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.
Keta Lagoon The lagoon is important in conserving several species of mangroves, crabs, shrimps and raffia plants. This lagoon holds variety of fishes from the marine environment and from rivers. It is a spawning zone for fingerlings and habitat is conducive for native fishes. With seasonal inflow of sea water, marine fishes migrate to breed in the calmer waters of the lagoon, especially the safe haven provided by the mangrove swamp section. Some of the freshwater species encountered were Oreochromis niloticus, Tilapia zillii, Hemichromis Fasciatus and H. bimaculatus. The common marine species found in the lagoon were the mojarra (Gerres melanopterus), half