Despite the considerable amount of work that has been carried out on the fisheries of African inland waters in recent years, surprisingly little effort has been directed at the biology of the fish of river systems. Rivers possibly contribute nearly half of the total freshwater fish caught on the continent and some of the individually most important fisheries in Africa are located on them. The lack of understanding of the ecological mechanisms regulating the fish population of such systems may have serious consequences for the future of such fisheries. Freshwaters, and rivers in particular are required for a range of domestic, industrial and agricultural uses, which if not properly controlled are inimicable to the continued existance of viable fish stocks. Integrated development of the river system within the framework of multi-purpose uses therefore presupposes adequate information upon which to evaluate the effects of changes in the ecosystem on the fish.
It has long been apparent that the major river fisheries are located either on the wide lower reaches of the river, or on the internal floodplains that occur in some systems. A strong correlation in fact exists between the width of the floodplain and the fish catch from the corresponding reach of the river (Welcomme, in press). The existence of important fish resources has resulted in studies in at least some floodplains. The most completely documented of such systems is perhaps the Kafue River in Zambia, where a number of scientists have worked on fisheries and related topics over a moderately long period. More recently the Senegal and Ouémé Rivers floodplains have been examined, and interest is being shown in the biology of similar areas of the Shire and Pongolo Rivers. It is perhaps symptomatic that nearly all these studies have been carried out either to predict the effect of dam construction or management for some other purpose, or to try to explain and improve a deteriorating fishery.
This paper is intended as a ‘habitat synopsis’ of the floodplains of Africa together with a consideration of their fisheries which will fill the general lacunae of knowledge in this field and serve as a basis for future work.
