Agro is not cool: DNA damage and oxidative stress in anurans evidencing the devastation of subtropical grasslands.

Changes in land use are considered the main factor in the degradation of ecosystems, especially in continental aquatic environments. In this study, we evaluated the genotoxicity potential of the environmental matrix using tadpoles from three anuran species as a model, to test whether more genetic damage and changes in oxidative stress biomarkers occur in ponds on farms than in native grasslands. Tadpoles were sampled from ponds in the subtropical highland grassland region of southern Brazil. We quantified DNA damage in tadpoles of Scinax squalirostris, Ololygon aromothyella and Odontophrynus asper using the comet assay and oxidative stress changes using glutathione as a biomarker. Our results demonstrated that the tadpoles of the three anuran species collected in agricultural ponds accumulated greater DNA damage and alterations in biomarkers of oxidative stress when compared with those collected in ponds in the native grassland, corroborating our initial hypothesis. The DNA damage detected in tadpoles from farm ponds suggests that these populations are suffering impacts from environmental contamination, mainly from heavy metals and fertilizers, as indicated by our complementary data. Our results highlight the importance of grassland remnants for the conservation of amphibians in the subtropical region, which are under severe threat due to the replacement of natural areas by agriculture. Moreover, we emphasize the importance of monitoring and quantifying agrochemicals in habitats and organisms to ensure the viability of populations and support adequate management and conservation strategies for the species of pond-breeding anurans in the region of subtropical grasslands in southern Brazil. [ABSTRACT FROM AUTHOR]