needed with regard to biological and economical aspects of fish stocks, to determine the optimum yields of these stocks and to ensure the suitability of production from certain fish species. In conclusion, the following measures are important to sustainably manage fish resources:

• Provide more information about fish stocks—important for management. This information may include, but is not restricted to, size, structure and other biological parameters of the stocks.
• Develop a plan for sustainably managing fish stocks that allows their responsible use and rebuilding of depleted stocks.
• Develop infrastructure in fishery communities.
• Improve fishing techniques and reduce the amount of by-catch.
• Educate local people in new techniques on fishing and quality assurance.
• Increase the participation of women in postharvest activities.
• Increase the cooperation between countries and international
  organizations.

Aquaculture. It is expected that aquaculture will grow significantly in some CWANA countries since the growing demand for fish will probably be met mostly through increased production from aquaculture. This growth will differ from one aquaculture sector to another (marine aquaculture, aquaculture in integrated agriculture, production of nonfood fish). Production may be increased either by expanding the cultivated area or by improving the production per unit area (Delgado et al., 2003). The increasing demand for fish, increasing domestic food supply and increasing export revenue are the main forces that will direct the expected growth of the aquaculture industry in the future. Many CWANA countries realize the importance of aquaculture as a valuable food source and an important source of employment, providing a development opportunity for rural communities. They will incorporate it in their development plans.

In poorer communities, small-scale integrated aquaculture can benefit local people and ensure food security. Growing fish along with agricultural crops can use scarce water in fish ponds for crop irrigation. In areas with saline groundwater that cannot be used for agriculture, fish species such as tilapia may be grown to increase the income of local farmers as well as to provide valuable food.

Challenges facing aquaculture differ from one country to another in CWANA, but in general they include limited availability of sites suitable for new aquaculture activities, uncertain provision of a continuous supply of fingerlings, limited availability of local species for aquaculture, risk of disease, and unreliable markets. In some cases, conflicting interests from different stakeholders, such as tourism, agriculture or other coastal uses, will have to be mediated to get access to and use suitable sites; this may often require collaboration between different authorities. In other cases suitable technologies for particular sites will have to be developed as some sites require special technology.

Constraints to developing aquaculture related to land, water and inputs may be faced through adapted technologies such as selective breeding, better health management, water control and modification of feed input (Delgado et

al., 2003). However, more research regarding the sustainability of aquaculture production is certainly required; joint development and transfer of technologies between countries may speed up success. Improved harvesting and processing techniques will increase output of high-quality products. Biotechnology in aquaculture may improve production, but it will be important to use such new technologies in a sustainable manner, regulated through proper legislation and monitoring.

Using local fish species is important for sustainable aquaculture as many problems are associated with using exotic species, principally disease transmission. Therefore, research should focus on determining suitable local species for aquaculture. They should have a high growth rate, be resistant to environmental changes and diseases, and be in demand in the marketplace. If an exotic species is to be used for any reason, special procedures should be followed such as a detailed risk assessment of the effect of introducing this species on the local environment and local species, and rigorous quarantine procedures. Some countries do not allow fingerlings of exotic species to be imported, but they allow importation of brooders. This gives the country more surveillance over both the brooders and the hatchlings.

It is essential for CWANA to address environmental issues in developing sustainable aquaculture. Therefore, an environmental impact assessment should be carried out for every commercial project. These projects should promote environmentally sound technologies for managing production. Monitoring is important to study possible negative effects and the best methods to reduce them. Likewise, codes of conduct for best practices and methods in aquaculture should be prepared to ensure sustainability. These codes can be written jointly between the government and the private sector in any country. Sustainable aquaculture requires effective policies, legal frameworks and institutions. In CWANA, some countries already have policies for developing aquaculture; others are lagging behind. Obstacles to overcome developing a legal framework include conflicting views between different governmental authorities, bureaucratic procedures and inconsistency among the various laws. Therefore, it is important to encourage cooperation among authorities to use suitable mechanisms to jointly develop a management plan for aquaculture.

5.2.1.4 Forestry and Agroforestry

The forested area in CWANA is limited—less than 5% in most countries—but it still harbors great plant biodiversity and offers considerable potential to serve as a carbon sink. Forest ecosystems in these countries are sources of timber, firewood and fiber as well as non-wood forest products in addition to providing many goods and services (IPGRI, 2001). The role of forests is particularly essential in the dry areas of CWANA with regard to their hydrological function in the ecosystem; under forest cover water infiltration is increased, runoff rates are reduced, and thus water availability may be improved. Furthermore, trees importantly protect land from degradation and desertification by preventing wind and water erosion.

Land degradation poses a major threat to sustainable forest development. Countries in the CWANA region, thereneeded