PD/A CRSP Eighteenth Annual Administrative Report
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Subcontract No. RD010A-04
The University of Michigan, Ann Arbor, Michigan
|James S. Diana||US Co-Principal Investigator, US Regional Coordinator|
|C. Kwei Lin||US Co-Principal Investigator (stationed in Pathumthani, Thailand)|
|Yang Yi||Postdoctoral Researcher (stationed in Pathumthani, Thailand)|
|Barbara Diana||Research Assistant|
Asian Institute of Technology, Pathumthani, Thailand
|Amrit Bart||Host Country Principal Investigator|
|Dao Huy Giap||Research Associate (through April 2000)|
|Chumpol Srithong||Research Associate|
|A.R.S.B. Athauda||Graduate Student (Sri Lanka; partially CRSP funded)|
|Ma Aye Aye Mon||Graduate Student (Burma; partially CRSP funded)|
|Potjanee Nadtirom||Graduate Student (Thailand; CRSP funded)|
|Ngo Van Hai||Graduate Student (Vietnam; partially CRSP funded)|
|A. Weerasooriya||Graduate Student (Sri Lanka; partially CRSP funded)|
The PD/A CRSP has been active in Thailand from the program's inception in 1982. The CRSP, through lead US institution The University of Michigan, has collaborated with the Asian Institute of Technology (AIT) since 1987. AIT is an important regional training center, providing not only excellent research facilities but also regional networking opportunities for outreach activities.
Studies conducted in the reporting period have concentrated on two areas of emphasis: environmental impacts of aquaculture and production optimization. CRSP research on semi-intensive culture of tilapia continues to examine new species and systems, including polyculture of tilapia with predatory snakehead, cultivation of tilapia in ponds planted with lotus for excess nutrient uptake, and tilapia culture in brackishwater ponds. An investigation of polyculture of tilapia and catfish addresses effluent release and pollution concerns. A new Reproduction Control investigation examines the use of ultrasound to induce sex reversal.
The following Ninth Work Plan investigation continued into the current reporting period:
This subcontract was also awarded funding to conduct the following Ninth Work Plan investigations:
Note: The schedule for 9NS2 has been modified. Please see Appendix 5, "Completion Dates for Work Plan Studies," for revised schedule information. The methods for 9NS1 and 9ER3 have been modified. 9RCR8 and 9NS4 were approved after publication of the Ninth Work Plan. The revised methods for 9NS1 and 9ER3 and the 9RCR8 and 9NS4 work plans will appear in the Addendum to the Ninth Work Plan.
CRSP researcher Yang Yi met with David M. Sims from the Sarasawathi Foundation, a Thai nongovernmental organization (NGO), to provide technical advice on integrated cage-cum-pond and fish-livestock farming for a project at the Ban Kai school of Chaiyapoom Province. The Foundation project is intended to provide poor students with a free source of protein through fish farming. Yi also sent information on semi-intensive low-cost tilapia culture to Robert Hartnell, who will use the data in his own low-cost tilapia culture experiment in South Africa under the United Kingdom's Department for International Development Genetics Program.
CRSP researchers at AIT have maintained contacts in Vietnam, including the Research Institute for Aquaculture No. 1, the Socio-Economic Development Center (SEDEC), and the University of Aquaculture and Forestry. Kwei Lin cooperated with SEDEC on coastal zone development and management in the Binh Thuan Province of Vietnam. He then discussed further cooperation with the director of SCALE (SAO (Southeast Asian Outreach) Cambodia Aquaculture at Low Expenditure), and later visited the USAID office in Cambodia.
Lin made a site visit to the Crescent Syndicate Fish Farm in Pakistan to provide technical advice, and he has continued correspondence with the farm via email and telephone.
Researchers at AIT hosted A.M. D'Silva from the University of Arizona and conducted discussions on the technical aspects of tilapia culture. AIT researchers later provided him with technical information on reservoir culture via email. D'Silva also maintains ties with the Philippines Project.
