Federal Ministry of Agriculture and Natural Resources
Federal Department of Fisheries
Garki - Abuja, Nigeria
The increase of population and their food needs demand action from the Nigerian authorities, including the reduction of post-harvest losses of fish and fish products. The country has important freshwater fish resources in the rivers, flood plains and in the numerous natural and man-made lakes. Together, these water bodies contribute significantly to satisfy the national food fish requirements. However, in the absence of proper handling, processing and marketing infrastructure, large quantities of fish were lost for consumption each year. Aware of this problem, the government has embarked on a programme of constructing roads and markets in the fishery areas. Losses are at present estimated at about 10% while fishermen incomes have substantially increased. It is concluded that losses can be reduced to a minimum through the use of modern technologies, including roads, cold chains and motorized transport.
L'accroissement de la population et de ses besoins alimentaires exigent une action des nigérianes, entre autres pour réduire les pertes de poissons d'eau douce dans les fleuves, les plaines d'inondation et dans les nombreux lacs naturels et artificiels. L'ensemble de ces plans d'eau contribue de manière significative à satisfaire les besoins nationaux en poisson. Cependant, faute d'une infrastructure permettant non seulement que la manutention, la conservation et la transformation soient correctes, mais aussi que l'écoulement de la production soit rapide, d'importantes quantités de poisson ont été perdues à la consommation chaque année. Le gouvernement, conscient de ces contraintes, exécute un programme de construction de routes et de marchés dans les zones de production. A l'heure actuelle, les pertes sont estimées à 10% environ et les revenus des pêcheurs ont beaucoup augmenté. On en conclut que c'est surtout grâce à la technologie moderne, y compris les routes de dessert, les chaines de froid et les moyens de transport motorisés, que les pertes peuvent être reduites au maximum.
The effective average annual fish demand in Nigeria between 1980 and 1990 was estimated at 1.2 million t and was projected to increase approximately to 2 million t by the year 2000. However, in practice, the actual catch, covering the period 1980–1987 averaged 0.6 million t.
Nigeria is a large country, both in size (923 000 km2) and with over 120 million citizens, and has about 120 million hectares of water bodies, which are made up of natural and man-made lakes (Kainji 127 000 ha) and Chad, and Rivers (Benue and Niger) Reservoirs, Shiroro (31 200 ha) Bakolori (8 000 ha) Goronyo (20 000) Jebba (35 000 ha) to mention but a few of the most important.
Fish production in some of these water bodies has been relatively low and constitutes less than 40% of the total national needs during the period under review.
Historical fishery statistical data on both fresh and processed fish and fishery products are lacking or unreliable on the major Lakes Kainji and Chad.
Table 1 represents the trend of fish products from all sources in Nigeria from 1985 to 1989.
Fish production in Nigeria, 1985 – 1989
|1985||201 383||140 873||60 510|
|1986||267 136||160 169||106 967|
|1987||248 987||145 775||103 237|
|1988||297 624||185 181||112 443|
|1989||303 454||171 332||132 122|
Source: Federal Department of Fisheries, Statistics Section (in press)
Lake Chad is located on longitude 14° North and latitude 13° East in Borno State, whilst Lake Kainji is located on longitude 4°5' North and latitude 10°11' East. Both lakes lie within the tropics where ambient temperatures are generally high.
2.1 Fish Production from Lakes Chad and Kainji
Over the years and before the establishment of the numerous man-made lakes in Nigeria, Lake Chad was the main source of inland fish production. The production situation before the advent of the drought in the 1970s was so abundant that the fish caught in the Lake Chad area was found in all parts of Nigeria under the popular name of “banda”, a smoked form of the product.
Fish production in the Lake Kainji area was high at the early post-impoundment stage of the lake, but the trend changed soon after, and it presently remains so. The pre-impoundment estimates of fish catch of 5 400 t/year (FAO, 1977) was made by various experts, such as Dagte and Bayagbona in 1961. They predicted the doubling of this quantity under adequate management conditions. Later, in 1972, Lelek used canoe counts and estimated a total production of 7 200 t/year. However, the conclusion from all these estimates was that with good resource management, an annual yield of 10 000 t was feasible.
In subsequent years (1969) actual catches reached 17 000 t. The corresponding figures for 1970–1971, 1972 and 1973 were 28 638.6, 11 037.3 and 10 000 t respectively.
Judging from the established production proposals, fishery technology experts claim that between 20% and 40% of fish is lost as a result of poor handling and processing. It can be observed from Table 1 that great quantities of fish are lost through post-harvest activities in the artisanal fisheries of Lake Chad.
