Lionfish are an exotic fish now found throughout the Greater Caribbean and eastern Atlantic that have become incredibly abundant on many reefs, especially in the Bahamas and off North Carolina. Lionfish are a piscivore (a fish that eats other fish) and were introduced from the Indo-Pacific by the aquarium trade in the late 1990s off Florida. Mostly likely, someone got tired of their fish and released them purposefully.
One hypothesis explaining their great success is the absence of natural enemies; predators, parasites and competitors. This is probably compounded by the fact that few Caribbean reefs have any predators left that could eat them (thanks to overfishing). Some gutsy local divers have been teaching sharks just how good lionfish are to eat in Roatan Marine Park off the coast of Honduras. They first spear the lionfish then feed them to the sharks.
Will it work? I’m not so sure. Lionfish are benthic (live on the ocean floor) and usually stay close to hiding places they can scoot into. Accepting a dead lionfish snack is one thing; hunting down a living one is another.