The invasive, venomous lionfish is killing Atlantic reefs. So please eat it.

KEY LARGO, Florida — What do you do with an invasive fish, covered from head to fin with venomous spines as sharp as hypodermic needles; a fish that can’t be caught with a rod or in a trawling net as it multiplies rapidly, deep in our oceans, flummoxing fishermen and scientists alike?

Conservationists are hoping you eat it.

The Indo-Pacific native lionfish arrived in the Atlantic about a decade ago, the product of well-meaning aquarium owners who released their charges into the ocean, not realizing they reproduce at an alarming rate, prey on more than 70 species of fish and hasten the dying-off of any coral reef they alight on. Scientists describe their invasion into Florida’s waters in the same words noted Key West fisherman Ernest Hemingway used to describe the onset of bankruptcy: slowly, and then all at once. Now estimated to number as many as 1,000 fish per acre, lionfish also have no known predators — except humans.

“They grow very quickly, so they can reach sexual maturity in less than a year. They eat a tremendous amount, and our native marine life don't see them as a threat,” said Lad Akins, a lionfish expert who recently retired from his job as director of special projects at the conservationist organization REEF.

Along the way, the fish, which can grow up to 17 inches, have decimated a number of ocean populations ecologists would prefer to see thrive: ornamental reef fish that draw tourists to Florida, commercially attractive fish like grouper and snapper, and ecologically important fish like grazers, which gobble up harmful algae.

With no natural predators, and the reefs to protect them from fishing lines and trawling nets, there’s really only one way for humans to kill these abundant fish: one at a time, by hand, with a spear or a small net. But for that to have any impact, there’s got to be a market. And that, Akins says, is the lionfish’s only real vulnerability: “They taste so good.”

Ryan Chadwick, an entrepreneur who owns restaurants in New York City, Aspen and Montauk, says that he first encountered lionfish in the Bahamas in 2014. He started spearing them, shearing off their venomous spines, and flying coolers-full back to New York, where he made them the star of a Caribbean-themed restaurant he owned at the time, replete with waiters trained to explain the lionfish problem.

Suddenly, he found a city full of enthusiastic lionfish predators.

“It caught on. It was quite popular. People were calling the restaurant to see if we had it,” Chadwick said. “If we don't have it, they won't come in until we have it on the menu.”

As the fish took off in his restaurants, Chadwick’s one-man cooler business turned into a full-fledged commercial operation, with a network of commercial divers, and distribution contracts with megastores like Wegmans and Whole Foods.

Chadwick says his company, Norman’s Lionfish, currently buys whole fish for about $6 a pound and sells them for about $8.95. He offers them as entrees in his restaurants for around $28 — about the same amount he’d charge for a grouper, which, unlike lionfish, is in growing danger of overfishing. In 2016, after the Monterey Bay Aquarium in Northern California endorsed it for consumption as a top sustainable catch on its influential Seafood Watch list, Whole Foods got on board. Their fillets currently sell for $9.99 a pound — about on par with what the store charges for wild salmon, and less than half the price of wild-caught grouper.

Conservationists were thrilled. “We have been so good as humans in wiping out fish stocks, because we eat them, and especially things that taste good,” Akins said. “If you eat a lionfish, you’re not eating a threatened grouper, or you're not eating a conch, or a lobster, that may need time to recover.”

But getting lionfish on the menu is just the first step.

Celebrity chef Tom Colicchio used to offer a lionfish taco at his now-shuttered Miami restaurant Beachcraft, donating a dollar per order to a conservation fund. He sees two major problems in the lionfish market: Not a lot of casual diners know what they are, much less why they should be eaten, and without a consistent supply, it’s a risky gambit, even for restaurants that do want to educate customers. Getting a steady supply of lionfish for Beachcraft before it closed in 2017 was “really hard,” he said — and that was only the start.

“I don’t think the average customer knows the issue. If you put lionfish on the menu, you have to explain it to them,” Colicchio said. “I think once you explain it, people are interested, but it’s a hard sell.”

So far, lionfish is most commonly found on the menu in restaurants in Florida, but according to REEF, interest is spreading nationwide. Chadwick says the 15,000 pounds he purchases annually aren’t enough to keep up with demand from restaurants, a frustration echoed by chefs. And even that haul is sometimes limited by weather, since his network of divers need visibility to spear the fish. Some restaurants, like Fort Lauderdale’s Piccolo Ristorante, have resorted to creative marketing, serving lionfish whenever they can source it and sending out blast emails to let people know when it’s back in stock.

