The grazing activities of the tropical echinoid Diadema antillarum Philippi can markedly influence the structure of the shallow-water epibenthic coral reef community. The elimination of an entire Diadema population from a patch reef in St. Croix, U.S. Virgin Islands resulted in a great increase in macro-algal biomass, alterations in species composition, shifts in dominance, an increase in species numbers, and a decrease in equitability....