Human activities threaten life in Zambezi Basin
Friday, April 25, 2003
Dar Es Salaam, Tanzania Panafrican News Agency, by Nicodemus Odhiambo
The Zambezi River basin, shared by eight Southern Africa Development Community countries, is increasingly endangered, according to a new report.
Endless deforestation, land degradation, pollution and loss of biodiversity have become a real threat to the basin environment.
Population pressure, amid mounting economic exploitation of the basin, feeds fears that the area may become 'ecologically ravaged', according to the 'State of the Zambezi Basin 2000' report.
Angola, Botswana, Malawi, Mozambique, Namibia, Tanzania, Zambia and Zimbabwe share the basin, which covers some of the region's best ecosystems.
Tanzania holds about 2.9 percent of the basin, which supports the lives of about 1.3 million people.
"A major challenge in the basin is feeding the growing population," the report says.
While agricultural production increases by opening up forests, grazing lands and irrigation, suitable land is limited. That poses more pressure to use marginal lands and add to the degradation problem.
The basin's population is estimated to be growing at 2.9 percent annually, although rates for individual countries vary.
The value of the wetland, including its overlying forests, both as a resource base and as an environmental control, remains undervalued in the face of dire economic needs.
As a result, mining, industrial, agricultural and domestic activities bring negative consequences to the basin with deterioration of lakes, streams and rivers.
Management of solid waste has become a major environmental problem in urban areas and the growing population, together with poor disposal systems of collection, landfill and recycling are bound to aggravate the situation.
As an example, the report cites Lusaka, where only 10 percent of the city's 1,400 tonnes of solid waste produced daily is collected.
Deforestation in the basin increases at a high rate mainly due to demand for building materials and fuelwood.
In Malawi forest cover has declined by 41 percent between 1972 and 1990, representing an average loss of 2.3 percent annually.
Fish species in lakes Malombe and Malawi and the Lower Shire river are also in danger of depletion.
The report says dam construction has probably had the greatest effect on biodiversity of wetlands and aquatic species within the region.
While Kariba, Cahora Bassa, Itezhi-tezhi and Kafue dams have greatly modified flooding regimes and habitat species composition, the introduction of alien species has seen some of them out-compete native species or modify the ecology of an area.
The introduction of the Lake Tanganyika sardine into Lake Kariba in the 1960s is however said to have been a major commercial success, spawning the 'Kapenta' inland fishery for the benefits of Zambia and Zimbabwe.
But some species such as the blue wildebeests in Malawi, the tssesebe in Mozambique and the kob in Tanzania have become extinct.
Species facing high risk of extinction include birds such as the wattled crane and mammals such as the African wild dog, the Kafue lechwe and the black rhino.
Although the report highlights ongoing efforts by the riparian states in conserving ecosystems and biodiversity, it agitates for the attainment of sustainability as an urgent priority "to reverse the current unsustainable path".
It says management of the Zambezi basin should involve SADC level structures and African initiatives in keeping abreast with global trends and developments.