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 commissioners were sent to inspect the state of the banks in the Rochford hundred, which included Foulness. The earliest record of sea walls is from 1271, and in 1348 there were problems with one of the marshes, which was flooding every day, indicating that it was below the level of normal tides. The sea walls were made of earth, and were thatched with hurdles of brushwood and rushes. The island was divided into 11 or 12 marshes, each with its own wall, rather than one wall around the whole area, and was extended in 1420 by a new wall around