Vransko Lake; 30/07/2012; County of Zadar and County of `ibenik-Knin; 5,747.51 ha; 43°53'28'N 15°34'36'E; Nature Park, Special Ornithological Reserve. Vransko Lake is the largest natural lake in Croatia, situated in a shallow karst bed and separated from the Adriatic Sea by a narrow karst ridge. Significant seasonal variations in water level and changes in salinity due to intrusion of sea water through permeable karst create conditions for development of very specific habitats. The shallowest northwest part of the site is characterized by reedbeds, floodplain and seasonally flooded arable land; the hills lining the eastern coast are covered by typical Mediterranean macchia and garrigue, while the lower western coast gives a more rocky appearance. Vransko Lake marsh is a remaining of what used to be a much larger Vrana swamp, drained by melioration canals in 18th century. This site is a nesting, wintering and resting area for many threatened waterbirds as the Ardea purpurea, Egretta alba or Porzana pusilla. Vransko Lake is the biggest reservoir of fresh water in this region of Croatia. During rainy season the marsh regulates floods. The reedbeds are excellent in purifying waters that enter the lake through melioration canals, carrying fertilizers that could enhance the lake eutrophication. The Management Plan for the Nature Park was developed in 2010 and since then being implemented. Ramsar Site Number: 2109. Most recent RIS information: 2012.