5. Conclusions
This experiment determined that the growth and yield of 50 Nile tilapia mm3 stocked in cages located in ponds with stagnant water was the best stocking density tested. The study also demonstrated that the amount of waste nutrients generated by large tilapia from one cage per pond was insufficient to fertilize the pond for rearing small tilapia in open pond. This tilapia-tilapia cage-cum-pond integrated culture system is particularly appropriate for small-scale farmers in countries such as Thailand, where large tilapia (> 500 g) fetch higher market price than 250-300 g tilapia. This approach is beneficial not only to augment total pond carrying capacity but also to recycle the wastes from cage culture. Further experiments should be conducted to determine appropriate biomass in cages required to support maximum fish production and to maintain acceptable water quality in open ponds.
Acknowledgements
The authors wish to thank MS B. Chintana, Mr. Y. Manoj and Mr. P. Supat for their field and lab. assistance. This research is a component of the Pond Dynamics/Aquaculture Collaborative Research Support Program (CRSP) supported by the US Agency for International Development, Grant No. DAN-4023-G-00-003 l-00, and by contributions from the University of Hawaii, the University of Michigan, Michigan State University, the Royal Thai Department of Fisheries, and the Asian Institute of Technology. This is PD/A CRSP Accession No. 1127. This is also a part of Mr. Yang Yi’s dissertation for the degree of Doctor of Technical Science supported by a research associateship from the project.