Invasion of the Lionfish
The Caribbean's coral reefs are struggling under intense pressure from overfishing, pollution, development, and climate change. Now these over-stressed reefs are facing an additional threat from an uninvited guest, which has the potential to tip them over the edge. Luckily, community efforts are helping to stem the problem.
Red Lionfish (Pterois volitans) in its native Fiji
Photo by Steve Turek
Lionfish are voracious predatory fish native to the Indo-Pacific. It is believed that they were introduced to the Caribbean in the early 1990s from local aquariums or fish hobbyists in Florida. Once loose in the marine environment and free from natural population controls, their numbers began exploding as they consumed vast quantities of reef fish.
Lionfish are known for eating anything they can fit in their mouths, and seem to eat nearly constantly. During a study of invasive lionfish in the Bahamas, one lionfish was observed to eat twenty small fish in the space of thirty minutes. The study also found that a single lionfish per reef could reduce the juvenile fish populations by almost 80% in just five weeks. Fast-growing and capable of reproducing year-round, lionfish are also out-competing native species and spreading more quickly than anyone predicted.
With their indiscriminant eating habits, lionfish directly impact populations of numerous fish and crustacean species, including commercially valuable species like snappers, groupers, and lobsters, as well as ecologically key species like parrotfish, which prevent algal overgrowth on reefs. The Caribbean lionfish invasion could become the most disastrous marine invasion in history by drastically decreasing the abundance of coral reef fishes throughout the entire region.
The Mitigation Strategy
|Once their venomous spines have been removed,
lionfish are perfectly safe to eat.
Although lionfish have no natural predators in the Caribbean, it turns out that these fish make quite a tasty dish for humans. The best option for controlling their populations seems to be for us to become their main predators. CORAL's Belize Field Manager, Valentine Rosado (Val), is helping with the effort.
Lionfish reached Belize in late 2008, and since then the country has declared all-out war on the invaders. The quickly-formed Belize Lionfish Project is working to educate stakeholders, including fishermen and dive instructors, on how to get involved in lionfish abatement, and has also begun a series of fishing tournaments whose sole purpose is capturing lionfish. A number of Belizeans, including Val, traveled to the Bahamas (where lionfish have been a problem for far longer) for a workshop on lionfish handling and preparation.
Unfortunately, catching lionfish is no easy task: they are armed with many venomous spines that can cause extremely painful injuries. Spear guns are one option for capture, but they are ineffective against small lionfish and are also being discouraged because of their potential for encouraging poaching. Furthermore, according to Val:
"I've been diving with tour guides and with tourists and I can personally emphasize that nets and bags will not work. It is too much of a hassle and inconvenience, and requires a few minutes to effectively capture a lionfish. I can see tourists complaining that their guide was more absorbed in the capturing and killing of lionfish than supervising the dive and divers."
However, Val came back from the workshop in the Bahamas with some great ideas for making lionfish control more feasible for dive instructors. He reports that a three-pronged spear is used widely against lionfish in the Bahamas. Dive leaders in San Pedro have devised a simplified version of the spear and have had good success with it in trials at home. The spear is safe, effective, unobtrusive, and easy to construct, and can even make a good pointer. Val is hoping to produce many of these tools and distribute them to tour guides. Instruction on their use could even become part of CORAL's Sustainable Marine Recreation workshops.
Although complete eradication of lionfish from the Caribbean is probably an impossible goal, keeping their numbers low can give other fish populations a chance to persist. Creative solutions to the problem will be essential to prevent lionfish from devastating Caribbean coral reef ecosystems.
For more information:
ECOMAR's Belize Lionfish Project
REEF's Lionfish Research Program
For a good list of lionfish recipes, click here.