LAKE VICTORIA BASIN

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.

Rubana/Grumeti/Mbalageti Wetlands System, Tanzania

The RubanaWetlands community taking care of tree nurseries