Influence of a trout farm on antioxidant defense in larvae of Ephemera danica (Insecta: Ephemeroptera)

Abstract

The aim of this study was to establish the influence of a trout farm on the activity of enzymes superoxide dismutase (SOD) and glutathione peroxidase (GPx), and total glutathione concentration (GSH), in larvae of Ephemera danica, and on environmental parameters in the receivingwatercourse. The investigations were carried out seasonally (April, July, and October of 2016 and January of 2017) at four localities (SK1control, and SK2, SK3, and SK430 m, 330mand 630mbelow the fish farm, respectively) along the Skrapez River. Discharged water had the greatest effect on the concentrations of dissolved oxygen (DO), ammonium ions, nitrates (NO3 ), and total phosphorus. In the case of SOD and GSH, seasonal changes were greater than longitudinal, with maximal values attained in spring and summer and minimal in autumn and winter. SOD showed the strongest correlation with DO, and GSH with total nitrogen. Activity of GPx demonstrated greater longitudinal variability with maximumat SK2in all seasons and the strongest correlation withNO3 .The obtained results indicate thatGPxactivity wasthemost sensitive to the trout farmeffects, while SOD and GSH were more influenced by natural seasonal changes of environmental parameters.