Scientists have traced the lionfish, native to the Indo-Pacific and the first exotic fish to invade the Caribbean, to the aquarium trade between oceans in the 1980s. The fish were likely released into the ocean near southern Florida.
“Genetic work has showed that the whole invasion began from a few releases,” said Dr. Green.
Divers have been relatively successful at removing lionfish from Florida’s shallow coral reefs, and there have been various efforts in the region to drive up dinner-table demand for the fish. The Reef Environmental Education Foundation Fund sells a cookbook devoted to lionfish recipes, as well as a list of local restaurants that serve lionfish. Conferences on the invasive species have ended with tastings of lionfish cuisine.
But deep-sea dives to the depths that the lionfish has now claimed are not possible, and humans have not been able to remove them. That raises concern that the fish might use the deep sea as a base from which to retake the shallower water.
“There’s some concern that the lionfish might be using a deep-sea refuge,” said Green, noting that further study is needed to confirm that hypothesis.
The effect of the lionfish, a venomous fish that plumes like a Japanese fan, is well known in the shallower Atlantic, but its impact on the deep sea is less well understood. The animal is what is known as a gape-limited predator, which means that the fish is limited in food consumption by the size of its mouths. The fish, growing up to 47 cm in length, can consume prey up to half its size, which puts about 70 percent of the fish population within their gulp. Studies have shown that at least 40 species of fish have dropped in number since the lionfish was introduced to their Atlantic environment, Green said.