As rapidly warming oceans continue to drive Maine lobster into more remote waters, some in the state’s fishing industry regard sea scallop farming as the prime candidate to help bring added stability to the industry and offset anticipated revenue losses.

But to fully capitalize on the species, renowned for its delicate texture and taste, the industry must solve a handful of nagging problems. Maine’s scallop fishery has been notoriously unstable over the past few decades, culminating in an outright crash in the mid-2000s from which the commercial fishery still hasn’t fully recovered.

Aside from concerns about overfishing, which Maine regulators have addressed through rotating fishery closures, harvesters also must contend with testing for biotoxins found naturally in scallops, which can add substantially to their cost.

Some believe scallops represent Maine’s best chance to offset lost revenue as the state’s commercial lobster fishery faces challenges from a changing climate. Carl D. Walsh/Staff Photographer

But automation technology and farming techniques borrowed from more mature scallop fisheries as far away as Japan are giving some Maine seafood harvesters cause for optimism. They believe the growth potential for sustainable, farm-raised scallops is nearly limitless in Maine, if they can just figure out the right approach and make it affordable.

A few Maine aquaculturists are pioneering this new frontier, but before it can appeal to the masses, the enthusiasts must figure out how to lower the costs for gear, make the technology more accessible and work out the testing requirements.

Some say scallops represent Maine’s best chance to replace the revenue expected to be lost as the state’s commercial lobster fishery faces continued threats from global warming, competing marine uses and tougher environmental regulations.


“One of the reasons we started (farming) scallops was because even though there’s a hesitancy for most people to admit it, there’s an awful lot of storms on the horizon for the lobster industry,” said Alex de Koning, of Bar Harbor-based ​mussel and oyster farm Acadia Aqua Farms. “It’s a tough nut to crack, but if you crack it, your potential … benefits are just tremendous.”

Acadia Aqua Farms has been open about its experimental approach to scallop farming and is eager to share that information with others – a practice that de Koning said is as much about building goodwill as it is about self-preservation.

If something happens to the lobster industry, Maine will need another fishery poised to pick up the slack, de Koning said. He believes scallops could fit the bill, but figuring out how to make scallop farming viable and sustainable on a large scale in Maine takes time and money.

“We’re pouring tens of thousands of dollars into trying to learn to farm scallops, and we’ve had three meals,” he said. “It’s not something you do thinking you’re going to make a quick buck, (but) hopefully, it will make it easier for the next group of people to come in.”


Valued at about $6.8 million, scallops were Maine’s third most lucrative catch in 2020, well behind the $406 million lobster fishery and the $15.6 million softshell clam fishery.


The state’s commercial scallop fishery has experienced several ups and downs in previous decades, including a near collapse in 2005, when it landed just 33,000 pounds of scallop meat valued at about $272,000, according to state Department of Marine Resources data. At the Maine scallop industry’s peak in 1981, it had hauled in 3.8 million pounds of meat valued at $15.2 million.

Following the 2005 collapse, Maine implemented new regulations to help rebuild the wild stocks and prevent overfishing, including rotating areas where scallops can be fished each year.

The fishery has stabilized over the most recent decade, bringing in a more moderate 506,000 to 796,000 pounds of meat each year since 2013, valued at between $4.6 million and $9.4 million. In 2020, scallopers harvested about 659,000 pounds of scallop meat.

Wild-caught scallops need to be shucked immediately, as the majority of a fully grown scallop can carry dangerous levels of biotoxins that can cause a slew of symptoms ranging from nausea and vomiting to seizures, short-term memory loss, and loss of motor control in the arms and legs.

Limited numbers of whole scallops are harvested in the United States, but in Maine, fishermen are required to shuck their scallops while still at sea and toss everything overboard but the adductor muscle – the meaty white cylinder typically recognized as a scallop.

The adductor, which does not take up the same levels of toxins, only accounts for about 15 percent of the total organism, so figures are generally reported as “meat pounds” rather than the total weight.


Maine scallop landings accounted for just over 1 percent of the U.S. scallop market in 2020.

That year, the United States landed almost 49 million pounds of sea scallop meat, valued at about $486 million, according to the National Marine Fisheries Service’s commercial landings database, with the majority coming from Massachusetts, Virginia and New Jersey. In 2019, before the coronavirus pandemic, the fishery was valued at around $572 million. 

U.S. interests imported an additional $195 million worth of scallops from other countries in 2020. In 2019, before the pandemic, the country imported more than $208 million in scallops.

What if Maine could pick up some or all of that business?

Dana Morse, a fisheries and aquaculture specialist at the Maine Sea Grant federal-state partnership program at the University of Maine, believes Maine is poised to capture a much larger share of the global scallop industry.

