Biomarker responses of the freshwater clam Corbicula fluminea in acid mine drainage polluted systems

Abstract

The environmental quality of an acid mine drainage polluted river (Odiel River) in the Iberian Pyrite Belt (SW Spain) was assessed by combining analyses of biomarkers (DNA strand breaks, LPO, EROD, GST, GR, GPx) in freshwater clams (Corbicula fluminea) exposed during 14 days and correlated with metal(loid) environmental concentrations. Results pointed that enzymatic systems are activated to combat oxidative stress in just 24 hours. Along exposure, there were homeostatic regulations with the glutathione activity that influenced in lipid peroxidation oscillations, provoking significant DNA strand damage 26 after 14 exposure days. EROD activity showed no changes throughout the exposure period. The Asian clam displayed balance biomarkers of exposure–antioxidant activity under non–stressfully environments; meanwhile, when was introduced into acid polymetallic environments, such as the acid mine drainage, its enzymatic activity was displaced towards biomarkers of effect and the corresponding antioxidant activity.