At national level the responsibility of aquaculture research lies primarily with NIOMR (Lagos) and NIFFR (New Bussa). Both institutes were created by a decree in 1975.
Several authors have identified the major constraints of aquaculture development in Nigeria (e.g. Dada, 1976; Uboma et al., 1981; Tobor, 1985). Such constraints include:
inadequate supply of inputs, mainly fish seed and fish feeds;
inadequate data base on the biology and ecological requirements of endemic fish species with aquaculture potential;
lack of rational aquaculture development plan;
insufficient extension services;
lack of technical expertise;
absence of research-extension linkage;
low priority given by the government to the sector in its plan and budget allocations;
lack of knowledge on the profitability of aquaculture as an industry;
lack of easy access to land and credit.
The objectives of the various research programmes of NIOMR, ARAC, NIFFR and the universities are defined in line with these major obstacles to aquaculture development in Nigeria.
Increased fish production by simple culture systems is the main objective of the research programmes. Some of the research projects carried out by NIOMR and NIFFR have considerably reduced the effects of these constraints but some of them still persist.
The research activities of NIOMR and NIFFR have covered to some extent the four major areas:
biotechnological, such as reproduction of species, culture techniques, etc.;
economical, such as feasibility of production models, markets, etc.;
environmental, such as zonation, impact on the environment, etc.;
social, such as activity profiles of target groups, consumption habits, etc.
Biotechnological Programmes
Qualified, high-level aquaculture manpower, hitherto a major constraint in NIOMR, NIFFR and the universities, is no longer a problem since 1988. What is needed now is proper coordination of research results for effective utilization in aquaculture development and future research. Several species of local catfishes and tilapias have been studied, leading to the commercial production of fingerlings. Genetic improvement of the species leading to the production of hybrids, has been perfected. The technology for the production of monosex tilapia populations has been defined. Various culture systems adapted to different ecosystems are major aquaculture research projects in both NIOMR and NIFFR. Integrated poultry-fish culture and other culture systems such as pens, enclosures, cages and homestead systems, are being investigated further.
Economics and Production Statistics
More research work is needed in NIOMR and NIFFR where facilities are available. Several papers have been published by staff of the two institutions: Asiaphil Fish.Corp., 1979; Wokoma and Ezenwa, 1982; Okpanefe, Ezenwa and Abiodun, 1984; Abiodun, 1986; Egwui, 1986; Otubusin et al., 1991; Okoye et al., 1991. The various estimations were based on actual work carried out in the field and the collection of data from farmers. Some of the major constraints (Satia, 1990) include the non-release of funds by the supervising Ministry, bureaucracies associated with government managed research farms, rocketing inflation, inability of farmers to keep accurate data and their reluctance to release such data to visiting research personnel. This has led Abiodun (1986) to hastily conclude that, except in a few cases, notably in Ogun State, “returns do not justify investment in fish farming”. Research projects on economics and production statistics need very urgent attention by donor agencies to reduce the negative effects of inaccurate data on which most aquaculture projects are still formulated, at both national and state levels.
Environmental Programmes
There is no major project yet in the two research institutions - NIOMR and NIFFR - on environmentally-related aquaculture programmes. However, from observations made during research surveys on the abundance of fish seed in Nigerian coastal waters, Ezenwa et al. (1986, 1990), the following environmental factors were recognized:
Since 1979, these factors were noted by the research team led by the author to have destructive impacts on fish, larvae, fry and fingerlings of wild stocks. The environmental impacts of aquaculture systems in Nigeria need to be properly addressed by both the Government and donor agencies. It is a priority area of research for the next decade due to the emphasis on global climate change. NIOMR, NIFFR and FEPA (Federal Environmental Protection Agency) need therefore to set up a joint research team for:
compatibility and integration of aquaculture systems with competing uses of environmental resources.
Socio-economic Programmes
Socio-economic issues related to capture fisheries have been treated in NIOMR and NIFFR but researchers have not yet studied the socio-economic aspects of aquaculture in Nigeria. Investigations are needed in the following areas (Edwards et al., 1991):
Such research requires highly trained personnel in social sciences, emphasizing the importance of other scientific disciplines to aquaculture research and development. Such level of manpower is not yet available in NIOMR and NIFFR.
The operational capability of the two fisheries research institutes, NIOMR (Lagos) and NIFFR (New Bussa) is grossly limited due to poor funding and low priority attached to aquaculture.
Research Infrastructure and Equipment
NIOMR has a 4-ha experimental fish farm at Ikoyi Park (Lagos), which consists of nine 0.1-ha production ponds, seven outdoor hatchery tanks (breeding, nursery and production) and one large concrete storage tank with a capacity for 500 000 to 1 million fingerlings at a time. For fish seed production and storage facilities, the farm has a capacity of 2 to 5 million fingerlings, depending on the species. The laboratory is poorly equipped but has water quality equipment for routine aquaculture research. Financial assistance is needed because of the strategic location of the farm in densely populated areas and the heavy demand for fish seeds of popular species, such as the catfishes, the prawns and shrimps. In addition to the above, NIOMR has the field station ARAC, near Port Harcourt. It consists of a 5.3-ha brackishwater fish farm at Buguma and a 3-ha freshwater fish farm at Aluu. These farms have functional laboratories, breeding/nursery/storage tanks and production/storage earthen ponds.
All these research facilities are likely to be improved under the auspices of a World Bank/Nigeria National Agricultural Research Project. Under the EEC-sponsored project on ‘Applied research for the innovation of a pond culture scheme with freshwater fish species in the oil palm belt of Nigeria’, eight production ponds were constructed at ARAC and some research equipment, including a computer, acquired.
Aquaculture research facilities at NIFFR (New Bussa) are very modest. They consist of 2.5-ha experimental fish farm with storage/production ponds and breeding/nursery/storage concrete tanks.
Research Financing
Financing of aquaculture research in Nigeria has been relatively poor because of the low priority attached to the importance of research for development, although it has improved with the establishment of DFRRI in 1986. For the period 1970–85, the total allocation and expenditure on aquaculture research for both NIOMR and NIFFR was below two million naira (about USD 400 000). Since 1986, DFRRI's mandate to the two institutes has led to the establishment of functional outdoor hatcheries for breeding, storage and marketing of fingerlings to fish farmers.
The poor funding of aquaculture research in Nigeria (Tables 4, 5 and 9) is a reflection of the lack of faith of policy planners on the value of aquaculture research for fisheries development.
