Features of indigenous lake fish allocation in areas influenced bytrout farms

A study of the impact exerted by the rainbow trout cage farms on characteristic features and distribution patterns of indigenous lake fish was carried out on the lake Vohtozero (Russia, Karelia) during open water period (May - October, 2011-2012). Species of indigenous fish were caught at three points: in close vicinity from the cage farm, at a distance of 100-200 m, and at a distance of 4,5 km - the most distant point from the cage farm. It was revealed that perch (Perca fluviatilus Linnaeus, 1758) and roach (Rutilus rutilus Linnaeus, 1758) accumulate around cages in large quantities during summer season. They actively feed on the remains of pelleted feed. Therefore, indigenous fish, inhabiting water reserves employed by cage farms,on the one hand, utilize waste feed and, on the other hand, contribute to the self-cleaning of the pond. The current ban on fish capture in water reserves hosting working rainbow trout fish farms is instrumental in preservation of indigenous fish population.