Bembridge Harbour is designated a Site of Special Scientific Interest (SSSI) in recognition of its significance as a habitat for wildlife.
The Harbour’s European importance is confirmed by its status as a ‘Special Protection Area’ and it is designated a ‘wetland of international importance’ under the Ramsar Convention.
The Harbour has an area of saltmarsh as well as other important habitats such as sand dunes, vegetated shingle and saline lagoons. The Harbour’s saltmarsh and inter-tidal mud provide feeding grounds for wintering and migratory waterfowl. The harbour mouth is a nursery for bass.
St Helens Duver

This sand and shingle spit is overlooked by the wooded St Helens Common. The short turf is emblazoned with sea pinks in May and June, and autumn squill in September. It was given to the National Trust in 1961 by the Royal Isle of Wight Golf Club.
The shoreline and salt marsh are important wildlife habitats. Many birds use these rich feeding grounds during migration and in winter. Since the early 1990s, little egrets have become increasingly common along the south coast of Britain and can be seen all year round. Wigeon and Brent geese breed in subarctic regions, then fly south for the winter to places like the Duver, where food is more abundant. Other migrating birds to look out for on the Duver include Redshank, Curlew and Teal.
Saltmarsh plants grow in the tidal millpond. On very high tides lower parts of the Duver are flooded. You can see how salt-tolerant plants, like sea purslane, have spread on to some of these areas. This contrasts with the rest of the Duver, where the plants are adapted to the dry sandy soils and can survive drought conditions.