Temporal Variability in the Community Structure of Fish on Coral Patch Reefs and the Relation of Community Structure to Reef Structure

Abstract

Fish assembled on 20 lagoonal patch reefs were censused eight times over 33 mo. Reefs, which ranged in size from 2.71 m 2 to 28.35 m 2 surface area, supported an average of 128 fish of 21 species at any one time. These were drawn from a total pool of 143 species, and, because of successive recruitments and losses of individual fish, each reef supported many more species during the study than were present at any one census. Structure of the assemblages on each reef, in terms of species number, of fish, and species composition, varied through time. Mean proportional similarity of assemblages on the same reef was 0.568, °15% greater than that between assemblages on different reefs (0.422). Structural attributes of reefs, other than size, were of little value in predicting the structure of the fish assemblages formed. The results are compatible with an essentially nonequilibrial view of reef fish communities. This view holds that species recruit to reef sites at varying rates, and independently of each other, while individuals are lost from sites (through death or emigration) also in a way unstructured with respect to the species composition of the resident fauna.