Posted by admin | 03.17.2011 | Marine Science

Alien Invaders In Our Waters

Chinese mitten crabs in California?  Asian swamp eels in Georgia? European green crabs in Massachusetts? As their names seem to indicate, these animals are far from home. These organisms are part of an alien invasion occurring all over the globe, one that has both environmental and economic consequences. They are invasive species.

As travel between continents becomes  increasingly prevalent, so does the likelihood of accidental (or intentional) introductions. One species of particular concern to our coast is the lionfish (Pterois volitans). This aquarium favorite originally hails from the Indo-West Pacific, but has set up residence in the Caribbean, Mexico, Gulf of Mexico, and the East Coast.

Courtesy: Paula Whitfield NOAA

The source of the introduction is unclear, but some point to the accidental release of six lionfish from a private aquarium during Hurricane Andrew. While it is highly unlikely that these six species spawned the current numbers,  their small population was probably bolstered by subsequent aquaria releases. What is clear, however, is that their population explosion is extraordinary. According to a recent USGS survey, there has never been a case of a non-native marine fish expanding and sustaining a population like the lionfish has. And the speed at which they have done this is also unprecedented.

The lionfish is still relatively new to Atlantic waters – it was only first reported in the mid-1980s – so their impact still remains to be determined. They are predatory fish, so they may suppress native fish populations. They also may have impacts on reef ecosystems. And since nothing seems to find their spiny protrusions edible, eradication may be impossible. Localized efforts to remove the species through “lionfish derbies” yield more than 600 individuals, but don’t put a damper on their reproduction and spread. Hopefully future studies will yield insight into ways to control their population and diminish their negative impacts. Or maybe it’s simply a matter of lionfish burgers becoming fashionable.