Aquaculture development is making significant strides in many countries, and it is estimated that the present world production of about 5 million metric tons could be increased at least five to ten times by the end of this century if the industry is given adequate scientific and organizational support.
Although fish culture is believed to have existed in Egypt, as early as 2 500 B.C., it has not been a traditional activity in the African continent in general. Production of trout in ponds, mostly for sport fishing purposes, commenced following their introduction between the two world wars; warm-water pond fish culture, mainly with Tilapia spp., was introduced and developed between 1950 and 1960 to improve the nutrition of rural populations. Initial development consisted mainly of subsistence level fish culture operations undertaken by farmers on a part-time basis. The developments that occurred during this period are partly described in the Proceedings of the Anglo-Belgian Fisheries Conference held in Elizabethville (now Lubumbashi, Zaïre) in 1949 and the fisheries symposia held later under the auspices of the Commission for Technical Cooperation in Africa South of the Sahara through its Scientific Council. These symposia were held in Entebbe, Uganda in 1952, in Brazzaville, Congo in 1956 and in Lusaka, Zambia in 1960.
Recently, there has been a resurgence of interest in furthering the development of this industry in Africa based on a growing realization that both freshwater and coastal aquaculture, under good technical management and adequate government support and initiative, could add considerably to the total production of fish and shellfish. Efforts are now being made by many fishery administrations in Africa to reorient their programmes to upgrade aquaculture, and development activities have been initiated in this sector in a number of countries. The results of recent production tests, in freshwater ponds, with improved techniques, and the prospects of large-scale brackishwater aquaculture have greatly contributed to this interest.
The FAO Committee for Inland Fisheries of Africa (CIFA) at its First Session in Fort Lamy, Chad, 29 November to 5 December 1972, expressed strong interest in furthering the development of aquaculture in the region and, inter alia, recommended (Recommendation CIFA/72/8) the holding of a symposium on the subject in conjunction with Second Session of the Committee.
The Government of Ghana very kindly offered its hospitality to the Symposium and, through its Department of Fisheries, Ministry of Agriculture, gave its full support in making the necessary arrangements.
The objectives of the Symposium were to:
review the present status and potential for the development of aquaculture in fresh, brackish and marine environments in Africa;
determine the major constraints to aquaculture development, including planning and organization , financing, scientific research, technical support, education and training, extension services, aquacultural inputs, marketing, economics, water pollution and related factors;
evalute, on the basis of existing information, the efficiency of currently cultivated species and the culture techniques employed;
recommend national and regional activities to be undertaken for the rational development of aquaculture.
The prospectus for the Symposium was widely distributed to CIFA member countries, other African countries and selected workers with recent experience in aquaculture research and development in the region. The Technical Secretariat of the Department of Fisheries, FAO, requested selected scientists, national institutions and agencies to prepare advance documentation to cover as much as possible the chief objectives of the Symposium.
The documents which formed the basis for Symposium discussions were grouped as follows:
Country statements - reviews of the status of aquaculture and potential for development in each participating country, prepared by the government agency concerned according to a recommended format.
Review papers - critical analyses of existing information on selected topics, indicating gaps in knowledge and recommending future lines of work.
Experience papers - contributions by volunteering workers on specific research and development activities relating to the identified Symposium objectives.
The Symposium was held at the Kwame Nkrumah Conference Centre in Accra, Ghana, 30 September – 2 October 1975, immediately preceding the Second Session of CIFA, 3–7 October 1975. It was attended by seventy-two participants from 24 countries and six international organizations (Appendix A).
At the opening session, Mr. J.N.N. Adjetey, Director of Fisheries, Department of Fisheries, Ministry of Agriculture, Ghana, welcomed the participants (Appendix B). He was followed by Mr. C.H. Clay, representative of the FAO Director-General and Assistant Director-General (Fisheries) (Appendix C). Mr. Clay reviewed the events and recommendations which lead to convening the Symposium and stressed the growing world-wide interest in expediting the development of aquaculture and the need to integrate such development with overall national economic development plans. In his concluding remarks he announced the names of the Chairman and Vice-Chairman of the Symposium. The opening session was concluded with an address by the Chairman of the Symposium, Mr. B.F. Dada, Acting Director, Federal Department of Fisheries, Nigeria (Appendix D).
The provisional agenda (Appendix E) was approved and there was a brief discussion of the working arrangements for the technical sessions of the Symposium.
