Conserving the catch!
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CTA. 1987. Conserving the catch! . Spore 7. CTA, Wageningen, The Netherlands.
Permanent link to this item: http://hdl.handle.net/10568/44567
Fishing: Conserving the catch!The seas of the world have enormous potential as sources of food. Despite the development of large-scale fishing enterprises, smallscale fishing activities remain important in most developing countries. Small-scale...
Fishing: Conserving the catch! The seas of the world have enormous potential as sources of food. Despite the development of large-scale fishing enterprises, smallscale fishing activities remain important in most developing countries. Small-scale fisheries have been developed in various ways, for example by improving the techniques and equipment used in traditional canoe fishing; but it has become clear that it is often preferable for governments to intervene at other points in the chain of events that linkc the fisherman to the consumer. More attention needs to be paid to developing improved methods of preserving and processing so as to waste less fish; increasing the catch need not always be the first objective. Sea fishing is a major trading activity in the ACP countries, where it provides hundreds of thousands of jobs and plays a significant part in feeding millions of people. On the West African coast over a million tonnes of fish are landed each year, providing on the average between 5.5 and 8.4 kg of fish per inhabitant annually. Yet the amount of fish on the market is not sufficient to meet demand, in spite of the fact that the seas around West Africa are among the most plentifully stocked in the world. Because of this shortfall in supply nearly half the needs of the local population are met by imported fish products and from fish landed by foreign fishing fleets operating on an industrial scale. These huge imports and the consequent currency losses can be avoided. There are considerable possibilities for increasing the amount of fish available in the region: at a conservative estimate, present losses amount to 192,000 tonnes per year, if one includes fish from a secondary catches which are not used; this is the equivalent of 20 % of the fish caught by small-scale fisherman . Increased production was, for many years, the aim of development projects for fisheries, especially in West Africa. The success of these projects proved to be limited, since they required large capital investments and involved the reorganization of social structures in the fishing communities. It is now clear that much more significant results can be achieved by making better use of existing fisheries; this can be done mainly by utilizing fish which trawler owners usually throw away, by encouraging consumption of hitherto neglected species and by improving methods of storing, processing and marketing the fish caught by traditional fishermen. Experience shows that more rapid and more enduring progress comes from improving traditional techniques than from introducing completely new methods. Improvements could be made by putting to use fish rejected from trawler catches. Large boats catch a variety of fish in their nets, but only keep those which can get the best prices; the rest are thrown away. It is difficult to obtain statistics, but the total amount of fish thrown away annually in the Gulf of Guinea alone could be 35,000 tonnes. In Senegal, trawlers are estimated to throw away 30 % to 40 % of the fish they catch. In other parts of the world especially Latin America, such a waste >> from industrial-scale trawling is put to good use. In general, and particularly in Africa, it is mainly technical and economic constraints which hinder more extensive use of these wasted fish. The canoes used by small-scale fishermen could transport these fish, provided they were fitted with simple equipment making it possible to handle the fish cheaply. Other solutions could be found by breaking down market barriers, provided that new technical and commercial measures were to be introduced at the same time. Industrialscale fishing on the Cote d'lvoire, for example, makes no use of one particular species which is caught in large quantities: the triggerfish is not much to the liking of consumers in the Cote d'lvoire, but it could find buyers in Ghana or Nigeria, where eating habits are different. There are much more significant limitations to increasing supply on the markets than those resulting from restricted fishing capacity or from the non-use of some species: these are the limitations imposed by the way the fish is handled, presented and processed. Take the case of pelagic and bottom-dwelling fish, which tend to be caught in large quantities over a short period; small and fragile, these fish have to be processed rapidly. Development programmes introduced over ten years ago concentrated on modernizing techniques (synthetic fibre nets, revolving seine nets and motorized canoes). The thinking nowadays is that before providing fishermen with the means of catching more fish it is essential to discourage them from wasting existing catches. These tend to rot quickly once they are exposed to the heat and humidity of the beaches where they are landed. Even more than in agriculture, where there is also much wastage after harvesting, limiting waste after the fish are caught is a promising approach to increasing food availability, with the twofold advantage of preserving marine stocks and of limiting the amount of work for the fishermen. For the West African coast alone, losses from small-scale fishing are estimated at 20 % = 156,000 tonnes out of a total production of 783,000 tonnes. There are two methods of reducing these losses: by keeping the fish fresh or by processing it in such a way as to slow down or stop deterioration. Small-scale fishermen already use both methods, as far as they can. But techniques which are already applicable or are currently being developed could in many cases enable them to significantly reduce these losses. Keeping fish fresh with cold water and ice is the best method preferred by consumers, but