Physical forces influence the trophic structure of reef fish communities on a remote atoll
Limnol. Oceanogr., 57(5), 2012, 1403-1414 | DOI: 10.4319/lo.2012.57.5.1403
ABSTRACT: We describe spatial patterns in fish abundance across the lagoonal patch reef system at Glover's Reef Atoll in Belize, and assess the relative influence of physical, biological, and abiotic structural variables on these patterns. Physical factors—specifically, distance from reef channels, current flow, and temperature—play a significant role in structuring overall patterns in fish abundance across the lagoon. The types of variables that best explained trends in abundance of specific groups of fishes were related to feeding habits of these groups. For example, fishes dependent on primary and secondary sources of productivity (herbivores and planktivores) were most highly influenced by physical factors. Abundances of benthophagous fishes were best predicted by benthic habitat variables such as coral cover, while abundance of piscivorous fish groups was best predicted by abiotic structural habitat variables such as reef area. While data on physical oceanographic properties are not normally considered in relation to abundance patterns of reef fishes, we find that such factors are good predictors of abundance for these species. Where physical data are not available, simple distance metrics may serve as reasonable proxies for physical oceanographic processes.