NCCOS Project Explorer (NPE)

Assessment of Lionfish Ecosystem and Fisheries Impacts(2010)

Project Description:
The Indo-Pacific Lionfish (Pterois volitans/miles complex), a venomous predatory fish with few natural enemies, is established (reproducing and dispersing) along the southeast shelf of the United States. Within the last seven years lionfish have spread from Florida to Cape Hatteras NC and Bermuda. Lionfish are now found throughout the Bahamas and have spread into the Caribbean and the Florida Keys. Our research is a continuation and expansion of an ongoing research project that initially began to examine the status and risk of the invasive lionfish in the Atlantic. Problem: The overall impact of an introduced species has been defined as a product of its range (distribution), density, and per-capita effect of the individual invader (Parker et al. 1999). Within the last three years, CCFHR researchers have examined both the range and density of lionfish over a broad geographic area. These results suggest that lionfish are now established within the western Atlantic (Cape Hatteras to Cuba) and that the density and geographic distribution of lionfish continues to increase, although the total population abundance of lionfish remains unknown. As the population size of lionfish continues to increase, so does the probability for trophic and competitive interactions with native fishes. Objective: We will combine field and laboratory studies to provide critical information on lionfish impacts to the Atlantic reef fish community and reef fisheries. These studies will directly assess impacts of lionfish in the distribution, density, and per-capita effect framework. Methods and expected results: 1. Experimental lionfish removal studies will be conducted in the field to examine impacts to fish communities and detect potential habitat change due to lionfish. We will utilize quantitative, repeated surveys and sampling methods to compare assemblage structure at control sites with lionfish and at experimental sites where lionfish have been removed. The experimental removal of lionfish aims to directly test the hypothesis that lionfish are responsible for any changes that may arise in the status of another species or assemblage. Lead Investigator: Muñoz. 2. Lionfish acoustic telemetry studies will be conducted to detect lionfish movements within and between reef habitats. The results from this study will provide site fidelity information on lionfish, key data for establishing confidence in lionfish removal treatments, above. In addition, this study will also help determine the accuracy of site-specific density estimates as well as the scale of individual lionfish impacts. Individual lionfish impact data when combined with yearly density data will be critical to predicting yearly impacts over a broader area (i.e. along a depth gradient). The results of this study will be available in late FY09. Lead investigator: Whitfield

Expected Outcome:
Outcomes: Results from our study will provide key data concerning fish assemblage structure in the presence and absence of lionfish, lionfish recruitment, movements and responses to winter water temperatures, and baseline characterizations of hardbottom community structure that might detect community/species-level changes and/or trophic cascades should they arise in the future. Baselines for species assemblages are often lacking when trying to determine the biological significance of impacts from invasive species. These varied data will be essential to forecasts of lionfish trophic impacts and together with ongoing studies of lionfish stomach contents and lionfish distribution should do much to help clarify the impact of this introduced predator to the ecology and fisheries of southeast U.S. hardbottom communities. In addition, the recruitment of lionfish to removal sites also has important implications for the feasibility of localized removal efforts in managed areas, and results from our studies might provide a model for future efforts in National Marine Sanctuaries such as Gray’s Reef or the Florida Keys NMS.