The Symposium was organized into six sections which were discussed in consecutive sessions. Each section had a Moderator and a Rapporteur; whenever a section had to be sub-divided, to ensure adequate coverage of specific topics, several moderators and rapporteurs were appointed (Appendix F). All the technical sections were discussed in plenary. The moderators presented their reports and recommendations, based on the documents submitted to the Symposium (Appendix G), for discussion in plenary. The recommendations of the Symposium were prepared on the basis of the conclusions of the five technical sessions and approved in a special plenary meeting convened for this purpose.
Moderator: Z.H. Shehadeh
Rapporteur: W.Q-B. West
Documentation
CIFA/75/SC 1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19
CIFA/75/SR 3
CIFA/75/SE 6,16,18,19
Aquaculture is not a traditional activity in Africa and its introduction and establishment in the continent, during the past 25 years, has been a major achievement.
The practice has had two basic objectives: the stocking of natural waters and improvement of the nutrition of rural populations. Its development has so far been mostly restricted to freshwater pond-fish culture. It is practised, by and large, on subsistence level and managed as a part-time occupation of farmers; private commercial enterprises have not developed to any significant extent.
There is a lack of basic information on areas under culture, total production from aquaculture and potential areas suitable for future development in the continent. Due to the part-time labour input in subsistence farming, it is also difficult to estimate present employment levels; the labour-intensive nature of the practice, however, is evident in Nigeria where about half a million people are involved in one phase of aquaculture or another.
Brackishwater aquaculture is still in the initial stages of development; at present, significant production through culture is limited to a few species of molluscs and finfish in a few countries. Government interest in this sector seems to be increasing, however, and this trend is expected to continue if rational development is ensured.
Recently, there has been a revival of interest in the further development of this industry and the upgrading and intensification of culture techniques. The results of recent production tests and improved culture techniques in freshwater ponds and the prospects of large-scale brackishwater aquaculture have greatly contributed to this interest.
Production rates ranging between 1.5 and 5 t/ha/yr have been obtained with imporved culture techniques of tilapia. In addition, combined culture of fish and pigs, or ducks and fish culture in rice fields have been demonstrated to hold major promise in Africa.
Discussions centred mostly on the high cost of pond construction and the inadequate supply of seed, in the case of some species, as major constraints to the expansion of the industry. It was suggested that costs could be reduced by the purchase, rather than rental, of heavy machinery, integration of pond excavation with other rural construction activities and through communal labour.
It was also agreed that significant near-term returns with relatively low capital investment could be achieved through extensive fish culture in flood plains, and through joint planning of water use in irrigation schemes, sewage treatment facilities and multipurpose use of reservoirs.
Adequate supplies of stocking material can be ensured by increased production from nurseries through adaptation of available techniques to local conditions, by exclusion of predators and the establishment of a specialized private seed trade.
Aquaculture development prospects in the immediate future in most countries will probably be restricted to small-scale fish farming integrated with rural development. Large-scale production schemes, using techniques developed in the region are, however, possible especially if governments take the initiative in starting such ventures.
The basic requirements for the orderly development of aquaculture, summarized during discussions, include (i) clear-cut development planning based on feasibility studies and a clear concept of goals and required inputs, (ii) the development of trained technical cadres of all grades and the establishment or expansion of extension services, (iii) the collection and dissemination of information, (iv) provision of incentives to the private sector to encourage commercial development, (v) the increased production of stocking material and (vi) intensification of research on species proven to have potential for culture.
| Moderators for the three subsections: | 1 | Fish: O. Lessent | ||
| 2 | Shellfish: M.A. Afinowie | |||
| 3 | Introductions: T.T. George | |||
| Rapporteurs: | 1 and 2: | S. Sivalingam | ||
| 3: | D. Chaytor | |||
Documentation
CIFA/75/SC 5
CIFA/75/SR 1,2,7,8,10
CIFA/75/SE 8
The tilapias, family Cichlidae, are the mainstay of warm-water pond culture in the region. A large number of species have been tried in pond culture during the past two decades; of these, the main species presently cultivated are:
Tilapia nilotica
T. rendalli (melanopleura)
T. mossambica
T. macrochir
T. galilaea
T. nigra
T. zillii
T. esculenta
The microphagous - omnivorous T. nilotica is the most commonly cultivated species, especially in intensive systems, due to its rapid growth and efficient utilization of both artificial and natural food.
Besides Tilapia spp., other cichlids are often stocked in ponds and/ or rice-fields to control tilapia populations and irradicate snail vectors of bilharzia. These include (for control of tilapia):
Hermichromis fasciatus
Serranochromis robustus
S. thumbergi
and (for control of snails) Haplochromis spp.
Astatoreochromis alluaudii
The prolific breeding of tilapias has necessitated the development of special management techniques aimed particularly at density control. These have included the controlled stocking of predators, culture of all-male stocks, and selective harvesting.