Table 9
Fund allocations for eight research projects made to NIOMR in 1991 (in thousand NGN)
P1 | P2 | P3 | P4 | P5 | P6 | P7 | P8 | Total |
---|---|---|---|---|---|---|---|---|
2 | 3 | - | - | 4 | - | 1 | 8 | 29 |
19 | 45 | 55 | 19 | 25 | 13 | 20 | 32 | 233 |
42 | 97 | 118 | 42 | 55 | 28 | 44 | 70 | 500 |
93 | 214 | 259 | 92 | 121 | 61 | 98 | 153 | 1 095 |
39 | 119 | 101 | 38 | 51 | 25 | 41 | 64 | 482 |
* | ||||||||
198 | 480 | 534 | 193 | 249 | 129 | 204 | 330 | 2 320 |
19 | - | 119 | 114 | 1 | 21 | 13 | 1 | 177 |
45 | 124 | 15 | 103 | 16 | 52 | 19 | 222 | 399 |
47 | 214 | 63 | 52 | 57 | 62 | 56 | - | 554 |
37 | 141 | 134 | 74 | 58 | 29 | 135 | 2 | 613 |
47 | - | 150 | 51 | 61 | 31 | 49 | 77 | 469 |
* * | ||||||||
(197) | (480) | (483) | (319) | (195) | (226) | (274) | (103) | (2 290) |
* * * | ||||||||
1 | 371 | 50 | (125) | 53 | (97) | (70) | 226 | 39 |
P1 Research into fish and shellfish breeding for mass production of fish seeds
P2 Strengthening of training and research facilities at the African Regional Aquaculture Centre
P3 Research into commercial abundance of deep water fish
P4 Utilization of marine fishery resources, etc.
P5 Marine geology and geophysics, etc.
P6 Extension, research and liaison services and library journals
P7 Establishment of oceanic data bank
P8 Development of improved fishing nets
* Total received (approximate)
* * Total expenditures (approximate)
* * * Balance (approximate)
Table 10
NIOMR aquaculture research staff as at December 1992 (Lagos and ARAC Stations)
S/N | Name | Post | Qualifications | Area of specialization |
---|---|---|---|---|
1 | Ezenwa, B.I.O. | Chief Research Officer | M.Sc., M.Sc., Ph.D. | Fish breeding and genetics (finfish, prawn, shrimp) |
2 | Ayinla, O.A. | Chief Research Officer | B.Sc., M.Sc., Ph.D. | Fish breeding and nutrition |
3 | Onuoha, G.C (Mrs) | Assistant Chief Research Officer | B.Sc., M.Sc., Ph.D. | Water quality |
4 | Dare, E., C (Mrs) | Principal Research Officer | B.Sc., M.Sc. | Culture systems |
5 | Marioghae, I.E. | Principal Research Officer | B.Sc., M.Sc. | Prawn/Shrimp production |
6 | Alegbeleye, W.O. | Senior Research Officer | B.Sc., M.Sc. | Live food organisms and fish nutrition |
7 | Anyanw, P.E. (Miss) | Senior Research Officer | B.Sc., M.Tech. (Aquaculture) | Fish breeding and aquaculture systems |
8 | Nwadukwe, F.O. | Senior Research Officer | B.Sc., M.Tech. (Aquaculture) | Fish breeding and genetics |
9 | Erondu, E.S. | Senior Research Officer | B.Sc., M.Tech. (Aquaculture) | Fish breeding and production systems |
10 | Idoniboye-Obu, T.I.E | Senior Research Officer | B.Sc., M.Sc. | Fish nutrition |
11 | Oresegun, O. | Senior Research Officer | B.Sc., M.Sc., Ph.D. | Fish nutrition |
12 | Oladosun, G.A. | Senior Research Officer | DVM | Fish pathology |
13 | Adeyemo, F.A. | Research Officer I | B.Sc., M.Sc. | Planktology |
14 | Deckae, S.N. | Research Officer I | B.Sc., M.Sc. | Economics of culture systems |
15 | Nlewadim, A.A | Research Officer I | B.Sc., M.Sc. | Culture systems |
16 | Mosugu, (Miss) | Research Officer I | B.Sc., M.Sc. | Water and soil quality |
17 | Aladetohun, A.F(Ms) | Research Officer I | B.Sc., M.Sc. | Fish nutrition |
18 | Oghenedo, A.E.(Ms) | Research Officer II | B.Sc. | Fish nutrition |
19 | Ajiboye, M.O. | Research Officer II | B.Sc. | Microbiology |
Table 11
NIFFR aquaculture research team as at December 1991
S/N | Name | Post | Qualifications | Area of specialization |
---|---|---|---|---|
1 | Ita, E.O. | Assistant Director | B.Sc., M.Sc. | Culture systems in lakes and reservoirs |
2 | Toubusin, S.O. | Assistant Chief Research Officer | B.Sc., M.Sc. | Cage enclosure culture systems |
3 | Mad, C.T. | Principal Research Officer | B.Sc., M.Sc., Ph.D. | Fish breeding |
4 | Omorinkoba, W.S. | Senior Research Officer | B.Sc., M.Sc. | Fish breeding and culture systems |
5 | Ovie, S.O. (Mrs) | Senior Research Officer | B.Sc., M.Sc. | Prawn hatchery and management |
Human Resources
Nigeria has skilled personnel for aquaculture research. During the past decade, the country has acquired a large pool of trained manpower from ARAC and the 13 universities and other tertiary institutions. Tables 10 and 11 show lists of aquaculture research staff at NIOMR/ARAC and NIFFR.
Despite poor funding and very limited research facilities at NIOMR and NIFFR, some programmes have been successfully carried out while others will take some more time to complete.
NIFFR
The aquaculture programmes at NIFFR have consisted of:
Management of reservoirs
The productivity of some reservoirs has been improved through the stocking of fingerlings. For example, 100 000 clupeids have been successfully transferred from Lake Kainji, Niger State, into Tiga Lake, Kano State. Also, 100 000 tilapia fingerlings have been transferred from Jankara reservoir into Ruwan Kanyan Lake, both in Kano State. Such efforts have over the years increased the productivity of the water bodies (Ayeni, 1991).
Fish hatchery management
Over one million fingerlings of Clarias gariepinus, 0.1 million of common carp and 1.5 million of various tilapias were produced and distributed to fish farmers in various parts of the country. Over 10 000 hybrid fingerlings (Heterobranchus and Clarias) were produced during the 1990 breeding season.
