For a small fish, it packs a mighty roar.
Environmental experts say this week's discovery and removal of the first nonnative lionfish seen in Florida Keys waters was a victory against the invasive species, but a bad omen in the ongoing effort to protect the fragile reef ecosystem.
Officials say the 4-inch fish, native to the Pacific Ocean and popular with aquarium owners, has invaded the Atlantic Ocean from North Carolina to Belize, predominately the Bahamas and elsewhere in the Caribbean.
Not only are lionfish extremely poisonous, they are voracious eaters with no known predators in the Keys. If left unchecked, scientists are cautious, if a bit unsure, of what their unfettered reproduction would mean for local waters.
"The Keys area is one of the last areas unaffected by the lionfish," said James Morris, ecologist with the National Oceanic and Atmospheric Administration. "They have no natural predators, and if they start reproducing locally, the battle is probably lost."
Studies have shown a decline in the number of prey fish in areas inundated with lionfish, and that concerns reef experts, who cited the complex and interrelated nature of reef ecology.
"It seems like initially very few fish show up, and within a short two- or three-year period, the population explodes," said Lad Atkins, director of special projects for Reef Environmental Education Foundation. "We hope that, as with this first fish, to bag them, remove them and control that."
One issue experts are exploring is why other predator fish such as grouper are not inclined to eat lionfish.
"While that's not surprising, we're not sure if they're recognizing them as a venomous prey item or if they're just a novel prey fish they're unsure about," Morris said.
Atkins said one reason the lionfish is so prevalent in North Carolina and the Caribbean but late to appear in the Keys probably is a result of ocean currents. Now that they're here, the lionfish could push into the Gulf of Mexico.
"What those impacts will be is beyond our ability to predict," Atkins said. "They feed on certain parts of marine life, some of which eat algae, which we're fortunate to have a lot of here in the Keys."
Where the lionfish came from is still being discussed, Morris said. It could have migrated from the Bahamas or elsewhere in the Caribbean, or been dumped by an aquarium owner. The lionfish reproduces by releasing gelatinous balls of eggs that float wherever the currents take them, Morris said.
"The short answer is we really don't know," Morris said.
A diver from Greenville, S.C., was diving near the Benwood wreck off Key Largo Tuesday when she spotted the lionfish in about 66 feet of water, Atkins said. She reported its location with pinpoint accuracy.
Sanctuary divers found the lionfish, bagged it and gathered data on the surrounding habitat in about 14 minutes, Atkins said, a testament to the importance of educating divers on how to locate nonnative species and provide scientists with accurate information on their whereabouts.
"We have a good opportunity with the number of divers here in the Keys to find them and control them," Morris said.
Divers should not try to capture a lionfish, as they are one of the most venomous fish in the ocean, Morris said. Though their dorsal sting usually is not fatal, their venom is extremely painful.
Lionfish can be found in inches of water to depths of 500 feet and in every conceivable Keys habitat -- from reefs to mangrove waters to man-made canals, Atkins said.
Officials encourage divers to become familiar with lionfish and report sightings immediately, said Dave Score, sanctuary superintendent.
"We've been proactive on trying to get a handle with what will happen when the lionfish arrived," Score said. "Our focus will continue to be on response and prevention. We've won this battle, but the war is ongoing."