The Lionfish Invasion in the Bahamas: What do We Know and What to do About It? NICOLA S. SMITH 1,2 and KATHLEEN SULLIVAN SEALEY 1 1 Marine and Environmental Studies Institute, College of The Bahamas, Oakes Field Campus, P.O. Box N4912 Nassau, Bahamas 2 Graduate Department of Zoology, University of British Columbia, Biological Sciences Building, 6270 University Boulevard, Vancouver, BC, Canada V6T 1Z4 ABSTRACT Biological invasions include both human and non-human mediated forms of dispersal in which an exotic or non-native species successfully arrives, survives and reproduces in a novel locality and then proliferates and spreads throughout a region (Carlton, 1989). The recent invasion of the Indo-Pacific lionfish (Pterois volitans) throughout the western Atlantic Ocean, including The Bahamas, is generally considered to be the result of several species introductions associated with both the intentional and uninten- tional release of specimens from private aquariums. Small Island Developing States (SIDS) like The Bahamas are particularly vulnerable to bioinvasions due to our: 1) import-driven economy; 2) heavy reliance on tourism; and, 3) biological fragility inherent in island ecosystems. A review of the pattern of invasion by habitat, island group and size distribution is presented from recent surveys throughout the archipelago. KEY WORDS: Lionfish, reef fish, Bahamas, invasive species La Invasión del Pes Escorpion en las Bahamas Las invasiones biológicas comprenden tanto las formas de dispersión naturales como las generadas por el Hombre, donde una especie exótica o no nativa arriba, sobrevive y reproduce en una nueva localidad, y prolifera y se propaga por toda la región (Carlton, 1989). La reciente invasión del pez escorpión del Indopacífico (Pterois volitans) a través del Atlántico occidental, incluyendo Las Bahamas, se considera el resultado de la liberación intencional y no intencional de ejemplares por acuarios privados. Los Estados Pequeños Insulares en Desarrollo (SIDS) como Las Bahamas son particularmente vulnerables a las invasiones biológicas debido a 1) una economía sustentada por la importación y la exportación; 2) a la gran dependencia del turismo; y 3) la fragilidad biológica inherente a los ecosistemas insulares. Se presenta una revisión del patrón de invasión por hábitat, grupo de islas y amplitud de la distribución, a partir de los resultados de prospecciones recientes a lo largo del archipiélago PALABRAS CLAVES: Pez escorpion, arrecifes, Bahamas, invasión Proceedings of the 60th Gulf and Caribbean Fisheries Institute November 5 - 9, 2007 Punta Cana, Dominican Republic INTRODUCTION Biological invasions include both human and non- human mediated forms of dispersal in which an exotic or non-native species successfully arrives, survives, and reproduces in a novel locality and then rapidly spreads throughout a region. On the one hand, species that disperse without the aid of humans into an area where they were not previously found are referred to as range expansions. On the other hand, species that have been released outside of their native range and have spread due to human activity are referred to as species introductions (Carlton 1989). The recent invasion of the Indo-Pacific lionfish (Pterois volitans * ) throughout the western Atlantic Ocean, including The Bahamas, is generally considered to be the result of several species introductions associated with both the intentional and unintentional release of specimens from private aquariums followed by the natural dispersal process (Hare and Whitfield 2003, Ruiz-Carus et. al. 2006). Biological invasions in the form of species introduc- tions, however, are not new. The introduction of non- native species has occurred since the dawn of early human migrations. Historically, flora and fauna were intentionally introduced to a new region usually to satisfy food demands or social needs while other non-native species would have been accidentally brought to an area in the form of hitchhikers. What distinguishes invasions today from those experienced in the past is that the current rate and magni- tude of human-caused invasions is unprecedented (Lowe et. al. 2000). Today’s worldwide trend in successful species introductions can be partly explained by the exponential increase in global trade, transport, tourism, and travel, which have all served to transfer species to places that would have otherwise been virtually impossible to access due to natural physical barriers (BEST 2003, Lowe et. al. 2000). Furthermore, invasion theory predicts that in- creased disturbance to an environment should result in increased invader success (Altman and Whitlatch 2007, Lozon and MacIsaac 1997). Interpreted from this perspec- tive, Carlton and Ruiz (2005) suggest that current world- wide increases in urban and other disturbed habitats may have created an excess of modified ecosystems that are more susceptible to invasion. Small Island Developing States (SIDS) like The Bahamas are particularly vulnerable to bioinvasions due to our: i) Import-driven economy; ii) Heavy reliance on tourism; and, iii) Biological fragility inherent in island ecosystems (BEST, 2003).