Salinas de Alverca e do Forte da Casa (19678)
Portugal, Europe
Site overview
KBA status: confirmed
Year of last assessment: 2002
National site name: Salinas de Alverca e do Forte da Casa
Central coordinates: Latitude: 38.8667, Longitude: -9.0333
System: marine, terrestrial
Elevation (m): 0 to 5
Area of KBA (km2): 1.95764
Protected area coverage (%): 15.47
KBA classification: Regional
Legacy site: Yes
Site details
Site description: This site is located at north bank of Tejo Estuary. Is formed by two salinas (salt pans) complexes: Salinas de Alverca and Salinas do Forte da Casa, extensive agricultural landscapes that separe them, and the final part of Verdelha river; it represents the only bird refuge in this riverbank. In the surrounding zone, the strongly built up and industrializated area of Alberca contrasts with the Natural Reserve of Tejo Estuary and Portuguese Air-Force installations. Besides the salinas banks and landscapes, there are also drainage trenchs and a stream with an important water fringe vegetation. Now, salinas are abandoned and water lever is conditioned by precipitation. Vegetation inside the banks is mainly constituted by aquatic plant, namely rushes and reeds. In the edges salt-marshes vegetation and rarely tamarisks are found.
Rationale for qualifying as KBA: This site qualifies as a Key Biodiversity Area of international significance that was identified using previously established criteria and thresholds for the identification of Important Bird and Biodiversity Areas (IBAs) and for which available data indicate that it does not meet global KBA criteria and thresholds set out in the Global Standard.
Additional biodiversity: The salinas of Alberca and Forte da Casa costitute one of the most important nesting site in Tejo Estuary for aquatic-birds like Himantopus himantopus whose colonny could ever hold thousands of breeding pairs. This is the only nesting place of Netta rufina in estuary. Circus aeruginosus, Recurvirostra avosetta, Glareola pranticola, Sterna albifrons and also Ixobrichus minutus, Anas strepera, Fulica atra are present here in significative numbers. The whole zone is important as feeding area for Ardea purpurea and C.aeruginosus who breed in Natural Reserve; and also for passerines and waders during wintering or migration seasons.
Habitats
Land use: agriculture | hunting | military | tourism/recreation | urban/industrial/transport | water management
| IUCN Habitat | Coverage % | Habitat detail |
|---|---|---|
| Artificial - Aquatic | 25 | |
| Artificial - Terrestrial | 25 | |
| Shrubland | 25 | |
| Marine Coastal/Supratidal | 25 |
Threats
Summary of threats to biodiversity at KBA: Part of the area was included in the National Ecologic Reserve, not now. The whole area is highly threatened by infrastructures namely a sewage-farm, a housing and respective gateways. The absence of management and the abandonement of the salinas, make the site short of its birdlife potential. Industrial and domestic pollution is mainly negative, significantly affecting Verdelha river and drainage trenchs. Garbage and ruins dumps are also visible. In the whole agricultural area hunting is avoid, beeing an important threat and a main disturbance to birds. The presence of people and four-wheels in specially sensitive areas (like banks) could be negative for some species nesting.
| Threat level 1 | Threat level 2 | Threat level 3 | Timing |
|---|---|---|---|
| Transportation & service corridors | Roads & railroads | Only in the future | |
| Residential & commercial development | Commercial & industrial areas | Ongoing |