1.1 BACKGROUND TO THE STUDY
Inland aquaculture is a technology driven industry which relies heavily on research to develop new and improved species and the appropriate technology for commercial production. At present, inland aquaculture in Nigeria is dominated by finfish and exciting new industry initiatives are presently underway that are exploring the culture of indigenous shellfish farming. However, despite these enterprises there is considerable scope for the sector to diversify further as a way of improving the production in the sector. In fact, expanding and improving the species base can be regarded as a prerequisite for the development of a globally competitive industry as well as for bringing appropriate technology to the small-scale, community-based operation. Nigeria is by far the most important state for the direct human consumption of fish, owing to a mixture of large population and relatively high per capita consumption levels. Its costal fisheries resources are depleted or close to depletion, so little growth could be expected from capture fisheries. Therefore inland aquaculture production must improve and increase to meet the further demands of the population.
The present study is intended to highlight some directions that could help arrive at more widespread and improved fisheries prosperity. There is now burgeoning knowledge, wide range of tool and scientific and technical approaches including insights into social, economic and cultural conditions. Inland aquaculture has relied on hatchery-produced seed which does not lead to overfishing of wild stocks. Overfishing has been reported in connection with tropical marine fish and shrimp culture, causing depletion of wild stocks (Beveridge and Phillips, 1990). The amount of seed available is not always enough, causing ponds to remain un-stocked, thus providing mosquitoes and snails with ideal habitats. This can increase the prevalence of schistosomiasis and malaria, as well as other mosquito-transmitted diseases such as filariasis. Fish seed production is a specialized farming system practiced by skilled farmers only.
An increasing number of hormones and growth promoters are used to change the sex, productive viability and growth of cultured organisms. It is capital intensive and time consuming. A fingerling production technique involves a series of breeding and feeding activities that can be grouped under several successive operational stages. Aquaculture activities are being carried out with floating cage made from reinforced foams. These reinforced foams have excellent resistance to a wide range of chemicals and solvents and is compatible with water and solvent based coatings and adhesives, polyester and epoxy resin-based coatings. Rigid polyurethane foam is highly impervious to fungi and mould growth, non-fibrous, odourless and non-tainting.
The first attempt at fish farming and inland aquaculture was in 1951 at a small experimental station in Onikan, Lagos, where different tilapias were cultured while modern pond culture started with a pilot fish farm in Panyam, Plateau State for rearing the common/mirror carp, Cyprinus carpio following the disappointing results with Tilapia culture. The success led to the establishment of fish farms at Buguma in Rivers state, Abagana in Anambra state and Agodi Garden farm in Ibadan. Although, the major species cultured include fin-fish (tilapias, catfish, and carp), catfishes of the family, Clariidae are the mostly farmed fish. Since the culture of Clarias gariepinus through hypophysation was initiated in Western Nigeria in 1973 (Elliot, 1975), the procedure has been widely practiced throughout Nigeria. The Clarias (Clarias anguillaris and Clarias gariepinus) and Heterobranchus (Heterobranchus longifilis and Heterobranchus bidorsalis) clariid catfish, are the most important fish species used in inland aquaculture in Nigeria. This species has shown considerable potential as a fish suitable for use in intensive aquaculture. This fish grows rapidly, it is disease and stress resistant, high fecundity, sturdy due to the presence of arborescent air-breathing organ and highly productive in polyculture, ability to grow on a wide range of natural and low cost artificial foods and ability to withstand low oxygen and pH levels (Zheng et al., 1988; Fagbenro et al., 1993). Sarotherodon galileaus, Tilapia zillii, Tilapia guineensis, Sarotherodon melanotheron, and Oreochromis niloticus are the cultured tilapia species.
However Oreochromis niloticus appears to be more popular among fish farmers. It is a popular species, endemic to most part of the country and grown by many farmers in inland aquaculture (Maluwa and Costa-pierce, 1993). This species has cultural advantages characteristics such as ease of production, ready acceptance of artificial feed, fast growth, and adaptability to a wide range of environmental conditions. One of the major problems in tilapia culture is its highly prolific nature having early maturity which results in stunted populations because energy is being diverted to gonadal development instead of somatic growth (Gale et. al., 1999). Current advances in aquaculture production have been achieved through the application of genetic principles which includes selective breeding, hybridization, chromosome manipulation, sex reversal, gene transfer and polyploidy (Aluko and Olufeagba, 1999). Hybridization has been used to increase growth rate, manipulate sex ratios, produce sterile animals, improve flesh quality, increase resistance, improve tolerance to environmental extremes and improve a variety of other traits that make aquatic animals production more profitable (Dunham et al., 2001).
