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
Keta Lagoon ponds. This is evidenced by the remains of oyster shells that are deposited at various spots in towns to the northern side of the lagoon. A third theory is that during the ice age these spots were the remains of the ice which melted due to rise in temperature leaving behind a fresh lagoon. The infiltration of sea water made it saline. The Köppen Climate Classification is "Aw". (Tropical Savanna Climate). Seva is an island located in the Keta Lagoon. By 2010, it has a population of 300 people with a terrain elevation of 43 metres above sea level. It