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 (>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

Marine debris in a World Heritage Listed Brazilian estuary

Using monthly otter-trawl deployments, spatial and temporal variability among the relative densities of marine debris were assessed in the Paranaguá estuarine complex; a subtropical World Heritage Listed area in southern Brazil. During 432 deployments over 12months, 291 marine debris items were identified; of which most (92%) were plastic, and more specifically shopping bags, food packages, candy wrappers and cups typically >21mm long. The most contaminated sectors were those closest to Paranaguá city and the adjacent port, and had up to 23.37±3.22 pieces ha. Less urbanized sectors had between 12.84±1.49 and 9.32±1.10 pieces ha. Contamination did not vary between dry or wet seasons, but rather was probably affected by consistent urban disposal and localized hydrological processes. Marine debris might be minimized by using more environment friendly materials, however a concrete solution requires adequately integrating local government and civil society