Bao Bolon Wetland Reserve (6354)
Gambia, Africa
Site overview
KBA status: confirmed
Year of last assessment: 2001
National site name: Bao Bolon Wetland Reserve
Central coordinates: Latitude: 13.5167, Longitude: -15.8333
System: freshwater, marine, terrestrial
Elevation (m): 5 to 40
Area of KBA (km2): 199.04303
Protected area coverage (%): 99.02
KBA classification: Regional
Legacy site: Yes
Site details
Site description: The reserve is situated on the north bank of the Gambia River almost opposite Kiang West National Park (GM007) and extends from the river to the country’s northern border with Senegal. Bao Bolon is a freshwater tributary of the Gambia River that originates 50 km north of the international border and is a permanent watercourse in an otherwise semi-arid region of Senegal. The shallow valley of the bolon is bordered with extensive tall swamps of Cyperus, Scirpus and Andropogon species and a few square kilometres of Phragmites karka. Further from the channel are seasonal fresh/brackish marshes which, during the rains, are a mosaic of shallow pools and low-growing Gramineae and Cyperaceae. To the west of the Bolon are extensive, sparsely vegetated saline mudflats, shallow lakes and inlets of the Gambia River. On raised ground are islands of scrub and open woodland. Further south, within the river’s tidal influence, are open Avicennia mangrove scrub interspersed with mudflats and, on slightly raised ground, meadows of Sesuvium portulacastrum saltmarsh. Within the daily tidal reach of the river is one of the most extensive and intact areas of tall Rhizophora mangrove forest in the country, cut by numerous inlets. Narrow mudflats border the inlets and the river. The reserve also includes a relatively undisturbed area of closed-canopy savanna woodland above a laterite escarpment.
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: See Box for key species. Most of the reserve is not well known ornithologically. The first complete survey, excluding the mangrove forest, was made in February 1998. The reserve is thought to hold more than 20,000 waterbirds regularly between August and December. It is certainly, measured by the number of waterbird species recorded, the most diverse inland wetland in the country. The open wetlands hold large numbers of herons, egrets, pelicans and Palearctic waders and, in addition to those species listed below, are suspected to be an important passage site for Himantopus himantopus, Charadrius hiaticula, Limosa limosa and Tringa nebularia. The site is of national importance for non-breeding congregations of Anhinga rufa, Pelecanus onocrotalus and P. rufescens. Known or suspected breeding species in the Rhizophora mangrove include Gorsachius leuconotus, Podica senegalensis, Scotopelia peli, Apalis flavida and Elminia longicauda. The bolon is a flyway for large waterbirds and raptors. The latter include Falco naumanni, several hundred of which passed through the reserve in a few hours in March 1994. In addition, two species of the Guinea–Congo Forests biome have been recorded; see Table 2. Non-bird biodiversity: There are occasional records of Trichechus senegalensis (VU).
Habitats
Land use: agriculture | hunting | nature conservation and research
| IUCN Habitat | Coverage % | Habitat detail |
|---|---|---|
| Artificial - Terrestrial | 54 | |
| Shrubland | 17 | |
| Forest | 3 | |
| Wetlands(Inland) | 25 |
Threats
Summary of threats to biodiversity at KBA: The reserve is managed by the DPWM and was The Gambia’s first designated Ramsar site (1996). The DPWM’s involvement has been to explain the purpose of the reserve to neighbouring villages and to discourage illegal activities. The reserve is used intensively by people from the surrounding villages and the Senegalese villages to the north. Rice cultivation is widespread. Cattle range throughout the open areas during the rains and early dry season. Later in the dry season large areas of tall swamp vegetation are cut for roofing and fencing. To date there are no plans to restrict rice cultivation, grazing or the harvesting of vegetation. The hunting of wildfowl and pelicans is not adequately controlled. The felling of mangrove has been discouraged with the assistance of staff from Kiang West National Park. The reserve is vulnerable to deterioration through the expansion of agriculture, grazing and hunting.
| Threat level 1 | Threat level 2 | Threat level 3 | Timing |
|---|---|---|---|
| Agriculture & aquaculture | Annual & perennial non-timber crops | Small-holder farming | Ongoing |
| Agriculture & aquaculture | Livestock farming & ranching | Small-holder grazing, ranching or farming | Ongoing |
| Biological resource use | Hunting & collecting terrestrial animals | Intentional use (species being assessed is the target) | Ongoing |
| Biological resource use | Gathering terrestrial plants | Unintentional effects (species being assessed is not the target) | Ongoing |
Additional information
References: DPWM (1997, 2000).