The role of environmental factors in the composition of anuran species in several ponds under the influence of coal mining in southern Brazil

Abstract

Environmental pollution caused by the disposal of chemicals or toxins into the environment represent a great threat to amphibians. In this study, it was evaluated which environmental factors of ponds under the influence of coal-mining influence the composition of anuran species. For this purpose, anuran samples were performed in ponds in coal extraction areas in southern Brazil. Physical and chemical characteristics of water, sediment and structural characteristics of the ponds were determined. The content of copper in the sediments of the ponds was the main variable to explain the composition of pond species. Besides copper, it is evident the relevance of number of vegetation strata at pond border and pond area on the composition of anurans. It is shown that the composition of species in ponds under the influence of mineral coal mining activity may be a result of historical perturbations, remaining only the most tolerant towards colonization. From the results obtained in this work it can be suggested that there is a synergistic interaction between environmental factors and the coal mining effects on the anurans fauna of impacted ponds. Thus, efforts should be directed to elucidate the effects of pollutants exposure levels on the species, the understanding of sub-lethal and lethal effects of each pollutant on each species, as well as how local populations can be maintained through recruiting rates of larvae and anurans of the impacted ponds.