KEY WEST, Fla. — Crawling through turquoise murk on the ocean floor near Tea Table Key, Rob Pillus glances at a half dozen lobsters that twirl their antennae in the fast-moving current. Mr. Pillus, an avid spear fisherman, would normally stuff the crustaceans into his mesh bag for dinner, but today he is after more exotic quarry: an invasive species called the lionfish that threatens to wreak havoc on this ecologically sensitive marine system.
Within a few minutes Mr. Pillus spots a lionfish and its extravagant zebra-striped fins on a bridge pylon. He steadies his homemade spear and skewers the fish, slicing off its venomous fins before putting it in his bag. He gives an enthusiastic thumbs-up and keeps moving.
Later, on the deck of his 28-foot motorboat, Mr. Pillus turns his bounty of five lionfish over to his teammate, Mike Dugan, who puts them on ice.
“Jackpot, fellas,” exclaims Mr. Pillus.
Mr. Pillus is team captain of the Lion Hunters, one of 18 groups of divers armed with nets or sharp spears who are here to compete in the final stage of a newly created lionfish derby in the Florida Keys.
Derbies like this are one way that officials and scientists are seeking to bring attention to the potential damage caused by this voracious, rapidly breeding fish and to control its spread, which in the Florida Keys has been so quick that wildlife managers are having a hard time adapting. The first fish wasn’t discovered until January 2009, when a single female was found and immediately removed by scientists from a reef in Key Largo. Now the lionfish is plentiful enough to have multiple derbies.
“We’re terrified,” says Dave Walton, site manager of Dry Tortugas National Park, a group of islands and an ecological reserve 60 miles west of Key West, where lionfish first appeared in September 2009.
If the lionfish’s impact on other parts of the Caribbean is any guide, Mr. Walton and others in the region are right to be concerned. It is a formidable predator that can devastate fish populations wherever it feeds. Researchers here examined more than 1,000 lionfish stomachs and found more than 50 species of prey fish inside, including juveniles of commercially important grouper and snapper. The fish also eat juvenile parrotfish, which graze on algae and keep it from overgrowing and killing corals.
“What we do know is what we can see in areas like the Bahamas where you go to a particular reef and all you can see is lionfish,” says Sean Morton, superintendent of the Florida Keys National Marine Sanctuary, a 3,900-square-mile park stretching from Biscayne Bay to Dry Tortugas National Park.
If the reef system here is depleted of other fish species because of the lionfish’s appetite, the impact could be devastating to the region’s economy, which relies heavily on commercial fishing and recreational diving. Bob Holston, the owner of Dive Key West, a local dive shop, says the potential threat could spell doom for his business.
“Imagine going into Yellowstone and not being able to see any birds, any bears, any deer or whatever — you would just be looking at trees,” he said.
A native of the Indo-Pacific Ocean and the Red Sea, the lionfish has no known predators. It is believed to have been released by aquarists sometime in the 1990s and has since spread up the East Coast to North Carolina and through the Caribbean.
Scientists say the fish can produce 30,000 eggs in a single spawning event, and can spawn as frequently as every four days. “That means we’re looking at annual output of two million eggs per female,” says Lad Akins, a research diver and the director of operations with the Reef Environmental Education Foundation, or Reef.
Scientists and policy makers are at a loss as to how to eradicate the fish, a goal that a 2003 report from the National Oceanic and Atmospheric Administration says is “nearly impossible.” The only hope, say officials, is some form of local control.
Which is where the derbies come in. On Nov. 13, 18 teams competed from sunrise to sundown to kill as many fish as they could with hopes of sharing $3,350 in prize money.
“We’re taking a part in the battle,” says Robert Hickerson, the captain of Team Frapper, a group of four divers from Vero Beach. Mr. Hickerson says he dives as often as twice a week. His “kill count” is a source of pride. “I’ve killed over a hundred of them. I try to kill them even when I’m on vacation.”
While lionfish numbers are growing, the fish can be elusive. Despite the best efforts of the 18 teams in the Lower Keys derby, only 109 fish were killed, adding to the 550 lionfish killed in the two previous contests in Key Largo in September and Marathon in October.
One potential solution is to promote the fish as food for another voracious predator: man. Lionfish are considered excellent eating. Indeed, after the lionfish derby here, participants feasted on fried lionfish nuggets.
“They taste a lot like hogfish,” says Mr. Dugan of the Lion Hunters. “They’re really good.”