Yi taught a short course on water quality and soil analyses to visiting research staff from the Vietnamese Research Institute for Aquaculture No. 1 in March. Lin taught a water quality management class for visiting Vietnamese masters program students in April. Later in the year, Lin also taught an aquatic ecosystems and water quality management class for masters and doctoral students, and Amrit Bart taught a short-course focusing on hatchery management of finfish. These courses were all held at AIT. Additionally, Lin presented a workshop on pond dynamics to fisheries officers in a workshop hosted by the Japan International Cooperation Agency (JICA) at the Thai Department of Fisheries.
Edwards, P., C.K. Lin, and A. Yakupitiyage.
Semi-intensive pond aquaculture. In: M. Beveridge and B.
McAndrews (Editors), Tilapia Culture and Exploitation.
Chapman and Hall, London. (in press)
Liao, I.C. and C.K. Lin (Editors), 2000. Proceedings of the First International Symposium on Cage Aquaculture in Asia. Asian Fisheries Society, Manila, the Philippines. 312 pp.
Lin, C.K. and K. Kaewpaitoon, 2000. An overview of freshwater cage culture in Thailand. In: I.C. Liao and C.K. Lin (Editors), Proceedings of the First International Symposium on Cage Aquaculture in Asia. Asian Fisheries Society, Manila, the Philippines, pp. 237242.
Lin, C.K. and Y. Yi. Development of integrated aquaculture in Southeast Asia. In: Proceedings of the SEAFDEC Workshop. (in press)
Lin, C.K., J.S. Diana, and Y. Yi. Stocking densities and fertilization regimes for Nile tilapia (Oreochromis niloticus) production in ponds with supplemental feeding. J. World Aquacult. Soc. (in review)
Mon, A.A., 2000. Use of lotus (Nelumbo nucifera) for nutrient retrieval from pond mud. M.S. Thesis, Asian Institute of Technology, Bangkok, Thailand.
Yi, Y., 1999. Modeling growth of Nile tilapia (Oreochromis niloticus) in a cage-cum-pond integrated culture system. Aquacult. Eng., 21:113133.
Yi, Y. and C.K. Lin, 2000. Integrated cage culture in ponds: Concepts, practice and perspectives. In: I.C. Liao and C.K. Lin (Editors), Proceedings of the First International Symposium on Cage Aquaculture in Asia. Asian Fisheries Society, Manila, the Philippines, pp. 217224.
Yi, Y. and C.K. Lin. Analyses for various inputs for pond culture of Nile tilapia (Oreochromis niloticus): Profitability and possible environmental impacts. Aquacult. Econ. Manage. (accepted)
Yi, Y. and C.K. Lin. Effects of biomass of caged Nile tilapia (Oreochromis niloticus) and aeration on the growth and yields in a cage-cum-pond integrated culture system. Aquaculture. (revised)
Lin, C.K. and K. Kaewpaitoon. An overview of
freshwater cage culture in Thailand. Presented to the First
International Symposium on Cage Aquaculture in Asia
at Tungkang, Taiwan, 26 November 1999.
Lin, C.K. and Y. Yi. Development of integrated aquaculture in Southeast Asia. Presented to the Workshop on Responsible Aquaculture Development in Southeast Asia at the Southeast Asian Fisheries Development Center (SEAFDEC), Iloilo, Philippines, 1115 October 1999.
Wu, Z.W., J.W. Guo, and Y. Yi. Current status and sustainability of cage culture in reservoirs: A case study in China. Presented to the First International Symposium on Cage Aquaculture in Asia at Tungkang, Taiwan, 26 November 1999.
Yi, Y. and C.K. Lin. Integrated cage culture in ponds: concepts, practice and perspectives. Presented to the First International Symposium on Cage Aquaculture in Asia at Tungkang, Taiwan, 26 November 1999.
