Masinga reservoir (6420)
Kenya, Africa
Site overview
KBA status: confirmed
Year of last assessment: 2001
National site name: Masinga reservoir
Central coordinates: Latitude: -0.9000, Longitude: 37.4833
System: freshwater, terrestrial
Elevation (m): 1050 to 1050
Area of KBA (km2): 212.62541
KBA classification: Global/Regional TBD
Legacy site: Yes
Site details
Site description: This is by far the largest reservoir of the five impoundments along the upper Tana river, and abuts on the eastern side with Mwea National Reserve (IBA KE032). Masinga dam, which is managed by the Tana and Athi Rivers Development Authority, was completed in 1981. The valley that it drowned has a highly convoluted shoreline and contains a number of sizeable islands. The maximum depth is c.50 m, near the dam wall. Because of periodic draw-down and flooding, the shoreline is bare ground with a mosaic of deposited silt, pebbles and mud. Further from the water, a narrow strip of grass gives way to open Acacia–Commiphora bushland. The area is semi-arid with an annual rainfall of between 250 and 500 mm.
Rationale for qualifying as KBA: This site qualifies as a Key Biodiversity Area of international significance because it meets one or more previously established criteria and thresholds for identifying sites of biodiversity importance (including Important Bird and Biodiversity Areas, Alliance for Zero Extinction sites, and Key Biodiversity Areas)
Additional biodiversity: See Box for key species. Masinga is notable mainly for its waterbirds, with breeding colonies of cormorants and Anhinga rufa. The terrestrial avifauna is not particularly diverse, but the threatened and restricted-range Turdoides hindei has been recorded in Acacia thickets 100–200 m from the eastern shores of the reservoir (and see Mwea National Reserve, IBA KE032). Regionally threatened species include Anhinga rufa (Masinga is one of the few known Kenyan nesting sites; 94 birds were counted in February 1999, with 228 altogether on the five Upper Tana dams); Casmerodius albus (260 in March 1995); and Polemaetus bellicosus (status unknown). Non-bird biodiversity: The dam supports substantial populations of Hippopotamus amphibius and Crocodylus niloticus. There is no information on other fauna or flora.
Habitats
Land use: agriculture | fisheries/aquaculture | water management
| IUCN Habitat | Coverage % | Habitat detail |
|---|---|---|
| Wetlands(Inland) | 100 |
Threats
Summary of threats to biodiversity at KBA: Subsistence fishing is widespread in the dam, and poorly regulated. Gill-net fishing is a major threat to diving birds, particularly Anhinga rufa—the 1995 survey found three that had been entangled in fishermen’s nets. The dam was built in part to provide irrigation water for agriculture, but poor land-use in cultivated areas nearby is leading to siltation and eutrophication from fertilizer run-off. The waterbird nesting colonies need regular monitoring, and any conservation plan for Anhinga rufa should focus on Masinga as a key site.
Additional information
References: Nasirwa (1997), Nasirwa et al. (1995a,b), Oyugi and Owino (1998a,b, 1999).