Ictiofauna da REBIO Córrego Grande e seus entornos: comunidades e conservação dos ambientes aquáticos

Abstract

In the state of Espírito Santo, only 11% of its original Atlantic Forest remains, in the form of small remnants, including the Córrego Grande Biological Reserve, which features headwaters and small tributaries of the Itaúnas River basin. Thus, the present project aims to contribute with the knowledge about the anthropic impacts on aquatic environments and their riparian zones in seven sampling sites around the Córrego Grande Biological Reserve, as well as to evaluate the influence of environmental variables on the ichthyofauna and identify possible species indicating water quality at these locations. Therefore, two samples field expeditions in seven reaches of the sub-basins around Córrego Grande Biological Reserve were performed. An integrated environmental quality index was applied to detect main points to be adopted as references for good ecological parameters. Besides this, analyses to evaluate which species of the fish fauna could serve as bioindicators were performed. A canonical correspondence analysis was used in order to graphically relate the presence and abundance of species with the sampled sections, environmental variables and the environmental quality index. Finally, an analysis of indicator species was applied to attest to the bioindication power of certain species in relation to specific environmental quality levels. As a result, 1134 specimens of fishes were sampled, belonging to four orders, nine families, 16 genera and 18 species. Of the seven sample sites, five could be classified as references to good environmental integrity, one of intermediate quality and one of poor quality. Canonical correspondence analysis reveals the influence of substrate types and the presence of vegetation, whether marginal or riparian vegetation, as the most important factors in the distribution of species in sub-basins. No species was significantly classified as an indicator of environmental quality in the study area. New studies need to be carried out to analyze the water quality of the sampling reaches and new practices, especially of agriculture, need to be implemented in the region, which has intense human impacts.