Welcome to invasivorism, the boldest solution to ethical eating yet
Turning invasive species into gourmet meals could blunt environmental and economic costs across the US. But can Americans stomach them? Chefs and biologists are taking a gamble.
THE DINING ROOM at Juniper Bar and Restaurant in Burlington is about as bespoke as one would expect from a woodsy Vermont establishment. Ferns top tables carved at a nearby tree farm, while granite slabs hewn from a local quarry tile the walls. Even the floorboards come from a reclaimed New England barn.
Then there’s the food. As staff scramble to serve plates of pastured lamb lasagna and birch-syrup-drizzled pistachio hummus, executive chef Doug Paine watches quietly, a calm island in a hectic sea, to ensure that each morsel of porchetta and dab of aioli meets his standard of “fresh and local.”
Few diners realize, though, that when they lift a forkful of Paine’s salad, the peppery bite in the dressing comes from chopped sprigs of garlic mustard. The quick-growing European weed is notorious for pushing into Vermont forest understories and lacing the soil with a chemical that prevents native plants from germinating. On the other hand, it’s tasty, which prompted Paine to join a boundary-pushing trend that combines ethical eating with invasive-species warfare.
It’s a conflict humans brought upon themselves. Whether it’s raccoon-size rodents called nutria using massive chompers to clear-cut Louisiana marshes into mud flats or shrubby Japanese knotweed smothering local flora up and down the East Coast, there are thousands of examples with people thoughtlessly introducing a species into a new environment, then battling to bring it under control. Invasives have cost the world an estimated $1.3 trillion by ruining agricultural yields, undermining tourism, and hurting public health over the past half century. Even worse, these outlaws are responsible for roughly a third of extinctions over the past 500 years, including, in 2021, the loss of the Maui ʻākepa bird and a Hawaiian variety of flowering mint. There are now 4,300 nonnative types of wildlife in the United States destructive enough for conservationists to label them as invasive.
The bold idea to eat them out of existence occurred to conservation biologist Joe Roman 20 years ago, when he developed the concept of invasivorism. Back then, it was considered more a topic for quirky cocktail conversation than a serious scientific discussion. Over time, however, Roman, based at the University of Vermont, has watched the stars align, with research and chefs like Paine advancing the practice, and individuals in general taking an interest in the ecological consequences of their gustatory habits.
“We‘re on the very edge of when this idea takes off,” Roman says.
[Related: Citizen scientists make great invasive-species detectives]
Like any chef worth their sea salt, Paine was acutely aware of trends in ethical dining. He saw that the granola-and-arugula-crunching crowds of Vermont particularly valued eco-friendly choices: Here, eating is about sustaining the land as much as it is about sustaining the body. Paine says the tiny, rural state “is among the world leaders of locavore cuisine” with its high density of vibrant farmers markets. The Union of Concerned Scientists ranked it first in the nation for its local food infrastructure—and that was before the state implemented a $500,000 program to pay public schools to put more community agricultural products into student lunches. Paine experienced this ethos firsthand during a childhood filled with gardening and rambling hikes in the woods. By the time he came into his own as a chef, using foraged and regionally sourced ingredients was second nature.
Paine’s vision of sustainable food gained a new dimension in 2017, when one of his suppliers, shrimp farmer and marine biologist John Brawley, approached him with an unusual request. He needed someone to cater an invasivore-themed lunch for a class Joe Roman was teaching at the University of Vermont.
Inspired, Paine started involving Juniper Bar and Restaurant in the invasive-species cooking experiment. It was surprisingly easy, he explains: He would occasionally slip 5 or 10 pounds of an exotic ingredient into the dinner service by, say, blending mild yet tangy bishop’s weed into a soup or making tart Japanese knotweed shoots into a sorbet.
As he thinks back on those recipes from the past five years, Paine walks into a large cooler behind the kitchen that holds neatly labeled containers of radishes, slaw, hummus, peppers, and a smattering of invasives. Sometimes there’s a 5-gallon bucket of European green crabs waiting to be turned into a delicate bisque. Or maybe periwinkle snails that Paine treats like escargot—boiled, pried out of their shells with a toothpick, and centered on a plate swimming with garlic-infused butter.
One species he longs to add to his menu is the sea lamprey, a slimy, eel-like infiltrator that uses a circle of monstrous teeth to suck out the bodily fluids of its scaled prey. Within decades of being accidentally introduced to some of the Great Lakes in 1919, the Atlantic and Mediterranean migrant was destroying commercial angling of trout and walleye in the region. It also likely caused the extinction of three endemic fishes: the longjaw cisco, deepwater cisco, and blackfin cisco. But Paine, and chefs with a similar eat-’em-to-beat-’em spirit, see pickled, smoked, and beer-battered promise in the devil’s flesh.
THE MODERN NOTION of invasivorism was born from a tizzy over the European green crab, a palm-size crustacean so successful at stuffing mussels, clams, and scallops into its tooth-lined stomach that it cost American fisheries nearly a billion dollars in lost revenue between 1975 and 2000.
