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Geoffrey R. Ames
Natural Resources Institute
Chatham, UK


Post-harvest technology serves to make fishery products available at the place, at the time and in the form required. Traditional technologies though often causing losses and not satisfying all the wishes of the consumer nevertheless involve little cost, utilize locally available material and are fully familiar to those involved. They are in harmony with the physical, cultural and economic environment. To be successful proposed improvements must be acceptable to producers, traders and consumers. To only propose a new technology is not sufficient if the technology is not known. Therefore new technology must be demonstrated and adapted to the point that the advantages are clearly seen by all. Most new technologies involve an increase in the level of investments, hence of the price of the final product. As a result, there will be a segmentation of the market in the sense that supply of better quality products, in particular fresh fish, will increase to the higher income groups in urban centres. Incomes in the fish production and marketing chain will increase, but supplies to lower income groups, in particular at rural levels, may suffer. These groups benefit from technologies that reduce post-harvest losses without increasing product cost, such as the application of approved pesticides on cured fish. Conditions or actions facilitating the adoption of new technologies include training, demonstration, applied research, consumer research, market research, infrastructure (roads, ice, chilled or frozen storage, communications) and credit.


Les technologies après la capture du poisson servent à rendre disponibles les produits de la pêche à l'endroit, au moment et dans la forme désirée. Les technologies traditionnelles, bien que causant souvent des pertes et ne satisfaisant pas tous les désirs des consommateurs (elles sont néanmoins des coût peu élevé) utilisent des matériaux disponibles sur place, et sont maîtrisées par les artisans. Elles sont en harmonie avec l'environnement physique, culturel et économique. Pour avoir du succès les améliorations proposées doivent être acceptables pour les producteurs, commerçants et consommateurs. La seule proposition d'une nouvelle technologie n'est pas suffisante si les gens ne la connaissent pas. Il faut en démontrer l'utilité et l'adapter aux besoins du milieu. Elle doit être démontrée et adaptée jusqu'au point ou les avantages sont évidents. La plus grande partie des nouvelles technologies implique une augmentation du niveau des investissements, donc une augmentation du prix du produit. Par conséquent, il y a une segmentation du marché: l'approvisionnement de produits de meilleure qualité, surtout du poisson frais, augmente au niveau des consommateurs plus aisés, surtout dans les centres urbains. Les revenus dans la filière augmentent alors, mais l'approvisionne-ment aux consommateurs moins aisés, surtout dans le monde rural, peut en souffrir. Ces groupes bénéficient de technologies qui permettent de réduire les pertes sans augmenter le coût du produit, comme par exemple dans le cas de l'application d'insecticides approuvées. Les conditions et actions qui encouragent l'adoption de nouvelles technologies comprennent: la formation, la démonstration, la recherche appliquée, la recherche du marché et des consommateurs, l'amélioration de l'infrastructure (froid, réseaux de transport et de communications) et le crédit.


In modern times, the idea that “Tomorrow can be different; tomorrow can be better” has become widespread.

Fishing communities in developing countries are generally extremely under-privileged. Fish produced by them often represents a vital component of the food supply. This is especially the case for many low-income groups in urban and rural areas, for whom fish is the only available animal protein, and particularly in Africa, where so much of the fish production is converted into traditional types of cured fish. Fishing communities, and those who depend heavily on fish, are definitely among those who need help to make tomorrow better. However, it is much easier to identify what ought to be improved than to achieve real and lasting improvement. This paper describes some of the problems involved in post-harvest operations. Much of what follows is obvious, and basically common sense, but unfortunately all too often a key issue has been overlooked, and attempts to help fishing communities have achieved much less than expected.


A basic issue at the outset: why do we need technology? If fishermen can sell their fish, in the natural wet form, to consumers within a few hours of catching, little post-harvest technology is needed. However, this is seldom the case, and nearly always fish has to be preserved in some way - iced, frozen or cured - so that it can be conveyed to the consumer in distant places. The call for new technology arises from the financial and material post-harvest losses and related problems, which are reviewed elsewhere in this symposium.


