Reclutamiento del coral Acropora palmata sobre sustratos de dos materiales

Abstract

During recruitment of corals, substrate characteristics influence the density and the spatial distribution of recruits. The influence of the material (limestone and sand) and of 4 groups arrangements (limestone/up, limestone/down, sand/up and sand/ down) in the distribution of the Acropora palmata recruits in 4 areas of the substrate used (upper face, side faces, bottom faces and base) was evaluated. The number of recruits per substrate was higher in limestone (median= 15.0) than in sand (2.0). Regarding the areas of recruitment, the upper face in limestone and the upper and side faces in sand presented greater number of recruits than the other areas of the substrate; notably the upper faces received more light during the conditioning of the substrates. Concerning the groups, the number of recruits per substrate was higher in limestone groups (limestone/up ≈ limestone/down) than in sand groups (sand/up > sand/down). The relatively low number of A. palmata recruits obtained (12500 m-2) was, however, 3-4 orders of magnitude higher than the recruits obtained in Caribbean coral reefs (3-39 m-2), with an abundance dominated by opportunistic corals that do not provide the ecological qualities fulfilled by A. palmata. The implantation in the field of recruits obtained in aquarium remains as a viable alternative to recover populations of this critically endangered coral species, which substantially contributes to the structural complexity of Caribbean coral reefs.