South Thames Estuary and Marshes are nationally scarce plants on dykes, and the diverse invertebra include nationally rare beetles, flies and true bugs. South Thames Estuary and Marshes South Thames Estuary and Marshes is a biological Site of Special Scientific Interest which stretches between Gravesend and the mouth of the River Medway in Kent. Part of it is a Nature Conservation Review site, Grade I, and part is a Royal Society for the Protection of Birds nature reserve. It is part of the Thames Estuary and Marshes Ramsar internationally important wetland site and Special Protection Area under the European Union Directive on the Conservation of
Canvey Wick Canvey Wick Canvey Wick is a 93.2 hectare Site of Special Scientific Interest at the south-west corner of Canvey Island in Essex. It is owned by the Land Trust and managed by the Royal Society for the Protection of Birds and Buglife. The site was formerly an oil refinery, and has been transformed into an area of grazing marsh. It has a nationally important population of invertebrates, including 22 which are endangered Red Book species, and three which had been recorded as extinct in Britain. It also has a nationally important population of shrill carder bees. Scrub edges provide additional