Site fidelity and movement patterns of invasive lionfish, Pterois spp., in a Florida estuary

Understanding how individuals within a population of invasive organisms disperse during various life history stages has obvious implications for long term population dynamics in the invaded range. With the rapid expansion of the invasive Indo-Pacific lionfish (Pterois volitans and Pterois miles) in the western Atlantic and Caribbean, it has become increasingly important to understand how individuals move following initial recruitment, as this may have critical implications for population control and management. We conducted a 10-month mark–recapture study in the lower Loxahatchee River estuary (Florida, USA) to identify movement patterns and site fidelity in juvenile and young adult lionfish. We tagged 55 lionfish, ranging in size from 45 to 185 mm standard length (66–256 mm total length). Eighty percent of the tagged fish were recaptured at least one time during the course of the study. Lionfish in this system exhibited extremely high site fidelity over extended periods of time and across multiple size classes. Maximum range occupied by individuals along the shoreline of the estuary was small (mean = 28 m, asymmetrical 95% CI: 10 to 51 m), and did not vary with lionfish size. The majority of lionfish recaptures (74%) occurred at or near (0–10 m) the previous capture site, even after weeks or months at liberty. In systems where lionfish exhibit extremely high site fidelity and small maximum ranges, localized population control may be feasible, since lionfish removed from a given habitat would be replaced largely through larval recruitment rather than migration of older individuals. However, since lionfish grow extremely rapidly (averaging 0.46 mm/day, but reaching as high as 0.78 mm/day in one individual), localized control efforts would need to be carried out frequently in order to maintain a younger, smaller population. Localized control may be less effective if lionfish exhibit greater movement and lower site fidelity in other invaded systems.

► Lionfish exhibit extremely high site fidelity over extended periods of time. ► Many tagged individuals remained in the same location throughout the study period. ► Home range did not vary with body size for the size range we examined. ► High site fidelity may facilitate local population control in certain habitats.