Hierarchical Levels of Biomarkers in Amphibian Tadpoles Exposed to Contaminants: From Enzyme Disruptions to Etho-Toxicology Studies in Argentina

Abstract

Monitoring different biomarkers in amphibians is an effective way to evaluate and characterize the risk of pesticides and contaminants of emerging concern that are currently present in all types of aquatic systems. Biomarkers are considered early warning signals and have been used extensively to relate with contaminant exposure (e.g., pesticides and pharmaceuticals). Ecotoxicological studies involving these vertebrates have high ecological relevance because amphibians are sensitive and occur in almost all aquatic environments where contaminants have been recorded worldwide (ponds, lagoons, rivers, streams). This chapter shows different biomarkers at varying hierarchical levels (ranging from alteration of B-esterase enzymes and antioxidant systems, hormone disruption, DNA damage, micronuclei, dysplasia, erythrocyte abnormalities, cardiac rhythm and function, to abnormal development and general ethology) used to obtain line of evidences in anuran tadpoles that occur in Argentina and that have been exposed to diverse pesticides and pharmaceuticals. In addition, a brief description of the usefulness of each biomarker for conducting ecotoxicological studies with amphibians is provided. Finally, some considerations were made on the impact of agribusiness on native amphibians in Latin America.