Red Lionfish (Pterois volitans) Invade San Salvador, Bahamas: Early Population Characteristics, and Comparisons of the Coral and Fish Communities on Shallow Patch Reefs in 2001 and 2007

Abstract

Biological invaders are a leading contributor to global losses of biodiversity. A recent invader to the waters surrounding San Salvador, Bahamas, the red lionfish, Pterois volitans, was first reported in 2006; by 2009 they were common in waters 2 - 40 m deep around the island. Among the 5,078 fish observed on shallow patch reefs in 2007, only two were P. volitans; they were much more prevalent in deeper water along San Salvador's "wall." Captured P. volitans ranged in size from 19-32 cm, all longer than maturity length. Pallid goby ( Coryphopterus eidolon), black cap basslet ( Gramma melacara) and red night shrimp (Rynchocienetes rigens) were the most commonly identified stomach contents. My study in 2007 also collected data on coral communities and fish assemblages at three patch reef complexes (Rice Bay, Rocky Point, Lindsay Reef), during the initial phase of the invasion, and compared the results to a similar study done in 2001, before P. volitans colonized San Salvador. Scleractinian and, therefore, total coral species richness decreased significantly from 2001 to 2007; however, coral percentage cover increased significantly by ~50% from 2001 to 2007, probably due to a more precise estimation procedure rather than a real increase in coral cover. Significantly more fish species and numbers were observed in 2007 than in 2001, again probably due to a difference in counting procedures (2.25 more and increasing population of P. volitans on San Salvador's reef ecosystem are uncertain at this time; future monitoring of lionfish and potential changes in coral and fish communities on the patch reefs of San Salvador is recommended.