Spatial and seasonal patterns of the surf-zone ichthyofauna on a tropical Atlantic dissipative coastline

Abstract

The surf-zone of twelve sandy beaches on a tropical Atlantic dissipative coastline (Sergipe, Brazil) was studied to assess whether fish assemblages may be affected by spatial (proximity to estuaries) and seasonal (wet vs. dry) variations. Sampling locations were classified into sites of greater estuarine (EC) and marine (MC) contribution according to the coastal geomorphology. Samples were obtained by beach seining, and selected environmental variables including distance from estuarine mouths were recorded for each location. A total of 2134 fishes belonging to 21 families and 33 species were collected. The eight most abundant species were Mugil liza, Anchoa januaria, Polydactylus virginicus, Atherinella brasiliensis, Caranx latus, Trachinotus carolinus, Menticirrhus littoralis, and Trachinotus goodei. Species abundance varied significantly between sites and seasons, and taxonomic distinctness only between sites. Distance from estuaries, water salinity and temperature, and rainfall were the best predictors of the spatial and seasonal changes of fish assemblages in the surf-zone of tropical Atlantic dissipative sandy beaches. The occurrence of juveniles and recruits from most of the species recorded supports the nursery habitat hypothesis of shallow surf-zones.