One attractive way to help fishing communities is to improve the technology they use by introducing new or better ways of processing, handling, and packing fish. The traditional ways are often inefficient, involving substantial post-harvest losses in terms of mould, fragmentation, infestation by blowflies and beetles, loss of quality by charring, etc. All these aspects can be improved; in experimental trials these losses can all be reduced greatly. However, having the improved technology adopted and used widely is not as easy so countless unsuccessful projects have shown.

It is recognized that traditional technology may not be as efficient as modern, but it meets other important requirements: it is cheap, uses locally available materials, craftsmen are familiar with the construction or manufacturing methods, operators know how to use it, and it fits in with the way people live and work. It does not necessarily date far back: 44 gallon oil drums cannot have been used for fish smoking in West Africa for that many years (perhaps a century?), but evidently they were an improvement on earlier fish smoking equipment, and clearly they met other criteria.

The adoption, whenever it was, of oil drums for fish smoking is a useful example of the introduction of improved technology. First, fish processors or enterprising individuals saw a need to improve on earlier smokers, and their neighbours saw the advantages. It is likely that all fish processors needed to improve their technology, in that the use of oil drums was easier and/or more efficient. They also wanted a general improvement.

In seeking to introduce technological improvements in fish production, every possible effort is made to meet the basic criteria: any “improvements” must respond not only to the needs but also the desires of the people concerned. Fishermen, fish processors, fish traders and fish consumers must want improvements, and those improvements must meet their wishes. The improvements have to be economically worthwhile, either from the outset or in reasonable time if interim financial support can be provided to start the progress. They have to conform to local habits and customs, although people will adapt to some extent if they see clear economic advantages in doing so. The improved technology has to be able to operate and continue to operate in the relevant society and environment, with the human and material resources available. This is not easy to achieve, but the issues have to be addressed to avoid adding to the long list of “good ideas” which vanished into the sands of time.


This is one of the key issues but it is not a simple matter. We all have “wants” which are vague, and which we know are often incompatible: “more money for less work” for example. Most of us realize that these are more dreams than “wants” and we have to be far more specific when considering technological improvements. If we think of the customer's wants in simple terms like “more money”, we are in danger of adding to the list of “good ideas”.

One difficulty is that the customer's “wants” in terms of technology depend on him/her knowing about the technology. Fishermen have not been sitting on beaches since time immemorial saying to one another, “I want a synthetic fibre fishing net”. However, the speed with which these lines and nets were adopted throughout the world shows that once fishermen knew about them, they did want them.

This example also illustrates another aspect: the new technology has to be developed to the point where its advantages are evident: the general idea is not enough. New technology may need to wait while users become accustomed to it. Zip fasteners and ballpoint pens are examples: both were invented a long time before they became so widely accepted.

Thus people need to know about the possible technology before they are likely to want it. Establishing a need for a technological improvement is not just a matter of asking fishermen or fish processors what they “want” and then inventing something to fit. Finding out what they want has to go along with the development of the technology. We need to find out as clearly as possible what their problems are and then try resolving them. If it seems promising, then we can demonstrate it to fishing communities and see their reaction. That does not mean simply asking for comments, as they are usually polite, rather than candid. We need to convince fish processors or traders to try out the new technology themselves - not only when we are there. If they continue to use it after we have left, it is encouraging, but the real test is whether neighbours take up the idea or techniques themselves. If they do, we may have found an improvement which really fits their needs, their wants, their situation, and the way they live.


So far the term customer has been used to denote the group of people at which a technological improvement project is aimed: the fishermen, and the fish processors, distributors, or traders. Equally as important is the group the fish is provided for: the consumer.

Consumers have very strong views about food. That if people are hungry they will eat anything is true only when they are starving. Otherwise, people do not want nutrients: they prefer food, or rather what they recognize as food. Any efforts made to improve or increase fish production have to be linked to what the consumer wants, and is prepared to pay for. In most countries, consumers are prepared to pay higher prices for better quality fish. In others, this does not happen: fish which is partly spoiled, or even nearly putrid, sells at the same price as fish in prime condition. Under such circumstances, there is no return for money spent on, say, improved containers or ice, to improve quality.

