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.
Vadamarachchi Lagoon has extensive mudflats, seagrass beds and mangrove swamps, particularly Avicennia. The lagoon attracts a wide variety of water birds including American flamingoes, ducks, gulls, terns and other shorebirds. Vadamarachchi Lagoon Vadamarachchi lagoon () is a lagoon in Jaffna District, northern Sri Lanka. The lagoon is sometimes referred to as Thondamannar lagoon. The lagoon separates the Vadamarachchi region from the Valikamam and Thenmarachchi regions. The lagoon is connected to the Indian Ocean by a narrow channel to the north, near the town of Thondamannar. The lagoon's water is brackish to saline. There is a sluice gate at Thondamannar to prevent sea