the absence of adequate financing and technology is an obstacle to setting up proper cold storage and transport systems. This would require containers suitable for canoes, ice- producing units on the fishing beaches and insulated containers, in addition to modifications at landing-points and markets. Ice units have been installed in some of the larger fishing centres. But ice remains a costly luxury, beyond the means of most fishermen. When ice is not available in sufficient quantities, fish can be kept fresh in a mixture of seawater and ice or by compacting ice-flakes made from seawater. Although these intermediate methods are not yet widely used, they provide savings in fresh water use and are easy to handle and store on board which could encourage their adaptation in the Deep-freezing would of course be ideal for long-term preservation of the pelagic fish found along the coast, but this technology is well beyond the means of small-scale fishermen, even if they organize themselves into cooperatives. Because of the absence of adequate infrastructure for cold-storage, traditional processing methods are widely used. Many of these techniques are inadequate, in terms of both productivity and quality: estimates for waste resulting from the primitive nature of the equipment used vary from 30 % to 50 %. Salting, smoking and drying are traditional techniques, yet there is scope for innovation even here, provided this carries with it prospects of profitable outlets in the short term and of an improvement in the working conditions of those who do the processing, who are essentially women. Tropical sunshine is largely responsible for the rapid deterioration of fresh fish, but its heat is also used as a preserving agent by means of drying techniques perfected by the fishermen. However, even with precautions such as gutting and opening the fish, traditional sun drying has a number of disadvantayes. Fish are generally placed on grids, in conditions of inadequate hygiene and with inadequate air circulation: insects feed on them, they ferment and go bad. If air circulation is increased, the fish dry more quickly: for this reason, the grids should be carefully placed in the windiest spots available, usually at the edge of the beach. Salting is also used for preserving fish, although less extensively. Improved methods, such as salting in brine, can make better use of the salt by increasing penetration into the fish without making them any less palatable to the consumer. Moreover, efforts to improve the hygienic quality of the brine can prevent certain bacteria developing and can limit the extent to which fats turn rancid. Finally, a combination of salting and drying provides an efficient method for reducing waste caused by insects, especially where the aim is to reduce the use of dangerous pesticides applied directly to the fish. The insects which attack fresh fish are mainly flies and beetles, which can account for losses of 30% in processed fish after a few weeks in storage. Some traditional methods (using pepper or powdered dry leaves) are used, but they do not really provide the answer. Specific insecticides exist, but they are expensive and should be used cautiously. For example, Gardona or Malathion can be recommended for use in places where the processing is carried out or on the straw mats in which the fish is wrapped for transport. In West Africa this technique has made it possible to reduce this type of wastage from 42 % to 8 %. Finally, another method of fish processing is hot smoking. Here, traditional techniques are generally inefficient and of limited capacity, providing products of poor commercial quality. Significant improvements can be obtained if the fish is specially treated before smoking: presalting, or a combination of predrying and pre-salting, makes the fish less fragile and reduces the risk of them disintegrating during handling and transport. Improvements in the equipment used for smoking can also be beneficial: improved traditional ovens (see sketch) could help to limit deforestation by reducing wood consumption to a fifth or seventh of that required for traditional ovens. For fishermen, the advantage is that much better temperature control is possible with these ovens, thereby preventing crusts from forming or the fish from disintegrating. There are some difficulties in matching these ovens to local habits. The solution could well lie somewhere between the traditional ovens and the improved ovens which have been proposed to date. Such possibilities are at present being examined, in particular mobile ovens which would be of great use to migrant seasonal fishermen. There is no point in increasing fish catches from canoes unless the means of preserving them are available, and it is also pointless to stock fish on beaches because the equipment and infrastructure needed for marketing them are non-existent. Marketing of fish caught by traditional methods follows a set of rules which are often very ancient and is carried out by way of people and circuits which often oppose changes for fear of losing the advantages the system brings them. Many programmes aimed at modernizing canoe fishing have failed because of this. As for the fishermen themselves, with their highly organized compartmentalized and hierarchical society, they will only accept technical innovations if these do not violate traditional rules and oractices. Traditional small-scale fishing is complex and no doubt brings with it many difficulties for countries wanting to turn it into a profitable agent of national economic development. However, from the sea to the consumer's plate, the entire sequence has to be taken into account and we now know that for fishing, even more than for any other rural activity, new technology alone cannot provide the answer. BIBLIOGRAPHY: Fish handling. preservation and recycling in tropical climates. 2 vol TDRi. London Evaluation of fish wastage in west-Africa. TDRi (London). CEASM (Paris), 1986, 92 p. Small-scale processing of fish ~ Technology Series, Technical Memorandum No3. Internabonal Labour Office, CH 1211 Geneva 22, 1982 109 p