Discussions revolved around the present practicability of tilapia hybrid culture and possible hazards of interbreeding of hybrids with tilapia species in natural waters. It was pointed out that the culture of hybrids is not a wide-spread practice in Africa and has been limited by difficulties encountered in the maintenance of pure parent stocks and adventitious entry into ponds of tilapia species from natural waters. In view of the observed intraspecific variations and frequent confusion in the taxonomy of cichlids, opinion was divided as to the extent of damage that may result from interbreeding.
The carp, Cyprinus carpio (Cyprinidae), which has been widely introduced into the continent, is presently cultivated in many countries including the Arab Republic of Egypt, Malagasy Republic, Nigeria, Lesotho, Uganda, Sudan, United Republic of Cameroon, Ghana and Morocco among others. Its culture in the continent is secondary only to the tilapias. The carp has been, and continues to be, the centre of controversy on the introduction of exotic species.
The mullets (Mugilidae), which are widely distributed along the coasts of the continent, represent an underutilized resource especially in countries with an abundant natural supply of fry. Mullets are presently cultivated both in fresh and brackishwater, in the Arab Republic of Egypt, Tunisia and Nigeria. The major cultivable species include:
Mugil cephalus
M. capito
M. falcipinnis
M. grandisquamis
M. auratus
M. saliens
Trout, salmo gairdneri and S. trutta, (Salmonidae) have mostly been used in stocking of natural waters for sport fishing; their culture as food fish is not widespread. The bass, Micropterus salmoides (Centrarchidae), introduced mainly for sport fishing, is also used to control tilapia populations in ponds.
Recent research has revealed excellent potential for pond culture of some African species not yet utilized for this purpose on a significant scale. These include, notably, Clarias lazera and C. senegalensis (Claridae), Chrysichthys nigrodigitatus and Bagrus docmac (Bagridae) Heterotis niloticus (Osteoglossidae) and Lates niloticus (Centropomidae). Techniques for pond culture of Clarias lazera are in an advanced stage of development but the lack of adequate supply of seed is limiting further development.
Participants agreed that research on the biology and culture of these fishes as well as other indigenous species such as Barbus spp., Labeo spp. should be intensified. It was recognized that inter-institutional co-operation in the region aimed at the exchange of information, experience and personnel would expedite such research.
Documentation
CIFA/75/Sc 4,12
CIFA/75/SE 4,15,17
Limited work has so far been carried out on the cultivation of molluscs and crustaceans; there is consequently, a marked paucity of information on the subject.
A total of ten species of molluscs belonging to four genera are presently cultured to varying extents. These are:
| (Ostreidae) | (Mytilidae) | |
| Crassostrea angulata C. gigas C. gasar C. cucullata Ostrea edulis | Mytilus galloprovincialis M. edulis | |
| (Veneridae) | (Pteriidae) | |
| Venerupis (=Tapes) decussatus | P. margaritifera |
Significant production of mussels, oysters and Venerupis is reported only in Tunisia; the culture of Pinctada spp. is limited to Sudan. Test culture of Crassostrea gigas, C. virginica and Ostrea edulis in Mauritius have been discontinued due to the poor performance of these species under local conditions.
Culture of crustaceans is yet to be developed on a significant scale; Penaeus duorarum (Penaeidae) is cultivated in Nigeria to a limited extent in association with mullets, tilapias and Chrysichthys. Hatchery production of Penaeus kerathurus is in the experimental stage in Tunisia.
Hatchery production of Macrobrachium rosenbergii has been perfected in Mauritius and test production in ponds is underway. Preliminary tests on the rearing of M. macrobrachion and M. vollenhovenii have also been carried out in the Ivory Coast and Liberia.
Although some studies have been carried out on some shellfish, such as Anadara senilis, Crassostrea gasar and Ostrea tulipa, it was noted that there are major gaps in knowledge on the biology of most indigenous species. This information is basic to the identification of cultivable species and the development of techniques for their culture.
Consideration should also be given to gaps in technical knowledge on culture techniques and requirements for trained personnel.
Documentation
CIFA/75/SC 4, 5, 8, 10, 11, 12
CIFA/75/SR 7, 8
CIFA/75/SE 3, 6, 8, 10, 19
According to information from country reports and distributed questionnaires, 32 species of exotic fishes belonging to seven families have been introduced into Africa since 1859.
The great majority of these species was introduced for stocking natural waters; those presently cultured to any measurable extent include:
Cyprinus carpio
Carassius auratus
Tinca tinca
Salmo gairdneri
Micropterus salmoides
Three species of molluscs and two species of crustaceans are also known to have been introduced for culture purposes; these are:
| Crassostrea gigas C. virginica Ostrea edulis | Procambarus clarkii Macrobrachium rosenbergii |
In addition, there has been a great number of transplantations of endemic species within the continent.
