Site Fidelity and Movement of Reef Fishes Tagged at Unreported Artificial Reef Sites off NW Florida

Data were analyzed from an ongoing reef fish tagging study to examine species-specific site fidelity to and movement from unpublished artificial reefs in the northern Gulf of Mexico. Fish were captured at reefs (n = 9) located between 15 and 20 miles south of Pensacola, Florida, USA. A total of 2,678 fish was tagged with internal anchor tags on quarterly tagging trips from March 2005 to June 2007. The most frequently tagged species were red snapper (n = 1,765), red porgy (n = 368), gray triggerfish (n = 256), gag (n = 101), and vermillion snapper (n=66). Eighty-one tagged individuals were recaptured at tagging reefs on subsequent tagging trips, with red snapper, gray triggerfish and grouper recaptures being 41, 28, and 9, respectively. Fishers reported a total of 187 fish caught away from tagging sites, with 133 red snapper, 20 gray triggerfish, and 19 grouper recaptures reported. Mean distance moved among all recaptured red snapper was 28.4 km, while lower mean distances were estimated for gray triggerfish (10.4 km) and groupers (16.6 km). Size of fishes present at reef sites was estimated with a laser scaler attached to a remotely operated vehicle with which study sites were video sampled quarterly. Few red snapper (< 5%) observed at study sites were above the recreational fishery’s legal size limit (406 mm total length), while more than half (52%) of the gray triggerfish measured were above that species’ legal size limit (305 mm fork length). Overall, results indicate that red snapper displayed lower site fidelity to and greater movement from unreported artificial reef sites than did gray triggerfish; grouper site fidelity and movement were intermediate to red snapper and gray triggerfish parameters. It appears higher movement observed in red snapper made that species vulnerable to high recreational fishing mortality at artificial and natural reefs in the region, hence the lack of larger, older red snapper observed at our study sites. Therefore, unreported artificial reef sites may not serve as effective harvest refugia for species that display low site fidelity and move between fished and unfished areas.