Direct effects on fish biodiversity and biomarkers due to alterations in the water quality from semi-arid region river

Abstract

The Conlara river basin, one of the most important surface water network in the semi-aridregion of Argentina, but is impacted by a variety of anthropogenic activities (wastewatereffluents, tourism and agriculture). Previous studies demonstrate that environmentalcontaminants are exceeding those recommended for the protection of aquatic life, withadverse effects on fish physiology. The objective of the present study was to evaluate thepotential effects of the anthropogenic activity on fish biodiversity and biomarkers in theConlara river. Four sites were sampled along the river considering lower (S1 and S2), medium(S3) and higher (S4) anthropic impact. Physicochemical parameters were determinedto calculate water quality index (WQI). Fishes were sampled to evaluate abundance andrichness, and to determine different biomarkers: body mass index (BMI), glucose, catalaseand micronucleus. Results show that, S2 had better WQI, higher biodiversity indexes andexcellent BMI. However, S3 had very poor WQI, lower biodiversity and BMI, as well asdominance of introduced species. Results showed poor WQI due to conductivity, dissolvedsolids, biological oxygen demand, coliforms and nitrates by effluents. This first study inprovince demonstrate that the integration of physical-chemical parameters with fish biodiversityis a useful tool for biomonitoring aquatic semi-arid ecosystems.