The impact of invasive species in African lakes

Pests, pathogens and poverty: biological invasions and agricultural dependence

“…The weed is also believed to harbor disease-carrying organisms, and has little potential for economic utilization. Kasulo's (2000) estimate of the annual cost of the hyacinth in terms of its impact on fisheries in this group of lakes was USD71.4.…”

“…Exceptions include the African Lakes and the South African Fynbos. Kasulo (2000) analysed the ecological and socio-economic impact of invasive species in African lakes focusing on introduced fish species and water weeds-the Nile perch (Lates niloticus), the Tanganyika sardine (Limnothrissa miodon) and water hyacinth (Eichhornia crassipes) into Lakes Victoria, Kyoga, Nabugabo, Kariba, Kivu, Itezhitezhi and Malawi. While the introduction of Nile perch had a major impact on the structure and profitability of fisheries, it is believed to have caused the extinction of numerous endemic species.…”

As the world gets smaller, the chances of invasion grow

“…But generally speaking, GISP (2001) advocates four main management approaches: first, subject all alien species proposed for introduction to expert consideration, following the precautionary principle; second, improve the scientific basis for predicting which species Kasulo, 2000) proposed for deliberate introduction are likely to become invasive and which are likely to be beneficial; third, improve control of pathways for unplanned introductions (through international trade, wooden packing material, and so forth); and fourth, improve management techniques to eradicate or control invasive alien species once prevention has failed or become impractical. Human societies seem to have a great capacity for contradiction, with quarantine inspections, for example, being the responsibility of the same governments that promote globalization that undermine government capacity to apply effective quarantine measures (Low, 2001).…”

Elton and the economics of biological invasions

“…Among aquatic species, there have been studies of the effects of the comb jelly, Mnemiopsis leidii , in the Black Sea (Knowler 2005 ). Within the African Lakes, Kasulo (2000) analysed the ecological and socio -economic impact of invasive species in African lakes, focusing on introduced fi sh species and water weeds: the Nile perch ( Lates niloticus ), the Tanganyika sardine ( Limnothrissa miodon ) and water hyacinth ( Eichhornia crassipes ) into Lakes Victoria, Kyoga, Nabugabo, Kariba, Kivu, Itezhitezhi and Malawi. There are no estimates of damage costs, but the introduction of Nile perch -which had a major impact on the structure and profi tability of fi sheries -is believed to have caused the extinction of up to 350 haplochromine cyclid species.…”