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.
Freshwater Lagoon following subsidence events. The relatively small catchment basin tributary to Freshwater Lagoon has allowed formation of a durable coastal sand bar which has not been breached by recent storm events. Precipitation usually percolates through the bar without forming a surface channel. U.S. Route 101 traverses the coastal sand bar between Freshwater Lagoon and the Pacific Ocean. Convenient parking on the sand bar adjacent to the highway has made the lagoon a popular scenic rest area for motorists in Humboldt Lagoons State Park. There is also a Redwood National and State Parks visitor center near the north end of the lagoon.