How are fish assemblages and feeding guilds organized in different tropical coastal systems? Comparisons among oceanic beaches, bays and coastal lagoons

Coastal ecosystems can vary considerably in their habitat characteristics and environmental conditions, resulting in divergent fish community structures. However, comparisons among coastal systems, such as oceanic beaches, bays and coastal lagoons, have not been thoroughly evaluated. We test the hypothesis that coastal systems that differ in wave exposure, habitat structure, salinity gradients and productivity show different assemblages and feeding guilds. The fish assemblages were significantly different among the systems. The bays had the largest number of species, whereas the lagoons had the highest numerical abundance and biomass. The planktivorous guild dominated in numerical abundance in all systems, whereas the opportunists dominated in biomass. The benthivores contributed greatly in abundance to the bays, the opportunists to the coastal lagoons, and the hyperbenthivores to the oceanic beaches. Water transparency and temperature explained a small portion of the variation in the community structure. This study highlighted the complex role that local factors have on the distribution of fishes at the species and trophic levels. These approaches were efficient to describe the structure and functioning of the assemblages in these different coastal systems. This should be viewed as essential for any comparisons of coastal systems, and in particular for conservation planning.