Fenland WA members have the right to shoot over nine miles of the tidal marshes on the coast between the rivers Nene and Great Ouse (under lease from the Crown Estate). The leased area falls within the Wash National Nature Reserve, the largest NNR in the UK
The Wash is located on the east coast of England and is the largest estuarine system in the UK. It is fed by the rivers Witham, Welland, Nene and Great Ouse that drain much of the east Midlands of England. The Wash comprises very extensive saltmarshes, major intertidal banks of sand and mud, shallow waters and deep channels. The eastern end of the site includes low chalk cliffs at Hunstanton. In addition, on the eastern side, the gravel pits at Snettisham are an important high-tide roost for waders. The intertidal flats have a rich invertebrate fauna and colonising beds of Glasswort Salicornia spp. that are important food sources for the large numbers of water birds dependent on the site. The sheltered nature of The Wash creates suitable breeding conditions for shellfish, principally Mussel Mytilus edulis, Cockle Cardium edule and shrimps. These are important food sources for some water birds such as Oystercatchers Haematopus ostralegus. The Wash is of outstanding importance for a large number of geese, ducks and waders, both in spring and autumn migration periods, as well as through the winter. The SPA is especially notable for supporting a very large proportion (over half) of the total population of Canada/Greenland breeding Knot Calidris canutus islandica. In summer, the Wash is an important breeding area for terns and as a feeding area for Marsh Harrier Circus aeruginosus that breed just outside the SPA. To the north, the coastal habitats of The Wash are continuous with Gibraltar Point SPA, whilst to the east The Wash adjoins the North Norfolk Coast SPA.
The Wash is of outstanding importance for wildlife and it is a valuable natural resource that people have long exploited. It has the second largest area of intertidal mudflats and sandflats in Britain and supports the largest numbers of migrating waterfowl of any site in the UK. It has the largest colony of common seals in England and is an important nursery ground for flatfish. As well as its large-scale subtidal and intertidal habitats, The Wash has a number of valuable fringing habitats of conservation significance, such as saline lagoons, shingle structures and dune complexes.