Acoustic positioning and movement patterns of red snapper Lutjanus campechanus around artificial reefs in the northern Gulf of Mexico

Over a 3 yr period fine-scale (m) movements of red snapper Lutjanus campechanus were estimated with the Vemco VR2W Positioning System (VPS) on 3 artificial reefs, and wider scale (km) movements were estimated with surrounding receivers (n = 23). Tagged red snapper (n = 56) were tracked for extended periods (17-1096 d). Residency (23 mo) and site fidelity (82% yr(-1)) showed that red snapper maintained a close association with the artificial reef structure (34.5 +/- 44.0 m). Fine-scale monthly home range (95% kernel density estimates [KDE]) and core areas (50% KDE) were positively correlated with water temperature. In the winter, all red snapper showed less movement, and during the warmer months most (63%, 29 out of 46) fish used a secondary reef site. Over diel periods, fish showed significantly greater movements during day hours on 2 reef sites and during night hours on 1 reef site. The surrounding receiver array validated 88% (15 of 17 fish) of the VPS-determined emigrations. Many (53%, n = 9) fish moved short distances (similar to 1.5 km) to nearby reefs, and some red snappers (n = 3) that emigrated returned to their original release site. Red snapper showed some prey-like behaviors, e. g. close association with reef structure, quick movements over open habitat, and paired emigrations to nearby sites. These behaviors suggested that red snapper are subject to predation by larger apex predators, and as stocks increase, such factors will become increasingly more important for future management.