Invasion of the Lionfishby Doug Bell
Every May, marine science professor Erin Burge takes a group of CCU students to the Discovery Bay Marine Laboratory in Jamaica for field research. In their underwater dives in 2008, they spotted one lionfish. In 2009, they saw around a dozen. By 2010, the waters were infested with them.
The lionfish is a beautiful but aggressive fish known for its ornate array of venomous spines and tentacles—and for its hearty appetite. Its invasion of the waters of the Southeastern coast, Gulf of Mexico and Caribbean in the past few years has alarmed marine observers and the fishing industry in particular.
“Overfishing of species like grouper and snapper has created an opportunity for the lionfish to move in on their habitat,” says Burge. The lionfish eat and reproduce at a faster rate than other species, and as a result they are flourishing at the expense of other kinds of fish and crustaceans in Southern waters. They use their elaborate fins, or pennants, to herd and trap their prey against the rocks of the coral reefs. Suction feeders, they wolf their food down whole at a lightning-fast rate.
Two of Burge’s students—Erin Cziraki and Zach Hart—did some serious research on the lionfish phenomenon during their recent Maymester course at Discovery Bay. Cziraki is a graduate student from Dayton, Ohio, in CCU’s coastal marine and wetland studies program; she also earned a bachelor’s degree in marine science from CCU in 2007. Hart is a senior marine science major from Fort Loudon, Pa.
Cziraki and Hart catalogued data on a total of 594 lionfish that were collected in the bay by CCU students and faculty during the two-and-a-half weeks of the course. The fish were captured by gigging with the aid of a special spear, and the champion hunter was Steve Luff, a lecturer with CCU’s Burroughs & Chapin Center for Marine and Wetland Studies. The largest lionfish captured was 16 and a quarter inches long.
“The lionfish are doing horrible damage to the ecosystem of the coral reefs,” says Cziraki, “and the more that are eliminated, the better.”
In addition to helping eradicate this aquatic terrorist, the lionfish project undertaken by the CCU group is contributing to our scientific knowledge about the species. Cziraki and Hart recorded essential data on each of the 594 fish caught, including length, weight, sex, fin size as well as information on when the fish were caught and if they were alone or in groups. They also examined the digestive tracts in 270 of the lionfish.
Hart’s research focused on examining the stomach contents of the lionfish to determine what species of fish and crustaceans are most prevalent in their diet. This would indicate not only which species are most endangered due to lionfish, but also how their reduction affects the food supply of other fish up the food chain.
Hart found that shrimp and parrotfish were the captured lionfishes’ favorite dishes. “Small shrimp are a major food source for grouper and snapper,” says Hart, which makes the lionfish a direct and formidable competitor of two of the most valuable commercial species. “Parrotfish are major herbivores and consume lots of algae,” he says, “which poses a problem for the coral ecosystem since the reefs are in the process of shifting from a coral- to an algal-dominated system.”
Cziraki would like to expand her research on the lionfish’s digestive habits—how often they feed, how quickly they break down their meals, etc.—and incorporate it into her master’s thesis on feeding ecology.
Primarily because of its venomous spines, the lionfish has not been viewed as a suitable fish to eat. “But once the spines are removed, it’s perfectly safe and very good,” says Cziraki. Hart says that, even though the lionfish is invasive and a threat to the ecosystem, the conservation-conscious team at Discovery Bay was careful not to waste a single fish. The Maymester lionfish harvest provided five meals for 21 hungry students and professors during their Jamaica trip. The remainder were given away to the laboratory staff.
According to Professor Burge, there is growing interest within the food industry in harvesting lionfish for seafood. One Charleston restaurant has it on the menu.