SAN JUAN, Puerto Rico (AP) – Lionfish. It's what's for dinner.

Fighting a losing battle against the invasive, candy-striped aquarium fish that is the Western Hemisphere's worst oceanic menace, conservationists, tour operators and chefs are out to slow their spread the only way they know how: finding and catching them fast, and then turning them into batter-fried, roasted and grilled delectables.

The hope is that by sponsoring fishing tournaments, encouraging anglers to go after the slow-swimming species and marketing it to restaurants and diners, the region may stave off an already severe crisis that could lay waste to the delicate web of undersea life if left unchecked.

"The goal is to eat it out of existence," said US National Oceanic and Atmospheric Administration outreach specialist Renata Lana, who is organising a five-city tasting tour with celebrity chefs in the US this summer as part of a campaign to get lionfish commercialised. "This is a fish that fishermen can go out and catch without worrying about overfishing – we want to overfish it!"

The tropical native of the Indian and Pacific oceans already has colonized large swaths of the Eastern Seaboard, the Caribbean and recently the Gulf of Mexico, and threatens to wreak ecological chaos as far away as South America.

Scientists say local predators such as sharks are put off by the poisonous spines and have shown little appetite for lionfish, leaving them free to multiply and fatten themselves on a smorgasbord of smaller swimmers.

Preparing the lionfish for human consumption, however, is simple. Unlike the pufferfish – a delicacy in Japan known as "fugu" that contains lethal toxins in various internal organs – the lionfish has venom only in its spines. Once those are sliced away or burned off with a torch, the meaty filets are ready for the frying pan.

Chefs say lionfish has a mild, versatile flavour that lends itself to everything from a basic fry to marinated ceviche. It can be dried into lionfish jerky, or served raw on sticky rice as sushi.

Nicely portioned for dinner plates, the filets marry well with assertive dashes of habanero, salt and lime juice, according to Julie Lightbourn, owner of Sip Sip restaurant on the Bahamas' Harbour Island.

"It's extremely mild, so we tend to season it quite heavily," she said.

Bruce Sherman, a chef and partner of North Pond restaurant in Chicago who served lionfish during a pilot programme last year, said there's no reason it couldn't become a popular entree if diners "can overcome their aquarium bias."

"Texturally, it might be comparable in some sense to a monkfish," Sherman said. "We would put it on the menu if it were available regularly."

The trick is that lionfish often swim too deep for divers or linger around reefs and rocky crevices where they cannot be snared in commercial nets. The best and cleanest way to capture lionfish is when they venture into the shallows, by divers using hand nets to avoid reef damage and bycatch.

Nowhere are there more prowling lionfish than in the vast archipelago of the Bahamas, where they first appeared in 2004 and have been known to grow as big as footballs, gobbling up smaller creatures as if they were royalty being served peeled grapes.

Yet the local market there is still in its infancy, said Alexandra Maillis-Lynch, a caterer and chef at August Moon Cafe, the first Bahamian restaurant to start serving lionfish back in 2007.

"It is very difficult to get, believe it or not, because we just never get a consistent catch," Maillis-Lynch said. "But when I do get lionfish from fishermen, I can't serve them fast enough."

Bahamian fishermen who do catch lionfish are able to charge a relatively high market price – about $12 a pound, compared with $3 to $5 for snapper – due to the lack of a formal fishery and factoring in a premium for the risk of a painful sting.

To encourage anglers, dive shops, activists and governments have organised lionfish-catching tournaments from South Carolina to Bonaire. In the Turks and Caicos Islands, the government put up a $3,000 prize for the first fisherman to catch 3,000.

Meanwhile, a few US companies also are trying to rev up the trade, developing relationships in the Caribbean and the Gulf with the goal of establishing a reliable supply.

David Johnson, whose Minnesota-based Traditional Fisheries trades in hand-caught walleye, is looking to expand into lionfish and has contacted a half-dozen cooperatives along Mexico's Caribbean coast. He believes the lionfish has distinct commercial advantages despite the difficulty involved in the catch.

"It's good for the fishermen because it's a market that is 12 months per year," Johnson said. "The season doesn't close, because the goal is to get rid of it. When they close their lobster and their conch seasons, they can take lionfish all they want."

It remains to be seen exactly how much impact fishing can have. For now, it's the only hope in sight.

Scientists are still researching what keeps lionfish in check back home in their native range even as they're going gangbusters in the Atlantic and Caribbean, mostly untouched by the local sharks, moray eels and grouper.

"If they do try a lionfish, they quickly spit it out, probably because of the venomous spines," said Mark Hixon, an Oregon State University marine ecologist who has conducted feeding trials in tanks. "We are now exploring whether smaller predators will consume baby lionfish."

Another scientist working with Hixon's team, Paul Sikkel of Arkansas State University, said invasive lionfish have almost no parasites compared to native grouper, snapper and grunts. This oddity may let lionfish pour more energy into growth and reproduction.

They also have demonstrated a startling ability to wolf down the locals – scientists observed one lionfish eating 20 small fish in less than 30 minutes – hurting populations that feed on seaweed and keep it from overwhelming fragile coral reefs in the Caribbean.

And it's not just happening in the reefs, which lionfish call home in their native waters. In the Americas, "we are seeing them in mangrove habitats, artificial structures and sandy and muddy bottoms. ... They're very versatile," said Stephanie Green, a doctoral candidate in biology at Canada's Simon Fraser University who is studying the invasion.

"It really is quite extraordinary how far these fish will potentially be able to spread, in terms of temperature tolerance," she added. "All the way down to Brazil and South America could potentially be lionfish territory."