Vistula Lagoon million. However, major ecological considerations stand in the way. For example, mammal migration along the lagoon could be disrupted. Also, the inflow of brackish waters from the Baltic sea could result in serious unbalancing of the lagoon's freshwater ecosystem. From 1772 until 1918, the lagoon was part of the Kingdom of Prussia, which had become part of the German Empire in 1871. Between 1920 and 1946 it was split between Germany and the Free City of Danzig. At present state since 1945 its eastern part belongs to Russia (formerly USSR), Poland has 43.8% of its area at lagoon's western side.
Venetian Lagoon the network of dredged channels are called, while around 80% consists of mud flats, tidal shallows and salt marshes. The lagoon is the largest wetland in the Mediterranean Basin. It is connected to the Adriatic Sea by three inlets: Lido, Malamocco and Chioggia. Sited at the end of a largely enclosed sea, the lagoon is subject to high variations in water level, the most extreme being the spring tides known as the "" (Italian for "high water"), which regularly flood much of Venice. The nearby Marano-Grado Lagoon, with a surface area of around , is the northernmost lagoon in the