Fine-Scale Movements and Home Ranges of Red Snapper around Artificial Reefs in the Northern Gulf of Mexico

Red Snapper Lutjanus campechanus are generally associated with artificial reef habitats in the northern Gulf of Mexico, but whether this association results in fish production is still controversial. Information on fine-scale habitat use patterns would be helpful in evaluating this. Little is known about the fine-scale movement patterns of Red Snapper around artificial reefs. The present study examined fine-scale (similar to 1-m accuracy) movements of Red Snapper with the Vemco VR2W Positioning System. This system enabled continuous monitoring of tagged fish from 100 to 694 d. Locations of individual fish were recorded approximately every 10 min and totaled over 1.9 million accurate locations of Red Snapper from August 2010 through May 2012. Red Snapper showed close association with the reef structure (mean +/- SD distance = 26.3 +/- 35.4 m) but differential habitat use in relation to both diel and seasonal periods. Home range areas (95% kernel density estimates [KDE]) were significantly larger during day than night periods and showed the lowest area use at dawn and dusk. Monthly home ranges (95% KDE) and core areas (50% KDE) were significantly larger in spring, summer, and fall than in winter and were significantly correlated with water temperature, suggesting colder winter temperatures reduced Red Snapper movement. Home range area was significantly correlated with fish size (407-590 mm standard length), and the fish in this study showed the highest site fidelity (88% still present after >10 months) of any Red Snapper in other previous studies. Red Snapper also showed use of multiple reefs within the monitoring area, as home ranges (95% KDE) showed a second peak around other artificial reefs. The high site fidelity, long-term use, and concentrated use of multiple artificial reefs confirm the importance of structured habitat for Red Snapper.