Workshop on Responsible Aquaculture Development
in Southeast Asia at the Southeast Asian Fisheries Development Center (SEAFDEC), Iloilo, Philippines,
1115 October 1999. (Lin)
First International Symposium on Cage Aquaculture in Asia at Tungkang, Taiwan, 26 November 1999. (Lin, Yi)
PD/A CRSP Annual Meeting at New Orleans, Louisiana, 31 January2 February 2000. (Bart, Diana)
Aquaculture America 2000 at New Orleans, Louisiana, 25 February 2000. (Diana)
International Conference on Aquaculture in the Third Millennium at Bangkok, Thailand, 2025 February 2000. (Lin, Yi)
This study was initiated in February of 2000 and is expected to be completed by December 2000. The experiment is designed to reveal the application of cavitation-level ultrasound to enhance delivery of androgens using immersion protocol. This experiment is in two parts: 1) a preliminary study to detect the effect of ultrasound on sex reversal using two commonly available androgens in Asia (17-methyltestosterone and andostrenedione); and 2) an examination of the effects of two novel and more potent hormones using a protocol established by CRSP researchers. In the preliminary experiment, the variables tested were androgens (17-methyltestosterone and andostrenedione), duration of treatment (1 or 2 h), and hormone concentrations (100 or 500 mg l-1). Fish were treated on days 10 and 13 post-hatch. This study has been completed, and the results clearly indicate an effect of ultrasound. Although the rate of sex reversal was less than 100% in all cases, significant differences were observed between those treated with and without ultrasound in two-hour treatments, irrespective of the hormone concentration used. The highest number of males (88 to 94%) was obtained from the two-hour ultrasound-treated group, while the lowest number of males (44 to 75%) was observed from the same group without application of ultrasound. The second experiment is underway to examine the hormones trenbolone acetate (TA) and 17-methyldihydrotestosterone (MDHT) at different concentrations (250 or 500 mg l-1) and duration of treatment (1 or 2 h). We expect a higher and more consistent rate of sex reversal between treatments by varying these parameters.
This experiment started in February 2000 and will be terminated in September 2000. The purposes of the experiment were to: 1) assess the pond mud nutrient recovery by lotus plants (Nelumbo nucifera); 2) assess pond mud characteristics after lotus-fish culture; and 3) compare fish growth in ponds with and without lotus integration. There were three treatments: A) lotus-fish integrated culture; B) fish alone; and C) lotus alone. Lotus plants were transplanted at 20 plants per pond in treatments A and C. Sex-reversed all-male Nile tilapia (Oreochromis niloticus) fingerlings were stocked at 2 fish m-2 in ponds of treatments A and B. Treatment ponds stocked with tilapia (treatments A and B) were fertilized weekly with urea and triple superphosphate (TSP) at rates of 28 kg N and 7 kg P ha-1 wk-1. No fertilizer was applied in treatment ponds with lotus alone (treatment C). Fish growth and survival will be assessed only at the end of the experiment due to sampling difficulties. Fish and lotus plants will be harvested by draining. Nutrient budgets will be determined for all ponds. Partial budgets will be estimated for cost of inputs and value of fish and lotus.
An experiment was conducted in eighteen 200-m2 earthen ponds at the Asian Institute of Technology, Thailand, during May through October 1999. The purposes of the experiment were to: 1) assess the efficiency of snakehead (Channa striata) in controlling overpopulation of mixed-sex Nile tilapia (Oreochromis niloticus) in ponds and 2) assess growth and production characteristics of Nile tilapia in monoculture and polyculture with snakehead. The six treatments were: A) monoculture of sex-reversed tilapia; B) monoculture of mixed-sex tilapia; C) polyculture of mixed-sex tilapia and snakehead at 10:1 ratio; D) polyculture of mixed-sex tilapia and snakehead at 20:1 ratio; E) polyculture of mixed-sex tilapia and snakehead at 40:1 ratio; and F) polyculture of mixed-sex tilapia and snakehead at 80:1 ratio. All ponds were fertilized weekly with urea and triple superphosphate (TSP) at rates of 28 kg N and 7 kg P ha-1 wk-1. Sex-reversed all-male and mixed-sex Nile tilapia were stocked at 2 fish m-2 at sizes of 42.3 ± 1.0 g and 31.0 ± 0.5 g, respectively. Snakehead dug holes in the pond dikes and moved freely between ponds and the canal. The experiment showed that snakehead can control overpopulation of mixed-sex Nile tilapia. This experiment is currently being repeated, starting in March 2000 and terminating in September 2000.