The principal reasons motivating introductions were discussed and identified as follows:
the establishment of sport fisheries;
the control of aquatic vegetation;
the control of vectors of human diseases;
to fill what appeared to be unoccupied niches or to replace indigenous species with species of higher market value and/or faster growth rates;
the pond culture of species with established culture techniques that could make use of unutilized niches in ponds, or capable of faster growth than cultivated indigenous species;
the production of all-male interspecific hybrids of Tilapia spp.
Despite what appears to be a recent revival of interest in the introduction of cultivable exotic species, the subject remains a controversial matter. Intensive discussion took place on the advantages and disadvantages of introductions. Objections to introductions were raised on the following basis:
Many introduced species, including carp, gambusia and black bass could be replaced by endemic species that occupy the same niche and are more adapted to local climatic conditions if adequate effort is focused on the study of their biology and culture.
The introduction of exotic species would probably reduce research efforts on cultivable indigenous species.
Ecological damage or displacement of valuable indigenous species cannot be ruled out.
Introductions based solely on the basis of transfer of available technology do not necessarily guarantee successful culture under local conditions.
The danger of introducing diseases and parasites that could spread rapidly under tropical conditions.
Arguments in favour of controlled introductions were based on the following points:
The low probability of the establishment of non-predator exotic species in natural waters in the presence of strong indigenous carnivores as Hydrocyon, Lates, Clarias, Hepsetus, Gymnarchus, etc.
The absence of any deleterious ecological effects resulting from the introduction of carp in the Arab Republic of Egypt, Cameroon, Nigeria and Malagasy Republic.
The benefits to be derived in terms of production from pond culture.
Agreement was, however, reached on the following points:
Rational guidelines for effective legislation on this issue are needed. The collection and analysis of data on the ecological impact of past introductions would be of great value for this purpose.
Indiscriminate introductions should not be sanctioned.
Introductions should not be made to the detriment of research for local substitutes.
Research on the biology and culture of suitable indigenous species should be intensified to obviate, in the long run, the need for introduction of exotic species.
Widespread introduction should be preceded by adaptive research tests under very controlled conditions.
Care should be taken to prevent the introduction of diseases and parasites.
Moderators for the three subsections:
Controlled reproduction and seed production: A. El-Bolock
Stock manipulation, fertilization and feeding practices: J.Q. Miller
Combined culture techniques: M.J. Vincke
| Rapporteurs: | 1. | K.H. Ibrahim |
| 2. | J.B.E. Awachie | |
| 3. | A.G. Coche |
Documentation
CIFA/75/SC 1, 2, 6, 7, 8, 9, 11
CIFA/75/SR 2, 8, 9, 10
CIFA/75/SE 2, 4, 5, 6, 7, 9, 10
The specialized trade which has developed in Asia in connection with fry production (i.e. professional fry collectors and private fry producers) does not exist in Africa. In most countries seed is supplied to farmers from government fry production centres.
Controlled breeding in ponds is practised with goldfish, trout, Bagrus docmac and, to a lesser extent, Lates niloticus, Heterotis niloticus and Clarias lazera. Induced breeding by injection of pituitary glands and hormones is only practised on a small scale with Clarias lazera.
In countries where fry of indigenous cultivated species are abundant in natural waters, this serves as the major source of stocking material. It was stressed that care should be taken in such cases to avoid collection and stocking of fry carrying parasites such as Lernea and Argulus.
In the case of tilapias, juveniles and undersized fish harvested from production ponds are a major source of stocking material for subsequent crops. A major discussion resulted from consideration of the possible anti-selective effects of this practice over a prolonged period of time. The possibility of recommending action for the preservation of a genetic pool for the genus Tilapia was considered.
It was noted however that Tilapia spp. appear to be in a state of rapid evolution in natural waters; furthermore, anti-selective pressure can be avoided by controlled mating of males and females from different strains.
Where culture of molluscs is practised, spat are collected from coastal areas; spat production in hatcheries is not practised in any of the CIFA member countries. An experimental hatchery is planned in Tunisia.
Penaeid post-larvae are collected from coastal waters; hatchery production of Macrobrachium rosenbergii has been perfected in Mauritius and is planned in Malawi.
A major seed-supply problem is reported in the case of carp, in Nigeria and the Malagasy Republic due to low fry production from nurseries. This is reflected in high fry production costs in both countries. An increase in the area of nursery ponds will also be needed in some countries if carp culture is to be expanded.
