For more than 50 years, Vesuvio, a white-tablecloth seaside restaurant here, has done a brisk business serving up local specialties caught from the Caribbean. But lately, along with menu mainstays like snapper, grouper and mahi-mahi, diners are inquiring about a new item: lionfish.

“People aren’t sure what it is,” says maître d’ José Esteves, who has been explaining the fish to would-be consumers for the past year. “But if we can sell them, it helps preserve the Caribbean and our native fish.”

Invaders from the Pacific, lionfish were first spotted in the Atlantic in the early 1980s and subsequently spread to the Caribbean. They are now found in coastal waters ranging from New York to Venezuela. Divers spot lionfish all over the Caribbean eating up small fish, many of which are key cogs to commercial fisheries and to maintaining healthy reefs.

“It’s a huge threat because they have no natural predators in the Atlantic or Caribbean and the numbers are just exploding,” says Carl Safina, co-founder of the New York-based Blue Ocean Initiative. “They are extremely voracious, eating the juveniles of just about every fish that lives on a reef.”

But the mere fact that lionfish appears on restaurant menus reflects an important, albeit gradual, shift in the Caribbean. Lionfish are becoming the hunted.

After decades of multiplying with little to no resistance, lionfish finally have a predator: humans. Across the region, fishermen, tour operators, divers and conservationists are teaming to spear lionfish, and restaurants and markets are selling them to a public that fish sellers say is gradually developing an appetite for the white, flaky filets.

“Most of the region has come quite a ways … The need for removing lionfish and marketing them for consumption is widely acknowledged now,” says Lad Akins, director of special projects at REEF, a marine conservation organization headquartered in Key Largo, Florida.

REEF encourages citizens to take lionfish by participating in fishing derbies that award cash prizes. Says Akins: “Many restaurants now have it on the menu, but there is still no large scale demand. … It may take a while.”

While the market is developing slowly, restaurants and fishmongers that sell lionfish report sales are up markedly from just a few years ago, when consumers were skeptical. Local fishermen and consumers have recognized the fish as a threat.

“Spear them,” says Carlos Sarubbi, a member of The Barracudas, a group of seven Santo Domingo bank employees who heeded the call to do something about the lionfish incursion. The Barracudas perform monthly dives in La Caleta, a Dominican marine park that was overrun with lionfish two years ago, when the group began its control efforts. “We, humans, are the only things that can control them … In La Caleta, we’ve seen a substantial drop in the population since we started.”

Humans can only dive so deep, however, and researchers believe that large lionfish more than a foot long in size lurk at depths of more than 150 feet. A submersible vessel spotted lionfish off the coast of the Bahamas 1,000 feet down.

Work is being done to develop traps and other devices that could capture lionfish at those depths.

Lionfish are ravenous, gobbling up the small reef fish that are key to keeping reefs healthy, such as parrotfish, which feed on the algae that can choke coral.

To learn just how destructive lionfish are, researchers compared the population of lionfish against that of 16 native predators on nine reefs off the coast of New Providence Island in the Bahamas between 2008 and 2010.

At the start of the period, lionfish made up 23% of the predator biomass; by the end, they represented 40%. Meanwhile, the population of small reef fish that lionfish fed on fell by 65%, according to the study, “Invasive Lionfish Drive Atlantic Coral Reef Fish Declines.”

The Atlantic and Caribbean are a virtual smorgasbord for lionfish. Some 70 different species of native fish have been found among their stomach contents. Among the fish they consume are the young of species that help support commercial fishing worth $2.6 billion a year to U.S. Atlantic and Gulf Coast states, according to National Oceanic and Atmospheric Administration (NOAA) data from 2011, the most recent available.

“We’re trying to understand just what is the impact on some of our native fish stocks and how it will influence fisheries,” says James Morris, an ecologist at NOAA’s Center for Coastal Fisheries and Habitat Research in North Carolina. Morris says lionfish consumption of young snapper and grouper is of particular concern.

Although they can go weeks between feedings, lionfish are eating so much and so frequently that Morris has found signs of obesity in captured specimens.

“We’re finding very high levels of fat content in lionfish in North Carolina,” Morris says, adding that studies are underway to compare lionfish fat levels to those of native species. “I’ve caught, studied and processed a lot of fish. It definitely stands out.”

Along with eating everything they can—their stomachs can expand dramatically during a large feeding—lionfish are also prolific reproducers.

Capable of spawning around the year, females can lay roughly 2 million eggs annually, with the larvae sometimes floating hundreds of miles.

While other native fish are capable of producing more eggs, lionfish have no predators in the region and their population has multiplied. Once localized to the coast of Florida, lionfish are now found from Rhode Island south to the coast of Venezuela.

With merlot and white striations and deceptively harmless looking fins that fan out around their bodies like manes, lionfish are visually striking.

“When I started diving in the Pacific 10 years ago, it was a really rare and exciting thing to see them,” says Serena Hackerott, a graduate student at the University of North Carolina–Chapel Hill, who is studying the lionfish invasion. “They were deep within caves on the reefs and the dive master had to find them. But in the past few years in the Caribbean, I’ve seen them on almost every reef, during the day, and boldly hovering above the coral or in open spaces around the reefs.”

While scientists hoped that native predators would start eating lionfish, new research suggests that’s unlikely.