Cage, pen and enclosure culture systems
Species such as Heterobranchus bidorsalis, Clarias gariepinus, Oreochromis niloticus, O. galilaeus, Distichodus spp., Alestes baremose and Citharinus citharus have reached an average weight of 335–715 g within one year of culture in floating growout cages at the Shagun station.
Pond engineering, construction and consultancy services
Technical assistance was given to individuals and groups from the private and public sectors in setting up hatcheries for fingerling production.
Fish feeds and nutrition
The best feed formulation for the semi-intensive culture of mud catfish and tilapia fingerlings has been identified. Feed loss during storage due to powdering by Tibolium castaneum and Rhyzooertha dominica have been estimated at 15 per cent.
NIOMR
The aquaculture research programmes at NIOMR have consisted of:
Major Achievements (1975–1992)
The technology for breeding, out of season, selected popular species, including Chrysichthys nigrodigitatus, Clarias gariepinus and Heterobranchus bidorsalis was developed, standardized and made available to farmers. The experimental crossing of C. gariepinus and H. bidorsalis produced fertile hybrids which attained early maturity at 9 months instead of 3 years for the parent, Heterobranchus sp. This early maturity however exceeds that of the parent Clarias gariepinus by 3 or 4 months (Nwadukwe et al., 1991).
Acute shortage of seed of cultivable indigenous species of fish constitutes a major problem in the development of viable fish farming in Nigeria (Tobor, 1991). NIOMR attacked this problem from two angles - hatchery production of fingerlings and research on seed collection from the natural environment. Between 1986 and 1989, the breeding and nursery grounds of six major groups of fish and shellfish, including shrimp/prawn, catfishes, tilapias and mullets, were located along the entire Nigerian coastline (Ezenwa et al., 1990). Water and soil parameters characterizing breeding and nursery grounds, the best season for seed collection, together with the most suitable harvesting gear, were determined.
The development of culture systems based on indigenous species of fish has also been addressed. Integrated polyculture of Clarias gariepinus and Oreochromis niloticus with broiler chickens was investigated. Trial cultures yielded production rates of 4–5 t fish/ha/year and 6 t chickens/ha/year. This production system has been standardized and introduced to fish farmers.
In the field of promotion of the production of high quality fish feeds, NIOMR has developed pellets for Clarias and Tilapia. An annual production of 100 t was attained with the limited facilities. With DFRRI funds, NIOMR has been able to expand its facilities to produce annually 500 t (in Lagos) and 700 t (in ARAC) of high quality feeds for farmers.
In January 1987, DFRRI launched a special programme to promote homestead fish husbandry in Lagos State using the NIOMR aquaculture research team for the successful execution and operation of the scheme. From regular scientific data collected from privately owned homestead ponds by the NIOMR research team, yields from a concrete tank 8m × 4m × 1.2m ranged from 32 to 38 kg/32 m2 per 6 month cycle (Anyanwu, Ezenwa and Uzukwu, 1987 and 1989). NIOMR identified a high incidence of “broken skin disease and infectious abdominal drops” among Clarias gariepinus. The diseases, however, disappeared with frequent renewal of water in the tank to improve its quality (Anyanwu, Ezenwa and Uzukwu, 1989). The above programme is now very popular in all states of Nigeria.
The previous locations of the two fisheries research institutes in ministries or agencies different from that of FDF raised questions on the proper utilization of fishery research information in Nigeria.
This anomaly was corrected in January 1992 by the military administration which transferred all the 18 National Agricultural Research Institutes under the supervision of the Federal Ministry of Agriculture. The statutory functions of the ministry include promotion, coordination, and administration of scientific and technological research and development activities in agriculture. In addition to formulation of agricultural research policies which cover crops, livestock, fisheries, forestry and related subjects, the ministry is also deeply involved in the monitoring, evaluation and coordination of agricultural extension and research liaison and training. Each of the fisheries research institutes (NIOMR and NIFFR) has a Board of Governors (Figure 4) whose membership includes scientists, economists, politicians, and a representative of the supervising ministry. Its major function is to scrutinize and evaluate selected aquaculture research programmes and budgets, while the supervising ministry gives a preliminary budget approval. The National Planning and Budget Division, located in another ministry, has the final powers to reject, reduce or approve fisheries/aquaculture research programmes submitted by the institutes through their Boards of Governors and supervising ministry. It is at this point that the institutional framework becomes problematic.
The low priority accorded to aquaculture research in 1970–1980 changed during the last decade because of the realization by fishery administrators of the importance of research in development plans. Public institutions such as DFRRI and State Fisheries Departments increasingly see aquaculture research information obtained from NIOMR and NIFFR as a means of support to fisheries development schemes, while the supervising ministry utilizes aquaculture research data in the preparation of development plans in the short, medium or long terms.
The First National Rolling Plan (1990–1992) has aquaculture as a major component. The programme ‘Research into fish and shellfish breeding for mass production of seeds’ was considered by fishery administrators in 1989 as a surer way of bridging the gap between the decline in capture fisheries production and population growth in Nigeria.
It was recognized that high quality fish seeds are always in greater demand. Conservative estimates (1989) put the figure at approximately 10 million annually. Simple techniques for controlled breeding and larvae/fry rearing, when developed, could result in higher fingerling survival and production in small-, medium- and large-scale fish farms. Population genetics and hybridization of selected cultivable species for improved seeds with certain desired characteristics were considered part of the major thrust of the programme. Since 1986, the programme was vigorously carried out by NIOMR and NIFFR, with further financial support from DFRRI.
To support the fisheries sectoral development process, it was further recognized in the Fourth National Development Plan (1980–1987) that Nigeria had an extensive system of lakes and reservoirs numbering over 300 and covering approximately 300 000 ha (Ita et al., 1985). To enhance the productivity of these water bodies and raise the fish catch by fishermen within the communities, NIFFR was mandated to carry out artificial stocking of some of these lakes and reservoirs.
The impact of aquaculture research on fisheries development was insignificant in the earlier years (1970–1980) due to the low priority attached to the sector by the Government. The situation, however, improved tremendously during the last decade due to the general recognition in both the public and private sectors of the advantages of developing fish farming to complement declining capture fisheries.
