LAKE VICTORIA BASIN

Sango Bay, Uganda

Sango Bay is located on the south-western shores of Lake Victoria. It is found in Rakai District, Uganda, on the border with Kagera Region, Tanzania. It is a low- lying area, dominated by plains and raised beaches. There are different types of wetlands in the bay, all rich in biodiversity. The wetlands are associated with three major drainage systems: the Lake Victoria Basin system (Kibale-Bukola Wetlands and Naludugavu Wetlands), the Kagera River Basin system (Lwemukunya Wetlands), and Lake Kijanebalola-Kacheera Basin systems (Lake Kacheera Wetlands, Lake Kijanebalola Wetlands, Kimanywa Wetlands, Kijonjo Wetlands) (Lake Victoria Basin Commission 2007). The Kagera River system is associated with permanent wetlands dominated by papyrus. It is characterized by small hills and broad, low-gradient valleys; fluctuating water levels periodically flood the plains, creating seasonal wetlands, which are used mainly for grazing. Lake Kijjanebalola and Kacheera are formed in two deep depressions and the edges of these two lakes and the surrounding valleys are covered by permanent swamps. These lakes eventually drain into Lake Victoria through the Kibaale/Bukola River/Wetlands system. The plant ecosystems in the seasonal wetlands are made up of both of monoculture and mosaic stands. The monoculture stands are forming woodlands made up mainly of acacia species. The mosaic stands are comprised primarily of a mixture of grasses, albizia, acacia, euphorbia and Carisa edulis. Similarly, permanent wetlands have both monoculture and mosaic stands. The monoculture stands – papyrus, miscanthus, typha or vossia – merge into each other, forming mosaic plant communities. Sango Bay is home to a range of animals such as antelopes, wild pigs, rabbits and birds (guinea fowls, partridges, crested cranes, ibis, herons and egrets).

Common fish species include lungfish, catfish, mudfish and tilapia, and these are found in the seasonal wetlands. The permanent wetlands provide a habitat for animals such as sitatungas and water bucks, as well as birds such as ibis, crested cranes, herons, kingfishers and hammerkops. There is commercial fishing of tilapia, catfish, lungfish, haplochromis and Nile perch in Sango Bay (Lake Victoria Basin Commission 2007). Over 75 per cent of the soils in the bay are ferralitic – representing the final stages of weathering – with little or nomineral reserve remaining. Some heavy clay varieties have some fertility but sandy varieties are particularly poor. Common soil types include lithosols, alluvial and lacustrine sands and alluvial clays. Lithosols and humus loams are dominant in the uplands, while grey sandy soils derived from hill wash or river alluvium, grey clays of the valley bottoms and lacustrine sands dominate the lowlands and wetlands (Lake Victoria Basin Commission 2007). The Sango Bay Wetlands are mainly used for crop cultivation, grazing and fishing. They also provide a variety of goods and services such as mulch grass, thatch grass, craft materials, poles, firewood, timber, charcoal and water for both livestock and human use. The Sango Bay Wetlands supply water to the Rakai District’s four urban councils: Rakai, Kyotera, Kalisizo and Lyantonde. The water supply for each town is drawn from Kijanebalola and Kasesa; Katango and Naludugavu; Bulimbale, Kacheera and Kikasa; and Bwasa, respectively. None of these urban areas has a waste treatment plant, so effluent enters directly into the Wetlands (Lake Victoria Basin Commission 2007). Burning, drainage for settlement encroachment or conversion, overgrazing and urbanization are major threats to the Sango Bay Wetland system.

Kingfisher

69