The Thames Estuary was proposed in an attempt to safeguard rare moths. Although a lot of the marshland remains, it has suffered from habitat loss and at least one rare species of moth is now extinct. Nonetheless, the Thames Estuary supports an important population of overwintering wildfowl and waders. It has a number of reserves sited along it, and much of it is designated as an internationally important wetland (Ramsar site) and a Special Protection Area (SPA) for its birdlife.
(Above) the original SPNR survey documents for Thames Estuary