Hackerott was the lead author of a 2013 study published in the journal PLOS One that examined whether a mass of large native predators correlated to fewer lionfish on reefs. “We found no relationship at all,” she says. “There are less lionfish in protected marine parks in general, but that is likely due to reef managers removing them.”

Researchers have tried feeding speared lionfish to large groupers and sharks in hopes that this might make them appealing as prey. But those efforts have accomplished little, with only a handful of reports of live lionfish being eaten by native species.

“I see it as a no-win situation, and I think the most reasonable possibility is that in a few places lionfish can be controlled so that their numbers are not entirely plague-like,” says Safina, who dedicated a 2013 episode of his PBS television series, “Saving the Ocean with Carl Safina,” to the scourge.

Conservationists believe that the only way to make a dent in the population is to work with local groups to regularly remove the fish from reefs.

“Control efforts can absolutely be successful,” says Ricardo Gómez, director of Mexico’s Cozumel Reefs National Park.

In late 2009, before divers and tour operators began spearing lionfish, the Cozumel park counted between 60 and 70 lionfish per hectare. Today, after regularly removing the fish, the number has fallen to 17 per hectare. Elsewhere, such as in the Bahamas, the number can climb as high as 400 lionfish per hectare.

“One of the things that we’re promoting is to include local groups in control efforts,” Gómez says. “As soon as coastal communities realize that it’s a threat to their ways of life, they will support any effort.”

Gómez worked with Cozumel fishermen to teach them how to catch lionfish—most efficiently by spear because they are difficult to catch on a line—and process the meat.

Lionfish carry a painful dose of venom in their fins, which is completely harmless to humans after they are out of the water for roughly 15 minutes. They also can carry the ciguatera toxin, which can cause food-borne illness, the U.S. Food and Drug Administration recently warned, but that is a risk associated with other reef fish as well.

More formidable than food-safety concerns is the challenge of establishing a market where fishermen can sell their catch. To do so, conservation groups are working side-by-side with restaurants and grocers to promote lionfish for consumption.

Reef Check Dominican Republic, for example, last year launched its campaign, “Eat a Lion,” in which conservationists work with chefs and well-known restaurants, such as Vesuvio, to develop recipes.

Reef Check also persuaded the country’s largest supermarket chain, Nacional, to sell lionfish alongside the calamari, conch, shrimp and Caribbean fish that have long been popular with Dominicans.

Lionfish sells for less than grouper or snapper, due to the fact that it’s less well known, but the chain is promoting the fish with in-store signs and on its social media channels.

“We also include information about how the fish is damaging the marine ecosystem,” says Hilcia Ferrúa, the organization’s executive director. “The best way to combat [the spread of the species] is to eat them, we say.”

Similar efforts have been occurring across the region, resulting in lionfish popping up on restaurant menus from Cozumel to the Florida Keys and beyond. In Turks and Caicos, the Department of the Environment pushed for sales of the fish in restaurants across the small islands, whose human population is just 39,000. The result has been a range of innovative menu items, including a lionfish pizza.

Elsewhere, chefs are experimenting with dishes involving traditional sauces or using the fish in ethnic dishes. Lionfish sushi has appeared at several restaurants. In the Honduran island Roatán in the western Caribbean, the fish even inspired a restaurant’s name, Lionfish Louie’s. Several U.S. restaurants also serve the fish.

“Our [Cozumel] fishermen are selling one ton of the fish per month, exporting small quantities to restaurants in New York and Washington,” Gómez says.

In 2011, for the first time, the lionfish catch in the United States registered on NOAA’s count of commercial landings. While the catch was small, only 1.1 tons worth a paltry $11,237, it signaled an increase in consumption.

Still, researchers say a great deal needs to be done to develop the market necessary to spur more fishermen to undertake the laborious practice of spearing the needed numbers of lionfish.

A January 2011 study published in the journal Biological Invasions concluded that roughly one-fourth of the adult lionfish population would need to be removed each month in order to cause any significant reduction in the regional population.

“What’s been lacking is a unified effort across the Caribbean,” Gómez says. But that would require broad collaboration.

Gómez says that an effort of that sort is exactly what’s about to happen. Conservation groups, NOAA, Caribbean governments and other stakeholders are set to launch a regional strategy targeting lionfish.

The group’s members are finalizing a strategy that they hope will, for the first time, result in the standardization and sharing of research, the promotion of education across the region and action by governments to adopt specific legislation to address the lionfish invasion.

“The focus here is to triage the problem,” says Morris, who represents NOAA on the committee. “We know we can’t eradicate [lionfish] or even control them on a regional basis. But we can do things like create protected areas to control them in places.”

Such protected and managed areas, where lionfish would be regularly removed, would give native species a lionfish-free environment in which to reproduce.

A regional approach is also needed to prepare for other invasive species, Morris says. “We have little experience with invasive marine species in the region,” he says.

Yet the Atlantic and Caribbean are already starting to feel the effects of yet another intruder, the Asian tiger shrimp, which can spread viruses that are fatal to the region’s native shrimp populations.

“Marine invasive species will be a major threat in the future,” Gómez says. Working together on lionfish, he adds, “will help us prepare a process that allows us to work in a coordinated way to confront the threat.”