The year 2000 also marked when Roman set out to decipher how, precisely, the crab had made the leap from European waters to North America’s Eastern Seaboard. He soon found himself elbow deep in a chilly Nova Scotia tidal pool, pulling dozens of slimy, pinching scuttlers out of the salt water for DNA analysis. “It was a great gig,” he recounts.
As Roman worked, he was distracted by another man just yards away removing handfuls of another European shellfish, the common periwinkle, which is problematic because it outcompetes native snails and carries nasty parasitic flatworms.
It’s not every day that one guy collecting invasive aquatic animals from tidal pools bumps into another, so Roman struck up a conversation. He learned the man was selling the periwinkles to fish markets that supplied large cities such as Boston and New York. The encounter gave Roman the idea of drawing a direct line between green crabs and Earth’s ultimate apex predator: humans.
“As a conservation biologist, most of my time was spent telling people not to harvest,” Roman says, “but here was a case where I could tell people to harvest as much as they wanted.”
Head spinning, Roman went home and wrote a seminal article that was published in Audubon magazine in 2004. “Just look at our track record: Atlantic cod, bison, right whales, and Pismo clams have all but disappeared due to our voracious demand,” he noted. He urged everyone to turn this avarice against invaders with advice like “Instead of dressing your yard with herbicides, you might want to consider balsamic vinaigrette.” He also published a handful of easy recipes to get readers started.
Then he sat back and waited for the world to recognize the solution he had presented. It was a long wait. “The response was crickets,” Roman says. “And not invasive crickets.”
By 2010, the economic impact of invasives in North America alone had grown to $26 billion per year. In the Florida Everglades, Burmese pythons had squeezed up to 99 percent of native populations of deer, bobcats, and raccoons out of existence; in Michigan, emerald ash borers had felled tens of millions of ash trees; and in the Chesapeake Bay, wriggling snakehead fish could have crowded out their neighbors.
Roman decided to make his appeal for invasivorism another way. That year, he started a website, EatTheInvaders.org, to try to convert foodies with an appetite for the unusual into believers. His weapon? Visions of plates piled high with periwinkle fritters and European crabcakes.
NO MATTER HIS AUDIENCE, Roman always came back to the argument that invasivorism could turn unwanted mountains of exotics into manageable molehills. He likens it to biologists killing off caterpillar populations in an area by releasing hordes of predatory wasps. “It’s a form of biological control,” he says. “It’s just using us instead of an insect.”
But he acknowledges that not all scientists agree with him. Daniel Simberloff, a conservation biologist with the University of Tennessee, blasted invasivorism for its potential to unintentionally perpetuate the presence of the very species it is meant to eradicate.
“Creating a market engenders pressure to maintain that problematic species,” Simberloff and his co-authors wrote in Conservation Letters in 2012. In other words, building demand for invasives on consumers’ plates might actually encourage their persistence in the long term.
Simberloff’s paper rekindled the debate over invasivorism within the conservation community. That led two biologists, Susan Pasko and Jason Goldberg, who both now work for the US Fish and Wildlife Service, to seek answers. “We wanted to bring some objective data and science to the argument,” Goldberg says.
In their paper, published in 2014 in the journal Management of Biological Invasions, they reviewed programs that incentivized harvests with bounties and other rewards and searched for commonalities among successes and failures. They compiled 11 recommendations for wielding invasivorism as a strategy. For example, one needs to know the minimum viable population of a species and put in place controls to ensure that it isn’t immediately reintroduced.
They learned that, as with most unwanted things, prevention is the best and cheapest way to keep invasives out of an ecosystem. But once that fails, they found harvest incentives have real potential.
“We look at it as another tool to manage invasive species, and like any other tool, it is something that needs to be carefully planned,” Pasko says. “Are you going for complete eradication or just focusing on managing populations in high-priority areas?” However, the study warned that even light predation by humans could stimulate biological overcompensation, similar to when damaged plants rebound by producing more seeds, or coyotes react to culls by having large litters.
Goldberg and Pasko agree that invasivorism’s ability to capture the public imagination has been a big boon. “Eight years ago, when we wrote that paper, even my family barely knew what an invasive was,” Pasko says.
Roman calls their work an important step forward and key to incorporating invasivorism into conservation policies. The research also led to more practical ideas about how harvesting can work.
In 2019, Jesse Bull Saffeir drew on Goldberg and Pasko’s work to propose a set of criteria to determine if a region’s invasives would make good targets. Saffeir, then an enterprising study-abroad student focused on climate change and food security in Iceland, concluded that four of the island nation’s 19 recognized invasives—the rock crab, European flounder, brown shrimp, and European rabbit—would be ideal candidates for culling, because, among other things, they are easily harvested and have a high population density. On the industrial side, she found there must be an existing commercial infrastructure that can be easily repurposed to the task: say an existing fishing industry that could be nudged into pursuing an invasive so a new fleet doesn’t have to be built for the job.
Given those factors, it’s easy to see why the lionfish, a Pacific looker with a mohawk of poisonous spikes, has been invasivorism’s most brilliant success. In the 1990s, it began eating its way through the native inhabitants of coastal reefs in the Southeast US and the Caribbean. Once Jamaican fishermen learned to handle it safely and bring it to market, lionfish sightings in that region declined by two-thirds. Meanwhile, in the Bahamas, native reef fish rebounded.
