The Study of Toxic Effects of Wastewaters Discharged From the Vilnius Treatment Plant on Fish

Abstract

The aim of this study was to assess the toxicity of wastewaters discharged from Vilnius treatment plant (VTP) using rainbow trout, at different stages of development, and evaluating alterations in fish biological parameters. The results of the present study demonstrated that untreated wastewaters (UTWW) could induce significant adverse effects in developing fish (the increase in mortality of larvae and juveniles of rainbow trout, reduced gill ventilation frequency, heart rate, relative body mass increase of larvae). Treated wastewaters (TWW) also caused negative alterations (reduced growth of larvae, decreased immunotoxicity responses in juveniles) of rainbow trout. Generalizating of our results, it should be recognized that treated wastewaters of VTP still are toxic to fish at sensitive stage of development (larvae, juveniles). The toxicity tests demonstrated the need of applying new treatment technologies for reducing the negative impact of effluents on natural water receivers.