ReviewPredatory fish invaders: Insights from Indo-Pacific lionfish in the western Atlantic and Caribbean

- Predatory Indo-Pacific lionfish have invaded marine habitats of the western Atlantic, Caribbean Sea and Gulf of Mexico.
- Their geographic spread has been rapid and population growth exponential.
- Invasive lionfish have reduced the abundance of small native fish by up to 95% on some coral reefs.
- Culling reduces lionfish numbers but it needs to be intense and continuous.
- Trade legislation and consumer education are needed to prevent future invasions.

The invasion of western Atlantic marine habitats by two predatory Indo-Pacific lionfish, Pterois volitans and P. miles, has recently unfolded at an unprecedented rate, with ecological consequences anticipated to be largely negative. We take stock of recently accumulated knowledge about lionfish ecology and behaviour and examine how this information is contributing to our general understanding of the patterns and processes underpinning marine predator invasions, and to the specific issue of lionfish management. Lionfish were first reported off Florida in 1985. Since their establishment in The Bahamas in 2004, they have colonised 7.3 million km2 of the western Atlantic and Caribbean region, and populations have grown exponentially at many locations. These dramatic increases potentially result from a combination of life-history characteristics of lionfish, including early maturation, early reproduction, anti-predatory defenses, unique predatory behaviour, and ecological versatility, as well as features of the recipient communities, including prey naïveté, weak competitors, and native predators that are overfished and naïve to lionfish. Lionfish have reduced the abundance of small native reef fishes by up to 95% at some invaded sites. Population models predict that culling can reduce lionfish abundance substantially, but removal rates must be high. Robust empirical estimates of the cost-effectiveness and effects of removal strategies are urgently needed because lionfish management will require a long-term, labour-intensive effort that may be possible only at local scales. The ultimate causes of the invasion were inadequate trade legislation and poor public awareness of the effects of exotic species on marine ecosystems. The lionfish invasion highlights the need for prevention, early detection, and rapid response to marine invaders.