At first glance, relatively modest areas of the African continent appear to be predisposed for warm water fish farming; 31% at a subsistence level and 9% at a commercial level. Nevertheless, in absolute terms, the areal expanses that range from suitable to optimum in potential are vast. The results of this study are encouraging; they indicate that 40 of 48 countries studied have potential. Said another way, lack of suitable area does not appear to be a constraint on warm water fish farming in many countries.
An important implication of the study results is that countries with large absolute areas apt for warm water fish farming, or countries with relatively large expanses apt for the same, should implement national-level studies to better define their potential as a first step towards accelerating the development of fish farming.
Because of the continental scale of the study, the resolution of the underlying data and the assumptions employed, the estimates of warm water fish farming potential are indicative. A conservative approach has been adopted throughout. Thus, estimates are apt to err on the low side. Further, the area expanses identified in the study should be thought of as encompassing or containing warm water fish farming potential at the stated levels. This is because some of the land identified may already be devoted to other uses, or the returns may be greater if the land is used for endeavours other than fish farming in ponds.
The basic approach - the use only of data that are comparable Africa-wideensures that comparisons can be made among countries and regions. Thus, development work can be planned and executed to take advantage of similarities of needs and potentials among neighbouring countries, or regionally. A related use of the results has been to look at the possible contribution of warm water fish farming to overall fish supply and to food security in Africa in the coming years (Kapetsky, in press).
This study was constrained by the need to use already digitized maps, or data that could be easily put into a digital format. The reliability of the results can be improved by increasing the spatial resolution of some of the criteria, by adding criteria and by re-examining some of the assumptions used to establish thresholds.
Most of the basic work for an Aquaculture GIS for Africa already has been completed. At this point it is possible to enlarge the study to estimate the potential for farming of temperate-water fish, such as common carp and for cold-water fish such as rainbow and brown trout, with a minimum of additional effort. Taken one step further, the GIS can be expanded to examine the performance and potential of inland fisheries in terms of their physical and economic environment and eventually to look at aquaculture and inland fishery potentials together.
Finally, it should be remembered that the study aimed at assessing warm water fish farming potential in ponds. Some countries that appear to have little warm water fish farming potential may possess potential for other kinds of fish farming, such as that for temperate-water species.
