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.
Rekawa Lagoon Kirama-oya river (Tangalu-oya river) that enters the lagoon at the sea ward end of the inlet canal is the main freshwater supply. Apart from the main freshwater inflow, there are two small freshwater streams function only in rainy season and provide surface runoff from the catchment. The total hydro-catchment of the lagoon outlet is about . Shrimp fishery is one of the main livelihoods among the lagoonal community. However this supports the people only during the shrimp fishery season which extends from October to April. The most abundant shrimp species in Rekawa lagoon and commercially most important shrimp species is