The culture of Clarias lazera, which has been proven to have excellent potential in extensive and intensive culture and as a predator for control of tilapia populations, is limited by poor survival of post-yolk larvae in outdoor nurseries.
It was agreed that in view of the projected plans for expansion of aquaculture in many countries in the region, it is unlikely that government stations will be able to meet the demand for stocking material. The problem will be especially critical if fish culture in rice fields is expanded, as larger fingerlings will be required for this type of culture. Difficulties will also be encountered in the production of adequate seed of all-male tilapia through visual sexing and/or hybridization.
Urgent action is needed to correct this situation; possible avenues include:
Increasing fry production by adaptation of established intensive techniques.
The control of predators in nurseries.
Expansion of nursery areas where possible.
Establishment of private commercial fry centres, possible through government initiative.
Training of personnel in intensive fry production techniques including induced breeding by hormone injection and controlled incubation of eggs and rearing of larvae.
Documentation
CIFA/75/SC 1, 2, 6, 7, 8, 9, 11, 13
CIFA/75/SR 2, 4, 6
CIFA/75/SE 2, 4, 5, 6, 7, 9, 11
The prolific breeding habits of Tilapia spp. have led to the development of special management techniques aimed particularly at density control.
Discussion of recent results revealed some impressive developments in culture techniques and production rates. Higher production and a greater percentage of marketable tilapia have been obtained by:
Maximizing growth prior to the commencement of breeding through intensive stocking combined with pond fertilization, supplementary feeding or the use of high protein pelleted feeds. Production rates reported ranged from 2–6 t/ha/yr.
Controlled stocking of predators such as Lates niloticus, Clarias spp., Serranochromis spp., Bagrus sp. and Micropterus sp. Production rates of up to 5 t/ha/yr were reported.
Culture of all-male tilapia obtained by both visual sexing and interspecific hybridization. Production rates of 1.5–2 t/ha/yr of 150–200 g fish were reported. This practice is limited to very few countries due to problems related to the adventitious entry of wild tilapias and difficulties in the maintenance of pure lines of parent stocks.
Staggered stocking of mixed age groups with regular harvesting through selective mesh seines. The technique affords maximum use of water as draining would be infrequent.
It was stressed that the production of tilapias with individual weight below 75–100 g is not always a disadvantage since market prejudice against small fish is lacking in many countries. It was also pointed out that undersized fish are used as stocking material and constitute an income.
Phosphate fertilizers have been shown to be the most essential fertilizer for increasing fish production.
Organic manures, especially when combined with inorganic fertilizers are also equally effective. Cost and availability factors often limit the use of both types of fertilizers in many countries. It was pointed out that combined culture of fish and fowl, or pigs, could alleviate this problem in some countries.
The supplemental feeding of fish in Africa has increased in practice during the past few years. Research on feed technology, however, has experienced a slow development; studies on formulation of fish diets have been carried out in Togo, Nigeria, the Central African Republic, the Ivory Coast and the Arab Republic of Egypt with excellent results.
The quantity and quality of by-products used in feed formulation is expected to increase with the further development of agriculture and the use of supplementary feeding and pelleted feeds in fish culture in Africa is expected to increase.
Culture of carp is practised in many countries, notably Nigeria, Uganda, Arab Republic of Egypt, Lesotho and Malagasy Republic. Yields of 2.5 t/ha/yr were reported form the Arab Republic of Egypt with supplementary feeding. Clarias lazera is one of the most promising new species for pond culture in Africa and its wide-spread culture is expected once an adequate supply of seed is assured.
It was also noted that intensive and extensive culture of fish in flood plains, as presently practised in Dahomey, would be an effective means of increasing fish production with low capital investment and should be encouraged, especially in West Africa.
The encouraging results of cage culture of tilapias especially in the Ivory Coast warrant continued research; yields of 50–60 kg/m3 have been obtained with pelleted feed at stocking rates of 20 kg/m3.
Shellfish culture in Africa is still in the early developmental stages; significant production of molluscs is reported only in Tunisia and Sudan. Much research is required on the biology of cultivable endemic species.
In summing up, it was agreed that:
the availability of highly productive culture techniques is not a constraint to aquaculture development in the region;
efforts should be made to ensure immediate application of proven results;
standard data recording procedures should be adopted to assist in economic analysis and improvement of management techniques;
research on formulation of fish feeds from locally available ingredients should be accelerated and the use of pelleted feeds encouraged when economically feasible;
research on the controlled reproduction and nursery techniques for Clarias lazera and Cyprinus carpio should be intensified;
fish culture in floodplains and in cages and enclosures, in lakes and reservoirs, should be encouraged;
efforts should be made to intensify research and development work on culture of fish and shellfish in brackishwaters.
