Abstract
Investigations of diversity of ichthyofauna in the National park Una have been intensified during last few years through various studies, and in order to get better insight into total biodiversity in this area. The importance of knowledge and preservation of biodiversity in protected areas is clear considering increasing human impacts on rivers. Investigations of the state of ichthyopopulation have covered river Una and its tributaries rivers Unac and Krka at nine sites within the area of 347 km2 of National park Una. The obtained results indicate relative low fish species diversity. Seven species from four families have been regsitered: Salmonidae, Cyprinidae, Thymallidae and Cottidae. Despite relative low species diversity, it could be concluded thta fish fauna diversity is at satisfying level, particularly taking into acount that investigated sites are positioned in the upper parts of waterways in the National park Una, which belong to salmonide river regions.
Keywords: biodiversity, ichthyofauna, National park Una