This experiment was started in June and will be terminated in November 2000. The purposes of the experiment were to: 1) determine appropriate fertilization regimes in brackishwater ponds; 2) investigate nutritional value and digestibility of specific marine phytoplankton as food organisms to tilapia; and 3) exploit underutilized or abandoned shrimp ponds for tilapia production. Two fertilization regimes (28 kg N and 7 kg P ha-1 wk-1 and 28 kg N and 14 kg P ha-1 wk-1) and three levels of salinity (10, 20, and 30) were tested by a 2 x 3 factorial design. Eighteen cement ponds (6 m2) were filled with 15 cm of soil and then flooded with water of differing salinities by diluting hypersaline water to the appropriate concentrations. Thai red tilapia fingerlings were stocked at 2 fish m-2. All ponds were fertilized weekly at the two rates using urea and triple superphosphate (TSP). Water levels will be maintained at 0.8 m depth, and salinity levels will be checked and adjusted weekly. Plankton composition will be assessed biweekly. Partial budgets will be calculated to estimate cost of inputs and value of fish crop.
An experiment was conducted to test using effluents from intensive hybrid catfish (Clarias macrocephalus x C. gariepinus) ponds as nutrient inputs for Nile tilapia (Oreochromis niloticus) culture, which would reduce effluent effects from catfish culture, gain extra fish production at low cost, and possibly make aquaculture more profitable to farmers. Three treatments were done with three replicates each in seven 200-m2 earthen ponds at the Asian Institute of Technology (AIT), Thailand, for 87 days. The treatments were A) catfish alone (control); B) catfish and tilapia without artificial water circulation; and C) catfish and tilapia with artificial water circulation. The pond used for control treatments was partitioned by 1.0-cm mesh plastic net into three equal compartments with 67 m2 each for the replicates. The six other ponds were partitioned into two compartments: 1/3 for catfish and 2/3 for tilapia. Sex-reversed all-male Nile tilapia were stocked at 2 fish m-2, and catfish at 25 fish m-2. Catfish were fed twice daily with commercial pelleted feed at rates of 3 to 10% body weight per day. During the first month, tilapia compartments were fertilized weekly using urea and triple superphosphate (TSP) at rates of 28 kg N and 7 kg P ha-1 wk-1. In the artificial water circulation treatment, the water in the catfish compartment was continuously circulated by a submersed pump to the tilapia compartment at a rate of one exchange per week, starting the second month.
There were no significant differences in growth performance of catfish among all treatments. Mean catfish weight at harvest ranged from 237.8 to 249.0 g, giving extrapolated net yields of more than 200 t ha-1 yr-1. Final mean tilapia weight was 114.9 g in treatment B and 115.0 g in treatment C without significant differences. Although there was no significant difference in survival rates between treatments B (92%) and C (70%), high mortality of tilapia was observed in two replicates of treatment C due to heavy waste loading in the tilapia compartment by artificial water circulation. Extrapolated net tilapia yields (7.2 ± 1.3 t ha-1 yr-1 in treatment B and 4.9 ± 0.3 t ha-1 yr-1 in treatment C) obtained by using catfish wastes in this study were comparable to those achieved in organically and inorganically fertilized tilapia ponds. Nutrient budgets showed that total nitrogen and total phosphorus contents in pond effluents in treatments B and C were significantly lower than those in treatment A. Nile tilapia recovered 3.30 and 2.12% of total nitrogen and 1.29 and 0.84% of total phosphorus from feed wastes andfertilizer inputs in treatments B and C, respectively. Concentrations of total Kjeldahl nitrogen (TKN), total phosphorus (TP), and soluble reactive phosphorus (SRP) were also significantly lower in treatments B and C than in treatment A. This experiment indicates that Nile tilapia can effectively recover nutrients contained in wastewater of intensive catfish culture and suggests that natural water circulation between catfish and tilapia compartments can reduce nutrient contents in pond effluents and is cost-effective.
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