Daily movement patterns of red snapper (Lutjanus campechanus) on a large artificial reef

Red snapper (Lutjanus campechanus) are at the center of many artificial reef efforts in the Gulf of Mexico. To elucidate red snapper use of artificial structure for fisheries management, their fine-scale movements need to be examined further. Much effort until now has focused on examining movement patterns of red snapper at isolated reef structures, yet fish may behave differently on reefs covering larger areas. To address this, 15 red snapper were internally tagged with V9P transmitter tags and tracked with VR2W receivers for three months at a large artificial reef (PS-1047, 0.8 km2, bottom depth range 21 m-23 m) that was comprised of a tugboat and over 4800 concrete culverts deployed randomly around the area. Ten receivers were arranged on the reef to calculate center of activity and depth for each fish every 20 min. Kernel densities (KDE) were calculated at 95% (77,905.04 ± 1843.27 m2) and 50% (16,797.25 ± 413.02 m2) to address home range and core area use, respectively. There were differences in KDE and depth per day, and depth exhibited diel patterns. There were significant decreases in KDE and increases in depth use after a drastic drop in sea surface temperature. Overall fish use of PS-1047 resulted in two key areas (50% KDE), which comprised of two main groups of fish without overlap and highlighted two different structure areas (tugboat vs. culvert). Home range and core area values were more than 4 times larger than reported in other studies on red snapper.