Fish are an important source of both food and income to many people in developing countries. In Africa, as much as 5 per cent of the population – some 35 million people – depend wholly or partly on fisheries for their livelihood. While fisheries based on species that are presently exploited seem to have reached their natural limits, there is considerable potential to expand inland fisheries in Africa to improve food security. In Nigeria, the rearing of African catfish is proving to be a lucrative option for small-scale inland fisheries.
The history of aquaculture in sub-Saharan Africa is relatively recent, with most known aquaculture systems introduced over the past 35 years.During the 1960s, aquaculture development regressed sharply. Most ponds were abandoned because of the limited security of land tenures, reluctance of farmers to adopt technology, labour shortages, drought, and political unrest. Following increased technical and financial assistance from government and non-government donors, aquaculture began to regain its development path from the 1970s onwards. The continent contributes only 0.2 per cent of total global aquaculture production. Extensive to semi-intensive cultural systems produce limited fish yields, which are mostly consumed directly, bartered or sold locally as a cash crop. Most fish farming is carried out by rural small-scale operators, in small freshwater ponds and as a secondary activity to agriculture.
There is therefore still a great deal of unmet potential for African aquaculture. It has been estimated that about 31 per cent of the land area in Africa is potentially suitable for warm-water fish farming on a small-scale level, and that about 13 per cent of the land area is suitable for commercial farming. An increase in pond surface area per farm would provide a significant increase in fish production. Thus, inland-water fish farming could play an increasingly important role in filling the gap between fish demand and supply.
In the few countries where fish farming is already well established, significant contributions have been made to food security by inland-water fish farming. Economic studies have demonstrated that fish farming in Africa can be a good source of income. Findings show that fish farming provides cash to a family in addition to supplementing the diet of the farmers. Fish can be an important cash crop, even for farmers with limited resources.
In Nigeria, aquaculture development has been driven by social and economic objectives, such as nutrition improvement in rural areas, generation of supplementary income, diversification of income activities, and the creation of employment. This is especially true in rural communities, where opportunities for economic activities are limited. Only in recent years has aquaculture also been viewed (on a small scale) as an activity likely to meet national shortfalls in fish supplies, thereby reducing fish imports. Recent recognition of the potential for inland aquaculture has gone hand in hand with the Sustainable Fisheries Livelihoods Programme.
Sustainable Fisheries Livelihoods Programme
The Sustainable Fisheries Livelihoods Programme (SFLP) was established in 1999 for an initial five-year duration. The project is funded by the UK’s Department for International Development (DFID) and executed by the United Nations Food and Agriculture Organisation (FAO). It covers 25 countries in Western Africa, including Nigeria. The main objective of the project is to assist both coastal and inland fishing communities to improve their livelihoods through the sustainable use of aquatic resources. By working with local institutions and community-based organisations, the SFLP is able to provide a setting in which the variety of people who depend on fish for their livelihoods can prosper from this dependency.
Annual domestic fish supply in Nigeria stands at about 400,000 tonnes. The fisheries sector accounts for about 2 per cent of national GDP, 40 per cent of the animal protein intake and a substantial proportion of employment, especially in the rural areas. The sector is a principal source of livelihood for over 3 million people. The sector’s contribution, though minimal, is also evident on the export market.
The major species cultured include fin-fish (tilapias, catfish, and carp), molluscs and shrimp. Freshwater fish comprise over 80 per cent of the total aquaculture harvests. Nigeria is the largest African aquaculture producer, at 15,489 tonnes a year. Egypt (5645 tonnes) follows Nigeria, and then there are only five other countries (Zambia, Madagascar, Togo, Kenya and Sudan) that each produce more than 1000 tonnes.
Farming African Catfish
The African catfish Clarias gariepinus is one of the most suitable species for aquaculture in Africa. Since the 1970s it has been considered to hold great promise for fish farming in Africa. The African catfish has a high growth rate, is very resistant to handling and stress, and is very well appreciated in a wide number of African countries, including Nigeria (where it is often referred to as lungfish).
The large African species of catfish belong to the subgenus Clarias. In 1982 this subgenus was found to contain only two species (C. gariepinus and C. anguillaris). Clarias gariepinus, which is widely considered to be one of the most important tropical catfish species for aquaculture, has an almost pan-African distribution, from the Nile to West Africa and from Algeria to Southern Africa. Clarias anguillaris has a more restricted distribution and is found in Mauritania, in most West African basins and in the Nile. In general C. gariepinus lives in most river basins sympathetically with C. anguillaris.
The Clarias gariepinus has an elongated cylindrical body with extremely long dorsal and anal fins. Both fins contain only soft fin rays. The outer pectoral ray is in the form of a spine and the pelvic fin normally has six soft rays. The head is flattened and highly ossified. The skull bones (above and on the sides) form a casque (helmet) and the body is covered with a smooth scale-less skin. The skin is generally darkly pigmented on the dorsal and lateral parts of the body. The colour is uniformly marbled and changes from greyish olive to blackish according to the substrate. On exposure to light, the skin colour generally becomes lighter.
The Clarias species inhabit calm waters such as lakes, streams, rivers, swamps and floodplains, some of which are subject to seasonal drying. The most common habitats are floodplain swamps and pools in which the catfish can survive during the dry seasons due to their additional organs that breath air while out of the water.
Finding the Water
Water is essential for all forms of aquaculture and is a key factor in determining where aquaculture may develop. Sub-Saharan African aquaculture therefore faces a serious dilemma: growing demand for water that results from an expanding aquaculture industry creates increased competition with other water users for this limited resource. Yet, if water is used carefully and sourced in a variety of ways, then it is certainly possible to overcome this dilemma.