Documentation
CIFA/75/SC 6, 11
CIFA/75/SR 3, 11
CIFA/75/SE 1
Fish culture in rice fields and in combination with pig and duck rearing, presently not too widely practised, has significant potential in Africa.
Despite production tests carried out in seventeen countries, fish culture in rice fields has developed to a significant extent only in the Malagasy Republic. In that country 20 000 ha, from a total of 75 000 ha of irrigated rice fields, are being used for this purpose; fish production in 1973 was estimated at about 252 tons. In the Arab Republic of Egypt, a total fish production of 30 000 t/yr could be obtained if only half the available rice fields were used for this purpose. Production of 112 kg/ha of fish was also demonstrated in Tanzania. The maximum yield so far obtained from well managed rice fields is 250 kg/ha.
The economic viability of the practice has been proven in the Malagasy Republic. In addition, preliminary tests in Egypt demonstrated a 5–7 percent increase in rice production as a result of fish culture. It was pointed out that, in view of the minimal capital investment and low production cost involved, the practice is economically viable even with low fish yields.
Two major constraints to the spread of this technique in Africa were recognized: the widespread use, in many countries, of persistent pesticides in rice culture, and the need for great numbers of fish fingerlings of 20–50 g weight; the latter constraint received special attention at an earlier session.
Fish culture in combination with pig or duck rearing was practised only in five countries prior to 1966; since then, interest in this technique has increased and ongoing trials were reported in Cameroon, Congo, Gabon, Malagasy Republic, Central African Republic and Tunisia.
Reported fish yields ranged from 2 000 to 4 000 kg/ha/yr with ducks and 8 500–8 900 kg/ha/yr with pigs; yields of 3 600–4 900 kg/ha/yr were obtained in Gabon in association with poultry rearing. The rentability of the technique has been substantiated in the Central African Republic and Tanzania.
It was concluded that:
combined culture practices offer tangible means of integrating fish culture and agriculture
the techniques would reduce the need for expensive inputs, such as fer fertilizers and feeds, in fish culture and should be applied where possible in Africa
techniques developed in the Malagasy Republic could be used as the basis of adaptive research in other parts of Africa
arrangements should be made, in cooperation with agricultural and public health services for the discriminate application of pesticides to rice fields especially where associated fish culture has significant potential.
| Moderator: | A. Imevbore |
| Rapporteur: | K. Meecham |
Documentation
CIFA/75/SR 5, 12
CIFA/75/SE 6, 7, 12, 14
A number of environmental parameters, both biotic and abiotic, natural and man-made, of particular relevance to aquaculture, were discussed.
Among natural biotic factors, predators, fish parasites and vectors of human diseases are of special importance.
The adventitious entry of strong predators into ponds and rice fields often cause significant losses in production and special precautions need to be taken to avoid this problem. Fry production is also often limited in many countries due to excessive predation by amphibians; fencing of nursery ponds is necessary in such cases.
External parasites appear to be the major problem in warm-water pond fish culture in Africa; high water temperatures and organic content accelerate the life cycles of parasites and promote their spread. Many forms of parasites, which cause little harm in temperate environments, can bring about serious losses under tropical conditions due to heavy infestations. Methods, facilities and services for the diagnosis and treatment of diseases and parasites will be needed as the industry expands, and should be developed locally.
Endemic diseases such as malaria and bilharzia can be aggravated if proper pond management, such as the manual removal or biological control of aquatic plants and snails and the control of filamentous algae, is not practised. Effective biological control, using herbivorous and malacophagus fishes has been demonstrated in some countries.
Abiotic environmental parameters such as evaporation, turbidity, altitude, temperature, salinity and pH have special significance in relation to the ecological requirements of cultivated species and pond productivity.
Excessive evaporation relative to rainfall increases water use in pond culture and magnifies production costs where water must be purchased. In addition, the resulting fluctuation in salinity, especially in some lagoons, can limit the choice of cultivable species. The use of low-cost recirculating systems, where this technology can be practised, to reduce evaporative loss in arid zones was suggested.
High water turbidity brought about by land runoff during the wet season reduces primary production and oxygen levels in ponds and often increases the incidence of fungal diseases. It was noted that the use of settling ponds, wherever possible, could alleviate this problem.
The ecological requirements of cultivable species, with particular reference to their growth and reproduction received special attention. Failure of introduced fish to become established, especially in cool climates and high altitudes, was attributed to lack of adequate knowledge of their ecological requirements and, quite frequently, to errors in the identification of introduced species.
