DISTRIBUTION OF THE NURSE SHARK, GINGLYMOSTOMA CIRRATUM, IN THE NORTHERN GULF OF MEXICO

The distribution of nurse sharks, Ginglymostoma cirratum (Bonaterre, 1778), in the northern Gulf of Mexico was examined using fisheries-independent bottom longline data collected from 1995 to 2009. Results indicate that nurse sharks are most abundant in the eastern Gulf of Mexico and their occurrence is relatively rare west of the Mississippi River Delta. While the eastern Gulf of Mexico had significantly different abiotic characteristics than the central and western regions, it is hypothesized that nurse shark distribution in the Gulf of Mexico is most associated with hard bottom substrate. Most nurse sharks were captured in groups of two or more individuals, indicating this species frequently aggregates. Nurse sharks in the region likely aggregate in response to prey availability, rather than for predator avoidance or mating purposes.