Chadwick’s focus now is on getting teams of commercial divers, both in the U.S. and abroad, permanently focused on lionfish — at least until technology enables an underwater evolution away from primitive spear and net hunting.

Spurred by advances in robotics and a spate of government grants, inventors are currently testing out things like underwater drones that can zap and vacuum up the fish at depths far deeper than humans can traverse, smart traps that are able to snap up lionfish without trapping other species, and even fake lionfish noises that can be used as lures. The issue has even inspired legislators from both sides of the aisle to come together in a bipartisan effort to “award competitive grants to combat the certain species of lionfish in the Atlantic Ocean and the Gulf of Mexico.”

But until those large-scale inventions come to fruition, commercial fishing likely won’t be enough to offset the lionfish’s explosive growth or ecological and economic impacts. Akins says when a single lionfish is present in a lobster trap, the catch can be reduced by more than half, and recalls dissecting a foot-long lionfish to find 64 different species of fish — and a shrimp — in its stomach.

The phrase “mating like rabbits” should also really be changed to lionfish at this point, Akins says. In 2010, he did a weeklong survey and removal team dive in Florida that yielded about 50 lionfish. When the team returned nine months later, he says they gathered more than 500 from the same site.

That’s where the derby circuit comes in.

Like a well-organized flotilla, conservationist groups have organized a reserve unit of recreational divers in the watery showdown. The competitions happen only a few times a year, but their combined impact on the lionfish population can be substantial, allowing native fish populations to recover at rates as high as 95 percent. Akins says ecologists don’t like to use the “e word” — eradicate — but notes that there’s a growing consensus the population can be kept below a threshold where they can cause harm.

On a warm September morning in Key Largo, Florida, 15 teams of divers set off before sunrise for a race a hundred feet below the water’s surface. The competitions, which take place fairly regularly in Florida and the Bahamas, draw recreational divers of all ages and from all walks of life with prizes for overall hauls, biggest fish, smallest fish, and first-timers. One contestant got the entry fee as a gift for his 12th birthday.

The impact of the derbies on the environment is not insignificant. According to REEF, more than 23,000 lionfish have been removed in its derbies since 2009. And studies show that on average, single-day derby events can reduce the population of lionfish by 52 percent across almost 200 square kilometers of area.

“We didn't expect that kind of positive result. But when you have those divers out there scouring the reefs removing every lionfish they can find, it really does knock the population down,” Akins said.

There’s a friendly rivalry among the regulars, some of whom gathered the night before over beers at a nearby beach bar to strategize the best hunting grounds and lob pleasant insults at one another.

“We have some [rivalries], but we're all really friendly at the end of the day. It's fun to poke at each other, and try to text, and check their Facebook during the day, just to see what they might be doing or where they're going,” said Emily Pepperman, an IT specialist with a background in diving.

For this competition, Pepperman, who’s competed in nine derbies so far this year, joined forces with Allie ElHage, the inventor of the Zookeeper, a plastic tube that enables spearfishers to store their catch while hunting underwater.

“This is addictive,” ElHage said. “Hunting lionfish is addictive.”

Pepperman, who speared her first lionfish about seven years ago in the Bahamas and promptly ate it for dinner, jumped at the chance to participate in a sanctioned hunt.

“I'd already started collecting them for a few years before that, so it was fun to go, ‘Oh you mean we can have fun and it's a competition?’ So I got involved in derbies,” she said. Along the way, she estimates she’s speared about 400 lionfish, though at least one speared back, leaving a small scar on her right hand. By the end of the recent Florida Keys derby, she had speared an additional 60 fish, putting her in eighth place — the lowest she’s ever scored, which she attributed to the strength of the competition.

The idea for the derbies actually started at a bar in the Bahamas in 2009, Akins said, after a female snorkeler raised the alarm. The first derby, which had about 14 teams competing, yielded more than 1,000 fish in a single day. The derby in Key Largo last month, presented by Whole Foods, yielded 1,192.

Akins is excited by the momentum created by the derbies, bringing together what he says are often different groups at odds: the research community, the management community, recreational divers and commercial spearfishermen.

And while it’s unlikely the lionfish will ever be fully eradicated from the Atlantic Ocean, the combination of commercial fishing and derby competitions are looking like an effective method of population control. It’s kind of like weeding a garden, Akins says. With enough care and attention, the invasion can be kept at bay.

“We're not ever going to stop weeding the garden. But, you know, we can control those weeds,” Akins said.

Cover: Invasive lionfish speared by a diver in the Caribbean Sea, Dominica (Photo by Reinhard Dirscherl/ullstein bild via Getty Images)