An invasion is underway off our shores.
Two species of lionfish (Pterois volitans, Pterois miles), native to the Asian and African waters, have been introduced to the Gulf of Mexico and the Atlantic coast of the US after being imported to North America as aquarium fish.
Lionfish are beautiful but they are also a growing problem, an invasive species destroying native ecosystems and, because they are venomous, a threat to divers and fishermen. It is now illegal to bring lionfish into Florida but the law banning them came late.
Lionfish were first reported off Florida's Atlantic Coast near Dania Beach in 1985. In the 2000s, the species began to be recorded off the Atlantic coasts of North Carolina, South Carolina and Georgia, while reports from Bermuda and Florida continued.
In 2011, charter fisherman and avid diver Grayson Shepard was the first to spot one of these “toxic butterflies” off Franklin County, a fish only three inches long. He said he was both excited to have finally seen one and disturbed by the knowledge they were here. It was a few months before he saw a second one but they gradually grew common.
“Now, every dive spot we go to is covered with them,” Shepard said. “You have to be careful not to get stung.”
On Aug. 14, Tamara’s Tapas Bar hosted a Sci-Café presented by the Apalachicola National Estuarine Research Reserve (ANERR) and Florida Fish and Wildlife Conservation Commission's (FWC) Lionfish Action Control Team. Lead speakers were FWC lionfish expert Meaghan Faletti and Shepard.
In her overview of lionfish biology, Faletti described the fish as a tropical predator, although it has now been spotted as far north as Rhode Island. Lionfish mature at one year of age but live for up to 15 years. Females can lay 15,000 to 30,000 eggs every four days. Larvae, which hatch 36 hours after fertilization, are strong swimmers and begin feeding four days after conception.
Saltwater dwellers in their native habitat, lionfish can adapt to a variety of habitats and have been found in water with as little as five parts per million of salt. They have been found in the Loxahatchee River in South Florida, and can be found at depths of up to 1000-feet, and as little at 5 feet of water in the Florida Keys.
Lionfish are reef dwellers and in their native range are found around coral reefs. In Florida waters, they have taken up residence in the 2,700 artificial reefs deployed to encourage grouper, snapper and other commercially valuable fish. They have also been found in mangroves, seagrass beds and estuaries.
They eat anything that fits in their mouth
Lionfish are generalist carnivores, that eat anything that will fit in their mouth. They will consume prey that is half their length, and their stomach can triple in size to accommodate large meals. Larvae eat microorganisms. Adult fish feed on any fish or shrimp and spiny lobsters. Parrotfish are important to the coral reef ecosystem because they remove algae; lionfish have reduced the number of parrotfish in Florida waters.
To stay healthy, reef fish are dependent on “cleaners,” small fish and shrimp that remove parasites from larger fish. Lionfish happily consume cleaners and are rarely troubled by parasites.
Faletti said lionfish behave differently than native predators. They are slow moving and use their flowing fins to corner prey with slow, deliberate movements, then fan it into the mouth with those fins so they appear to vacuum it up.
Because they are nonnative, prey fish do not recognize lionfish as a threat and native predators do not recognize it as food.
Faletti said biologists have been unable to identify predators that feed on lionfish in their native range. She and Shepard said attempts are being made to train large predators in the Gulf and Atlantic to feed on lionfish. Faletti said the attempt is controversial because it is unclear whether large fish are being trained to feed on lionfish or on any fish that has been speared.
Shepard said he believes sharks feed on lionfish. He said goliath grouper, will not eat them but other grouper species will eat injured ones. Snapper will eat them after they have been cut into pieces.
Handle with care
Another strategy for controlling lionfish is to encourage spear hunters and anglers to take them. The fish are delicious but care must be taken when handling them because of their toxic spines.
Faletti said a lionfish has 18 spines, 13 on its back and five on its underside. The needlelike spines are covered with skin that slides back when the spine enters a target, revealing grooves containing poisonous tissue.
Shepard said the he believes the rough surface on the head also contains some toxin. He said he has been stung by lionfish and the sting is painful like a wasp sting, but, for him, the effects were short-lived.
Fishing guide Tommy Robinson had a different experience. Several years ago, after he was stung while fishing the Keys, he called a doctor friend who advised him to soak the sting in hot water. Because he was on a boat, no hot water was available so the sting went untreated until he reached shore.
Robinson became ill and was flown to Thomasville, Georgia where he received treatment. He became sicker than is normal because a piece of the spine remained in the sting until almost a week after he was injured. Robinson said he is now fully recovered.
Those stung by lionfish should remove the spines, clean the wound and apply heat, not ice, until medical help can be reached. Most people experience pain for less than 24-hours but it is wise to seek medical help because reactions can vary. So far, nobody has died from a lionfish sting in the US.
Following the discussion by Shepard, Faletti and Robinson at the Sci-Cafe, attendees were treated to lionfish supplied by Shepard and prepared by Tamara’s Chef Danny Itzkovitz, who said he dredged the fish in seasoned flour and pan-fried them whole. They were crisp and tasty with white meat similar to grouper.
While attendees sampled the fish, Shepard demonstrated the safe way to clean them. He said the best way to hold a lionfish is by inserting a finger into the mouth. He used sharp shears to cut away the entire length of the spines. Removing the entire spine is important; they are poisonous for their entire length.
After removing the spines, Shepard gutted the fish, and said the scales could be removed by squirting the fish with a strong stream of water. “You can scale them with a garden hose,” he said.
Both FWC and US Fish and Wildlife encourage catching lionfish of all sizes whenever possible. You do not need a saltwater fishing license to harvest them in Florida, there is no bag limit or minimum size, and they can be harvested year-round. Destroying young lionfish before they reproduce is vital. Divers may also harvest lionfish using a rebreather.
FWC and local entities across the state have begun staging lionfish roundups. A record was set last month in Jacksonville when 1042 lionfish were taken in a single day.
Everyone is encouraged to report lionfish when they are sighted. You can do so at myfwc.com. Smartphone users can download an app that allows them to report sightings of the fish.