Lionfish, popular aquarium fish native to the Indo-Pacific region, have invaded Caribbean and Pacific waters and appear to be unstoppable, decimating local fish populations. The fish is out-eating its competitors and local predators seem unable to keep up with the invasive species. Predators can control fish populations either by eating them or by limiting their access to prey, UPI.com explains, but local predators such as sharks and groupers have been unable to keep up with the large numbers of lionfish. Thus, allowing lionfish to take over large areas on the reefs.
Executive order EO 13112 defines an invasive species as one that is nonnative to a particular area and is causing economic or environmental problems or harm to human heath. They can be plants, pathogens, or animals, such as the lionfish. Even a single invasive species can cause great damage to an ecosystem, the National Invasive Species Council explains.