EIS was made for capacity increase of the white fish farm situated near Dugi Otok, between the Žman and Gubac Capes. Biocenological examination was carried out for the study purposes, with the aim of exploring the marine habitats, while the special attention was paid to the presence of protected habitats and species. Four variants of planned breeding area volumes were analysed and the cage emissions for each variant were calculated. The seeping of the substance and the oxygen concentration at the bottom were estimated by using the numerical model and the calculated emissions. Lastly, the impact of the emissions on the environment for the considered variants was estimated based on the environmental data and model results.