Influence of trout farm effluents on selected oxidative stress biomarkers in larvae of Ecdyonurus venosus (Ephemeroptera, Heptageniidae)

Abstract

The aim of the present study was to establish the extent to which the outlet waters of trout farms affect the ecosystems of the Crnica and Skrapež rivers in Serbia. We monitored selected biomarkers of oxidative stress: superoxide dismutase (SOD), glutathione peroxidase (GPx) and total glutathione (GSH) in larvae of the species Ecdyonurus venosus, and simultaneously analyzed the changes in the physical and chemical parameters. The investigations were carried out in spring at four localities along the Skrapež and Crnica rivers: one upstream (the control localities), and three downstream from the fish farm outlets. On the Skrapež River, the fish farm was clearly visible and was markedly changed by the chemical parameters of the water, manifested as a decreased concentration of dissolved oxygen, increased concentrations of nitrates, nitrites, ammonium ions, total phosphorus and total organic carbon, and increased SOD and GPx activities and decreased GSH concentration in larvae from the first downstream locality as compared to the control locality. On the Crnica River, due to the high values of water flow (around 3 m 3 /s), effluents from the fish farm had no effect on the chemical parameters of the water or on the tested biomarkers.

Effectiveness of Biomass/Abundance Comparison (ABC) Models in Assessing the Response of Hyporheic Assemblages to Ammonium Contamination

“…Furthermore, Ecdyonurus species are reported to be bioindicators of unpolluted small and slow-flowing streams [45]. In particular, E. venosus is very sensitive to organic pollution [46]. On the contrary, in the downstream stretch, the biomass and abundance curves overlapped, identifying a disturbed community, where the drop of the biomass curve was due to the dominance of small-sized, opportunistic taxa such as the cyclopoid D. bisetosus.…”

Springs and Headwater Streams in Serbia: The Hidden Diversity and Ecology of Aquatic Invertebrates

“…In recent years in Serbia, there have been analyses of the influence of trout farms on the macrozoobenthos communities of headwater streams by examining the oxidative stress enzymes response [61][62][63][64][65]. This response is the first line of defense of the organism against pollutants from the environment [30].…”

“…This response is the first line of defense of the organism against pollutants from the environment [30]. There is special emphasis on research into the effects of trout farm discharges on components of the antioxidant defense system (superoxide dismutase-SOD, catalase-CAT, glutathione peroxidase-GPx, reductase-GR and S transferase-GST enzyme activities, and total glutathione concentration) in the larvae of Dinocras megacephala (Plecoptera), Ephemera danica (Ephemeroptera), Ecdyonurs venosus (Ephemeroptera), and Gammarus dulensis (Amphipoda) [61][62][63][64].…”

“…In bioindicator species Ephemera danica and Ecdyonurus venosus (Ephemeroptera), the activity of SOD, CAT, and GPx was measured, as well as the concentration of GSH in the Skrapež and Crnica streams (Fig. 9.1) [62,64,65]. Characteristically, CAT activity could not be registered, SOD activity was not sensitive to farm effects, while the most sensitive biomarker was GPx activity which was characterized by a statistically significant increase, except for E. venosus in the Crnica stream.…”

“…Characteristically, CAT activity could not be registered, SOD activity was not sensitive to farm effects, while the most sensitive biomarker was GPx activity which was characterized by a statistically significant increase, except for E. venosus in the Crnica stream. If we take into account that waste water did not influence increase in GPx activity in E. venosus larvae in Crnica [64], and that in the case of E. danica it was 6 times lower than in Skrapež [65], we can conclude that this biomarker shows significant sensitivity to the intensity of organic pollution, as well as that E. danica is a more sensitive bioindicator of organic pollution compared to E. venosus [62,64,65].…”