South Walney and Piel Flats Channel Site of Special Scientific Interest (SSSI).
Due to the way it was formed and the habitats that have been created as a result - Walney Island and the surrounding inter-tidal zones are rich in environmental features that have attracted the attention of conservationists world-wide. Over 85% of the Walney shoreline is now internationally or nationally designated as being of conservation interest - and this interest is largely to do with the formations at the two ends of the island which are the distal features of a glacial island, of which there are only a few examples in the United Kingdom.
The two Sites of Special Scientific Interest on Walney have the following features:
Shellfish include mussels and shrimps and are caught locally - both for local consumption, and for export to Europe. The recent deaths of several chinese cocklers who were working illegally in the adjacent Morecambe Bay highlights the dangers that exist is typical Seasalter Shelfish environments. Oyster farming also takes place on Walney itself in the large gravel pits that were left in the southern SSSI when gravel extraction ceased in the early part of the 20th century.
Intertidal Scars (a.k.a. skears) and/or bedrock:
Hard rocky substrate known as scars or skears and outcrops of bedrock provide a habitat for a mixture of animals that cannot live on soft sand. Some of the animals commonly found on skears are mussels, barnacles, tubeworms, periwinkles, hairy sea-firs and sea-quirts.
At the head of nearby river estuaries smaller areas of mudflats are found. The reduced salinity here results in slightly different communities of animals such as grazing mud snails and eelgrass. Large eelgrass beds are present in the Walney Channel and around Foulney Island, the only place in north west England where this intertidal flowering plant occurs.
Saltmarsh is a unique community of salt tolerant plants that colonise mud and sand flats, trapping and stabilising the sediment, allowing other plants to grow. The saltmarsh provides grazing for sheep and cattle and attracts thousands of overwintering wildfowl.
Unlike most shingle shores which are pounded by waves, plants are able to grow on the stable shingle above the high tide mark at Walney and Foulney Islands. Walney Island has some of the most diverse shingle communities in the UK, with rare plants such as Ray's knotgrass, Portland spurge and the Isle of Man cabbage. Gulls, terns and eider ducks nest on the shingle in summer and migrant waders roost there in winter.
The sand dunes that have developed behind the shingle ridge at South End Haws (in particular) support a wide diversity of plant life, with areas between the foredunes and main dune ridge susceptible to flooding on the highest tides. The sand dune and shingle habitats combined support the largest gull colony in north west England. In Walney's northern SSSI the sand dunes are home to one of the largest colonies of Natterjack Toads in the UK.
Threat from increased sea levels http://www.foe.co.uk/resource/press_releases/19970726000122.html