The government has a duty to designate as an SSSI any area of land which it considers to be of special interest by virtue of its fauna, flora, geological or physiographical features.
The designation can be made by English Nature, Scottish Natural Heritage, the Countryside Council for Wales or the Environment and Heritage Service (Northern Ireland). In Northern Ireland some areas are designated as Areas Of Special Scientific Interest under the Nature Conservation and Amenity Lands (Northern Ireland) Order 1985, which is essentially the same as SSSI legislation. An SSSI is not necessarily open to the public, or owned by a conservation organisation or by the Government — in fact, they can be owned by anybody.
Sites of SpecialScientificInterest, in the United Kingdom, term designating areas of land that are protected to ensure the maintenance and enrichment of their characteristic diversity of wildlife and natural features.
Sites of SpecialScientificInterest (SSSIs) are notified under the Wildlife and Countryside Act 1981, in recognition of their special biological or geologicalinterest.
Before notification takes place, the site is surveyed with the permission of the owner or occupier, after which the council of the notifying body decides if the site is to be notified or not.
The site is notable for its ecological diversity, from characteristic sedge fen to fen meadow, chalk grassland, Alnus/Salix carr and ancient woodland (Fraxinus, Quercus, Betula).
The site is of particular importance for several species of breeding waders, and nationally important numbers of ducks and swans breed or winter at the site.
The site is a complex of rain-fed, brackish, floodplain grazing marsh with ditches and intertidal marsh and mudflat.