Effect of river flow changes on habitats of aquatic vegetation in the Senegal River, West Africa

摘要

The lower part of the Senegal River is under a serious threat of an increasingly severe aquatic weed infestation, and other parts of the river corridor could be invaded by aquatic vegetation. Although problems with S. molesta do not exist in the Delta area at present, vigilence is advisable. Management of Typha will be difficult because no effective ways of biological control exist, and large scale mechanical control is expensive. However, the problem with Typha in the Diama dam reservoir might be solved by construction of dikes, so that the area will dry out during the dry season. No ecological feasibility study has been made regarding this management proposal. Water hyacinth is potentially one of the most serious threats to the Senegal River ecosystem and could lead to a new ecological disaster. Despite the present absence of water hyacinth from the upstream part of the Senegal River in Mali, it should be noted that the plant is widespread in Mali in the River Niger catchment. Tributaries of the rivers Senegal and Niger are situated very close to each other, with less than 50 km between them.