Native predators do not influence invasion success of Pacific lionfish on Caribbean reefs (2013)

Undergraduates: Serena Hackerott, Abel Valdivia, Courtney Cox Stephanie J. Green, Isabelle M. Cote, Lad Akins, Craig A. Layman, William F. Precht

Faculty Advisor: John Bruno
Department: Biology

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Biotic resistance is thought to be an important mechanism limiting community colonization. The idea is that predation by and competition with resident species can prevent or limit colonization by new species. We examined whether biotic resistance by native predators on Caribbean coral reefs has influenced the invasion success of red lionfishes (Pterois volitans and Pterois miles), piscivores from the Indo-Pacific. We surveyed the abundance (density and biomass) of lionfish and native predatory fishes that could interact with lionfish either through predation or competition on 71 reefs in three regions of the Caribbean. We also recorded protection status of the reefs, as well as abiotic variables such as depth, habitat type, and wind/wave exposure at each site. We found no relationship between the density or biomass of lionfish and that of native predators. However, lionfish densities were significantly lower on windward sites, potentially because of habitat preferences, and at protected sites, most likely because of ongoing removal efforts by reserve managers. Our results suggest that interactions with native predators do not influence the colonization or post-establishment population density of invasive lionfish on Caribbean reefs.