Abstrakt: |
Reservoirs serve important functions for the socio-economic needs of the people in tropical Africa, which include fish production. However, the limnology of these reservoirs is usually not taken into consideration during the planning, construction, operation and management of the reservoirs. The impoundment of water usually brings changes to the physico-chemical and biological properties of the water with attendant serious impacts on the fish biodiversity and fisheries of reservoirs. Eutrophication, multiple uses of reservoirs, soil erosion and siltation, thermal stratification, aquatic macrophytes explosion, reservoir construction, operation and management are some of the limnological challenges facing the fisheries of shallow tropical African reservoirs. Various mitigation measures to overcome the challenges such as the use of Best Management Practices (BMP) on the reservoir watershed, carrying out Initial Environmental Examination (IEE), Environmental Risk Assessment (ERA) and Environmental Impact Assessment (EIA) on the reservoir before construction and other limnological driven management programmes were proposed. A better way to ensure that fish biodiversity does not decline or totally collapse is to incorporate fish production into the reservoir management programmes and the use of limnological data for reservoir design and operational management. In the light of this, limnologists, aquatic ecologists and fisheries biologists should be consulted and carried along in the initial planning, construction, execution and subsequent management of the reservoir to ensure wise use and sustainable fish production from the reservoir irrespective of the purpose of creation of the reservoir. [ABSTRACT FROM AUTHOR] |