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.
Vistula Lagoon Gdańsk Bay by the Strait of Baltiysk. The Poland–Russia border runs across the lagoon. Localities on the lagoon include Kaliningrad, Baltiysk, and Primorsk in Russia's Kaliningrad Oblast and Elbląg, Tolkmicko, Frombork, Krynica Morska in Poland. The Polish port of Elbląg used to see a substantial amount of trading traffic on the lagoon, but that has declined owing to the current border situation. Kaliningrad and Baltiysk are currently major seaports on the lagoon. The earliest version of the name of Vistula Lagoon has been recorded in historical sources by Wulfstan, an Anglo-Saxon sailor and merchant at the end of the 9th