Figure 4. Organizational chart of NIOMR
Several factors motivated this greater awareness of the importance of aquaculture research for fisheries development:
Collaboration between research and production in the identification of development policies: DFRRI's creation (1986) and its location in the Presidency prompted an accelerated approach to applied aquaculture research within the institutes. In 1987, the research institutes produced approximately 3 million fingerlings, 55 per cent of their target of 5.45 million. The homestead pond programme was vigorously pursued nationwide by DFRRI through NIOMR, NIOMR/ARAC and NIFFR. This led to the establishment of over 3 000 small concrete tanks of varying dimensions, located in living premises. Fish production as a result of DFRRI's direct participation in the selection, identification and execution of development projects, led to a dramatic increase from an estimated average production of 1 t/ha/year to 3–4 t/ha/year for earthen ponds and 15–25 t/ha/year for homestead tanks.
Due to the greater awareness of the potentials of the aquaculture industry in Nigeria, over 2 000 earthen ponds (0.02–1 ha), and several large commercial farms (Table 3) were established. This in turn led to closer contacts between aquaculture research scientists and investors in small-to-large-scale aquaculture and the financing sector. Consultancy units were established in NIOMR and NIFFR to cope with demands on site selection, pond design, water and soil analyses, species identification, fish feeds, culture systems, socio-economic analysis and general farm management techniques. Feasibility reports are sent to the institutes by the potential financing agency before any approval is given for project financing. The institutes have designed programmes to promote integrated livestock/aquaculture farming and carried out large-scale stocking of lakes and reservoirs. NIOMR has investigated since 1988 the polyculture of C. gariepinus and O. niloticus with broiler chickens.
The major subjects on which such collaboration has developed during the last decade include:
Technical subjects: Large scale production and distribution of fingerlings of C. gariepinus, Oreochromis niloticus; Heterobranchus spp. and hybrids of Clarias/Heterobranchus, C. nigrodigitatus and Tilapia spp. Restriction on food imports after the oil boom period, together with the government's new policy in which it was recognized that “agriculture is essentially a private-sector activity”, strongly increased the demand for quality fingerlings by fish farmers. It annually ranged from 10 million to 50 million fingerlings (1986–1992). In addition, stocking of natural lakes and reservoirs required over 50 million fingerlings.
Economical subjects: Economic programming of the production of selected culture systems such as livestock-fish culture, cage/pen culture and crop/fish culture, access to both rural and urban markets are investigated through the consultancy units of the fisheries research institutes.
Institutional subjects: The institutes in collaboration with the Federal Department of Fisheries, DFRRI, the State Department of Fisheries, the River Basin Development Authorities (1979–1985), the State ADP's and the commercial banks and other financial agencies, participate in the definition of sectoral policies, regulations and legislations.
Social subjects: The major items of the institutes' aquaculture programmes include the identification and selection of appropriate technologies, the organization of production for various target communities (particularly women) to reduce the rural-urban migration of youths. Socio-economic research surveys of communities in coastal villages and close to inland waters have been carried out by NIOMR and NIFFR, though more research work is needed in this sector.
Satia (1990) rightly observed that many of the research results from the institutes and universities have been published as technical papers but are not widely disseminated. The benefits of these works, he noted, are not very apparent, owing to the undefined link between research and development institutions and the private sector.
At national level, there exists a National Agricultural Extension-Research Liaison Services (NAERLS) in Zaria. Its mandate includes “overall planning and co-ordination of all agricultural extension: specialist support activities in crops, livestock, fisheries, forestry, irrigation, agricultural engineering and food technology; collation and dissemination of agricultural innovations to States extension services”.
Within the research institutes, also exist Extension-Research Liaison Services units that are supposed to establish effective communication linkages with NAERLS. In practice, such linkage and cooperation do not exist. Research results from each institute are passed to farmers through its Extension- Research Liaison Services unit by seminars, workshops, training of extension agents, mobilization and organization of interested rural and urban people to participate effectively in aquaculture. During workshops, relevant publications are collected by participants who normally have the possibility of discussing their problems with experts in various disciplines.
The above topic dominated the activity of aquaculture research from 1970 to 1980, due mainly to the wide variety of popular fish species inhabiting the diverse ecosystems (Sivalingam, 1972; Ezenwa, 1976, 1979; Ezenwa et al., 1986, 1990). Ezenwa (1979) summarized the results obtained for the past two decades (Table 12).
Between 1980 and 1989, the breeding and nursery grounds of six major groups of fish and shellfish were located along the entire Nigerian coastline (Ezenwa et al., 1990). Water and soil parameters characterizing the breeding and nursery grounds, the appropriate seasons for seed collection from their natural environment, and the most suitable harvesting gears were determined. As a result of this, markets for fish seeds collected from the wild have flourished among fishing communities, thus providing an estimated 70 per cent of the national demand for fish farmers, in the absence of well developed hatcheries. The sale of fish seeds by fishermen for the past decade has greatly improved their socio-economic welfare.
Of all exotic species experimented in Nigeria, only common carp has had a 100 per cent establishment in most freshwater fish farms. The other exotic species, e.g. the channel catfish and the largemouth bass, have failed to establish themselves in the farms after a series of experiments by Johnson (pers.comm., 1976) of Auburn University. The fate of Xiphophorus maculatus, a popular aquarium species, is not known but Poecilia reticulata, introduced from Britain in 1972 for teaching purposes, has established itself in the country and is available at the University of Ibadan (Satia, 1990).
Fish seeds are very expensive and seed inputs in fish farming practices constitute a major operational cost, about 20 per cent (Abiodun, 1986). A major research programme for NIOMR and NIFFR dealt with hatchery production of fish species generally preferred by consumers - C. gariepinus, H. bidorsalis, C. nigrodigitatus; O. niloticus; Penaeus notialis and Macrobrachium vollenhovenii. Successes were obtained in the hatchery production of the catfishes, including hybrids of Clarias and Heterobranchus. In 1987, NIOMR and NIFFR produced 3 million fingerlings, equivalent to 55 per cent of their target under a DFRRI-sponsored research on pilot production of fish seeds. By 1992, the target was met and exceeded. The continuity of this project depends on continuous funding from the government or on the use of funds generated from the sale of fingerlings to offset operational costs.
