Tagus Estuary Natural Reserve (Reserva Natural do Estuário do Tejo) is a natural reserve in Portugal. It is one of the 30 areas which are officially under protection in the country. The estuary of the Tagus River is the largest wetland in the country and one of the most important in Europe, a sanctuary for fish, molluscs, crustaceans, and especially to birds that stop-over on their migration between northern Europe and Africa. It is the largest estuary in western Europe, with about 34,000 hectares (84,000 acres), and regularly hosts 50,000 wintering waterfowl (flamingos, ducks, waders, etc..).
The Nature Reserve was established in 1976, covering an area of 14,192 hectares (35,070 acres), characterized by an extensive surface of estuarine waters, vast fields intersected by creeks, marshes, salt flats and alluvial agricultural land (marshlands). Not exceeding 11 metres (36 ft) above sea level and a depth of 10 metres (33 ft), distributed by the counties of Alcochete, Benavente and Vila Franca de Xira, the reserve falls in the most upstream of the estuary of the Tagus which, extending over an area of about 32 km2 (12 sq mi), is the largest in Western Europe.
In the estuary develops the marsh, whose floristic community lives under the influence of water brought by the tide. Region of high level productivity of polychaetes, molluscs and crustaceans, is authentic motherhood for various fish species. But the water birds provide the Tagus estuary its international importance. The flocks of wintering species reach up to about 120,000 individuals. The scores indicate that winter regularly carried out in this protected area more than 10,000 ducks and 50,000 shorebirds, of which stands the Pied Avocet (Recurvirostra avosetta), with a number of up to 25% of the population wintering in Europe. Many other species also attest to the biological richness and value for the Conservation of Nature in this region: the American Flamingo (Phoenicopterus ruber), the Greylag Goose (Anser anser), the Dunlin (Calidris alpina) and the Black-tailed Godwit (Limosa limosa).
Includes salt in some areas Tagus River / Sea of Straw.
- 1976 - Is created the Natural Reserve of the Tagus Estuary, through Decree-Law No. 565/76.
- 1980 - Moves to make the Wetlands of International Importance by the Ramsar Convention.
- 1994 - Is hereby established a Special Protection Area for Wild Birds, under Directive 79/409/EEC.