LAKE VICTORIA BASIN

Rubana/Grumeti/Mbalageti Wetlands System, Tanzania

The combined wetlands system comprises of the Rubana riverine system and its tributary Grumeti and Mbalageti riverine systems. The Grumeti and Mbalageti rivers originate in the Serengeti National Park and discharge into Lake Victoria through the Speke Gulf. The Mbalageti River forms the border between Mara and Mwanza regions. The Rubana/Grumeti River is in Bunda district, Mara Region (Lake Victoria Basin Commission 2007). The Rubana River is 210 km long and has a catchment area of about 1.3 million ha, while the Mbalageti is 224 km long with a catchment area of 331,100 ha. The area of permanent wetlands is located around the river mouths and is dominated by Cyperus papyrus and Phragmites mauritianus . The rest of theWetlands are in the Serengeti National Park, which is dominated by grasses, shrubs and woodlands (Lake Victoria Basin Commission 2007). The Rubana Wetlands contain the shallow waters of the Speke Gulf, an area of permanent swamp. The Wetlands widen in the middle of the Rubana Delta where papyrus dominates. Sesbania trees grow mainly along the shoreline. Grass ( Echnochloa spp) and water hyacinth also grow at the river mouths (Lake Victoria Basin Commission 2007). The permanent wetlands support many animals, including crocodiles, hippopotamuses, wild pigs, sitatungas and snakes. The crocodile population has increased significantly following the 1997 El Nino rains. It is believed that El Nino floods swept crocodiles downstream from the Serengeti National Park into the Lake. Rubana is the main breeding habitat for many species of fish, especially cichlids, cyprinids and catfishes. The peak breeding season starts in January and ends in July each year. Crop and livestock production aremajor economic activities in theWetlands. Crops include paddy rice, maize, sorghum, millet, cassava, sweet potatoes, cotton and horticultural

crops such as tomatoes, onions and cabbages. Cattle, goats and sheep are themain types of livestock.

Few chemicals are used in food crops and horticultural crops because of the prohibitive prices and the levels of soil fertility. The limited use of chemical fertilizers includes Triple Superphosphate (TSP), Sulphate of Ammonia (SA) and Urea. Pesticides such as Blue Copper, Bulldock, Carete and Thiodan, are used in cotton and horticultural crop production. Stelladone, Bacdip and Supadip are used in livestock production. Due to prolonged periods of drought, the flood plain is experiencing an influx of livestock from neighbouring districts. Papyrus is harvested to make mats (majamvi), reeds are used in house construction, firewood and fishing weirs, while esbania trees are harvested to make floats, construct houses, and for firewood and medicine. The RubanaWetlands are an important breeding ground for many fish species. Consequently, theWetlands have become an important area for many fishermen from surrounding areas. The main species caught include tilapias, cyprinids, catfishes and lungfish. Other economic activities include brick making, hunting (of hippos in particular), and bird trapping (cormorants and pelicans) Due to its importance as a fish breeding ground, the RubanaWetlands (including the shallow waters of the Speke Gulf ) was designated as a protected area in 1981. The area is closed for fishing activities from January to June, except for angling. The area between the main Mwanza- Musoma road and the lakeshore is a Speke Gulf Game Controlled Area (Lake Victoria Basin Commission 2007).

Concerted efforts have been made to rehabilitate the degraded floodplain by planting indigenous tree species.

The RubanaWetlands community taking care of tree nurseries

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