Some types of fish are always preferred to others. In Egypt, for example, mullet and tilapia are much preferred to carp. The reasons for such preferences vary. Sometimes there is a sound basis in terms of flavour, for example where less favoured species are prone to muddy flavour. In other cases the appearance of the whole fish may or may not appeal to prospective purchasers. In Australia fish markets find that any red species sells easily. It may be a matter of the name: in Britain dogfish are sold under the name “rock salmon”.

An important consideration is that consumers may take time to accept a new species. When tilapia were first produced from Lake Nasser, they were not readily accepted. A spectacular example is that of Nile perch in the Lake Victoria region. When the species first reached the Kenyan part of the Lake, it was unpopular, and Kenyan fishermen would exchange any Nile perch they caught for tilapia caught by their Uganda colleagues. An FAO consultancy was carried out in 1984 to consider ways of utilizing Nile perch (Cole 1984); the problem then was what to do with these fish. Suddenly, by 1987, there was an unsatisfied demand for the fish as food in Kenya and Tanzania (Rogers et al., 1988, 1990).

This raises again the issue of what people want. Consumers generally need to have access to and know about a product, before there is a sustained demand. In Kenya many landing sites have ice, and Nile perch can be sent to distant markets in its natural wet form. In Tanzania most of the perch can be distributed only when preserved by smoking. This changed when a consumer market for the smoked fish developed, and smoking kilns were set up; these two events had to happen together.

A curious feature of fisheries development in recent years has been the great expansion of aquaculture in Asia and its very limited use in Africa. The reasons for this are not relevant here, but one issue is noteworthy. It cannot be assumed that fish species which could be produced by aquaculture will necessarily be acceptable to consumers in the relevant area. They may not, at least for a time.

The reputation that a product has is very important. In most parts of the world, consumers accept and believe that iced fish is fresher than un-iced fish. However, there are some places where iced fish is regarded as inferior to un-iced. This happens when fish is usually sold immediately after catching, while still in good condition; however, if a market trader has some fish left unsold at the end of the day, he or she put it in ice to sell next day. Under these circumstances, un-iced fish is today's fresh; iced is yesterday's and stale.

When a new product is being supplied, it is vital that a good reputation is established at the outset. On one island freezer facilities were set up to store surplus fish in periods of glut. In practice, what was frozen was the unsold surplus, generally of lower quality as buyers had inevitably already selected the better fish. Thus the frozen fish was of poor quality and unattractive when it was released later, and it became generally accepted that “frozen fish is of poor quality”. Once such views became prevalent, is not easy to overcome them.

The appearance of a new product may be very important. When tilapia was introduced to Jamaica, people were not used to freshwater fish, and they were reluctant to buy it. This response was partly due to the fact that the variety introduced first was very dark in colour and unattractive (de Boer, 1988). Later silver grey and pinkish varieties had a better response.


Environmental aspects of any new technology must be considered. They could be beneficial or harmful, according to circumstances. Traditional technology may be harmful, for example if smoking methods use unnecessarily large amounts of fuel, thereby aggravating deforestation and soil erosion. The use of inappropriate pesticides, not suitable for use on any food product, may have been adopted by fish processors in order to control insect losses. In such cases the use of fuel efficient smoking kilns or more suitable insecticides could relieve the environmental problems. Equally, we need to consider carefully the environmental implications of the new technology we are developing.


In seeking to improve and increase fisheries production, we usually have two objectives: increasing the income of fishing communities and increasing the supply of low-cost food for the population. To some extent, these objectives are conflicting. If the food produced is low-cost, there is less scope for increasing the income of fishing communities. This applies particularly to cured fish, so important in inland Africa, and which provides a major food for low-income groups. The latter have little chance of paying the fishing communities more for their production, even if they wish. What can be achieved here is to increase the quantity of fish available for sale, without increasing the price, by reducing post-harvest losses of material. Prevention of insect infestation by the use of safe insecticides should greatly increase the quantity of fish reaching the consumer, and as the costs involved are low, there should be an increase in income to the production and marketing chain of fisherman, processor, distributor, and trader. (How any increase is shared between these groups is outside the scope of this review.) Again, more careful handling of the fish (if this can be achieved cheaply) and more careful processing should reduce losses due to fragmentation and increase the quantity available for sale, without a cost increase.

