For several years while teaching at the University of Vermont, Joe Roman, a conservation biologist, challenged students to an unusual exercise. Design an animal ideal for the role of marine invader, he’d say, a creature with the natural traits to colonize a territory not its own and, in the relentlessly competitive scrum of the wild, establish itself sturdily for the long term. Roman has spent decades studying how species travel the globe, multiply beyond pioneering toeholds to something like ubiquity and change ecosystems. His classroom exercise invariably landed as a living example on one little-known but astonishingly widespread member of the animal kingdom: the European green crab. Small, fertile, rugged and fueled by an expansive appetite, the species, he says, is “an exemplary invader, a perfect invader.”
European green crabs originally hail from the northeastern Atlantic Ocean and the southwestern Baltic Sea. Roman ticked off traits that helped them conquer much of the world. As omnivores, scavengers and cannibals, they sustain themselves on almost any organic food. They have a high fecundity, with females releasing as many as 185,000 eggs a year. They survive in water temperatures from freezing to 86 degrees Fahrenheit and tolerate sweetwater zones where salt meets fresh. Moreover, adult European green crabs can live 10 days or more out of water. Taken together, these characteristics explain why they were first documented along the United States coast in 1817 and continue their tour of the temperate world.
My curiosity about European green crabs began after witnessing their near indestructibility beside my own home. Our family fishes commercially in New England, where we grow or catch a substantial portion of our food. About 15 years ago, my children and I began capturing bushels of European green crabs for use as fertilizer. The process was simple. We harvested crabs in baited wire-mesh traps in an estuary in southern Rhode Island. Every so often we’d transfer bushels into coolers of tap water, where we expected they would die, as lobsters quickly do when immersed in fresh water. We’d then dump their limp carcasses into compost piles and cover them under a foot of decomposing leaves, vegetable scraps and manure.
One day not long after one of these deposits, a neighbor arrived at our yard’s edge. He seemed bemused, and he asked if I knew anything about the crabs picking their way across his property. He had discovered the exploded chitin exoskeleton of an itinerant crustacean after hearing a thunk under his lawn mower. Yes, I admitted, I did. Upon inspecting the compost, we found that an untold number of crabs we thought dead had unearthed themselves and walked off. Over the next week we found more — hiding in shade, crouched under purple dead-nettle, pressed against the base of a shed. A murder of crows feasted on them. Crabs kept turning up.
If self-exhumation and hundred-yard crab-walks sound like useful skills for population expansion, they are. But when I recounted the story for Roman over a crab dinner, he smiled knowingly and suggested that the amphibian prowess of an adult European green crab, impressive as it was, was not the species’ most infiltrative trait. That title was better assigned to the survivability of their larvae.
After hatching from eggs, larval green crabs drift for 60 days or more, which means they can ride oceanic currents for months to settle in new locales. Combine this natural endurance with patterns of human logistics, and a mechanism for planetary dispersal becomes clear. The first arrival of green crabs in North America, Roman says, were most likely adults clinging to ballast rocks and bricks in wooden ships. In more recent generations, globe-roaming cargo vessels have taken on seawater in ports as ballast, ingesting an uncountable quantity of green-crab larvae and discharging them wherever each vessel moored next. The scale can stretch the imagination. “In the ballast of a single ship,” Roman says, “you can have tens of millions of larvae of green crabs and other coastal species.” Most other larvae, he said, don’t survive long journeys. Green-crab larvae do. Aided by these skills, green crabs have established themselves in the Pacific Northwest, Japan, South Africa, South America and Australia. (Many modern ballast systems now have filtration and treatment systems to prevent the movement of small organisms.)
The crabs’ adaptability carries serious consequences for inshore habitat and fisheries in the Northeastern United States. European green crabs are voracious and feed on native crabs, shellfish and juvenile lobsters, driving down local abundance. In the process, they uproot native plant species, weakening marine nurseries and storm buffers created by eelgrass and spartina. Mary Parks, founder of GreenCrab.org, a nonprofit that educates the public on the harm green crabs cause, says their estuary-altering characteristics amplify the erosive effects of climate change; because they face few local predators, she added, their populations can explode. An exception appears to be an estuary on the California coast, where green crabs are enjoyed by sea otters.
The damage in New England drove Roman and Parks toward a shared goal: mitigating the crabs’ effects by encouraging people to be like those otters. Roman is founder and editor of the Eat the Invaders website (“Fighting Invasive Species, One Bite at a Time,” its banner proclaims), cementing his position in the movement to put nonnative plants and animals on plates. “As a conservation biologist, my goal is not to kill anything,” he says. “I wish it was that simple. I’m in this to protect native biodiversity. A lot of times when species are having an ecological impact, just letting it run its course is not always the right answer.”