In the Lake Chad area, the fresh fish is processed by various methods in order to preserve the shelflife of the catch. The catch so processed is given different local names. Sanda is prepared from fish of an adult size, scaled, eviscerated and cut up into pieces before being smoked and dried.
Another product is called “salanga” and is made up of fish of smaller size, such as Alestes baremoze and Alestes dentex. These fish species have over the years decreased in size, which could be an indication of dwindling stocks due to drought, accompanied by overfishing (Tables 1, 2 and 3).
3. OBJECTIVES OF THIS PAPER
It aims first to explain the large catches from Lakes Chad and Kainji yearly and second, to demonstrate by deduction the magnitude of fish losses after each annual harvest, as a result of poor handling, poor processing and lack of infrastructural facilities.
4. CAUSES OF FISH POST-HARVEST LOSSES IN LAKES CHAD AND KAINJI
Both lakes lie within the high tropical regions of extreme scorching heat, where temperatures in the shade can reach 45°–49°C and at other times fall very low. These extremes in weather affect the quality of fish in the following ways:
Once fish has been smoked, dried and sun-dried, it is not easy to convert the dryweight into fresh fish yields. The catch is often processed at fishing settlements far from the shore or nearest marketing centres. Fish losses in fresh fish weight occur during cleaning and preparation (evisceration, evaporation during smoking - depending on the species, sex and fishing season) and can be as high as 35–40%).
Fish produced in Lake Chad passing through
Baga Road Checkpoint, 1969/1977
|1969–70||8 730||60||8 790|
|1970–71||11 816||123||11 938|
|1971–72||20 608||115||20 722|
|1972–73||28 243||292||28 535|
|1973–74||34 036||805||34 841|
|1974–75||26 709||143||26 862|
|1975–76||14 483||NA||14 483|
|1976–77||13 414||9||13 423|
Source: FAO CIFA Technical Paper No. 5. Symposium on River and Floodplain Fisheries in Africa. Bujumbura, Burundi, 21–23 November, 1977
Table 2 shows the amount of fish in tonnes passing through Baga Road Checkpoint. Similarly processed fish from Lake Chad passing through N'Djamena Road Checkpoint (Table 3) also comes into Nigeria.
Other factors which contribute to post-harvest losses are lack of:
Finally, due to bad handling and organization which have not properly evolved to meet the ever-changing demands of the situation, attacks on the product by insects, particularly Dermestes and Necrobia and rodents, are greatly facilitated.
It is not possible to evaluate the loss caused by each of these factors which depends on the working conditions of each handler who intervenes in the chain, from the fisherman to consumer. Under prevailing conditions, it is estimated that between 25% and 75% of the nutritional value of fish is lost during the above operations and sometimes a sack of “banda” is composed of only the bones and skin of the fish.
Fish produced in Lake Chad passing through
N'Djamena Road Checkpoint
|1969–70||3 362||485||3 407|
|1970–71||4 998||577||5 575|
|1971–72||6 621||391||7 012|
|1972–73||8 031||372||8 403|
|1973–74||9 714||521||10 235|
|1974–75||7 588||280||7 868|
|1975–76||9 226||-||9 227|
|1976–77||6 837||5||6 842|
Source: CIFA Technical paper No. 5. Symposium on River and Floodplain Fisheries in Africa. Bujumbura, Burundi 21–23 November, 1977.
5. FISH PROCESSING
In both Lakes Chad and Kinji, the catches are processed by three basic traditional methods by the fishermen on the fishing grounds or by their families at the fishing settlements.
This is one of the oldest and most common methods used. The product is usually washed, gutted (in some cases), sun-dried and then smoked over a smouldering fire from below a rafter. The intensity of heat and smoke is not easily regulated. Some small fish is smoked whole. A minor proportion of catch is also smoked on drum kilns and mass scorching sometimes results. Only small quantities of catch are smoked at a time, with the result that large quantities of the catch spoil before they are processed and preserved.
In this process, the fish is simply washed, gutted and laid out on the sand to dry under the scorching heat of the sun in the arid zones of the Lake Chad area. The practice of sun-drying is limited to the processing of juvenile and undersized fish, which the fisherman and his family usually consume.
The fish is washed and gutted. It is then soaked in concentrated salt solution, left for some time, removed and is either sun-dried or smoked. This product tends to have a longer shelflife.
6. GOVERNMENT ROLE IN ARRESTING POST-HARVEST LOSSES
Recently, having realized the magnitude at the national level of fish post-harvest losses at the fish production centres, and in particular at Lakes Kainji and Chad, the Government took the positive action to establish in a modest way the much-needed infrastructure at strategic locations in the country. The first among the infrastructure to be put in place was the construction of 17 fish combination processing plants.
