The lionfish has dominated the western Atlantic Ocean for years, nearly eradicating all other reef species. But now a new study shows for the first time that efforts to control the lionfish populations, usually scuba divers using spears and nets, can lead to a resurgence of native species. Computer models and 18 months of field tests on reefs conducted by scientists from Oregon State University, Simon Fraser University, and other institutions have revealed that reducing their populations by 75 to 95% could allow a speedy return of native fish in the biomass treatment area, and benefit larger ecosystem restoration.
It’s exciting news for a battle that’s seen these predatory lionfish take out almost 95% of native species in the Atlantic, an invasion which reportedly began in the 1980s. Without intervention, their population is about the size of the entire U.S.
Researchers believe having small reefs with lower lionfish populations will help native species recover. Eradication of all lionfish is practically impossible, though reducing them has proven successful, but keeping their populations below a threshold density will reportedly increase the number of native prey fish by 50 to 70%.
These fish are real survivors. They have venomous spines, no real Atlantic predators, they eat anything smaller than they are, and can go without food for longer than their peers.
Governments, conservation groups, and others in the region want to pluck these invaders from their waters, but a larger issue going forward will be deciding where to allocate future efforts. The invasion is rapid and outweighs the resources needed to control and eliminate the fish. Keeping the lionfish population low is crucial.