In most cases improved technology in fish handling and processing will involve some increase in costs, compared with traditional methods. As far as the fishermen and fish processors are concerned, this will not be a disadvantage, provided the value of the product increases by more than the costs incurred. However, it may mean that product will now go to a consumer at a different income level. Improved handling methods, or the use of ice, may improve the quality of wet fish being marketed, and its commercial value. The improved product may be welcomed by consumers who are able to pay the higher prices, but it may put it beyond the reach of low-income groups.

These factors are illustrated by the contrasts in the production of Nile perch in Kenya and Tanzania. In Tanzania most of the landing sites are inaccessible, and a few have ice; the catch can only be sold in a preserved form, smoked or cooked. In Kenya, ice is available at many of the landing sites, and the fish can be sent in ice to the cities or for export, supplying very different markets from those in Tanzania. The transport of iced fish from Lake Turkana to Nairobi is another example.

This change is likely to occur whenever it becomes possible to market wet fish rather than cured products. It is happening in other parts of Africa, and elsewhere. For example in India, over the last 10–15 years a substantial trade has developed in iced fish which is sent long distances by rail or road to the major cities; presumably this fish is sold to the growing middle class and clearly some financial benefit returns to the artisanal fishery. Increasingly, fisheries production is being oriented towards urban rather than rural communities.

It is beyond the scope of this review to consider whether fishermen and fish processors ought to be encouraged to seek more profitable markets, or discouraged, so as to maintain the supply of cheap cured fish for low income groups. However, even if the latter was the intention, fishing communities are likely to pursue the better markets if and when they can.


In addition to the general issues concerning new technology, specific problems need to be considered. One is that people using traditional technology know from previous experience the key features of their equipment. With new technology, they may be unaware of essential aspects. An example of this arose when Chorkor kilns were introduced into Togo (UNIFEM, 1988). When the women processors built the kilns themselves, or hired untrained artisans to do so, they did not appreciate the need to have the trays fitting closely onto the smoker. The components did not match, so that there were holes through which smoke escaped, increasing fuel consumption, and trays caught fire.

A major factor is that new technology may need a suitable infrastructure. Freezer chains and stores have been set up in many African countries, but they need skilled maintenance engineers and supplies of imported spare parts; these have not always been available. Increasingly, food handling equipment is designed for countries with a high level of technology, and it may not be as effective under more difficult conditions. Freezer lorries have great advantages for long-distance transport of higher value species, but they are not always built strongly enough to withstand the dirt roads of Africa.

Even in laboratory work (which may be needed to support a project), problems can arise. It is now difficult to find a balance which does not depend on electricity; if the power fails, even the simplest laboratory work must stop.

Allowance must always be made for “gender issues”, such as the tasks which in particular societies are undertaken specifically by one sex. A non-fisheries example was that at one time a lot of effort was put into using the motive power of a bicycle to mechanize various rural and domestic tasks such as grinding corn. It was overlooked that in the target countries women grind corn but only men ride bicycles. In the fisheries context, one of the difficulties with the Altona oven (Kotnik, 1982) was that the trays were too heavy and too high for women to lift. This was just one of the social factors which emerged during the attempts to introduce the Altona oven in Sierra Leone (Beck and During, 1986).

In fisheries production there are usually various groups of people who have an established position, and due allowance has to be made for their role and influence. Traders and middlemen are often criticized but not necessarily resented by the fishermen and processors (Lawson, 1976). When the introduction of mechanized vessels was first attempted in Ghana in the 1950s, fishermen and traders combined to prevent landings (Lawson, 1967). An example quoted by James (1988) was that of the installation of ice crushing equipment in a fish market in Asia, which was strongly resisted by the labourers who broke up ice by hand.

The seasonality of fisheries may present problems. In Ghana, the main fishing season on Lake Volta is when marine catches are at their peak; as fish prices are low, processors on the lake can afford to use only very cheap, simple kilns (Mensah, 1988). The quantities of fish to be processed at particular times and in different places, influence the acceptability of new equipment. This has been a major factor affecting the adoption of the Chorkor kiln (Wentholt, 1988).


