Vistula Lagoon of the Ests". Over three hundred years later, in the first half of the 13th Century, the name of Vistula Lagoon occurs in deeds issued by Teutonic Order in Latin version as Mare Recens (1246 - "mare" - a pool or lake or sea and "recens" - fresh) in contrast to the contemporary name for the Baltic Sea - Mare Salsum (Salty Sea). Then in 1251 we find record about Mare Recens et Neriam (Frisches Haff and Frische Nehrung, now Vistula Spit) and finally in 1288 Recenti Mari Hab (Haff) which as one can see corresponds with later German "Frisches
Curonian Lagoon eventually assimilated by the Germans, except along the Curonian Spit where some still live. The Kuršininkai were considered Latvians until after World War I, when Latvia gained independence from the Russian Empire, a consideration based on linguistic arguments. This was the rationale for Latvian claims over the Curonian Spit, Memel, and other territories of East Prussia which would be later dropped. The Lagoon, formed about 7,000 years BCE, is a freshwater lagoon. Water depths average 3.8 meters. It is highly biodiverse, although troubled by water pollution. The presence of algal blooms was confirmed in the 2000s. Curonian Lagoon The Curonian