The purpose, costs and benefits of fish introductions: With specific reference to the Great Lakes of Africa

Abstract

AbstractFish introductions have been used to enhance fish production by filling a less utilized ecological niche, for aquaculture, sport and recreation, ornamental purposes and to control disease vectors and weeds. Introductions of the Nile perch Lates niliticus and the Nile tilapia Oreochromis niloticus into Lakes Victoria and Kyoga, and the clupeid Limnothrissa miodon into Lakes Kariba and Kivu have led to increases in fish catches. Unfortunately, predation by the Nile perch and competition between native cichlids and introduced tilapiine species have caused a severe decline and in some cases total disappearance of many native fish species from Lakes Victoria and Kyoga. This has generated conflicting opinions on fish introductions. This paper reviews the outcomes of introductions in the Great Lakes region of Africa in relation to the need to conserve the native fish fauna and to produce protein food for people living in the region. It also suggests guidelines to be followed before fish are introduced, e...