Zambia has big potential for fish farming with 37 per cent of its surface area suitable for artisanal and 43 per cent suitable for commercial fish production.
Aquaculture is the rearing of aquatic organisms in an enclosed water body under controlled conditions. Aquatic organisms may be plant life such as phytoplankton, lilies, and other forms of algae or animal life such as fish, crocodiles, oysters etc. Controlled conditions include physio-chemical water parameters (dissolved oxygen, temperature, pH, phosphorous, etc), water level, as well as feed. The basic idea here is to imitate what is prevailing in the natural waters so as to achieve optimum yields.
Aquaculture is in its infant stage of development compared to agriculture. Fish farming in Zambia dates back to the 1950s when the first attempts were made to raise indigenous species of the cichlidae family, mainly tilapias, in dams and earthen fish ponds. A number of donors have subsequently taken an active part in assisting the government to encourage farmers to adopt aquaculture.
Common aquaculture technologies used in Zambia:
- Earthen Ponds
This technology involves the use of the sides, bottom, and dykes of a pond to form an ecosystem. Such a system promotes growth of natural food items and so fish benefits extensively from the natural food. Supplementary feed may not be necessary. Production varies depending on management system employed; regardless of pond size. Pond construction and maintenance is relatively cheaper. Examples of species suitable for culture include Oreochromis andersonii or O. niloticus.
- Concrete Ponds
Pond walls and bottom are made of concrete. Since the bottom is cemented, no ecosystem is formed and so no natural food production. In this case, formulated feed is what the cultured organisms rely on. It is expensive to construct and maintain; thereby mainly used for production of high value species e.g. carp fish.
This is a narrow long body of water. It depends on a continuous flow of water and so limited presence of algae, bacteria, or fungi. Only stubborn algae are scarcely found. Catfish, Tilapia, Carp are among species that can be cultured.
- Floating Cages
Cages may be made of planks or steel and are placed in running water- in a natural water body (lake, river, sea). Since space is limited, artificial feed supplement is necessary. To curb environmental degradation, positioning of cages, feed type, and frequency is cardinal. Examples of species cultured in this system include i.e. O. niloticus or O. andersonii.
Cage farming is a relatively new practice in Zambia, which has attracted a lot of concern from the Environmental monitoring bodies such as the Zambia Environmental Management Agency (ZEMA). Their main concern is regarding the negative impacts that the practice has on the natural water body and its resources. For example,
- In the event of fish escaping from cages, such escapes may cause harm to the inhabitants and the ecosystem (especially if they are exotic species).
- Uneaten feeds that find themselves on the river bed would cause water pollution;
- Cages tend to divert or hamper natural water flow;
- The site of cages may compromise the beautiful scenery of the water body, affecting tourism;
- Cages would also affect navigation; etc.
There is therefore need to address such concerns before and during the project execution stage. Constraints and benefits must be compared to ensure that even as the farmer is gaining profits, the environmental damage is not compromised. In this vain, it is a requirement by the Zambian law that an environmental impact assessment (EIA) be carried out before project initiation to determine the possible impacts and propose remedial measures thereof.
Strong material such as planks, fibre glass, or plastic is used in construction. May be round, square, or rectangular in shape. Shape and size varies depending on purpose. Usually used for high value and delicate species such as breeders, juveniles, or ornamental fishes. Food is totally artificial and water should be allowed to run through or changed regularly.
- Conservation Dams
In most cases, the dam is originally intended for other purposes such as irrigation, livestock drinking, or human consumption. Instead of allowing the dam to serve only that intended purpose, fish may be reared in the same dam. In dams meant for livestock, animals fertilize the water (cow dung for instance), thereby promoting primary productivity, and thus natural food for the fish. Production is relatively low. Harvesting is not easy due to depth, stumps, and rocks. This kind of practice is commonly practiced in Southern and Eastern Province of Zambia. Species cultured mainly Tilapia, catfish.
Species Suitable for Aquaculture in Zambia
The commonly used species for aquaculture include the three spotted tilapia (Oreochromis andersonii), the longfin tilapia (Oreochromis macrochir) and the redbreast tilapia (Tilapia rendalli). The Kafue river strain of the three spotted tilapia is the most commonly farmed species, particularly in the commercial sector. Other species include the common carp (Cyprinus carpio), the Nile tilapia (Oreochromis niloticus) and the red swamp crayfish (Procambarus clarkii).
Challenges facing Aquaculture Production in Zambia
Lack of a national policy to guide aquaculture development, unfriendly investment policies, the absence of linkages between farmers, research/technology development and extension, and unfavourable investment climate. Long-term economic sustainability of Zambian aquaculture will depend on the development and implementation of a national policy that ensures the social and environmental sustainability of the industry.
Challenges and Opportunities for the Future
The entry of Zambian aquaculture into global prominence faces considerable challenges. There are, however, reasons for optimism. Despite high risks and investment costs, high and increasing demand and market value of fish are encouraging. If social and environmental sustainability issues can be successfully addressed, increasing market demand and higher prices should open opportunities for a range of producers and investors. Increasing productivity of both large and small-scale aquaculture will require major investments in research, development and extension as well as policy shifts. The strategies for addressing problems of the small-scale and larger commercial operations will probably be different.