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Naughty baboons save Botswana rivers

BONIFACE KEAKABETSE
Correspondent

MAUN: Baboons are famous for terrorising humans, especially female tourists and children whose bags and food they often snatch with impunity.


Now the mischievous primates have proved to the world that they are not just disobedient creatures but can be useful as well. They have literally saved a whole river bio-network from an invasive river-killing weed in the process saving Botswana millions of Pula that would have gone into weed eradication efforts.

The chance discovery that the baboons were feeding on the notorious water lettuce (pista startiotes) and karibu weed (salvinia molesta) was made by a team from the Department of Wildlife and National Park's Aquatic Vegetation Control (AVC) unit during a monitoring exercise. That was in 1986. The team had recently introduced weevils - which government had imported from Australia's Commonwealth Scientific and Industrial Research Organisation (CSIRO) - into the Chobe, Kwando and Linyanti rivers to combat the weeds. The weevils would feed on the weeds and thus help eradicate them. But one September day in 2000, while checking to see if the weevils were worth the money, a DWP team, found - to their astonishment a troop of baboons eating the water lettuce in the Selinda Canal. It was to become the first-ever sighting of the primates feeding on the weeds.

"This was the first record of baboons feeding on the water lettuce in the world," said Dr Gugundla Naidu, a biologist with the AVC. Naidu said a combination of the Brazilian weevil (Neohydronoumous affinis hustache) and the baboons has helped eradicate the weed. Naidu was making a presentation on the current status of alien weeds infestation in the Chobe, Kwando Linyanti and the Okavango river systems at a workshop for police officers in Maun recently. Weeds, he said kill rivers and all aquatic life. They also disrupt necessary human activity in the rivers. This is because they form a mat on the water, which then prevents people from using the river as boating - both rowing and engine - and swimming becomes impossible.

Communities around the river are dependant on the rivers from which they fish and get aquatic vegetables. The rivers are also important for the tourism business as either a habitat for wildlife or as transit routes. Because they smother the river, weeds also kill other aquatic life and have been credited with drastic reductions in fish populations. They are easy to disperse across areas and many people are not aware of existing legislation intended to curb their spread.

According to Section Three of the Aquatic weeds control Act, "no person shall import into Botswana, or, move from any point or place within Botswana, any aquatic weed."

The Chobe, Moremi and Linyanti areas have been declared weed infested waters under this Aquatic weeds control Act of 1986. Furthermore the Act stipulates that any boat must be chemically treated and certificated and be issued with certificates of inspection, treatment and authorisation before being allowed entrance from one area of Botswana or outside.

The community is ignorant of this provision. Law enforcement officers such as the police are supposed to inspect boats and canoes in the area, but they are often equally ignorant, hence the workshop for them.

The recent surge of waters in the Okavango has seen hitherto dead rivers come to life and there are fears that weed control may become difficult owing to increased rowing and boating in the river and its tributaries.