South Thames Estuary and Marshes 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 Wild Birds. Over 20,000 waterfowl use this site, and some species are present in internationally important numbers. There
Estuary of Bilbao reached high levels of contamination because of the industrial activities during the past century. see page:http://bilbaoenconstruccion.com/2010/07/06/bilbao-recupera-su-alma-plan-integral-de-saneamiento-de-la-ria/ Estuary of Bilbao The Estuary of Bilbao (Spanish: "Ría de Bilbao" / Basque: "Bilboko Itsasadarra") lies at the common mouth of the rivers Nervion, Ibaizabal and Cadagua, that drain most of Biscay and part of Alava in the Basque Country, Spain. In this instance, the Spanish word estuario is used to describe what in English would normally be called part estuary, part tidal river. The estuary becomes a tidal river which extends into the city of Bilbao, starting from the Bilbao Abra bay. It