Reference has already been made to many of the difficulties which have confronted attempts to introduce new technology in fisheries production in developing countries. To summarize, traditional technology is well proven, relevant to the prevailing conditions and social customs; it uses locally available materials, at low or sometimes zero cost; it gives products which are wanted and the quality of which is accepted or at least tolerated. Any new technology must be seen to overcome problems which are recognized by those concerned and/or offer tangible economic advantages without significant disadvantages in other respects.

If a new idea seems relevant to a recognized need or want, pilot scale trials must be performed to ensure that it functions, and to have a clear view of all the implications and side-effects. Then the fishing communities must be involved to ensure that the new technology does not need highly specialized scientists or engineers to operate it, and to clarify all the other issues discussed above. If all goes well, we shall have an improved method or equipment which really fits the local requirements.

Then we need to apply the improved technology in the relevant area. This implies an extension and training programme. Theoretically, an extension programme should not be necessary. If a new method is good, profitable and relevant to customs and attitudes, people ought to adopt it of their own accord. A simple demonstration should initiate the spontaneous spread of the idea. As other people in the same village and the next village see the new system and its advantages, they should try it out. This will probably be the case but only at a very slow rate.

If there are serious post-harvest losses or a serious operational problem, it would be ill-advised to wait for the new technology to disseminate itself. We need to demonstrate the new technology in as many areas as possible, at the village level, to make people aware of its potential and advantages. We may need to provide advice on building equipment, and train people to use it. Publicity material, such as leaflets and posters, in the local language and perhaps radio broadcasts, may help; a regular extension programme, in fact.

The cost of new equipment could be a constraint. If the advantages of the new technology are as good as we believe, and if using it will bring tangible economic benefits sufficient to cover the costs in a reasonable time, there is no reason why the operations should not pay for the equipment. It is widely argued that people will appreciate new equipment more if they have to pay for it than if it is simply provided by some remote agency. However, it is unrealistic to expect poor people to spend money on equipment which is new and unfamiliar, and of which the advances are not completely proved. Banks are sometimes reluctant to lend to fisherfolk, and credit has been another factor limiting the uptake of the Chorkor kiln (Osei-Opare and Tachie, 1988). A middle way is needed, and this can usually take the form of a special loan, repayable as the returns from the new technology accrue. As loans are repaid, the funds can be used to help other operators to install the equipment. The finance needed for these loans will usually be from public funds, either from a national ministry or agency, or an aid donor. In practice, operating these schemes involves many problems, as a recent collection of case studies shows (FAO, 1989).

In some cases, plans to introduce new technology for fisheries production may depend on public finance for infrastructure, such as electricity supply or all-weather roads. It is unusual that such facilities are built solely to improve post-harvest handling or processing of fish. In such cases, the new technology may have to wait until other factors combine to bring about the infrastructure development.


Within these limitations, there is still a great need for research. Traditional technology leads to serious post-harvest losses; it often involves much heavy labour; it is often wasteful of resources which are becoming increasingly limited. Improved containers, smokers and drying equipment are all needed, in a range of sizes suitable for the quantities of fish in particular places. Improved packaging materials are required, as are safe means of controlling insect infestation. All these need to be at a sufficiently low cost to meet the limited financial resources. However, research on the technology itself needs to be done in conjunction with research on the specific nature of the problems and the requirements of the people who, hopefully, are going to use it. Much can be learned from previous work: the reason why people did not adopt some other equipment may show clearly what is needed.


Traditional technology for fish handling and processing is generally relevant to local conditions and attitudes, and economically effective, although it frequently involves substantial losses. New technology can reduce these losses and increase profitability, provided it meets the requirements of all those involved in processing, marketing and distribution. Low-income consumers will benefit if losses of material can be reduced and more food made available without increasing the market price of the commodity. Fishing communities will benefit if new technology enables them to produce better quality products and/or supply more distant markets. Cases of new technology which did not meet all the requirements should help us to direct new projects better in future.


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