Levantamento das passagens para peixes da bacia hidrográfica do rio Paraná e caracterização do entorno dos sítios reprodutivos de peixes

Abstract

Aquatic ecosystems have been transformed by advances in impactful constructions such as dams for hydroelectric plants and extensive agricultural and livestock activities. These impacts contribute to the degradation of biodiversity in natural forests and fragment water resources. This research carried out the survey of fish passages in the Paraná River hydrographic basin and the characterization of the surroundings of the fish reproductive sites of four tributaries of the Porto Primavera plant's reservoir. To carry out the research, data from the Electric Sector System and Geographic Information (SIGEL), from the National Electric Energy Agency (ANEEL) were used for the survey, as well as research on scientific articles, environmental reports, by phone, e-mail. and on energy company websites. For the characterization of the surrounding reproductive sites, we used satellite images from the 2016 and 2017 period. For the supervised classification analysis, we used the Maximum Likelihood algorithm and con-firmed by geostatistics with the Kappa index. 362 projects in operation were identified and only n = 35; 8.8% with fish passage systems in the Paraná River basin, constituting a large part of the ladder type n = 29; 85.2%. In the classification it was verified that the hydrographic basin of the Verde River, presented better conditions of vegetation areas and the floodable ones indicating that they are the chosen places also among the fish species. The Paraná River basin is drastically disconnected, evidenced by the high number of hydroelectric dams, which interrupt the genetic viability of the species and that about 90% of the enterprises do not have STPs. Vegetation areas and floodplains are important habitats with a primary role in the per-manence and restoration of aquatic communities, maintaining and conserving aquatic diversity for neotropical migratory fish species.