Feeding and growth of young salmon trout Salmo trutta L. morpha lacustris have been studied in brooks, rivers and lakes in Paanajarvi National Park. In the rivers on the rapids and rifts basic food is aerial and terrestrial insects as well as amphibian insects on adult stages. In lakes food spectrum is broadened by zooplankton and freshwater shrimps Gammarus sp. Parrs of salmon trout (3+) from the River Olanga that inhabit upper rapids are significantly bigger compared to fish from lakes and small rivers.