Spatiotemporal variation among demersal ichthyofauna in a subtropical estuary bordering World Heritage-listed and marine protected areas: implications for resource management
Benthic trawl surveys were performed to quantify the spatiotemporal distributions of teleosts and key abiotic associations throughout an ecologically important estuary within Brazil’s Atlantic Forest biosphere. Approximately 52000 fish (51% juveniles) representing 75 species were sampled, with residents accounting for 36 and 61% of total species and individuals respectively. Five artisanally important species comprised 77 and 81% of individuals and biomass respectively. Cathorops spixii was most abundant (&gt;40% of total), whereas Stellifer rastrifer, Aspistor luniscutis, Sphoeroides greeleyi and S. testudineus collectively contributed towards 37 and 34% of individuals and biomass respectively. The abundance of A. luniscutis, C. spixii and S. rastrifer was negatively associated with salinity, whereas the presence of the latter two species was also positively associated with temperature, and S. greeleyi and S. testudineus (mostly adults) were more abundant in deeper areas. These relationships seemed to be affected by species-specific reproductive (S. rastrifer, C. spixii and A. luniscutis), habitat (S. greeleyi and S. testudineus) and prey preferences (juvenile C. spixii and A. luniscutis). Protection for these various species may be achieved via immediate fishing effort regulations, but more research is required to manage other anthropogenic effects. Such work should be a priority to ultimately preserve what is one of the most important South American biodiversity areas.