SPONGES COMMUNITIES THE CORAL REEF OF THE ARCHIPELAGO SABANA-CAMAGÜEY, CUBA

Abstract

The research was carried out in order to know the sponge community composition and structure of the Archipelago Sabana-Camagüey, and to assay their use as indicators of the environmental severity and predictability, as well as of the most important stressors of this territory.  For this purpose, sampling was done at stations located in 10 reef transects (between 10 and 20 m deep). Species which occurred more frequently with numerical dominance are typical of environments submitted to strong sedimentation and turbulence, which suggests that these environmental stressors and light are the main determinants of sponge community structure and composition in the studied reefs. The development of dense algal mats is also determinant in shallow stations. Species heterogeneity and species richness, and density tended to be higher toward deeper stations, which indicates an increase of environmental favorability for sponges with depth. Equitability tended to be more homogeneous across the studied depth range. Its values were generally high, which suggests relatively constant environments for sponges. Heterogeneity index was more frequently influenced by equitabiliy than by  species richness. For that reason, a greater influence of environmental stability than environmental favorability on the high values of this index in the studied reefs is suggested. By means of a meta-analysis process, the position of the values of some indexes within their universe of variation was analyzed. At more than 10 m in depth diversity indexes tended to be relatively higher than in other Cuban reefs. Also by applying meta-analysis, stations were classified within a bidimensional gradient of environmental severity and environmental predictability.   Univariate indexes and the dominant species, complemented with species dependent multivariate methods permit to infer the most important stressors, and environmental severity and predictability.