Fish and Coral Community Structure Are Related on Shallow Water Patch Reefs near San Salvador, Bahamas

we measured abundance and diversity of fishes and corals at three patch reef complexes near San Salvador, Bahamas, and examined relationships among species and ecological measures of fish and coral community structure. Generalized discriminant Analyses indicated which ecological variables distinguished reefs and which fish and coral species accounted for observed differences among reefs. Canonical Correlation Analysis revealed relationships between fish and coral species at each reef. Reefs with the greatest coral cover had the highest abundance and species richness of fishes. These results add to studies describing relationships between reef fishes and corals, and establish a benchmark for fish and coral community structures and relationships near San Salvador in the Bahamas during a time of region-wide declines of Caribbean corals. The physical complexity of coral reefs provides a myriad of microhabitats supporting numerous fish species, many of which are site-attached or strongly tied to reef habitats. Coral abundance, diversity, or cover may influence the resident fish community by providing increased reef surface area or structural complexity. Fish abundance has been positively correlated with scleractinian corals responsible for the construction of reefs (Bell and Galzin, 1984; Lirman, 1999). In Caribbean waters, gorgonians are prominent members of the coral community and may provide additional microhabitat or cover for fish species or, conversely, discourage the presence of certain species either by displacing important scleractinians or through chemical deterrence (Goldberg, 1973). Furthermore, decreased live coral cover has been associated with an increased abundance of herbivorous fishes, presumably due to increased algal cover (Bell and Galzin, 1984; Galzin, 1987; Carpenter, 1990; Gladfelter et al., 1991a,b; Lirman, 1999). Fish-habitat associations on coral reefs are well documented; previous work has shown linkages between fish abundance and microhabitat availability (Caley and St. John, 1996), habitat complexity (Jones, 1988), habitat abundance (Tolimieri, 1998) and richness (Ault and Johnson, 1991), substratum diversity (Gladfelter and Gladfelter, 1978; Roberts and Ormand, 1987), live coral (Garpe and Öhman, 2003), and algal community structure (Chittaro, 2004). however, several studies have not supported such relationships (Luckhurst and Luckhurst, 1978; Molles, 1978; McManus et al., 1981; Lewis and wainwright, 1985; Roberts and Ormond, 1987; Bohnsack et al., 1992; Syms and Jones, 2001), possibly due to sampling-scale issues, diverse sampling methodologies, or lack of powerful statistical analysis tools. we tested for abundance and diversity relationships between fish and coral communities on contrasting shallow-water patch reefs using non-destructive, underwater visual surveys near San Salvador, Bahamas (walter, 2002). we compared three regions known to differ in terms of percent coral cover and diversity (McGrath and Smith, 2003). Our objective was to determine whether reef fish community strucBULLETIN OF MARINE SCIENCE, vOL. 79, NO. 2, 2006 366 ture could be related to selected aspects of coral community structure. Using data collected from all reefs, we also examined relationships between abundant fish and coral species.