Status of shark resources in the Southern Gulf of Mexico and Caribbean: Implications for management

This paper reviews current knowledge on shark biology, ecology, and fisheries in Mexican waters of the Gulf of Mexico, focusing on management implications. Original and literature data are summarized covering distribution, migrations, nursery areas, structure of the landings and catch trends. There are at least 34 species of shark in the area, most of them from the genera Carcharhinus and Sphyrna. Fourteen of these species are important in the fisheries. The biology and ecology of shark stocks in the southern Gulf of Mexico are poorly known. Tagging studies have shown movements of shark from the eastern US coast to the southern Gulf of Mexico, but migrations have not been properly characterized due to limited tagging in Gulf waters. There are important shark nurseries for at least five species in the protected waters of Chetumal Bay (Q. Roo), Yalahau Lagoon (Q. Roo), and Terminos Lagoon (Camp.). Sharks contribute approximately 3.5% of the total fishery catches in this region, averaging about 13 000 t during 1983-1992. Sharks are harvested by a diverse fleet of small-scale and large-scale vessels utilizing longlines or gillnets. There seems to be an excessive fishing of juveniles from many of the most important species. Areas of priority for future research that are pre-requisite for international management are: the life cycle of the main species in the southern Gulf of Mexico; in-depth study of coastal nursery areas; large scale tagging programmes coupled with population genetics studies; gathering of fisheries data and fisheries-independent abundance information; and socio-economic studies of the fisheries. Some precautionary management measures are proposed.