It’s difficult to travel anywhere outside the cities and towns in North Carolina before spotting what looks to be giant blankets of green leaves draped over shrubs, trees and abandoned buildings. It’s called Kudzu, and like all invasive species, it’s not supposed to be there.
Kudzu is native to southern Japan and southeast China. It’s an ornamental plant that was brought to the United States for erosion control. But what seemed like a good idea backfired when it was discovered that Kudzu grew incredibly fast and doesn’t have many natural predators in this area. It out-competes the native trees and shrubs by climbing over them and killed them because of heavy shading. That’s what invasive species do. They take over an area. And now North Carolina’s newest invasive species is doing the same thing about 40 miles off the coast.
“Lionfish are beautiful, but since they are voracious predators and they reproduce quickly, and they have no natural predators to keep the population in check, the population has exploded,” says Steve Broadhurst, a diver with the North Carolina Aquarium in Pine Knoll Shores. “And its causing a problem for our area because they are eating us out of house and home.”
Just like Kudzu, lionfish are outcompeting the native species in their new environment, which are the natural and manmade reefs and shipwrecks off the coast, in about 140 feet of water.
Dr. James Morris, an ecologist with the Center for Coastal Fisheries and Habitat Research of the National Ocean Service has been studying how lionfish change the reef community by altering the biodiversity of an area. Morris says that there two main concerns.
“It appears lionfish are eating the ecologically important species, which are fish that are important for the diet of top level predators like grouper and snapper, and that means commercially important species would not have a food source” says Morris. “We are also worried that lionfish are eating juveniles of commercially important species, like snapper and grouper.”
Lionfish are simply responding to their new environment. But if lionfish are not only eating the food supplies of grouper and snapper but also found to eating juvenile grouper and snapper, that response could seriously hurt the state’s commercial fishing industry. Lionfish eat about half their body weight each day, and can live for 30-years. What’s more, female lionfish produce about two million eggs per year. That gives lionfish a great chance of surviving and overwhelming the native species.
And here’s another part of the problem. With venomous spines running along the back and on its sides, the lionfish has no know predator in this part of the world. That is, except people.
So how did the lionfish get here?
Lionfish were first spotted off the coast of Florida in the early 1980’s. DNA tests have narrowed the first arrivals down to 7-or-8 fish, which means they were most likely released into the ocean by people emptying their home aquarium.
From that first observance in Florida, lionfish have spread incredibly fast. They were first spotted off the North Carolina coast in 2000. In 13 years, lionfish have firmly established themselves in the Carolinas. It appears lionfish can’t survive much father north because the water temperature gets too cold. However because the water is warmer, lionfish now range into the Gulf of Mexico and the Caribbean. Lionfish are moving towards South America.
“The local fish we have are just confused and they don’t know how to deal with lionfish because they are not their normal predators,” says Janelle Fleming, a researcher with the University of North Carolina Institute of Marine Sciences. “They know how to handle normal predators but these are new and they have different tactics. They flare out their fins and then suck the fish in.”
Right now, it appears the only way to attempt to control this invasive species is to catch them and kill them. That’s why More than a dozen coastal businesses, non-profits, and government agencies joined together this summer to sponsor the state’s first lionfish derby. The “if you can’t beat ‘em… eat ‘em" tournament aimed to thin out the lionfish population, restore some balance to the reef ecosystem, and create a new gamefish.
“The lionfish is here to stay because there are too many lionfish and they reproduce too quickly,” adds Fleming. “The fishing tournament will be more like a pruning process. We hope to create a little oasis where there are few lionfish and our native species can grow and develop from there.”
However traditional fishing methods don’t work with lionfish. They must be speared or captured. But divers who entered the two week tournament in June 2013 brought in 200 lionfish which were cleaned, cooked and served in area restaurants and taken to the local food bank.
“It’s not a fish most people are going to think about as a food source because it is not that easy to capture,” says David Osborne, a manager at Discovery Diving which helped sponsor the tournament. “But it’s a actually a very light, white meat, sort of like flounder and once the fish is dead, the venom in the quills breaks down in about 30 minutes, which makes it fairly easy to clean. The only issue is capturing them and getting people to see the lionfish as a new and more challenging type of gamefish.”
- Lionfish Recipes
- Reporter's Blog: Lionfish: If you can't beat 'em, eat 'em!
- What's My Story: Marine Ecologist
- InfoGraphic: Living with Lionfish
- Lesson Plan