Lionfish are strikingly gorgeous tropical reef fish, striped pink, red, silver and black with graceful frills decorating their fins. But these delicate-looking fish are anything but. Lionfish are venomous, sporting toxin-loaded fin rays that deter predators, fast breeders, highly adaptable, and, most importantly, voracious predators. Lionfish hang out around corals and clumps of algae, blending into the background with their stripes and frills. Then, when a fish swims by, the lionfish springs out, opens a gaping mouth, and sucks in its prey.
An invasive red lionfish looks for prey on a coral reef. "Red lionfish near Gilli Banta Island" by Alexander Vasenin - Own work. Licensed under CC BY-SA 3.0 via Wikimedia Commons -
Native to coral habitats in the Pacific and Indian Oceans, lionfish suddenly appeared on reefs around southern Florida in the 1990's, probably by accidental or intentional release from hobby aquariums. These expert predators found Florida reefs quite to their liking, with plenty of suitable prey and no animals adapted to eat them. The local fish were naïve, having never learned to avoid lionfish. So the lionfish population exploded and began expanding into new territory. Soon lionfish were gobbling up fish on reefs across the Caribbean and into the Atlantic Ocean. And they are still going, and going.
And yes, lionfish are now a fixture on Gray's Reef, the National Marine Sanctuary off the Georgia Coast.
Lionfish are a classic example of an invasive species, an animal or plant that is introduced to a novel habitat and is able to successfully colonize their new home. Most of the invaders are red lionfish, Pterois volitans, although some common lionfish, Pterois miles, have also become established in the Caribbean and Atlantic.
A common lionfish hunting small fish on a shipwreck.
https://commons.wikimedia.org/wiki/File:Common_lionfish_hunting_glassfish_at_El_Mina_wreck.JPG#/media/File:Common_lionfish_hunting_glassfish_at_El_Mina_wreck.JPG
Dr. Mark Hixon, a professor of zoology at Oregon State University where my husband and I worked before we retired, is an expert on the lionfish invasion. Hixon and his students had undertaken a long-term project on the ecology of coral reef fish around the Bahamas when, in 2007, the study was disrupted when lionfish suddenly appeared in their research plots. They were dismayed to discover that just one lionfish could reduce the natural increase of native reef fish on a coral patch by 80%. Hixon and his colleagues worry that the spread of lionfish could be the worst invasion of marine ecosystems ever recorded. See articles and videos from the Hixon lab here: http://hixon.science.oregonstate.edu/content/highlight-lionfish-invasion
And a video about invasive lionfish here:
A major problem with trying to rid reef ecosystems of this beautiful, but disastrous, predator is that lionfish are quite happy at depths down to 140 m (450 feet), too deep for divers to hunt them. So even though lionfish can be picked off reefs at shallow depths, deep-dwelling lionfish will just move up to replace them.
One way to cut back the abundance of lionfish is to have them for lunch. Lionfish fillets are tasty, though chefs have to be careful during preparation to avoid the fish's venomous spines. In 2010, NOAA began promoting the joys of cooking the invader by publishing a Lionfish Cookbook, with proceeds going to reef conservation and lionfish research.