Coral Populations on Reef Slopes and Their Major Controls

Abstract

Ecological studies of corals on reef slopes published in the last 10-15 y are reviewed. Emphasis is placed on controls of coral distributions. General coral distributions are synthesized from widespread reefs and are described in the order: shallowest, most exposed reef slopes; main region of hermatypic growth, deepest studies conducted by SCUBA or submersible, and cryptic habitats. Favoured methods of study have involved cover, zonation and diversity, although inadequacies of these simple measurements have led to a few multivariate treatments of data. Well studied controls include water movement, sedimentation and predation. All influence coral populations directly and by acting on competitors. Finally, controls on coral population structure by competitive processes between species, and between corals and other taxa are illustrated.