A major constraint to the expansion or the very practice of aquaculture in some countries is the massive use of persistent pesticides in agriculture and for public health purposes.
From information received and results of discussions the following needs were identified:
information on the ecological requirements of cultivated species;
information on major parasites of cultivated species and methods for their prevention and treatment;
efforts to be made, in cooperation with agricultural and public health services, to establish special pesticide-free zones for aquaculture and for the discriminate application of pesticides to protect aquacultural products.
Moderator: J.N.N. Adjetey
Rapporteur: J.J. Kambona
Documentation
CIFA/75/SC 1, 3, 6, 9, 10, 14
CIFA/75/SR 3, 11
CIFA/75/SE 18
It was recognized that aquaculture in Africa is practised mostly on a subsistence level and managed as a part-time occupation of farmers; private commercial enterprises have not developed in most countries. As a result, the economic infrastructure and supporting industries which have developed in connexion with aquaculture in other regions do not as yet exist in Africa.
It was also recognized that the major objective of aquaculture in the continent, to date, has been the improvement of the nutrition of rural populations. This subsistence-level farming has been, and continues to be, subsidized by governments to varying extents through provision of needed inputs and extension services.
It was realized that many governments, especially those with limited financial resources, are becoming increasingly reluctant to maintain the present level of support unless some financial return is assured. Discussion emphasized, however, that this stance is brought about mainly by contradictions in objectives and evaluation of aquaculture programmes. There was general agreement that subsistence fish farming, as an activity aimed at improving the nutrition of the lowest income group in the rural sector, cannot continue without government support; evaluation of benefits accrued from such programmes has to be made through some form of social accounting rather than cost-benefit analysis with immediate financial gain as a guideline.
It was agreed, however, that in order to ensure maximum return from government subsidy, priority should be given to the most efficient and least sophisticated small-scale animal protein producing systems. It was also emphasized that a tangible means of reducing government inputs and simultaneously expanding aquaculture, as well as ensuring proper planning, in its integration in rural development schemes. Thus irrigation schemes, rice farming, combined culture techniques, vocational training, social services and marketing systems could all be tackled together in an effort to increase food production and improve the lot of rural communities.
The considerable potential for the development of freshwater and brackishwater aquaculture in Africa was recognized. It was also evident that many countries of Africa have now recognized aquaculture not only as a source of animal protein for rural areas but also as a profitable activity which could provide employment and ensure maximum land utilization.
To realize this potential, and in view of the present resurgence of interest in this industry, it was agreed that a review and reorientation of government planning policies in respect of aquaculture development is urgently needed.
It was also recognized that, depending on the level of available technology, finance and other supporting systems in each particular country, aquaculture development is possible at three non-conflicting levels.
These were identified as:
Subsistence-level fish farming: aimed at prevention of nutritional inbalances or as a source of food in times of shortage or famine.
Private small-scale fish farming: where small-scale farmers are interested in aquaculture as a profit-making enterprise but lack the necessary capital to begin operations. Government incentive, in the form of reasonable credit arrangements, is needed to encourage this type of development.
Large-scale commercial fish farming: under suitable economic conditions and where technical expertise is available, large-scale commercial enterprises can be profitable.
It was recognized, however, that due to the present lack of involvement of the private sector in aquaculture and the restriction of technical expertise and supporting services to government agencies, it appears essential that governments take the initiative in starting such ventures. In this regard, it was noted that the concept of joint ventures between governments and the private sector is gaining acceptance in other regions and taking root in aquaculture development.
It was stressed, however, that large-scale pilot projects should be undertaken to prove the profitability of commercial ventures. Such projects could also provide facilities for training of personnel and production of seed.
In view of the limited financial resources of many countries in the region, it was stressed that outside assistance from international and bilateral agencies should be sought for this purpose.
It was unanimously concluded that:
proper development planning is the most critical requirement for the orderly and rational development of the industry;
development planning in respect of aquaculture must be based on technical and economic feasibility studies carried out by qualified and experienced personnel;
aquaculture development should be integrated in national fishery development and overall economic development plans;
integration of subsistence aquaculture and small-scale private fish farming in rural development schemes could yield immediate benefits and would help reduce the cost of government subsidies;
the training of technical personnel to undertake development programmes and strengthen government extension services should be given high priority;
governments should take the initiative, where justified, in starting commercial-scale enterprises, and should seek outside assistance for this purpose as needed.
The following specific recommendations were formulated on the basis of general conclusions of the different technical sections during the special session convened for this purpose.
