Foulness SSSI Foulness SSSI Foulness SSSI is a 10,702 hectare biological Site of Special Scientific Interest covering the shoreline between Southend-on-Sea and the Crouch estuary in Essex. It is a key site in "A Nature Conservation Review", and is part of the Essex Estuaries Special Area of Conservation. It covers two Ramsar wetland sites of international importance, 'Crouch and Roach Estuaries' and 'Foulness'. An area of 6.4 hectares is Shoeburyness Old Ranges, a Local Nature Reserve managed by the Essex Wildlife Trust. Most of the site is owned and managed by the Ministry of Defence. Natural England describes it as "extensive intertidal
Foulness Island and therefore should not be taxed by the Commissioners. Eventually, Foulness had its own Commission, from 1800 to the early 1900s. The size of the island has been increased several times by "innings". Saltings build up along the shore from silt which is carried to the sea by the rivers, and is deposited on the shore by the tide. Salt-loving plants then take root in the mud, and the salting is established. The plants trap sediments, and the surface rises until it remains above the level of most tides. Inning occurs when a sea wall is built around the edge