Impacts of Nile Perch, Lates niloticus, introduction on the ecology, economy and conservation of Lake Victoria, East Africa

摘要

Nile perch were secretly introduced into Lake Victoria in the 1950s, and officially in the 1960s, amid unresolved controversy. Proponents were of the view that the introduction would improve fisheries production and sport fishing. Although the former objective was achieved, the side effects were dire, including extinction of many native species, especially the ecologically important haplochromines, because of predation. The introduction also changed the habitat, trophic dynamics and water clarity. The change in water clarity is thought to be responsible for hybridization of haplochromines, further contributing to the loss of species diversity among cichlids. The establishment and expansion of the Nile perch also altered the fishery and socio-economic settings characterizing the lake. A local economy which, until the early 1980s, was based on native fish species has been replaced by an export-oriented exotic fish processing industry that destroyed the once-cherished traditional resource. Other socio-economic issues associated with Nile perch include the high HIV/AIDS prevalence among fishers, and border conflicts attributable to the migratory and transboundary nature of the fishery resource. Conservation measures for the fishery should include establishment of co-management units that have so far registered both successes and challenges. Other efforts include establishment of the Nile perch Fisheries Management Plans that focus on curbing overfishing and eradicating illegal fishing.