Item Details

Title: Human impacts on the African Great Lakes

Date Published: 1997
Author/s: Richard Ogutu-Ohwayo, Robert E. Hecky, Andrew S. Cohen & Les Kaufman
Data publication:
Funding Agency : International Development Research Centre IDRC
Copyright/patents/trade marks: Kluwer Academic Publishers. Printed in the Netherlands
Journal Publisher: Environmental Biology of Fishes
Affiliation: Fisheries Research Institute, P.O. Box 343, Jinja, Uganda
2 Freshwater Institute, Fisheries and Oceans, 501 University Crescent, Winnipeg, Manitoba R3T 2N6, Canada
3 University of Arizona, Tucson, AZ 85721, U.S.A.
4 New England Aquarium, Central Wharf, Boston, MA 02110, U.S.A
Keywords: threats, population growth, over-exploitation, introductions, eutrophication, pollution, fishes


The African Great Lakes are important sources of fishes and water for domestic use, are used as avenues of
transport, and receive agricultural, domestic and industrial effluents and atmospheric residues. Some of these
lakes have speciose fish faunas of great interest to science. The catchment areas of some of the lakes are highly
populated and user conflicts have increased the demands on the lakes’ resources. There have been drastic
reductions in fish stocks in most of the lakes due to overfishing. Introductions of new fish species, though
followed by increases in fish catches, have been accompanied by a decline and in some cases extinction of
native fish species. Some of the lakes have been invaded by the water hyacinth, Eichhornia crassipes. Agricultural activities, deforestation and devegetation of the catchment areas have increased siltation, and led to loss
of suitable habitats and biodiversity. There are increased nutrient inputs from agriculture, sewage and industrial discharges and combustion processes which can cause eutrophication. There are also increased threats of
toxic pollution from industrial waste discharge, mining, pesticides, and oil residues and spills. Climatic changes may also affect thermal stability of the lakes. These factors threaten availability of dietary protein, clean
water and biodiversity. National and international efforts are required to manage the fisheries, guide the
introduction of exotics, conserve biodiversity, control the water hyacinth, control eutrophication, reduce input of contaminants and manage climate change.

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