Vransko Lake is the only brackish natural lake on the coast of Croatia. It is situated in a shallow karst bed and separated from the Adriatic Sea by a narrow karst ridge. Significant seasonal variations in water level and salinity, due to the intrusion of sea water through the permeable karst, have created conditions for the development of very specific habitats. The shallowest north-west part of the Site features reedbeds, flood plain and seasonally flooded arable land; the hills lining the eastern shore are covered with typical Mediterranean scrubland, while the lower western coast is more rocky. Some of these areas are included in the EU Natura 2000 list of protected habitats. The Site is a nesting, wintering and resting area for many threatened waterbirds such as common pochard, spotted crake and Baillon’s crake. The Site also provides habitat to the critically endangered European eel. During the rainy season, the marshy areas regulate floods, while the reedbeds purify the waters of fertilizers carried into the lake through melioration canals, threatening its eutrophication. Notable threats to the Site, such as reed burning, illegal fishing and hunting, have been significantly mitigated since the establishment of the protected area, and continue to be addressed through local education and implementation of the management plan.