Some invasive species don’t lend themselves to eating; lanternflies won’t be on your favorite local restaurant’s menu any time soon. When it comes to crabs, the idea has promise. Americans consume enormous amounts of seafood, and several favorites — tuna, scallops, lobster, salmon, summer flounder, striped bass — can be prohibitively expensive for many households. It’s not hard to imagine low-cost crabs finding a customer base. They are abundant beyond measure, easy to catch and enjoyed in Italy and Spain, where diners eat European and Mediterranean green-crab eggs or molting whole crabs as delicacies. I know how delicious the crabs can be firsthand, as my family renders batches of green crabs into a savory, full-bodied stock. The result becomes the basis for ramen.
There’s one obstacle to eating our way out of the problem: A big bull green crab might boast a carapace four inches across. Most are considerably smaller. The carapace of a prized Maryland blue crab, for comparison, can spread nine inches across. The green crab’s small stature means their tiny claws, legs and the segmented chambers of their bodies — the parts people typically devour — are difficult to pick, which can make for time-consuming preparations and tedious eating. The species possesses many traits that aid its spread; its small size is the one that has protected it from human consumption, so far.
Zack Appeltofft eased his skiff alongside a yellow-and-green buoy floating above a serpentine channel on the Great Marsh, the estuary straddling the Massachusetts-New Hampshire line. Reaching for the buoy, he pulled a crab trap up through murky water and shook out a dense mass of crabs into a sorting box. Several dozen green crabs righted themselves and scurried to corners, seeking escape. The sound of legs scratching wood rose over the skiff’s idling engine. Working fast, Appeltofft swept the crabs through a hole in the box down into a sack, then throttled to the next trap. It was packed with green crabs, too. So was the third trap, and the trap after that. On it went, across the marsh.
A young clam harvester who yearns for a long career on the water, Appeltofft has watched the crabs’ effects up close. His clam catch has fallen as the crab population has soared. “We’re digging like three times less than we were,” he said, of the soft-shell clams, known as steamers, that provide his livelihood. The natural channel where he trapped crabs, he said, was formerly hemmed tight by marsh grass. Now the channel is wide. Scientists differ on how much damage green crabs do to plant communities. Appeltofft says their effects where he fishes are severe. “The crabs make burrows and turn the marsh into Swiss cheese,” he said. “Then storms come and peel the marsh away.”
He nodded toward Crane Beach, a natural sand barrier that has receded for years, exposing the estuary to waves during nor’easters. The marsh, he said, has lost resiliency to withstand powerful waves that roll through the widening gap. How this dynamic will play out is anyone’s guess. Appeltofft sees depressing possibilities: a retreat of vegetation; a dwindling of biodiversity and fisheries; an increase in erosion threatening roads, businesses and homes.
Declining clam stocks prompted Appeltofft to participate in a crab cull, even if markets remain stubbornly small. He pursues a three-pronged approach. On this day he planned to drop sacks of crabs at a farm for composting. On other days he provides crabs to tackle shops, for resale as bait. A portion of his catch also goes to Wulf’s Fish, a seafood wholesaler and retailer in Boston that sells green crabs online.
Wulf’s claims to be the first company to offer invasive crabs nationally. It introduced its frozen European green crabs in 2021; the company sold about 2,000 pounds the first year. “It was a ton of green crabs that hadn’t been removed from the water before, so in that respect it was a lot,” says Alisha Lumea, the company’s vice president for marketing. “But compared to anything else that comes through our warehouse it was a very, very minuscule amount.” Several chefs have since taken interest, and demand has ticked up slightly. Sales in 2024 reached 3,000 pounds, all of them provided by Appeltofft.
Wulf’s can feel like a glimpse into the future, if only because green crabs are not alone as an untapped nonnative food source awaiting a market. Many crabs are adept stowaways; other species have traveled far, too. The blue crab of the United States’ eastern shore, a culturally important species indelibly associated with the Chesapeake Bay, has colonized the Mediterranean Sea, where fishing communities and ecologists worry over its effects. In the Northeast, European green crabs have yielded habitat to a more recent arrival, Asian shore crabs, which are native to the western Pacific Ocean from Hong Kong to Russia’s Sakhalin Island. One egg-bearing Asian shore crab was discovered near Delaware Bay in 1988. Recognizing an opportunity to study an invasion’s real-time expansion, scientists tracked the spread. It happened quickly. By 1995 Asian shore crabs were documented from North Carolina to Massachusetts. By 2012, the species became, according to scientific literature, “the dominant crab in rocky intertidal habitat along much of the northeast coast.”
