Future food security, fish supply and demand

reviews e.g. King and Ibrahim, 1988; Huisman, 1990. The loss of confidence in small-scale com- mercial aquaculture led to considerable debate over solutions and reluctance among the assis- tance community to fund further work in any type of aquaculture. That these projects have not resulted in large, sustained increases in fish production, however, does not necessarily mean that aquaculture, per se, is a nonviable proposition in Africa. It is more likely that the point of entry and modus operandi for earlier development projects was incorrect. One proof of this is that aquaculture among smallholders has recently been expanding across the continent Nathanae¨l and Moehl, 1989; Mol- nar et al., 1991; van den Berg, 1994; Campbell, 1995; Murnyak and Mafwenga, 1995; Ngenda, 1995. These new projects have been based on participatory and evolutionary approaches and a rural development focus as recommended in the thematic evaluation of aquaculture FAONO- RADUNDP, 1987. Over the course of rural development, changes in land use, family and social structure may, in fact, be unavoidable. Smallholder aquaculture may cause problems associated with changes in internal household dynamics and community rela- tionships resulting from activities of rural devel- opment practitioners Harrison, 1994; Harrison et al., 1994. Relatively better off farmers tend to be early adopters and major beneficiaries e.g. Har- rison, 1994. However, recent experience has shown that, if sensitivity to the needs and problems of the user group can be built into development activities, these problems might be minimized. User friendly approaches can also speed technology uptake Brummett and Noble, 1995; Brummett and Chikafumbwa, 1998 and engender a spirit of innovation that can cause small-scale farming sys- tems to evolve Chikafumbwa, 1995.

4. Future food security, fish supply and demand

Population increase and economic growth are the two most important factors that affect the demand for food fish Westlund, 1995. In the current African situation of high population growth and economic stagnation, the former will most likely be the dominant factor, especially considering the relative inelasticity of demand for cheap fish in many markets Delgado, 1995. The 1990 African population of 800 million is ex- pected to reach 1066 million by 2010, requiring 9.6 million tons of fish compared to 5.2 million tons in 1990 Westlund, 1995. Capture fisheries that have been essentially static since 1987 will not be able to meet this demand FAO, 1995. Although unlikely to happen by 2010, aquacul- ture could still make a significant contribution towards filling the gap. Based on projections of past growth trends, Bonzon 1995 predicted that aquaculture production in sub-Saharan Africa would reach 80 000 tons by 2000 and 320 000 tons in 2010. Similarly, Satia 1991 predicted a total aquaculture output of 100 000 tons for all of Africa by 1995 – 1996. Recent projection methods that use newer ap- proaches and successes, however, are more opti- mistic about the potential. Using very conservative production figures, Kapetsky 1994 estimated that 31 of sub-Saharan Africa 40 countries, 9.2 million km 2 is suitable for small- holder fish farming. Extrapolating from more re- cent smallholder, development-oriented projects, Kapetsky 1995 goes on to estimate that this sub-sector alone could meet 35 of Africa’s in- creased fish need up to the year 2010 on only 0.5 of the total area potentially available. Kapetsky 1994 also found that, of the land suitable for subsistence fish farming, almost 13 is also suitable for commercial aquaculture. Aguilar- Manjarrez and Nath 1998 reassessed the poten- tial at a finer resolution and found that between 37 and 43 of the African land surface contains areas suitable for small-scale and commercial fish farming of the three main freshwater species, namely O. niloticus, Clarius gariepinus African catfish and Cyprinus carpio common carp. These estimates indicate the potential for African aquaculture, but the question of how to sustainably accelerate production in the available timeframe remains outstanding. Rapid commer- cialization might produce more fish in less time, but environmental degradation and social disrup- tion have followed the rapid and indiscriminate expansion of aquaculture in other parts of the world. Cage culture of carnivorous fishes in Japan, Hong Kong and Northern Europe, for example, has resulted in severe water pollution Csavas, 1993. Clearing of mangroves and inten- sification of shrimp farming has caused erosion, loss of fish habitat, soil acidification and saliniza- tion Beveridge et al., 1994, 1997 and displaced small-scale fishers and farmers in many coastal areas in Asia and Latin America Primavera, 1997. Similar growth patterns in Africa may solve some short-term economic problems, but at a cost that may be unsupportable in the longer term. More commercial fish production systems will most certainly develop and thrive, but to justify intervention on the part of the interna- tional community, the model for this development must take into consideration the important issues of equity and sustainability.

5. Promoting evolution at the farm level