can imagine,” he explained. The result is a distinct merroir—the marine equivalent of terroir in wine —shaped by salinity, water temperature, vegetation, and farming methods. “We’re in full-strength seawater, right around 33 parts per thousand,” said Harkins. “They’re growing in deep water and harbor water a pretty good distance away from any freshwater input, so what you’re left with is this really briny, salty oyster.”
Matt Herr of Grey Lady Oyster said that Nantucket oysters, especially those raised at the surface, have a uniquely clean and crisp flavor. “That’s the cool thing about oysters—they take on the essence of where they’re growing,” said Bender, who operates the only shallow-water farm on Nantucket.
In addition to taste, Nantucket’s colder waters provide a health benefit that distinguishes its oysters from those farmed in warmer waters. “You have to worry about a lot of different types of illnesses down south because of the extended period of time that they’re exposed to warm water,” said Riley, who grew up in Atlanta, Georgia.
On Sunday, June 8, Nantucket celebrated its fourth annual OysterFest. The event, hosted by the Nantucket Shellfish Association and Cisco Brewers, celebrates the island’s prized oysters and the people who farm them. This year, all five farms donated oysters for a special collaboration: a Nantucket Oyster Beer, brewed by Cisco’s lead brewer Silas Gilbert.
“This beer is a tribute to all the hard work Nantucket oyster farmers take on year-round during all seasons on this beautiful island we call home,” Nantucket Shellfish Association wrote in a recent Facebook post.
Among the 5 participating farms, a total of 11,000 oysters were shucked and slurped, according to Bender.
Riley said she would like to see more public events to introduce people to the importance of shellfish. “I would love to see some other events…to make that connection between the importance of water quality and a luxury seafood,” she said.
When looking to the future of aquaculture on Nantucket, Fitzgibbon sees opportunity not just for expanding the industry, but for deepening its connection to the environment. “I think it’s one of the best things we could be doing, as far as producing a close-to-home food source, and at the same time treating our harbor more like a garden and taking care of it, instead of just relying on wild caught,” he said. “No one’s growing clams. I would love to do that.”
Farming oysters on Nantucket comes with its challenges, too.
“It’s a labor of love,” said Herr. “There are a million ways to make more money on Nantucket than growing oysters.”
But when the labor pays off and a plump, shiny oyster raised from a tiny seed is served raw on the half shell, the reward is worth it. “If you put in the time and you create a product that you’re proud of, people really seem to gravitate towards it,” said Herr. “And the fact that you can be in the environment that you thrive in is all the better.”