Table 12
Summary of data on cultivable species of finish and shellfish
(modified after Sivalingam, 1972, and Ezenwa, 1976)
Species | Popularity with consumers | Availability of seeds for stocking | Salinity tolerance (in parts per thousand) | Remarks |
---|---|---|---|---|
Local species | ||||
T. melanopleura (T. rendalli) | Average | Year round and adequate | Up to 26‰ or more, depending on species | Hardy and good as standby species in absence of more popular species for stocking; uncontrolled breeding a disadvantage |
O. niloticus | " | " | " | " |
O. galilaeus | " | " | " | " |
T. zillii | " | " | " | " |
Chrysichthys nigrodigitatus | Very good | Year round but inadequate | Up to 26‰ | Hardy, but supplementary feed absolutely necessary. Has grown well with tilapias and mullets. |
Liza falcipinnis | Good | Year round and adequate | Up to 35‰ | Has given good results in brackish waters. Experiments in fresh waters underway. |
Mugil bananensis | " | " | " | " |
Liza grandisquamis | " | " | " | " |
Liza dumerili | " | " | " | " |
Mugil monodi | " | " | " | " |
Mugil curema | " | " | " | " |
Clarias gariepinus (mud catfish) | Very good | Year round but inadequate | Up to 25‰ | Can be stocked very densely, provided supplementary feed is given. Now cultured with tilapia. |
Heterotis niloticus | Low | Seasonal and inadequate | Freshwater only | Small sizes favoured. Larger sizes said to be of lower taste. |
Ethmalosa fimbriata (Bonga) | Good | Seasonal | Up to 35‰ | Comes into ponds with tide. Appears to be sensitive to oxygen deficiency, delicate and does not survive long once out of water. |
Penaeus duorarum (pink shrimp) | Very good | Seasonal | 0.5–3.5‰ | Comes into ponds with tide. Delicate and limbs easily damaged. Has grown to about 20 g in ponds. |
Macrobrachium spp. | " | Seasonal | 0–10‰ | Caught in abundance in certain areas of the country |
Lates niloticus (Nile perch) | " | Scarce | Fresh water only | Good predator for tilapias but preys on carps also. Fast growth. |
Pomadasys jubelini | Good | Seasonal | 5–10‰ | Comes into ponds with tide. Good predator for tilapias in brackish ponds. |
Exotic species (already introduced) | ||||
Cyprinus carpio (common carp) | Very good | Year round and adequate | Fresh water but tolerates low salinity | Responds well to fertilizers and supplementary feeding |
Ictalurus punctatus (channel catfish) | " | " | Fresh and brackish water | " |
Micropterus salmoides (largemouth bass) | " | " | Fresh water | " |
Lepomis macrochirus (bluegill) | Good | " | " | " |
Exotic species (worth introducing) | ||||
Ctenopharyngodon idella (grass carp) | Good | Nil | Fresh water | Some ponds are noted for the dense growth of grass and weeds. If introduced into these ponds, they may keep the vegetation under control. |
Hypophthalmichthys molitrix (silver carp) | " | " | " | Should increase production from ponds rich in phytoplankton. Available all along the coastline in the brackishwater areas. |
Heterobranchus spp. | " | Seasonal | " | Responds well to fertilizers and supplementary feeding. |
Distichodus engycephalus | " | Seasonal | Fresh water | Some ponds are noted for excess grass and weeds. This species is suspected to be able to keep weeds under control. |
Distichodus brevipinnis | " | " | " | " |
Distichodus rostratus | " | " | " | " |
Malapterurus electricus | " | " | " | Good predator for excess tilapias in ponds. |
Megalops atlanticus | " | Seasonal | 5–30‰ brackish water | Comes into ponds with tide. Good predator for excess tilapias in brackishwater ponds. |
Hemichromis fasciatus | Low | Adequate | Up to 26‰ | Good predator species for tilapia. Does not grow with large carps. Feds on tilapia fry and fingerlings only. |
Lutjanus apodus | Good | Inadequate | 1 to above 30‰ | Good predator species for tilapia in brackishwater ponds. |
Lutjanus agennes | " | " | " | " |
Gymnarchus niloticus | " | " | Freshwater only | Good predator for tilapias. Fast growth. |
Elops lacerta | Low | " | Up to 26‰ | Comes into ponds with the tide. Delicate and sensitive to oxygen deficiency, does not survive long out of water. |
Crassostrea gasar (mangrove oyster) | Good | Almost throughout the year and adequate | 2 to 32‰ | Of the three collectors tested for spat collection, spat settles better on hard timber than old oyster shells or asbestos. Better settlement in the shade than in open areas. Settlement more abundant in depths between about 30 and 100 cm from water surface. |
Over the years this problem has defied solutions despite persistent research efforts by NIOMR, NIFFR and the private sector. Achievements were, however, recorded in the identification of cheap raw materials, mainly of agricultural origin, and in the formulation and development of pelleted feeds for Clarias spp., tilapias, Chrysichthys spp. and C. carpio. Quantities produced each year remained small. Costs of production gradually went up with the introduction of the Structural Adjustment Programme (SAP). Feeds became very expensive and unaffordable for fish farmers.
Due to the above constraint, for the last decade the institutes intensified research on the production of live organisms for fry, fingerlings and table-sized fish, in particular of species that depend heavily on plankton and other herbivorous species. The identified species included all tilapias, mullets, Heterotis niloticus and Distichodus spp. Species with shorter food chains were recommended for small-scale fish farmers. Organic fertilizers, poultry manure and cow manure are now extensively used by such farmers. It is pertinent to mention that, despite successes recorded by NIOMR and NIFFR in the standardization and production of live food organisms, the technology developed needs further improvement for commercial fish farms.
The availability of Artemia in Nigeria is an area worth investigating since there are salt lakes in the country. Artemia research and production in Nigeria could be feasible as in Kenya's Mombasa laboratory, which attracted aid from Belgium.
According to several sources (Ayoade and Oyebande, 1983; Ita et al., 1985), Nigeria has an extensive lake and reservoir system covering about 300 000 ha. Over the years 1970 to 1980, these water bodies were ignored and used only for drinking and irrigation purposes. Investigations carried out by NIFFR since 1980 have shown that their productivity could be improved by stocking with popular fish species and the introduction of cage, pen and enclosure culture systems. In addition to the stocking activities, research on cage culture by NIFFR has recorded some positive results. Tilapias (O. niloticus, T. zillii, O. galilaeus) and catfishes (C. gariepinus and H. bidorsalis) were found to grow and survive in the floating bamboo net cage system. average weight observed varied from 335 g to 715 g per fish in 12 months. Citharinus citharus was observed to subsist on natural food with little supplementary feeding in floating cages at the Shagun station on the western shore of Lake Kainji (Otubusin et al., 1991). O. niloticus and S. galilaeus were observed to interbreed easily and naturally in captivity in the floating cages producing hybrid offsprings. Some of these findings, if fully applied to all the natural lakes and reservoirs in the country could increase their productivities by over 20 per cent.