“When you take a look at the magnitude of opportunity there, it’s pretty jaw-dropping,” Morse said.


Compared with other states, Maine has a relatively shallow fishery, meaning the animals are about as fresh as they can be, giving Maine a reputation for a pretty top-notch scallop, he said.

“When the Maine scallop is right,” Morse said, “you just can’t beat it.”


All scallop aquaculture in Maine relies on the wild population. Unlike with oysters, there are no scallop hatcheries, though scientists and aquaculturists are working to change that.

Scallops are “broadcast spawners,” meaning they shoot the sperm and eggs up into the water where hopefully they’ll meet to fertilize, said Phoebe Jekielek, director of research at the Hurricane Island Center for Science and Leadership.

Once fertilized, the larval scallops float in the water column for just over a month. It’s during this period that farmers will deploy mesh “spat bags” to collect the baby scallops.


They make their way into the bags, attach with the silky byssal threads they have when young, and grow there for a while until they’re eventually too big to swim back out.

Scallops, “the most charismatic of the bivalves,” according to Jekielek, are active, constantly clapping, swimming and squirting water.

Because of this, they require a great deal of space. If packed too tightly, scallops are prone to “knifing” one another, wherein their shells get intertwined and cut the other’s innards.

As they grow to a mature width of about 4 inches, which can take over four years, scallops frequently need to be thinned out and separated.

Spartan Sea Farms owner Ken Sparta, right, stands to port as partner Owen Heil pilots their boat back to the South Freeport town wharf after tending their scallop crop recently. Among Maine’s pioneering aquaculturists, they’re seeking to supply a live, whole-scallop market. Carl D. Walsh/Staff Photographer

In U.S. aquaculture, scallops are grown using two primary methods, though other technologies are being explored.

Lantern nets, the more common of the two, are large, accordionlike nets with 10 levels that hang vertically in the water column on horizontal lines. As they grow, the scallops are re-sorted into more lantern nets and given more space.


In the other technique, called ear-hanging, once the scallops are large enough, the farmer drills a small hole in the shell and attaches a plastic pin, allowing scallops to hang in pairs from a line in the water. With the pins, the scallops are kept in place, can’t knife each other and don’t need to be thinned out.

Other methods and tools have been used, such as the bottom cages typically seen on oyster farms, as well as pearl nets and stackable trays.

It may sound simple, but the work is labor-intensive, time-consuming, costly and requires significant space – all deterrents for many who might otherwise be interested in entering the burgeoning market.


There are some technologies that can help, though.

Alex de Koning, the Bar Harbor mussel farmer, said his family has been experimenting with scallops to determine whether farming the traditional 4-inch scallop for its adductor meat can be a profitable enterprise for the business.


The de Konings recently used funds from an Atlantic States Marine Fisheries Commission grant to buy a new automatic ear-hanging machine from Tokyo-based Towa Denki Co. Ltd. to streamline the ear-hanging process.

The machine, which the farm is sharing with others, allows it to pin more than 6,000 scallops in a day, more than three times the number it could do by hand, according to a recent article in The New York Times.

Brunswick-based community development group Coastal Enterprises Inc., or CEI, also has purchased a few of the Japanese machines for growers to use.

In 2016, CEI and Friends of Aomori, a sister-state group between Maine and Aomori Prefecture in Japan, organized a trip to Japan for shellfish growers and fishermen to see how a mature, successful scallop industry operates.

A shucked and cleaned Spartan Sea Farms raised scallop in the waters off the South Freeport town wharf. Carl D. Walsh/Staff Photographer

CEI and Maine Sea Grant also purchased a high-pressure scallop washer and a lantern net washer, to help rid both gear and shellfish of the biofouling material that is prone to collect on them.

Such technologies are expensive, though, and as a result aren’t accessible to all Maine farmers who might want to try their hand at scallops. The pressure-washer, for example, is priced such that it is being passed around among multiple farms, Jekielek said.



Marsden Brewer, owner of PenBay Farmed Scallops in Stonington, has been a commercial fisherman for most of his life.

When his son, Bob, was in high school, Brewer worried about what the future would hold. Neither ground fishing nor lobstering seemed like a stable occupation, given the fisheries’ ongoing problems, and he didn’t see a lot of opportunity for himself or his son.

Eventually, Brewer decided the problem wasn’t that there were too many fishermen, it was that there weren’t enough fish. So he looked to aquaculture as a way to grow more and develop a sustainable fishery.

“I got tired of worrying about limitations,” he said. “I wanted to do something where I could maybe realize my potential.”

Now, Brewer and his adult son operate the state’s most successful scallop farm with 8 acres of lease site between them and another 3 acres pending approval from the Department of Marine Resources.


