By SAM SMITH, Guardian Staff Reporter

samsmith@nasguard.com

Captain Bruce Purdy watched a teenage passenger collapse on the deck of his boat when she brushed the venomous spines of a skewered, dead lionfish. He's heard of recreational divers on Exuma being airlifted to Nassau after exposure to their prickly, poison-filled spines.

Though victims of lionfish stings have said the burning sensation can be so intense that they feel like dying, the venom isn't known to be fatal. What's really troubling Purdy and fellow researchers is the effect that the invasive species could have on the fragile ecologies of Caribbean reefs and the commercial fishing industry.

Lionfish have been found along the Eastern United States for at least a decade. Some research puts the first Florida sighting in the mid-80s. But the research group REEF, of which Purdy's company Blackbeard Cruises is a member, hadn't spotted the versatile predators, with no known enemies in Bahamian waters, until three years ago.

Since 2004, REEF (an acronym for reef environment education foundation) has witnessed a 500-fold explosion in the local lionfish population, and there's no telling how much damage the voracious predators might do.

Though researchers differ on the extent to which lionfish will affect the overall commercial fishing and diving operations in The Bahamas, Purdy wants to sound alarms now, before things have a chance to get any worse.

"It could be the worst ecological disaster the world has ever seen," Purdy said. The lionfish population increase "is just so rapid, it's mindboggling."

Effects on commercial fishing have been negligible, if intangible since the population explosion last year, but Purdy, who spends much of his days underwater counting tropical fish, has witnessed lionfish feeding in mangroves, where juvenile grouper and snapper typically find shelter from other, larger predators before reaching maturation.

Purdy said dissections and stomach inspections of lionfish caught in Bahamian waters have proved they eat young commercial fish.

Research from the United States National Oceanic and Atmosphere Administration on the lionfish population along the coast of the Southern states has found no local predators, though some speculate that mature grouper or sharks might brave the painful venom of a young lionfish.

So far, no one knows just how large the lionfish population could become, and speculation on their effect ranges from minimal to catastrophic.

"The interesting thing about invasive species is that it's not uncommon for them to actually get bigger or do better in a new habitat" than in their native range, American researcher Paula Whitfield of NOAA told Science magazine for a recent article about the invasion in the U.S.

"From all accounts, individual red lionfish off the Carolinas are growing much faster than native fish do. The phenomenon may reflect more food for the fish, fewer predators, or accommodations nicer than home in other ways," Science reported.

Mature lionfish can grow up to 18 inches long, and with their spines displayed broadly, they appear twice that size. Once fully grown, the lionfish have no natural enemies and can lay as many as 30,000 eggs several times a year.

"In all honesty, I believe they're here to stay," said Director of Fisheries Michael Braynen. "The challenge now is how to control their growth and gather as much information as we can."

Indicative of how well established the population has become, Minister of Agriculture and Marine Resources Lawrence Cartwright, himself a commercial fisherman, said his son trapped one just a couple of days ago while wading among mangroves near the Cartwright's family home on Long Island.

But characterizing the population's spread and identifying potential solutions will be easier said than done.

Because the invasion is so recent and the characteristics of Caribbean reefs so different than those along the Eastern seaboard of the U.S., local research efforts have started virtually from scratch.

Dr. Kathleen Sealey, dean of Natural Sciences at the College of The Bahamas, has been collecting and examining the reproductive organs of local lionfish populations with the help of graduate student assistants.

Her team has been working closely with local fishermen to ascertain where the populations are highest and identify environmental characteristics that effect their rate of reproduction.

Braynen said Fisheries and the COB group are teaming up to develop a national database that will allow divers, fishermen and casual beachgoers to report lionfish sightings, as a solution to the current redundancy of research that is available in Fisheries' hodge-podge lionfish.

The unwelcome and surprisingly adaptive predators have been found everywhere from waist-deep water around New Providence and Grand Bahama to mangrove shelters for commercial fish to 200-feet deep in blue holes around Andros and Eastern Cuba.

"Andros may have it the worst of all," Purdy said, indicating that in some of the blue holes lionfish appear to have eaten "100 percent" of the juveniles of several species during this year's spawn.

Cartwright said government has given "the green light" to kill lionfish on the spot, with or without fishing licenses. Just don't touch them. Lionfish venom remains active for a couple of days after death.

That's exactly how the teenage girl on Purdy's boat got stung. A research diver came up with a lionfish on a spear – not in a bag, as Blackbeard's Cruises requires. The boat lurched a bit, and the girl "stumbled onto it – took a few spines in her thigh," Purdy recalled. "I bet that's the last time she'll do that."