Priorities for aquaculture development already exist in Nigeria. The identification, selection and formulation of aquaculture priorities in the short and medium terms is the statutory responsibility of FDF, under the Federal Ministry of Agriculture. A technical committee, the National Fisheries Development Committee (NFDC), composed of State Directors of Fisheries, representatives of research institutes, universities, the Federal Agricultural Coordinating Unit, relevant State and private sector organizations, meets annually under the chairmanship of the Director of FDF to formulate and review fisheries policies. The committee is one of the technical committees under the National Council for Agriculture. The mandate of the NFDC is mainly on design and formulation of fisheries/aquaculture projects which FDF later presents to the National Council for Agriculture (NCA) for ratification.
At the 26th session of the National Fisheries Development Committee (29–31 July 1992), a communiqué was issued which:
identified the need to intensify aquaculture development in an effort to bridge the ever-increasing fish supply-demand gap;
noted the current wave of exotic fish species imported into Nigeria and urged FDF to pursue the establishment of a special unit in the department to check this trend because of the danger inherent in the practice;
noted that fishery research institutes are now part of the Federal Ministry of Agriculture and urged the institutes to design and implement relevant research programmes that will enhance fisheries aquaculture development.
In 1986, a national seminar on aquaculture development was also organized by DFRRI to map out short- and medium-term priority plans. Participants were largely drawn from all the relevant government agencies that make up NFDC, in addition to representatives of banks, financial houses, the press, both print and electronic media, and the private sector.
DFRRI's aquaculture programmes for development complemented those formulated by FDF through NFDC. Both recognized that Nigeria is endowed with an extensive inland water system, lakes, reservoirs, estuaries, lagoons, creeks, flood plains and approximately 800 km of marine coastline. Aquaculture potential therefore is tremendous.
Fish is the cheapest source of animal protein in Nigeria and the gap in the fish demand and supply cannot be bridged through capture fisheries. Current production is approximately one third of the estimated demand, while aquaculture production is estimated below 15 000 t annually.
Recognition of the scarcity of high quality popular fish seeds nationwide.
Non-availability of high-quality, low-cost, effective fish feeds.
Non-availability of credit facilities for project implementation, in addition to lack of easy access to suitable fish-farm sites by prospective fish farmers.
Poor transfer mechanisms of research results from NIOMR and NIFFR, in addition to poor publicity given by both print and electronic media to fisheries/aquaculture development.
There is no way Nigeria can solve the “interlocking problems of mass poverty, rising prices, food shortages and malnutrition without improving substantially agriculture and all aspects of rural production and rural life”. (DFRRI's Rural Development Day. 7 February 1993).
Through the launching of the homestead pond programme by DFRRI in 1986, each family is encouraged to produce 50 to 100 kg annually of fish for consumption by family members.
Improved funding of fisheries research institutes, NIOMR and NIFFR, to upgrade research facilities for pilot production of fish seeds and high-quality, low-cost fish feeds for farmers.
Reactivation and upgrading of selected fish seed multiplication centres of FDF as model farms for an increased fingerling production and for the training of fish farmers in basic aquacultural practices.
As the inventory of lakes, reservoirs and other water bodies has now been completed by FDF, a regular massive stocking of these water bodies by NIOMR, NIFFR and FDF to upgrade their productivities is recommended.
Strengthening and proper coordination of extension units of FDF, SFDs, NIOMR and NIFFR.
Encouragement of rural communities through extension agents to engage in integrated fish/livestock/ crop farming to increase annual revenues.
Strengthening of inter-agency cooperation in aquaculture development projects, especially between research institutes, FDF, SFDs and DFRRI.
The National Agricultural Land Development Authority should assist in solving the problem of easy access to suitable land for small- to large-scale commercial fish farmers.
Credit facilities by banks and financial houses to be extended to aquaculture projects.
Publicity to be fully given to aquaculture practices by both print and electronic media.
Since November 1988, the country is implementing the UNDP/FAO project on ‘Strengthening Agricultural Extension in Nigeria’. Its major objective is the provision of assistance to the Federal Government to meet its declared intention of self-sufficiency in food production and of increased agricultural export through the adoption of appropriate innovation by rural farming families.
The responsibility for the implementation of aquaculture strategies for development in Nigeria is shared between FDF (Figure 2) and the State Fisheries Departments (Figure 3).
DFRRI and ADPs are recent institutional arrangements for accelerated development of various agricultural projects including fisheries/aquaculture. In reality, the two government agencies have since 1986 played a dominant supporting role in the implementation of various aquaculture development projects:
Funding of research institutes, FDF and SFD for the production of targeted quantities of fingerlings for fish farmers. DFRRI made available approximately three million naira to all the states to construct fish hatcheries whose designs were provided by the Directorate in consultation with NIOMR and NIFFR.
Funding of research institutes, including the Project Development Agency in Enugu and the Lagos State Fisheries Department, to upgrade facilities for fish feed production and to design and manufacture a prototype pelleting machine to be made available to interested feed millers nation-wide.
Funding of the NIOMR extension unit for the organization of training programmes for extension agents and workshops for farmers nationwide.
The FDF and SFD have fish farm demonstration centres. The centres carry out two major activities, the pilot production of fish fingerlings and practical training of extension agents and fish farmers.
The private sector also implements some of the aquaculture development projects. Some fishing villages along the water bodies organize themselves into fisheries cooperatives for the production of fish through the culture-based fisheries approach and the establishment of community fish farms.
Due to the low priority attached to aquaculture development between 1970 and 1980 by both Federal and State Governments, the budgetary allocation was insignificant. The situation, however, improved during the last decade (Section 11(c)). Loans from agricultural, commercial, merchant and industrial banks, though relatively small, accelerated the development of private commercial fish farms.
It is relevant to point out that donor agencies and foreign technical assistance helped in increasing the rate of aquaculture development during the last decade. The establishment of the African Regional Aquaculture Centre (ARAC) in 1980 by UNDP/FAO/NIOMR was a major initiative for aquaculture development in the African region south of the Sahara. In 1989, a grant from the Government of Italy assisted FDF to upgrade the facilities at the Oluponna fish farm, becoming a nucleus for integrated livestock-aquaculture farming in the country. In addition, the International Fund for Agricultural Development (IFAD) agreed in January 1990 to fund a small-scale fisheries development project in Rivers, Cross River and Akwa-Ibom States, this project also contributing to aquaculture development.
