Biocontrol of the invasive lionfish population as an indicator of marine protected area success

Marine Protected Areas (MPAs) are important conservation tools for sustaining marine resources through a range of potential ecological benefits. However, MPAs may also have unforeseen benefits, such as controlling invasive species. Indo-Pacific lionfish (Pterois volitans and P. miles) are a successful invasive species in the western Atlantic. Some grouper and snapper species are believed to prey on lionfish. MPAs should increase the density and occurrence of these potential lionfish predators, resulting in a decrease of the invasive lionfish population. Reef Visual Census (RVC) data from 2010-2015 and National Park Service lionfish removal data from 2011-2015 were used to spatially analyze temporal changes in lionfish distributions as well as potential predator distributions throughout Biscayne National Park (BISC) and the Dry Tortugas as an indicator of MPA success. Population trends demonstrated that lionfish population metrics were higher in unprotected areas than in protected areas. The catch per unit effort (CPUE) of lionfish in Dry Tortugas National Park (DRTO) has decreased each year since lionfish data collection commenced in 2011. For multiple species of potential lionfish predators, statistically significant differences in occurrence and density were found between BISC and the Tortugas North Ecological Reserve (TNER). Lionfish declines in DRTO, lionfish population trends, and the statistically lower population metrics of potential lionfish predators in BISC than in TNER, may reflect the benefits of MPAs