Asian shore crabs tend to be more aggressive than their cousins from Europe, and eat shellfish and other small crustaceans too. The combination led to predictable results. In rocky areas where European green crabs once swarmed, Asian shore crabs have generally driven them off. The coastline where I live is now dominated by these two crustaceans: crabs from Europe in mud and marsh; crabs from Asia in the rocks. Almost no one is eating any of them.
Marking them for consumption based on their origin alone comes with a potential for hypocrisy, including selective use of the word “invasive.” Honeybees aren’t from North America, but there is no movement to knock their numbers down. Instead, there is substantial public distress around stories of their decline. You won’t often hear them called “invasive.” House cats are not native, either, and kill enormous amounts of indigenous (as well as invasive) wildlife every year. They remain immensely popular. Moreover, origin stories do not predetermine ecological effects; many native flora and fauna can cause harm.
Whatever label best applies to nonnative crabs, their rich taste positions them well for reconsideration. To put a dent in populations and enjoy free local food, some harvesters eat them whole, either seared, stewed, boiled or fried. “Deep fried green-crab bodies, I’m telling you, would be an excellent bar food,” says John Painter, a harvester and home cook in Maine who has been experimenting with recipes. “If you like seafood, it’s freaking amazing.” Painter is among the harvesters experimenting with holding green crabs in floating cages until they molt and can be eaten as soft-shells, a preparation rivaling the flavor and consistency of the soft-shell blue crabs of the Chesapeake. Other cooks shatter hard-shell whole crabs under a heavy object or in a blender, then boil the mash — techniques mimicking preparations in Vietnam, where small rice-paddy crabs are popular in a crab noodle soup known as bun rieu. Boiling broken crabs causes the meat to float, to be skimmed for use in crab cakes, fried rice or soups.
Still, green-crab consumers remain outliers. Those who sell crabs commercially have found markets not yet clamoring for many more. Even though Wulf’s is accessible to anyone with an internet connection, Appeltofft’s catch is enough. There is no need to employ a second harvester. Wulf’s takes the long view, seeing its effort as “an environmental project and a local fisheries project,” Lumea says. “We’re doing this because we think it is an important thing to do.” To put the crabs in front of consumers, Wulf’s blast-freezes them whole, swiftly bringing them down to –40 Fahrenheit before packaging them in two-pound bags that sell for $10. The sales pitch is straightforward. “It’s crab,” Lumea says. “It tastes like crab. It’s not strange.” But for the market to expand sharply, she says, someone will have to find uses with the mass appeal of an industrial-scale product. “That will be a tipping point,” she says. Until then, the movement relies on restaurants to put green crabs before the public. “Chefs,” she says, “are so important in helping make the fashion.”
One chef who has worked green crabs into his cooking is David Standridge, who with his wife, Kathleen, founded the Shipwright’s Daughter, a restaurant in Mystic, Conn., that emphasizes sustainability. Standridge first heard of the species almost 20 years ago when the renowned French chef Joël Robuchon, whom Standridge worked for in New York, assigned him to buy crabs for a dish on the menu, and urged him to find green crabs. “He said, ‘In Europe we use them for stock, and it is the best crab for stock,’” Standridge recalls. He struggled to find them, and when the Shipwright’s Daughter opened in 2020, he still had no source.
Parks connected him to a fisherman trapping green crabs in estuaries. The restaurant now goes through about 200 pounds a week, working them into several dishes, including seared scallops on green-crab fried rice with garlic aioli and a crudo of bigeye tuna drizzled with crab-infused oil. Standridge raves about the oil he makes with his weekly delivery of live crabs, which cost about a dollar a pound. “It’s crazy,” he says. “It’s basically free.” Last year, Standridge was recognized by the James Beard Foundation with a Best Chef in the Northeast award. The honor, he said, provides a platform to promote the crabs’ value. “When you get that kind of recognition,” he says, “other people start copying you. Which is what we want.”
Another project is in the works at St. Ours & Co., of Weymouth, Mass., which hopes to make the crabs a pantry staple. For decades the company has sold dehydrated clam broth. A few years ago, after hearing Parks speak about the damage invasive crabs cause, Sharon St. Ours, the company’s vice president, decided to add green-crab stock to its product line. The method gets around the crabs’ small size by focusing on a concentrate of the species’ flavor. “It just seemed like a perfect fit for what we do,” she said. In 2023 the company received an almost $50,000 grant from Massachusetts to develop a consumer product, and it plans to reveal it, St. Ours Crab Broth Powder, at an international seafood show in Boston in March. “Our next step,” St. Ours says, “is we need customers to buy it.”
