Conservação de anfíbios de riachos do parque natural municipal de Sertão, RS

Abstract

Vertebrate diversity is declining worldwide due to multiple causes such as habitat fragmentation, fungal infections and chemical contaminants in water. This study analyzes the influence of physical-chemical - including pesticides - and microbiological parameters on the health of an amphibian species in an Atlantic Forest reserve in southern Brazil. The study was carried out in the Parque Natural Municipal de Sertão (PNMS) in northern Rio Grande do Sul and the species Aplastodiscus perviridis was used as a biondicator, of which 147 tadpole specimens were used to analyze morphological and genotoxic damage. In the environments of the PNMS, seven different types of pesticides were found, amounts of ammonia nitrogen above what is allowed in Class I and II rivers, and differences in physical-chemical parameters such as biochemical oxygen demand and dissolved oxygen above what is proposed by the CONAMA 357 classification, especially in the edge and surrounding environments. Results showed that there is a difference between cloacal rostrum length and mass of A. perviridis tadpoles, being larger in the border and interior and smaller in the surrounding area, as well as nuclear abnormalities of erythrocytes that were larger in the border environment and smaller inside the PNMS. This difference may be associated with increased pesticide toxicity, ammonia nitrogen and biochemical oxygen demand, and dissolved oxygen, indicating that amphibian populations are being affected by agriculture in the matrix. We conclude that the PNMS needs enforcement and control actions associated with the use of pesticides and nitrogen fertilizers to keep A. perviridis populations healthy