Densu Delta Ramsar Site and vicinity (6342)
Ghana, Africa
Site overview
KBA status: confirmed
Global KBA criteria: D1a
Year of last assessment: 2001
National site name: Densu Delta Ramsar Site and vicinity
Central coordinates: Latitude: 5.5167, Longitude: -0.3333
System: marine, terrestrial
Elevation (m): 0 to 10
Area of KBA (km2): 24.49703
KBA classification: Global
Legacy site: Yes
Site details
Site description: The Densu delta wetland lies c.11 km west of Accra in the river valley between the Aplaku-Takuse and Weija McCarthy hills. It comprises an open lagoon, saltpans, freshwater marsh and scrub and sand-dunes. The greater part of the land is owned by the Panbros Salt Company. The wetland is fed mainly by the Densu river, which is dammed upstream (Weija dam), to supply water to the city of Accra. The dam has had profound effects on the lagoon and general hydrology of the wetland, since freshwater inflow into the wetland is controlled by the management of Weija Water Works. The water depth in the wetland varies, and can be over 2 m in some parts, during the rainy season. There is no direct outlet channel to the sea, but the lagoon often overflows into the sea after heavy rains. In other years, the Salt Company has to create an opening through the dunes to let water out of the pans. There is little vegetation on the dunes and in the saltpans; some coconut-palms Cocos nucifera fringe the dunes, while the banks of some of the pans are colonized by Sesuvium portulacastrum. Scattered stands of mangrove are found in some areas around the lagoon, while the freshwater parts of the wetland support stands of mainly Imperata, Typha and Cyperus. Scrub vegetation grows on other parts of the wetland.
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. Sixty species of waterbird have been recorded at this site, with estimated maximum numbers of c.35,000 birds. The site is particularly important for roosting terns and is the second most important site for the rare Sterna dougallii. In addition, the site supports large numbers of Egretta garzetta, Charadrius hiaticula, Calidris ferruginea and C. minuta. Three species, Glareola pratincola, Himantopus himantopus and Sterna albifrons breed regularly at the site. Its proximity to Accra and easy access around the site as result of the saltpan construction, make the site attractive for birdwatching. Non-bird biodiversity: Three species of marine turtle Lepidochelys olivacea, Chelonia mydas and Dermochelys coriacea (all EN)have been recorded nesting on parts of the beach.
Delineation rationale: Type 2 marine IBA: non-breeding (coastal) congregations.
Habitats
Land use: fisheries/aquaculture | nature conservation and research | urban/industrial/transport
Threats
Summary of threats to biodiversity at KBA: The site was designated a Ramsar Site in 1992. The main activities within the wetland are the large-scale commercial salt operation and lagoon fisheries, mainly for tilapia and lagoon crabs. There are human settlements all around the wetland and, indeed, the main threat is increasing urbanization, with uncontrolled and unauthorized housing development resulting in habitat destruction.
| Threat level 1 | Threat level 2 | Threat level 3 | Timing |
|---|---|---|---|
| Residential & commercial development | Housing & urban areas | Ongoing |
Additional information
References: Ntiamoa-Baidu and Gordon (1991).