In the Lake Chad area, a complete plant with ice-making unit was installed at Baga, a site then near the water front, but now the water has receded to about 60 km from the plant, making it useless. There are also problems of mechanical and electrical faults on the plant resulting from the of lack of spare parts due to the effects of the present Government's Structural Adjustment Programme (SAP) and lack of regular subvention to maintain the facilities, and unavailability of trained technical staff to service the plants.
For the Lake Kainji area, the fish processing plant was established at Anfani on the south-eastern shore of the lake near the water front. Like the one at Baga, the plant cannot function due to lack of spare parts. The purposes which these plants were to serve, arresting the fast rate of fish losses, is still to be fully realized. As identified earlier, one of the constraints facing the fishermen is lack of motorized fishing vessels which would allow rapid delivery of catch to the fish market and reduce post-harvest losses. Towards the achievement of this objective, Government has established a programme to review the provision of the existing infrastructure in the fishing communities. These include the construction of modern fish markets at the fishing grounds, and transportation routes.
The “Chorkor” smoking technique is receiving very positive attention from Government. The Chorkor smoking oven, even though modest, can smoke large quantities of fish at a time. Such innovation add impetus to the traditionally existing technology of arresting post-harvest losses.
In the marine and coastal fisheries environment, post-harvest losses are evident in that one can actually see the trash-fish being thrown overboard by the fishermen. Post-harvest losses in the fishing communities are not so obvious. At and near the lakeside and inland, fishing families are known to consume the small sized catches, and even rotten and “putrid” fish. Losses may be minimal under these conditions.
Among some fishing communities, rotten fish has been smoked, made into fish silage and used in various forms of human food. In the light of the above and the present effects of the Government's Structural Adjustment Programme (SAP), losses in practical terms can be regarded as minimal, perhaps 10%. However, profit margins to the fishermen have sharply increased.
It is pertinent to point out here that, when losses are considered, it is with regard to the secondary and tertiary consumers. The fishing families are the primary producers and are therefore not regarded as consumers. In the light of the above, post-harvest losses are estimated to be substantial in the two lake areas.
In the past, all fishing activities have been under the control of traditional fisherfolk. They practised the profession in their traditional life-style and traditional economy. Their fishing craft was made of bamboo or was dug-out canoes, with little space on board, accommodating only one or two fishermen at a time. The catches were therefore small.
Gradually, however, modern technology is being introduced and much of the fishing gear and craft have been modernized, featuring plywood canoes, outboard motors powering the various fishing boats, personnel and landings to their various destinations in good time. These efforts have had positive effects in reducing the high level of post-harvest losses. This trend is expected to continue and with the establishment of refrigeration systems, construction of feeder roads to and from fishing villages, to the consumer centres, and finally the introduction of simple and effective fish smoking methods, the end-product is expected to reach consumers in a better quality.
Nigeria, with the present high demographic growth rate, cannot afford to support large food losses. What already exists in the form of a natural resource in the two lake areas, has to be exploited such that maximum benefit is derived from it, without unnecessary losses. This can only be attained through the use of modern technology.
Azeza, N.I. 1976. Fish handling, processing and marketing in the Lake Chad Basin (North West Shores). Proceedings of the Conference on the handling, processing and marketing of fish, pp 348–52. Tropical Products Institute, UK
Eyo, A.A. 1988. An Appraisal of the Traditional Fish Handling and Processing in Kainji Lake Area, NIFFR New Bussa, Kwara State, Nigeria
Eyo, A.A. and M.D. Awoyemi. 1988. The effect of storage on proximate composition, mycoflora and insect infestation of salted sundried fish from Kainji Lake - Annual Report NIFFR New Bussa, Kwara State, Nigeria. pp. 175–82
FAO. 1977. CIFA Technical Paper No. 5, Symposium on River and Floodplain Fisheries in Africa, Bujumbura, Burundi
Okaeme, A.N. 1986. Flies (Diptera) Infesting Landed Fresh Water Fishes of the Kainji Lake Area, Nigeria. Int. Journal of Zoonotics, 13:49–53.
Okoye, F.O. 1989. Problems and Prospects of Fish Pond Culture around the Kainji Lake Basin - Paper presented at the Conference on 2 Decades of Lake Kainji, New Bussa, Kwara State, Nigeria
Osuji, F.N.C. 1976. The influence of traditional handling methods on the quality of processed fish in Nigeria. pp.319–22 of Proceedings of the Conference on the handling, processing and marketing of tropical Fish organized by Tropical Products Institute, UK
Fig 1. Map of Nigeria showing major existing and proposed water bodies