Antioxidant Response in Gills of Eurasian Perch (Perca fluviatilis) to Cyanobacterial Bloom Exposure in the Gruža Reservoir

Abstract

The aim of this study was to assess the impact of an Aphanizomenon flos-aquae bloom in the Gruža Reservoir on the antioxidant parameters measured in the gill cells of Eurasian perch (Perca fluviatilis). Effects of the bloom were evaluated through copper, zinc and manganese containing superoxide dismutase (CuZnSOD and MnSOD), catalase (CAT), glutathione peroxidase (GSH-Px), glutathione reductase (GR) and biotransformation phase II enzyme glutathione-S-transferase (GST) activities and glutathione (GSH) and sulfydryl (–SH) groups concentrations. The activities of CuZn SOD and Mn SOD decreased during the cyanobacterial bloom compared to the period before the bloom. The opposite trend was observed for CAT and GSH-Px activities that increased. During the bloom GR and GST activities and GSH concentration decreased significantly. CuZn SOD, GR and GST activities are detected as the most important parameters for individual variations. Our results indicated that an A. flos-aquae bloom promotes oxidative stress in the gills of P. fluviatilis. The investigated parameters could be used in environmental risk assessment procedures to monitor the effects of A. flos-aquae blooms on fish. Observed changes in the antioxidant parameters in P. fluviatilis gills make them potential biomarkers in the research of ecological risk situations in freshwater ecosystems with frequent cyanobacterial blooms.