Aquaculture CRSP 21st Annual Technical Report
Transfer of Production Technology to Nepal for Nile Tilapia, Oreochromis niloticus
Tenth Work Plan, Product Diversification Research 3 (10PDVR3)
Given the need for the production of low-input animal protein in Nepal, the technical feasibility of tilapia production was assessed. Delayed feeding and fertilization-only treatments as well as stocking in cooler versus warmer temperature were compared between Genetically Improved Farmed Tilapia (GIFT) and Chitralada strains in southern Nepal conditions. While reasonably good growth and final weight at harvest were achieved, no significant differences were observed between delayed feeding and non-feeding treatments (P > 0.05). Similarly, no significant difference in growth rate and final weight at harvest was observed between GIFT and Chitralada strains (P > 0.05). Stocking during the month of August (29 to 35oC) resulted in a faster growth rate with fish reaching market size (100 g) within three months. Fish stocked in December (16 to 25oC) required over five months to reach the same size. Results of this study indicate that low-input (fertilization only) tilapia culture is feasible nine months of the year without need for overwintering using either GIFT or Chitralada strain. Moreover, stocking during the early spring (March or April), when morning temperature reaches 25oC, would provide at least two crops (four-month cycle) annually.
CRSP studies have made significant contributions to aquaculture of Nile tilapia, Oreochromis niloticus. These contributions include determination of optimal fertilization regimes for warm and cool weather conditions (Brown and Bolivar, 2001; Veverica et al., 2001), feeding rates and methods (Diana, 1997), production of monosex populations (Green and Teichert-Coddington, 1994; Phelps and Warrington, 2001), and polyculture of tilapia with other species (Syzper and Hopkins, 1997). The tilapia production industry, particularly in southeast Asia, has benefited a great deal from these and other innovations. Problem-based research studies at the Asian Institute of Technology (AIT) in Thailand have played a pivotal role in providing technical and research support that has facilitated the industry to expand in many different areas.
Additionally, low-input tilapia production has especially benefited resource-poor farmers in southeast Asia. Small-scale tilapia growers tend to consume their own fish, thus production increases have provided high-quality protein
in household diets. Although fish is highly desirable in the Nepalese diet, annual consumption is only 1 kg per person (Edwards, 1998). Tilapia, lauded as a low-input aquaculture species, has the potential to provide cheap protein in a daily diet if culture technology is developed to benefit small-scale farmers. Unfortunately, tilapia production in Nepal suffers from lack of seed and production technology.
Lack of tilapia production in Nepal is also partly due to previous government policy to not introduce exotic species that might have negative impacts on local biodiversity and indigenous species. Although Nile tilapia was first transported to Nepal in 1985 and held in various government research stations for research and development purposes (Pullin, 1986), the origin of these strains is unclear, and further development work has not been carried out. There is an increasing need-driven interest among farmers to raise tilapia, evidenced by proliferation of imported seed from neighboring India across the open border. A number of farmers have brought tilapia seed to stock in their ponds and hapas. This uncontrolled and unchecked introduction of tilapia may have a negative impact on the livelihood of