Abstract
The Savica significant landscape is the only wetland area within the boundaries of the city of Zagreb and as such is of great value. The lake comprises a small section of an old arm of the Sava River, and 13 interconnected lakes created by the expansion of old lake arms. In terms of its biological classification, it is a eutrophic lake and provides adequate conditions for the survival of fish populations. The aim of the study was to investigate the qualitative and quantitative composition of the ichthyofauna in Lake Savica, while determining biodiversity indices, the presence of nonnative species and species composition by trophic and ecological groups. Sampling was carried out by electrofishing at 11 sites in the important landscape of Savica. A total of 20 fish species were recorded, of which 7 were non-native species. These results were compared with previous surveys of the lake. Lake Savica is inhabited by fish from standing waters of the lowlands, and the species present are generally opportune, with some interesting species for sport fishing.