Though subject to periodic review and fund availability, the major priorities, both short- and medium- term, centre on the following:
Geographic information System
Results of monitoring of stocking programmes.
Adaptive research subjects
Rice-cum-fish culture where commercial rice production is developed.
Species identification and selection to suit various ecological conditions of the country.
Breeding, genetics and pilot production of fish fingerlings of popular fish species.
Fish feeds and nutrition, on the basis of local raw materials; formulation and production of good, low-cost fish feeds.
Socio-economic aspects of aquaculture.
Methodology for the effective transfer of research results to fish farmers.
The identification, selection, formulation and execution of these research priorities are the statutory responsibilities of the fisheries research institutes and the universities.
National seminars and workshops are periodically organized to identify the major constraints in aquaculture development. Participants are drawn from FDF, DFRRI, SFDs, universities, professional bodies, the Fisheries Society of Nigeria (FISON), the Nigeria Association of Fish Farmers and Aquaculturists (NAFFA), financial houses and the private sector. At the end of each seminar or workshop, the research institutes identify and formulate projects aimed at removing the constraints on short and medium terms. The selected projects are later presented to the Board of Governors by the Director of each institute for critical appraisal and recommendation; approval is then requested from the supervising ministry for financial allocation.
Nigeria is endowed with numerous fish species in marine, brackish and fresh waters and many have qualities suitable for fish farming (Table 12). Research is therefore essential to select for each ecosystem the best species that are popular, record fast growth in ponds with a good food conversion ratio, are easy to breed and to manipulate in a confined environment.
Scarcity of fish seed has over the last decades constituted a major setback to rapid development of fish farming in Nigeria. Presently, most hatchery production do not reach 10 per cent of the national demand, estimated at 20–50 million fingerlings annually (Ezenwa et al., 1990). Continuous research is crucial on induced breeding, genetic manipulation, development and perfection of simple technologies for the controlled breeding, hatchery management and pilot production of fingerlings of popular species.
Formulation and production of cheap, effective fish feeds using local raw materials remains a major problem for fish farmers in Nigeria. There are very few well organized fish feed mills in the country. Their operational costs make fish feeds expensive and unavailable to over 80 per cent of the fish farmers. In addition to investigating other alternative sources of raw materials, the institutes are also involved in identifying other culturable fish species with short, lower food chains such as tilapias, mullets and Heterotis niloticus and conducting research on the pilot production of live organisms for the rearing of their juveniles.
Land acquisition, as well as fish pond siting and construction, are beyond the reaches of most prospective fish farmers due to deregulation of the economy. Intensive research is therefore mandatory on other alternative forms of culture (cage, pen, enclosures, flood plain culture and homestead culture) that are not capital-intensive for the average rural and urban farmers.
Nigeria has abundant natural and artificial lakes, inland water bodies, estuaries and lagoons (Figure 1). The productivity of these water bodies is declining annually, which results in poor returns to the local fishing communities. Research is required on stock evaluation, identification and selection of relevant species for hatchery production of fingerlings for re-stocking of the water bodies.
Socio-economic benefits of aquaculture for rural and urban communities, as well as the development of simple technologies for the effective transfer of research results are the major thrusts of DFRRI's aquaculture development and research programme. In order to succeed, such a programme must be backed up by well designed research projects.
Proper funding of NIOMR and NIFFR to upgrade hatchery facilities and other infrastructures for pilot production of juveniles of selected fish species and fish feeds, while strengthening also their extension units for effective dissemination of research results to farmers.
Continuous research on identification and selection of cultivable indigenous species, with more emphasis on popular species and export-oriented prawns and shrimps.
Intensified investigations on induced breeding, genetics and improved simple technologies for the pilot production of the catfishes (C. gariepinus; Heterobranchus spp and C. nigrodigitatus), the tilapias (O. niloticus; T. zillii, S. galilaeus), common carp, shrimp (Penaeus notialis) and prawns (Macrobrachium spp.).
Due to the high cost of earthen pond construction in Nigeria, further research is required on other cheaper alternative culture systems (cage, pen, enclosures, flood plain, homestead) and on the economic profitability of each culture system.
Research on the socio-economic aspects of aquaculture to improve the transfer to the farmers of simple technologies from research institutes and universities.
Due to the limited funding of aquaculture research projects, NIOMR, NIFFR and the universities have been mandated to explore the possibilities of receiving foreign technical assistance in the execution of priority projects.
At national level, NIOMR and NIFFR have the statutory mandate since 1975 to conduct applied research in aquaculture.
While NIOMR is involved in marine and brackishwater aquaculture, NIFFR investigates all aspects of freshwater fish farming, including culture-based fisheries. In universities, where facilities are very limited, research is carried out mainly at the postgraduate level. Universities located within the coastal states (University of Lagos, Lagos State University, University of Port Harcourt, Rivers State University of Science and Technology, University of Calabar) concentrate on brackishwater fish farming. Those located in the inland states (University of Nigeria at Nsukka; University of Ibadan; University of Jos; Ahmadu Bello University; University of Agriculture at Abeokuta and Makurdi) are more involved with some aspects of freshwater fish farming.
There is a very reasonable pool of trained aquaculture research personnel in NIOMR and NIFFR (Tables 9 and 10) as well as in Universities, but all staff need to be motivated to ensure that end users benefit from research undertakings (Satia, 1990). Presently, it is difficult to retain trained personnel in all the institutions because of greater attractions in the private sector.
Budgetary allocations for aquaculture research from 1970 to 1980 was extremely poor but there was an improvement during the past decade.
In the rolling plan, 1990–1992, for example, out of a total sum of NGN 700 000 approved in the budget, NGN 340 000 were released and spent by NIOMR on its aquaculture capital project, Research into Fish and Shellfish Breeding for Mass Production of Fish Seeds (see also Table 9). In addition, approximately NGN 700 000 were released, out of a total approved budget of NGN 1.8 million for another capital project at ARAC on the strengthening of research and training facilities. Allocations made to NIOMR in 1991 were rather limited (Table 12). Similar poor funding was recorded at NIFFR and the universities.
Between 1986 and 1989 (Table 5), DFRRI, through the Federal Ministry of Science and Technology, released approximately NGN 1.74 million to the two research institutes for upgrading of hatcheries, feed mills and accessories, and for strengthening of their extension units.
