The impact of fish farming on the Tarasmozero Lake ecosystem, Onega Lake basin

Abstract

The Tarasmozero Lake ecosystem (Onega Lake basin), affected by fish farming was assessed prior to and after the construction of a rainbow trout farm. Lake Tarasmozero receives waste water from the farm. The results of our studies show that when the farm began operating, phosphorus and nitrogen concentrations in the water have increased, affecting aquatic organisms and their environment. It was shown that phytoplankton is now dominated by diatoms, zooplankton species, characteristic of eutrophic water bodies, have appeared, and amphipods now make up the bulk of zoobenthos’ biomass. This evidence indicates that Lake Tarasmozero gradually passes from an oligotrophic type to a mesotrophic type.