Arquipélago dos Bijagós (6389)
Guinea-Bissau, Africa
Site overview
KBA status: confirmed
Global KBA criteria: B1, D1a
Year of last assessment: 2001
National site name: Arquipélago dos Bijagós
Central coordinates: Latitude: 11.2500, Longitude: -16.0000
System: marine, terrestrial
Elevation (m): 0 to 34
Area of KBA (km2): 1429.14889
Protected area coverage (%): 50.38
KBA classification: Global
Legacy site: Yes
Site details
Site description: The Arquipélago dos Bijagós is composed of 88 islands and a large intertidal area of mudflat and mangrove. Some 20 of the islands are permanently inhabited as, seasonally, are a further 20. The archipelago is situated just off the coast, opposite the mouth of the Rio Gêba. The land area of the archipelago is some 90,000 ha while a further 100,000 ha or so are uncovered twice daily by the retreating tide, of which 76,000 ha are mudflats and 35,000 ha mangroves. The Ilhas de Orango National Park includes the most southerly group of islands, of which the main ones are Orango, Canogo, Imbone, Meneque and Orangozinho, which have a land area of 27,000 ha. The boundary of the park extends to 10 km offshore and the park includes forest, coastal wooded savanna, mangroves (17,400 ha), channels and shallow seas. The João Vieira / Poilão Marine National Park includes four small islands in the south-east of the archipelago and a large area (495 km²) of ocean (mostly excluded from the IBA). Although part of the Biosphere Reserve, the Ilha de Bolama, the island nearest the mainland, is excluded since it forms part of IBA GW005, for the reasons given in the description of that site.
Rationale for qualifying as KBA: This site qualifies as a Key Biodiversity Area of international significance that meets the thresholds for at least one criterion described in the Global Standard for the Identification of KBAs.
Additional biodiversity: See Box for key species. This area is second only in importance in West Africa to the Banc d’Arguin in Mauritania (IBA MR007) for the numbers of Palearctic waders present during the northern winter. It has been estimated that up to 700,000 birds occur in the archipelago at this time. The area also includes a number of heronries as well as breeding colonies of ibises, gulls and terns. Non-bird biodiversity: Five species of turtle breed in the archipelago; Chelonia mydas (EN), Caretta caretta (EN), Lepidochelys olivacea (EN), Eretmochelys imbricata (CR) and Dermochelys coriacea (EN). The Ilhéu do Poilão is the main nesting area for C. mydas in the eastern Atlantic. Ilha João Vieira and Ilha Orango are also important nesting sites. The largest Trichechus senegalensis (VU) population in West Africa is found here. The crocodile Osteolaemus tetrapsis (VU) also occurs while the dolphins Sousa teuszii (DD) and Tursiops truncatus (DD) are common. Mangrove species include the rare Laguncularia racemosa.
Delineation rationale: 2012-12-17 (BL Secretariat): the original site boundary (RSPB) has been clipped to the coastline (marine areas removed) to avoid overlap with the new marine IBA identified adjacent to this site in October 2012; site area has been correspondingly reduced from 190000 ha to 142915 ha.
Habitats
Land use: agriculture | fisheries/aquaculture | nature conservation and research
| IUCN Habitat | Coverage % | Habitat detail |
|---|---|---|
| Savanna | 8 | |
| Forest | 84 | |
| Artificial - Terrestrial | 3 | |
| Unknown | 2 | |
| Shrubland | 2 |
Threats
Summary of threats to biodiversity at KBA: The archipelago was declared a Biosphere Reserve in 1996, and incorporates Ilhas de Orango National Park and part of João Vieira/Poilão Marine National Park. Some 20,000 people live in the reserve as a whole, with 2,260 in the National Park. Threats include wood-cutting for fuel and land reclamation for rice production while disturbance of breeding colonies and hunting, although not currently significant, are potential problems. However, commercial overfishing may pose the greatest threat to the area. As a result of the area becoming a Biosphere Reserve, a system of zoned management has been set up throughout the archipelago, which seeks to promote the traditional human uses of natural resources while maintaining the biodiversity of the site.
| Threat level 1 | Threat level 2 | Threat level 3 | Timing |
|---|---|---|---|
| Biological resource use | Logging & wood harvesting | Unintentional effects: subsistence/small scale (species being assessed is not the target) [harvest] | Ongoing |
| Agriculture & aquaculture | Annual & perennial non-timber crops | Small-holder farming | Ongoing |
| Biological resource use | Hunting & collecting terrestrial animals | Intentional use (species being assessed is the target) | Only in the future |
| Biological resource use | Fishing & harvesting aquatic resources | Unintentional effects: subsistence/small scale (species being assessed is not the target) [harvest] | Ongoing |
| Human intrusions & disturbance | Work & other activities | Only in the future |
Additional information
References: Altenburg et al. (1992), Asbirk et al. (1994), Maretti and Sales (1994), Quadé (1994).