1. Estimation of aquaculture potential
Reviewing data on the present status and potential of aquaculture, on the basis of the country reports presented to the symposium;
Recognizing that the lack of information on development potential is chiefly due to the fact that in many countries no complete exploration of areas or adequate feasibility studies have yet been done;
Noting that information on aquaculture development potential is an essential prerequisite for national development planning;
Recommends that governments undertake surveys of the aquaculture potential in their countries.
The Symposium further recommends that governments avail themselves, wherever necessary, of the assistance that may be obtainable through the FAO, the United Nations Development Programme (UNDP), the World Bank, the Regional Development Banks, bilateral aid agencies and other national and international agencies.
2. Aquaculture planning
Noting that the lack of rational aquaculture development planning is one of the major constraints to the orderly development of the industry;
Considering that inadequate planning can lead to the failure of programmes;
Recommends that governments draw up plans for aquaculture development with the assistance of qualified specialists, wherever necessary, and that they lay down in advance the concrete objectives to be pursued and procedures to be followed.
The Symposium also recommends that governments integrate aquaculture development in national fishery development, rural development schemes and overall economic development plans.
3. Development of pilot commercial farms
Having recognized that certain systems of aquaculture have proven technically and economically feasible in some countries and are ready for development on a commercial scale;
Being aware that the economic infrastructure associated with aquaculture in other regions does not as yet exist in Africa;
Noting that trained technical personnel and extension services are essential for and basic to the success of aquaculture;
Recommends that governments whose programmes are approaching the stage of large-scale development take the initiative to establish pilot commercial farms.
The Symposium further recommends that established pilot farms be subsequently used as national research and training centres.
The Symposium also recommends that governments avail themselves of the assistance that may be available from the FAO, the United Nations Development Programme (UNDP), the World Bank, the Regional Development Banks, bilateral aid agencies and other national and international agencies for this purpose.
4. African centre for aquaculture
Bearing in mind that aquaculture is being promoted in Africa and requires concerted efforts for its development;
Noting the urgent need for qualified and experienced technical personnel to undertake the necessary developmental work;
Recognizing that regional cooperation in research and training can enhance the efficiency and yield of these activities;
Recommends that a centre for aquaculture be founded in Africa to conduct research on problems of a regional scope and organize advanced training for aquaculturists.
The Symposium further recommends that this regional centre maintain close ties with selected national research and training centres;
The Symposium also recommends that FAO seek the assistance of the United Nations Development Programme (UNDP) and other financing agencies for the establishment of this centre as soon as feasible.
5. Research on endemic species
Recognizing that the lack of adequate basic data on the biology and ecological requirements of endemic species has been a major constraint to the development of techniques for their culture;
Noting that the culture of some endemic species of proven potential in aquaculture is limited by the lack of reliable techniques for their controlled breeding and the production of stocking material;
Being aware that many research institutions do not have the necessary resources to carry out the needed studies;
Recommends that governments of the region give these institutions the support needed to develop an intensive programme of studies aimed at determining the suitability of endemic species for cultivation and expediting domestication of those proven to have potential.
The Symposium also recommends that studies on the impact of introduced species on the ecology of indigenous species receive special attention
The Symposium further recommends that research programmes include studies on the development of artificial feeds from locally available ingredients and upgrading of nursery management techniques.
6. Use of low-cost production systems
Noting the capital-intensive nature of conventional fish culture systems;
Being aware that culture of fish in cages and enclosure, in lakes and reservoirs, special fish culture in flood plains and fish culture in rice fields can increase fish production substantially with relatively low-capital investment;
Recommends that governments of the region undertake feasibility studies aimed at the integration of aquaculture in these environments.
7. Coordination of aquaculture research
Noting the increasing number of national research programmes on aquaculture in the region;
Recognizing that transfer of information and techniques would expedite aquaculture development in the region;
Recommends that governments in the region endorse and support the exchange of information, experience and personnel.
The symposium also recommends that the CIFA secretariat investigate the possibility of establishing a cooperative programme of research on aquaculture among participating countries along lines followed in other regions.
8. CIFA Working Party on Aquaculture
The CIFA Working Party on Aquaculture, created at the First Session of CIFA, 1972 met in Nairobi, Kenya on 19–22 March, 1974. Document CIFA/75/4 gives the report of the Working Party.
The symposium recommended that the Working Party be continued with the following terms of reference:
To collect and disseminate information, to government agencies and research workers, on:
aquaculture economics available from national UNDP development projects and government fish culture establishments;
the major parasites and diseases of cultivated fishes and methods for their prevention and control;
the ecological impact of introduced exotic fish and shellfish.
Considering that these terms of reference constitute information-gathering activities it is suggested that the Working Party be enlarged and initiate its work by correspondence.
