1.1 BACKGROUND TO THE STUDY
The world production of farm shrimp in 1996 was valued at over $10 billion. In Nigeria, the bulk of producers are also small farmers that operate on average on 15 ha of ponds. Penaeus monodon is the most important farmed shrimp species West Africa (Dunlap, 2002). Infectious diseases are consistently identified as the major threat to the long-term viability of the shrimp farming industry in the west Africa sub-region, and recurrent massive outbreaks of viral diseases have caused serious financial losses among smallholders (Dunlap, 2002). To address this situation, researchers have worked towards developing effective farm-level, shrimp disease-control programs. This study will produce relevant expertise and information, but because of lack of definitive, on-farm program validations and inadequacies in the delivery of extension programs, smallholders have generally failed to benefit in the previous practical disease control programs set up by government.
Shrimp farming is a clear example of outstanding development in the aquaculture industry in Nigeria (Lin, 1989). In the last 10 years, shrimp production worldwide has been more than doubled. This rapid development came at a cost and the need for a more sustainable approach to reduce the environmental impact, improve shrimp health and quality became clear to several stakeholders. A Consortium Program involving the World Bank, the World Wildlife Fund (WWF), and the Food and Agriculture Organization of the United Nations (FAO) was initiated in 1999 and was later joined by the United Nations Environment Program (UNEP). Through this program, principles for responsible shrimp farming were developed following a process of stakeholder consultations (WB/FAO/WWF/UNEP, 2005). At the same time Better Management Practices to help farmers in the implementation of those principles were also developed and their implementation by farming communities promoted. Facing a compelling need to control shrimp diseases such as White Spot Disease (WSD), which continued to claim a huge share of shrimp harvests, and the resulting quality problems associated with the use of banned chemicals and antibiotics, the government took a leading role in the process by taking part in stakeholder consultations and by supporting both directly and indirectly the implementation of best management practice approaches (FAO/NACA, 2001).
Despite the explosive growth in world production of cultivated shrimp, there have also been staggering, periodic losses due to disease. A global shrimp survey by the Global Aquaculture Alliance (GAA) in 2001 revealed a rough overall loss to disease of approximately 22% in a single year. Given a total production of 700,000 metric tons in 2001 valued at roughly US$8 per kg, this translated into an estimate of about US$1 billion loss in a single year. This was probably a conservative estimate, since farms with very bad results may not have responded to the survey. Thus, a conservative estimate for the total loss to disease over the past 15 years may be in the order of US$15 billion (Chen et al, 2005). This illustrates the importance of disease control to the industry. With respect to disease agents, the GAA survey revealed that 60% of losses were attributed to viruses and about 20% to bacteria. Thus, the majority of our effort on disease control (80%) should clearly be focused on viral and bacterial pathogens. Indeed, that has been the case as that should be the focus point of practical disease control programs. The control effort must emphasize prevention, and this has required the development of good diagnostic tools, trained personnel and a better understanding of the hosts and their pathogens.
1.2 STATEMENT OF THE PROBLEM
Serious viral and bacterial disease outbreaks revealed that the shrimp industry had to be better prepared with more knowledge and practical approaches about shrimp and their pathogens so that disease prevention methods could be improved and effective disease control measures should be adopted. This need shifted attention to biosecurity, that is, possible methods of cultivating shrimp in restricted systems designed to prevent the entry of potential pathogens and organization pf practical disease control programs. The industry also realized that a good number of disease outbreaks originated from careless transboundary movement of contaminated but grossly normal aquaculture stocks. More than any other problem, the white spot shrimp virus pandemic served as a “wake up” call that shocked the industry into concerted actions. The catastrophic losses had serious impacts on whole national economies all the affected countries including America. They resulted in increased support for research and development/delivery of practical disease control programs on shrimp diseases (including epidemiology) and in increased farmer awareness of the need for biosecurity.
1.3 OBJECTIVES OF THE STUDY
The following are the objectives of this study:
1. To examine various shrimp diseases and how they affect productivity of small scale shrimp farmers in Nigeria.
2. To develop and deliver a practical disease control programs for small scale shrimp farmers in Nigeria.
3. To identify the effect of practical disease control programs for small scale shrimp farmers in Nigeria.
1.4 RESEARCH QUESTIONS
1. What are the various shrimp diseases and how do they affect productivity of small scale shrimp farmers in Nigeria?
2. How can a practical disease control programs be developed and delivered for small scale shrimp farmers in Nigeria?
3. What are the effects of practical disease control programs for small scale shrimp farmers in Nigeria?
1.5 SIGNIFICANCE OF THE STUDY
The following are the significance of this study:
1. The results from this study will educate on approaches to develop and deliver a practical disease control program for small scale shrimp farmers in Nigeria. It will also educate on way to increase productivity in shrimp farming through effective disease control measures and prevention of diseases.
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 the approaches used in developing and delivering a practical disease control program for small scale shrimp farmers 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.
FAO/NACA. 2001. Manual of procedures for the implementation of the Asia regional technical guidelines of health management for the responsible movement of live aquatic animals. FAO Fisheries Technical Paper No. 402, Supplement 1. Rome, FAO. 106 p.
Dunlap, P.V. 2002. Quorum sensing and its potential application to vibriosis, pp. 59-71. In Lavilla-Pitogo, C.R, and Cruz-Lacierda, E.R. (eds.). Diseases in Asian aquaculture IV. Fish Health Section, Asian Fisheries Society, Manila.
Chen, J.-Y., Chuang, H., Pan, C.-Y., Kuo, C.-M. 2005. cDNA sequence encoding an antimicrobial peptide of chelonianin from the tiger shrimp Penaeus monodon. Fish Shellfish Immunol. 18:179-183.
Lin, C.K. 1989. Shrimp culture in Taiwan, What went wrong? World Aquaculture 20:19-20.