The Mediterranean Shag (Phalacrocorax aristotelis desmarestii) is a fisheating sea bird from the family of Cormorants, which is distributed only in the Mediterranean and Black Seas. In the Northern Adriatic they gather in large numbers during the summer and autumn months, as this shallow and fish-rich sea is highly favourable for their foraging. The project SIMARINE-NATURA aims at defining and designating the most important areas for conservation of the Mediterranean Shags in the Slovenian sea which will become part of the Natura 2000 network.