DISTRIBUTION, DENSITY, AND ABUNDANCE OF THE QUEEN CONCH, STROMBUS GIGAS, IN LOS ROQUES ARCHIPELAGO NATIONAL PARK, VENEZUELA

摘要

Due to decades-long high levels of exploitation, in 1991 Venezuela closed the fishing of queen conch, Strombus gigas (Linnaeus, 1758). A visual assessment was carried out between July and September 1999 providing the most current data on distribution, density, and abundance of queen conch for Los Roques Archipelago National Park. The assessment involved two random surveys. The overall estimated mean density and abundance were 18. 8 conchs ha~(-1) (SD= 44.5), and 1,374,640 conchs (95% bootstrapped C.L.: 640,474-2,023,897) for the 73,197 ha of the platform, < 40 m depth. Overall density values were close to those obtained in overfished areas of Belize and St. Thomas/St. John, U.S. Virgin Islands. The survey revealed zones with potential nursery areas and the largest aggregations of adults on sand plains at depths > 16 m, actively mating. Given the relatively low densities found, the susceptibility of the species to overfishing, the current economic alternatives in the area, the precarious enforcement of fishing regulations, and the presence of important breeding aggregations, we recommend that Los Roques Archipelago be kept as a sanctuary for this species, thus prohibiting the re-opening of the fishery.