Bun Lai, a chef who has advocated for invasive-crab consumption for more than 20 years, stood in a food-preparation zone that he calls his “lab,” checking on small crabs in a dehydrator. A print of Picasso’s “Don Quixote” hung on a wall. Lai’s lab is one part of Miya’s in the Woods, a private embassy from the world of sustainable sustenance in a meadow in the oak forest of Woodbridge, Conn. It is the latest physical iteration of a food ethos formerly embodied in Miya’s Sushi, a restaurant in New Haven, now closed, that held a vanguard position in bringing invasive species to patrons. The grounds contain stands of wild invasive plants, an outdoor kitchen and dining area and a personal bistro for Lai’s guests.
Lai is not strictly an invasivore, as consumers of nonnative species sometimes call themselves. But he insists that targeted eating of certain invasive species can relieve pressures on ecosystems and be healthier than many store-bought meal choices — with the potential, he says, “to be environmentally regenerative, unlike our current food system, which is often destructive.” As long as 20 years ago, Miya’s Sushi offered European green crabs and Asian shore crabs on its menus, as well as silver carp, lionfish, mugwort, Japanese knotweed and other nonnative species the Lai family considers fine-dining ingredients that supermarkets overlook. Nowadays, with the same species, Bun and his sister, Mie, host dinners as forage-to-feast food diplomacy, with Bun as chief gatherer, supervisory cook and, not least, knowing ambassador from the world of sustainable sustenance.
All this was on display at an invasive-crab supper last year. Lai froze a sack of live European green crabs provided by Harvey Cataldo, an oyster-farming friend of mine in Rhode Island who traps crabs to protect juvenile oyster stock, along with a haul of Asian shore crabs caught by volunteers scouring the shoreline of Long Island Sound. The organization Parks leads, GreenCrab.org, promotes recipes that center European green crabs, including spicy curry green crab, Furlong bisque, green-crab-tomato soup and green-crab scampi. Lai has his own dishes to add, from appetizers to desserts. He pitched the results boldly, suggesting in essence that whatever their origins, invasive crabs are now local and merit a place on tables. “European green crabs and Asian shore crabs belong in the pantheon of New England coastal ingredients,” he said, “standing proudly alongside lobsters, oysters, clams, mussels, haddock and cod.”
Lai stepped inside to check the cooking. The European green crabs from Cataldo’s oyster farm simmered in a tall pot with water, kelp, cardamom, cinnamon sticks and Sichuan pepper. The smaller Asian shore crabs, after seasoning and arrangement on dehydrator trays, had undergone conversion to a crunchy hand food to be eaten whole, like popcorn shrimp or potato chips.
To spread awareness, Lai often invites community organizers, authors, scientists and artists to his meals. This dinner included two fellow travelers in the invasivore movement — Lula Luu and John Crilly, partners from Kentucky who have been marketing silver carp, another invasive — and Roman, the professor from Vermont. Roman chatted about scale as we ate bowls of simmered crabs in broth and congee with whole Asian shore crabs atop. “There is no way we are going to eradicate something like European green crabs just by harvesting them; I just don’t see any practical way,” he said. “However, there is this idea of functional eradication. Through harvest, you can reduce the number of green crabs in a particular area, and that can increase the proportion of native shellfish.”
In this way, Roman said, targeted crab culls could benefit areas of priority, while the crabs would remain entrenched elsewhere. Studies have shown such an effect with densities of lionfish — a spiny, venomous fish from the Indo-Pacific now abundant in the Atlantic from Brazil to the Carolinas. The fish has been targeted by tournaments and culls, and its frozen meat is sold online. In some areas, as its numbers fell, native species rebounded. “I see that as probably being a reasonable way forward,” Roman said. “Rather than thinking of them as pests, maybe they could be an opportunity. Here is a way that we could combine both our efforts at conservation as well as improving cuisine.”
Next came a custard with silver-carp roe and green-crab broth. Atop each bowl of custard sat a whole European green crab, its formerly dark exoskeleton transformed by heat to a pinkish-orange hue.
Luu spoke up. “That custard was delicious,” she said. “That extraction — I’m blown away.” Green crabs, she said, gave the dish a flavor so savory that she could envision the crabs being used to enrich a new kind of surimi, which is commonly sold as imitation crab, made with silver-carp meat. The market for surimi is vast, exceeding several billion dollars in sales a year, and projected to grow. Luu also saw ethnic markets as a potential customer base eager for small, local crustaceans. “I would like to experiment with them,” she said. “It’s an incredible market.”
For his send-off, Bun and Mie placed before each guest a bowl of ice cream made, Bun said, “out of a whole bunch of different weeds.” A dried Asian shore crab squatted on top as a garnish. It crunched like a cookie when bitten. Smiles filled the room. We could have eaten a whole bag.
The post Invasive Crabs Have Taken Over New England. One Solution? Eat Them. appeared first on New York Times.