Foreign donor agencies have also assisted in funding specific aquaculture research projects in Nigeria. The International Foundation for Science assisted NIOMR (1975–1981) in funding a research project on the biology of the catfish C. nigrodigitatus, and the hatchery production of fingerlings for distribution to farmers. The European Economic Community is funding a research project at ARAC on ‘Applied Research for the Innovation of a Pond Culture Scheme with Freshwater Fish in the Oil Palm Belt of Nigeria’. Since 1992, a World Bank-assisted aquaculture project is in the pipeline at NIOMR.
Abiodun, A., 1986. Issues in fish farming economics. Experiences from some coastal states of Nigeria. J. West African Fish., (11): 75–88
Afinowi, M.A. and I. Marioghae, 1986. Summary of aquaculture activities in Nigeria. In H. Parles (ed)., Research Priorities for African Aquaculture. I. International Development Research Centre, Canada, DRC-MR 149:83–9
Amadi, I.F., 1989. Financing agriculture: Contributions of the credit institutions to fisheries development in Africa. NIOMR Tech.Pap., 46:20 p.
Anyanwu, P., B. Ezenwa and P. Uzukwu, 1987. Studies on homestead pond programme in Lagos State. NIOMR Ann.Rep.: 19–20
Anyanwu, P., B. Ezenwa and P. Uzukwu, 1989. Fish culture in homestead tanks in Nigeria: Practices, problems and prospects. ICLARM Aquabyte, 2(3): 8–10
Asiaphil Fisheries Corporation, 1979. A prefeasibility study of brackish and freshwater fish farming in Nigeria. Manila, Philippines.
Asiaphil Fisheries Corporation, 1980. Full feasibility studies of three fish farm projects of 500 ha each in Bodo, Buguma, and Pereambir, Rivers State. Manila, Philippines
Ayeni, J.S.O., 1991. Recent achievements of the National Institute for Freshwater Fisheries Research. In J.G. Tobor and B. Ezenwa (eds), Proceedings of CODRI 4th Annual Seminar, pp. 20–23.
Ayoade, J.O. and Oyebande, B.L., 1983. Water resources. In J.S. Oguntoyinbo, O.O. Areola and M. Filani (eds). A geography of Nigeria development. Heineman Ed. Book (Nigeria) Ltd, Nigeria, pp. 71–88.
Dada, B.F., 1976. Present status and prospects for aquaculture in Nigeria. CIFA Tech.Pap., (4, Suppl.1):79–85
Edwards, P. et al., 1991, Tropical aquaculture development: research needs. Washington, World Bank Tech.Pap.Fish.Ser., (151):52 p.
Egwui, B.C., 1986. Yields of the African catfish, Clarias gariepinus (Burchell) from low input, homestead concrete tank. Aquaculture, (55):87–91
Eyo, A.A., 1987. Financing fish farming under the agricultural credit guarantee scheme. In O.A. Ajayi and A.M. Ajana (eds), Proceedings of the Aquaculture Training Programme (ATP) of DFRRI, Lagos, pp. 115–8
Ezenwa, B., 1976. Fish seed production in Nigeria. CIFA Tech.Pap., (4, Suppl.1):441–449.
Ezenwa, B., 1979. Supplementary diet in fish culture and feed formulation technology in Nigeria. NIOMR Occ.Pap., 30
Ezenwa, B., W. Alegbeleye, P.E. Anyanwu P.E and A. Ugwumba, 1986. Cultivable fish seeds in Nigerian coastal waters. A research survey: 1977–1985. FISON Proceedings, pp. 99–112
Ezenwa B., W. Alegbeleye, P.E. Anyanwu and P. Uzukwu, 1990. Cultivable fish seeds in Nigerian coastal waters. (Second Phase: 1986–1989). NIOMR Tech.Pap., 66
FAO, 1989. Aquaculture production (1984–1986). FAO Fish.Circ., (815):106 p.
Fadayomi, N.O. et al., 1982. Report of the World Bank. Nigerian fisheries sector review study. Centre for Agricultural and Rural Development, Department of Agricultural Economics, University of Ibadan, 213 p.
Ita, E.O et al., 1985. A preliminary checklist of inland water bodies in Nigeria with special reference to ponds, lakes, reservoirs and major rivers. Kainji Res.Inst.Tech.Rep., (14)
Nwaduke, F.O., O.A. Ayinla and N.J. Kalio-Abby, 1991. Effect of various doses of acetone dried powdered carp pituitary extract and seasonal changes on fecundity and hatchery propagation of Heterobranchus longifilis (Vol.1840). In J.G. Tobor and B. Ezenwa (eds), Proceedings of 4th CODRI Annual Seminar, pp. 40–48.
Okpanefe, M.O., B. Ezenwa and A. Abiodun, 1984. Aquaculture fish production statistics in Nigeria. NIOMR Tech.Pap., (19)
Okoye, F.C., W.S. Omorinkoba, J.O. Ayanda and E.O. Ita, 1991. Commercial fish farming in earthen ponds: prospects and problems. In J.G. Tobor and B.Ezenwa (eds), Proceedings of 4th CODRI Annual Seminar, pp. 61–70
Otubusin, S.O, J.O. Ayanda, G.O. Opeloye and I.G. Asekome, 1991. Economic feasibility of cage fish farming. In J.G. Tobor and B. Ezenwa (eds), Proceedings of 4th CODRI Annual Seminar, pp. 71–84
Satia, B.P., 1990. National reviews for aquaculture development in Africa. 29. Nigeria. FAO Fish.Circ., (770.29):191 p.
Sivalingam, S., 1972. Fish culture possibilities around Lagos lagoon and results of recent trials. Fed.Fish.Occ.Pap., (13):21 p.
Tobor, J.G., 1985. An appraisal of fisheries development efforts in Nigeria. In E.O. Ita (ed), Proceedings of the 4th Annual Conference of the Fisheries Society of Nigeria (FISON), Port Harcourt, pp. 78–95
Tobor, J.G., 1991. A decade (1981–1990) of fisheries research activities at NIOMR. Hope for self-sufficiency in fish production in Nigeria. In J.G. Tobor and B. Ezenwa (eds), Proceedings of 4th CODRI Annual Seminar, pp. 23–8
Uboma, B.M., et al., 1981. Fish production plan for Nigeria. National Committee on Green Revolution. Study Group Report on Fisheries
Wokoma, S.A. and B.I. Ezenwa, 1982. Construction of fish ponds in the mangrove swamps of the Niger Delta. NIOMR Tech.Pap., (9):27 p.