Water for levee and contour ponds may originate from several sources: precipitation, runoff, pumped or gravity water from perennial water bodies such as streams, rivers, lakes and reservoirs and pumped groundwater. Precipitation is considered the main source of water for small-scale fish farming. Other water resources such as perennial streams and rivers often exceed the economic limitations associated with small-scale farming. However, rainfall in Africa is variable throughout the year and it is difficult to know which areas would not have sufficient water during the dry months of the year. To meet aquaculture water requirements, it is necessary to balance inputs from the source (e.g. precipitation, stream water) against losses due to evaporation and seepage from ponds.
Seepage can be one of the most important variables affecting water requirement for a pond. The amount of seepage will depend on the soil composition and on the structure of the pond bottom. For example, if the composition of the soil is coarse, as in sandy soils, large volumes of water will be lost by seepage. Thus, the assessment and use of soils is a very important aspect of aquaculture site selection, development and management. This is particularly the case in pond farms, where soil quality has a great influence on construction and maintenance costs, and on productivity. It is also important in selecting sites and developing designs for other components such as water supply channels.
The Through-flow Pond
A through-flow pond is designed to provide the fish with a clean and oxygen-rich supply of water. Using outlets also creates an easy method of catching the fish: draining water onto a collection surface removes fish from the pond, preventing the need for nets or other collection devices.
The ideal position for a pond is one where it can receive a water supply under gravity, and discharge the used water under gravity. This can be achieved where water is fed to the pond from a small dam constructed upstream of the pond location. After passing through the pond, the water is discharged back to the stream.
Impermeable soil is optimum, which is best offered by clay soils. With relatively light soils it is often possible to mix clay to give a watertight covering to the pond bottom. Sandy soils and rocky soils are not suitable. Sites containing tree roots and reeds can produce problems, as they create escape holes for water. Excessive seepage often results from unsuitable site selection. Soil properties should be clearly investigated and identified during site selection.
The pond is usually constructed by excavating the pond area and using the excavated material to form the pond dykes. Depending on the topography of the site, the dykes may have to be constructed on one to four sides of the pond.
Dykes (also referred to as the pond walls, embankments or dams) are often built of compacted layers of soil. The dykes must be built to withstand the entire pressure of the pond and must be watertight. The size of the dyke depends on the depth and size of the pond as well as the soil type used. In Nigeria breeze-blocks (lightweight blocks for building, made from ashes of coal, coke etc and mixed with sand and cement) have become locally available and so are being used to help create an impermeable dyke or, if necessary, an entire impermeable pond.
The bottom is smoothed and compacted and then a system of drainage ditches is dug. The main ditch runs down the length of the pond, ending at the outlet. The minimum fall of the ditch is about 1 cm in every 1000 cm of length. However, falls of 2 cm per 1000 cm (10 metres) of length provide better drainage. The central ditch drains the side of the pond via a series tributary ditches. The tributary ditches should have a fall of 5 cm per 1000 cm length.
Inlets enable the supply of water to be turned on and off, and can keep out unwanted organisms. The entrance is covered by a trap of fine-meshed material, which filters out the eggs etc. of undesirable species. The inlet filter should be regularly checked and cleared to prevent blockage of the water flow. It is also useful to spray or bubble the water into the pond, so that it picks up oxygen from the air. Oxygen can also be added by stirring the pond water.
The outlet flow of the pond should be controllable. Where the water flows out of the pond, a collection basin should be built to form a base for the collection of fish.
Fishing for Profit
Yumi Alabi has run a catfish farm for five years. He is self-taught in some of the best fish-farming techniques and his knowledge is now of great value in Lagos. His cheap version of the through-flow water system, which is constructable from local materials, provides him with an annual production of 4 tonnes of fish. Yumi was able to profit from the pond in his garden and has now moved on to breeding catfish in small nurseries.
Other Nigerians, such as Babatunde Akiode, have also benefited from farming the African catfish. Babatunde and his wife Bola Akiode began with two ponds in their back garden and little practical experience. After the first year, their business took off. Babatunde capitalised on the trend towards catfish farming and has begun to offer courses for those seeking to establish their own business.
The experiences of people like Yumi and Babatunde demonstrate the ability of catfish farming to give them a fresh start. They invested time and effort in catfish farming and are now reaping the rewards. For many resource-poor people in Nigeria, catfish farming presents a viable and accessible option.
Cowx, I. G. (1992). Aquaculture Development in Africa: Training and Reference Manual for Aquaculture Extensionists. Hull: Humberside International Fisheries Institute.
De Graaf, G. and Janssen, J. (1996). Handbook on the Artificial Reproduction and Pond Rearing of the African Catfish Clarius Gariepinus in Sub-Saharan Africa:A Handbook. Rome: FAO Fisheries Technical Paper.
Hussein, K. and Zuondi, J. (2002). Contribution of Fisheries Research to the Improvement of Livelihoods in West African Fishing Communities. Case Study: Nigeria. FAO and DFID Sustainable Fisheries Livelihoods Programme.
Swift, D. R. (1993). Aquaculture Training Manual. 2nd Edn. Oxford: Fishing News Books.
Sustainable Fisheries Livelihoods Programme
Donor and Supporting Organisations
Department for International Development (DFID) www.dfid.gov.uk
World Bank www.worldbank.org
ITDG Technical Briefs answers.practicalaction.org
Other relevant Hands On case studies
Net Profits – Cameroon, Hungary, Peru, St Lucia, Sweden, UK
Hungary for Fish – Hungary
Small Fry, Big Catch – Thailand
Gone Fishing – Bangladesh, Indonesia, Mozambique