State officials hope that incentive programs can work on a small scale too. In Vermont, they’ve distributed invasivespecies recipes and encouraged elementary school students to turn garlic mustard into pesto. In 2020, Colorado anglers were handed $20 per northern pike. And the Idaho Fish and Game Commission created a system for culling unwelcome rainbow trout by implanting microscopic coded tags inside some individuals’ noses; anglers who snag one can win $50 to $1,000.
However, Saffeir also identified the nonnegotiable baseline in determining whether the human appetite can be harnessed for ecological virtue: The fugitive flora or fauna must taste good.
FROM THE START, Roman touted invasivorism by coupling his message with how-tos. He wanted people to see nutria as not just a swamp rodent but also a potential egg roll ingredient. It remained a hard sell.
And so, as the years passed, he began collaborating with professional cooks, who proved far better at dressing up invasives as culinary delights. “I’m a biologist,” Roman points out. “If I tell you crabs are delicious, you’re unlikely to listen to me. But if you go to a restaurant and Chef Bun serves you this, that’s probably the best way to convince you.”
That would be Bun Lai, a sushi artist in Connecticut who was already making his mark as a leader of the ethical dining movement when he and Roman teamed up for some high-profile invasivorism projects. In the fall of 2014, the pair served wild boar and Asian shore crabs to other interested experts and foodies from around the world at the Chefs Collaborative Sustainable Food Summit in Boulder, Colorado.
Lai’s ability to consistently turn the abstract idea of invasivorism into a real-life mainstay of high-concept menus has made him a celebrity chef and netted him the 2016 White House Champion of Change Award for Sustainable Seafood.
In 2020, he closed his restaurant, Miya’s Sushi, in favor of pop-ups, catering, and “restorative eating experiences” at his farm, at prices of up to $425 per person. A meal might start with slivers of cannonball jellyfish (Lai says their population has exploded along the Georgia coast due to climate change and ocean acidification) and Florida lionfish sashimi with Kiribati sea salt; main courses include Asian shore crab (overwhelming native mud crabs in Chesapeake Bay since the 1980s) seasoned with invasive plants and gyoza dumplings stuffed with wild boar (from Texas, where their crimes include gobbling up endangered sea turtles). All this might be capped off with mochi ice cream flavored with a plant harvested from Lai’s property: mugwort (known for copious amounts of allergy-triggering pollen and an aggressive underground root system that shoulders aside native plants).
Lai is full of the virtues of invasivorism, which he argues has crucial benefits for the planet. Substituting wild boar and nutria for beef lowers greenhouse gases, he says, while eating weeds reduces the need for the 5 billion pounds of harmful pesticides and herbicides used globally each year.
He says there are real signs that the movement is reaching critical mass. A few years ago, he couldn’t source any invasive species from supply chains. But a combination of public awareness, government support, and market interest has made it possible for people curious about cooking and eating undesirables to overcome logistical barriers. A key breakthrough happened when Lai successfully lobbied the Monterey Bay Aquarium to recommend lionfish and blue catfish on its influential ethical sourcing list, Seafood Watch. Today, he can easily procure these, as well as silver carp from Kentucky.
The change isn’t limited to restaurant supply chains. In 2016, grocery giants Whole Foods, Wegmans, and Publix began offering lionfish, promoting it along with recipes for coconut curry. Dog-treat companies are incorporating nutria and Asian carp into their regular offerings.
Ultimately, the success of the invasivore movement relies on eaters who are willing to seek out sustainably sourced food, whether at restaurants or for their own kitchens. Vermont’s conversion to that ethos is on full display among a robust community of foragers whose Facebook page boasts 11,400 members. If Lai is making waves at the haute cuisine end of the locavore spectrum, these folks are making a splash at the other end, where everyday people are turning nature’s invasive bounty into home-cooked dishes.
[Related: How to forage your way through your neighborhood]
Even as Chef Paine navigates meal prep at Juniper, longtime forager Melanie Brotz can be found at nearby Callahan Park, picking her way through more than 60 species of edibles, including Japanese knotweed, which she describes as resembling “a really chunky asparagus.” She sometimes sees it hawked at local farmers markets for more than $12 a pound.
“Eating food closest to how you would find it growing is the healthiest thing to do,” says Brotz, a registered dietitian. She hopes to organize a local invasivore festival featuring recipe contests and tastings.
Roman has noticed the trend flourishing in tandem with the forager community. As that momentum has built, it has been matched by a burgeoning body of academic research and commercial interest, an emerging network of interested culinary experts, and mounting numbers of government-funded bounty and harvest campaigns. It all adds up to an idea that’s creeping in from the fringes.
Now that he’s comfortable cooking invasives, Paine says his own enthusiasm, and that of his invasivore diners, isn’t likely to diminish anytime soon. He sees the movement growing.
“It can be scaled up,” he says. “If you think about truffles or wild fish, all those markets have been developed over time. I think invasives can find that same path.”
This story originally ran in the Winter 2021 Taste issue of PopSci. Read more PopSci+ stories.