Ilha de Bolama - Rio Grande de Buba (6387)
Guinea-Bissau, Africa
Site overview
KBA status: confirmed
Global KBA criteria: D1a
Year of last assessment: 2001
National site name: Ilha de Bolama - Rio Grande de Buba
Central coordinates: Latitude: 11.5000, Longitude: -15.5000
System: marine, terrestrial
Elevation (m): 0 to 5
Area of KBA (km2): 171.97055
Protected area coverage (%): 76.90
KBA classification: Global
Legacy site: Yes
Site details
Site description: The Ilha de Bolama is an island on the central-eastern part of the coast which lies just to the north of the mouth of the Rio Grande de Buba. The Rio Grande de Buba is unusual in Guinea-Bissau in that it mostly merges directly into dry and semi-humid forest rather than mangrove forest. Nonetheless, there are extensive mudflats and mangroves at the river mouth and around Ilha de Bolama. Immediately to the north of Bolama, extending as far as the Ilha das Areias on the southern side of the Canal do Gêba, is a large complex of intertidal flats, mostly of mud in the south, merging gradually to sandflats in the north and with many rocks in the west. The estuary of Rio Grande de Buba contains a mixture of mud- and stoneflats. The site includes 13,000 ha of rocks and mudflats and 17,000 ha of mangroves.Although the Ilha de Bolama is included in the Arquipélago dos Bijagós Biosphere Reserve, the remainder of which forms site GW007, it is here treated separately, since much of the extensive area of mudflats, which are almost contiguous with Bolama to the north, is excluded from the Biosphere Reserve. It seems more appropriate therefore to unite in one site these flats, those around the shoreline of Bolama itself together with the estuary of the Rio Grande de Buba, immediately to the east.
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. The total number of wintering waders estimated at Ilha de Bolama and Rio Grande de Buba in 1988 were 46,970 and 30,940 respectively. Non-bird biodiversity: The mammal Trichechus senegalensis (VU) occurs.
Delineation rationale: 2012-12-17 (BL Secretariat): the original site boundary 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 30000 ha to 17197 ha.
Habitats
Land use: agriculture | nature conservation and research
| IUCN Habitat | Coverage % | Habitat detail |
|---|---|---|
| Forest | 100 |
Threats
Summary of threats to biodiversity at KBA: Unlike the Ilha de Bolama, the banks of the estuary of the Rio Grande de Buba are relatively sparsely inhabited and there has been comparatively little clearance for agriculture.
| Threat level 1 | Threat level 2 | Threat level 3 | Timing |
|---|---|---|---|
| Agriculture & aquaculture | Annual & perennial non-timber crops | Small-holder farming | Ongoing |
Additional information
References: Zwarts (1988).