Recruitment dynamics of coral reef fishes in Barbados

Recruitment and population density of coral reef fishes were studied on artificial and natural reefs on the west coast of Barbados. Recruitment of all species combined and of 3 commons species (Thalassoma bifascaiatum, Stegastes partitus and Halichoeres garnoti) occurred mostly from May to November. Recruitment rate varied little across reef types and reef locations. Population density of all species combined and of the 3 common species varied little throughout the year, but did vary across reefs and locations. The observation that patterns of seasonal and spatial variation in densities did not reflect the patterns of seasonal and spatial variation in recruitment suggests that reef fish populations in Barbados may be primarily regulated by post-settlement events. Recruitment of all species combined and of the 3 common species was not affected by the density of all the species combined. No evidence could be found for interspecific competition, i.e. a negative relationship between the density of one species and the recruitment of another. However, recruitment of H. garnoti was inhibited on some reefs by high densities of conspecifics. Post-recruitment mortality of all speceis combined was not affected by density of all species. However, post-recruitment mortality of T. bifasciatum and S. partitus was higher on reefs of higher conspecific density. These results provide evidence for the regulation of reef fish populations in Barbados by post-settlement processes, and suggest that intraspecific interactions may be particularly important in limiting population size.