Hybridization between species can also result in offspring that are sterile or have diminished reproductive capacity. The more distantly related the two species, the greater likelihood of their hybrid being sub-viable or sterile (Chevassus, 1983). The hybrid cross between Heterobranchus and Clarias species is receiving considerable attention in Nigeria’s aquaculture industry. These hybrids have been reported to show heterosis (Madu et al., 1992; Salami et al., 1993). Aquaculture has the unique opportunity and responsibility to conserve natural (wild) populations while maintaining desirable production traits as disease resistance, fast and efficient growth, increased product yield, and lower input costs. Therefore, to support the growth of aquatic food consumption, domestication and genetic improvement of the cultivated species is a critical R&D need.
1.2 STATEMENT OF THE PROBLEM
Inland aquaculture is dependent on progressive science and technological innovation to be competitive in world seafood markets, sustainable in development, and compatible with evolving social expectations. Productive aquaculture will require building a next generation of human capacity in diverse scientific fields to find solutions to scientific, economic, social, and management needs of aquaculture systems, natural resources, and 21st century communities. Public education and understanding of new areas of science, contemporary issues, and performance of diverse aquaculture systems create a scientifically literate population leading to sound policy-making. Science-based information, integrated with new information delivery systems, offers new outreach opportunities to the public and the aquaculture community. However, this study is looking into how there can be improvement in technologies used in inland aquaculture in Nigeria.
1.3 OBJECTIVES OF THE STUDY
The following are the objectives of this study:
1. To examine the technologies been used for inland aquaculture in Nigeria.
2. To identify the improvements in technologies been used in inland aquaculture in Nigeria.
3. To identify the factors hindering improvement in technologies for inland aquaculture in Nigeria.
1.4 RESEARCH QUESTIONS
1. What are the technologies been used for inland aquaculture in Nigeria?
2. What are the improvements in technologies been used in inland aquaculture in Nigeria?
3. What are the factors hindering improvement in technologies for inland aquaculture in Nigeria?
1.5 SIGNIFICANCE OF THE STUDY
The following are the significance of this study:
1. The findings from this study will expatiate on the modern technologies that can be adopted in the industry of inland aquaculture in Nigeria with the aim of bringing improvement to the sector.
2. This research will be a contribution to the body of literature in the area of the effect of personality trait on student’s academic performance, thereby constituting the empirical literature for future research in the subject area.
1.6 SCOPE/LIMITATIONS OF THE STUDY
This study will cover all the modern technology been used in inland aquaculture industry all over the world. It will also cover the level of practice of inland aquaculture in Nigeria.
LIMITATION OF STUDY
Financial constraint– Insufficient fund tends to impede the efficiency of the researcher in sourcing for the relevant materials, literature or information and in the process of data collection (internet, questionnaire and interview).
Time constraint– The researcher will simultaneously engage in this study with other academic work. This consequently will cut down on the time devoted for the research work.
Aluko, P. O. and Olufeagba, S. O. (1999). Genetics and food security in Nigeria in the 21st century. Genetically modified fishes; risk and prospects. P.205-206. Genetic Society of Nigeria Annual Conference.
Chevassus, B. (1983). Hybridization in fishes. Aquaculture 33:245-262.
Dunham, R. A.; Majumdar, K.; Hallerman., E. and Main G. (2001). Review of the status of aquaculture genetics. In K.R.P. Subasinghe, P. Buemo, M. J.
Philipa; C. Haugh; S. E. and J. R. Arhur (eds). Aquaculture in the third millennium. Proceedings of the conference on Aquaculture in the third millennium, Bangkok, Thailand, 20-25 February, 137-186.
NACA, Bangkok and FAO, Rome. Elliot, O. O. (1975): Biological observation of some species used for aquaculture in Nigeria.
Fagbenro, O. A., Adedire, C.O., Owoseni E. A. and Ayotunde E. O. (1993). Studies on the biology and Aquacuclture potential of feral catfish; Heterobranchus bidorsalis (Geoffrey St Hillaire 1904). Tropical zoology 6: 67-79.
Gale, W. L.; Martin, S. F.; Michael, L.; Contretras-Sanchez, W. M and Scherck, C. B. (1999). Masuilinization of Nile tilapia (Oreochromics niloticus) by immersion in androgens. Aquaculture 178: 349 – 357.
Madu, C. T.; Mohammed, S.; Mezie, A.; Isa, J. and Ita, E. O.(1992). Comparative growth, survival and morphometric characteristics of Clarias anguillaris, Heterobranchus bidorsalis and their hybrid fingerlings. Annual Report of the National Institute for Freshwater Fisheries Research, New Bussa, Nigeria. 7pp.
Maluwa, O. A and Costa- Pierce B. A. (1993). Effect of broodstock density on Oreochromics chiranus fry production in hapas. Journal of Applied Aqualculture 2:63 – 74.