Unlike most scallop farmers, the Brewers grow petite and medium-size scallops, which don’t take up the same level of toxins and can be sold whole. The shorter growing period, a year-and-a-half to two years compared with four or more, allows them to sell more scallops. The bivalves are also less likely to knife each other when smaller, thus requiring less space and using up less gear.

Last year, the Brewers harvested about 90,000 scallops, and they expect to harvest similar numbers again next year. This year, they collected roughly 350,000 juvenile scallops, or “spat,” which will be ready in another few years. Brewer expects about two-thirds of those will make it to market.

As one of the first in Maine to try such a thing, Brewer admitted it was “pretty scary” at the outset and said there are definite challenges – frequent, expensive testing for biotoxins being one of them – but he’s grown optimistic.

Last year, Brewer and local author Marnie Reed Crowell published a book, “Recipe Ideas for Farmed Sea Scallops: The Whole Story,” showcasing recipes from around the world that exemplify cooking with the whole scallop.

International markets, especially in Asian countries, are chock full of whole-scallop offerings. In the United States, it’s more limited, with chefs currently being the main buyers, said Morse, the UMaine aquaculture specialist.

“It allows chefs … to play with new ideas, try new things,” he said. As they experiment more, “it really opens the door to more than just the scallop meat market. It’s essentially a whole new market within the United States.”


Like the Brewers, Ken Sparta, of Spartan Sea Farms in Freeport, is hoping to carve out his own path, one virtually untrodden in Maine, and grow a live, whole-scallop market.

Sparta, who grows scallops, quahogs, oysters and kelp, believes scallop aquaculture could one day eclipse oysters – one of the biggest farmed ocean species in the state.

“Certainly the audience is much bigger,” he said about scallops.

Sparta estimated he has about 8,000 scallops that will be ready for the meat market next year and another 35,000 ready for the half-shell market almost immediately, as soon as he gets approval from the Department of Marine Resources.

Spartan Sea Farms owner Ken Sparta hoists some of his scallop crop from the waters off the South Freeport town wharf as partner Owen Heill and Gregory Foote pass in another boat while tending their crop. Carl D. Walsh/Staff Photographer

With oysters, he said, you eat the whole animal and it’s just one texture. With scallops, there are three textures and three flavors. There’s the adductor muscle that everyone knows and loves, he said, comparing it to a perfect piece of steak. Then there’s the roe (the reproductive glands) which are more akin to that of an oyster in texture, and the mantle, which is almost crunchy, like minced cucumbers.

According to Jekielek, the Hurricane Island Center research director, the market presents a unique opportunity to get a fresh scallop product all year round.


“If we can develop the testing, how to safely and successfully implement a whole-scallop market, that’s pretty amazing,” she said. “It’s a really unique way to tap into a whole new area we can’t access with wild-caught right now.”

There are currently 37 leases approved to farm sea scallops, most of which are designated for multiple species and are not actively farming scallops or are not focused on scallops.


It’s the testing challenge that remains one of the biggest hurdles for developing a fully realized market for whole scallops.

Because of the high levels of biotoxins in scallops, in order to sell them safely (and legally), samples need to be tested frequently.

In the summer months, Brewer will drive scallop samples to the laboratory once per week, roughly six hours round trip, for up to $150 for a round of tests.


That drops down to every few weeks in the fringe seasons, but it’s still costly in both time and money.

“It’s nuts,” Brewer said. “It won’t kill the industry, but it’s been holding it back.”

For now, Maine Sea Grant is able to help cover the cost of testing, Morse said, but ordinarily, that cost falls to the producer. It is unclear whether the Department of Marine Resources might consider covering those costs in the future.

Some Maine scientists are working to develop a lower-cost comprehensive testing technique, which Morse said will need federal approval.

Climate change also presents a set of challenges, Morse said, but the direct impacts are still largely unknown.

For example, water temperature, salinity and other factors could impact the currents and therefore the distribution of scallop larvae, the timing of spawning, larval development and settlement, pests and potential pathogens such as bacteria. Warming waters also may have an effect on scallop growth and survival. The “sweet spot” for scallop growth is between 50 and 63 degrees.

The gear is also expensive and requires significant capital in order to produce enough scallops to be profitable. There’s no spat hatchery, so the industry is still reliant on wild scallop reproduction, which, as mentioned, may be vulnerable to climate change.

Despite these challenges, Brewer is confident that within a few years, the scallop segment of Maine’s aquaculture industry will have grown substantially.

“Right now, there’s a lot of sitting back and waiting,” he said. “Fishermen are opportunists. … Once they’ve seen someone has been really successful with it, there will be plenty of interest.”

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