PD/A CRSP Nineteenth Annual Administrative Report
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Subcontract No. RD010A-04
The University of Michigan, Ann Arbor, Michigan
|James S. Diana||US Principal Investigator, US Regional Coordinator|
|C. Kwei Lin||US Principal Investigator (stationed in Pathumthani, Thailand)r|
Asian Institute of Technology, Pathumthani, Thailand
|Amrit Bart||Host Country Principal Investigator|
|Yang Yi||Host Country Principal Investigator|
|Chumpol Srithong||Research Associate (through November 2000)|
|Htin Aung Kyaw||Research Associate (through January 2001)|
|Vu Cam Luong||Research Associate (May and June 2001)|
|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 (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 concentrated on two areas of emphasis: environmental impacts of aquaculture and production optimization. CRSP research on semi-intensive culture of tilapia continued 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 addressed effluent release and pollution concerns. An additional investigation examined the use of ultrasound to enhance hormone-induced sex reversal.
The following Ninth Work Plan investigations 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 was modified. The schedule and methods for 9NS1 were modified. 9NS4 was approved after publication of the Ninth Work Plan. The revised schedule and methods for 9NS1 and 9NS2 and the 9NS4 work plan appear in the Addendum to the Ninth Work Plan. 9NS5, 9ADR11, and 9RA1 were approved after the publication of the Addendum to the Ninth Work Plan. The work plans for these investigations will appear in the Second Addendum to the Ninth Work Plan.
Bart visited Nepal (Kathmandu, Bitatnagar-Tarahara, Rampur, and Pokhara) to determine a research location suitable for a CRSP companion site and met there with Bhola Pradhan, Director of the Nepal Agricultural Research Council, and A.K. Rai, the Fisheries Station Chief for the Council. Bart also visited with three graduates from the AIT aquaculture program at the Institute of Agriculture and Animal Science in Rampur, where all three teach. The Asian Development Banksupported site in Tarahara was selected as the companion site.
Yi traveled to Bangladesh where he discussed potential CRSP collaborations with Abdul Wahab of Bangladesh Agricultural University, John Grover of the International Center for Living Aquatic Resources Management (ICLARM) Office in Bangladesh, and Anwara Begum Shelly of the Caritas Fisheries Program in Bangladesh. Yi also corresponded via email with Bitu D'Costa, Executive Director of Caritas; Thomas Costa, Development Director of Caritas; Mokarrom Hossain, Senior Regional Manager (Fisheries) of the Bangladesh Rural Advancement Committee (BRAC); Greg Chapman, Rice-Fish Project Coordinator, CARE-Bangladesh; and Mr. Marahman of the NGO PROSHIKA, regarding potential collaboration between Caritas and the CRSP.
Lin traveled to Vietnam to visit Can Tho University and the University of Agriculture and Forestry in Ho Chi Minh City to engage in research collaboration.
James Rakocy, University of the Virgin Islands, visited AIT and discussed with Lin, Bart, and Yi the potential for future collaboration. Additionally, Syed Mannan, Director of United Aqua Farms (Bangladesh), visited AIT and discussed possibilities for future collaboration in tilapia culture with Lin and Yi.
Marc Verdegem and Anne van Dam of Wageningen University similarly visited AIT in April to discuss the possibilities of future collaboration with Lin and Yi.
Yi provided technical information on supplemental feeding of tilapia to Randall Reid Bevis, a member of a Christian NGO tilapia project in Chiang Mai, Thailand. Yi also provided technical information on tilapia culture to the Chiang Mai Rehabilitation Center in Thailand.
Lin, Yi, and Bart discussed aquaculture development with Mr. Rabindra and his colleague, both representatives of the Department of Aquaculture, Nepal.
Bjørn Myrseth, President of Marine Farms ASA, Norway, visited AIT. Yi briefed him on the PD/A CRSP and provided information on tilapia brackishwater culture.
Muhammad Mustafizur Rahman, a research assistant from Bangladesh Agricultural University, was invited to visit AIT and several fish farms in Thailand 6 to 14 June 2001. CRSP researchers at AIT briefed him on the history and current activities of the PD/A CRSP and trained him in analysis of water quality parameters using PD/A CRSP standard methods in data collection, data management, and data analysis.
Bart presented a lecture series to the Faculty of Aquatic Sciences, Burapa University, Chonburi, Thailand, on the sexual differentiation of teleost fish using tilapia as one of the model species.
Bart also worked with University faculty to improve aquaculture curriculum and teacher training in Bangladesh for the Support for University Fisheries Education and Research Project funded by the UKs Department for International Development (DFID).
Lin taught a water quality analysis course at the Research Institute for Aquaculture No. 1, Vietnam, in December 2000. Additionally, Lin gave a seminar on the status of aquaculture and fisheries management in the Mekong Delta in Jakarta, Indonesia, on 5 April 2001.
Yi presented a day-long lecture on Small-Scale/Rural Aquaculture Development for Rural Livelihood and Poverty Alleviation to 30 senior fisheries staff from Asia, Africa, South America, and Australia. The lecture was organized by the Asia-Pacific Regional Research and Training Center for Integrated Fish Farming at Wuxi, China, on 30 October 2000. Yi also gave a half-day lecture on tilapia production to a group of five Indian senior fisheries staff in a training course organized by the Network of Aquaculture Centres in Asia-Pacific (NACA) on 16 December 2000.
Athauda, A.R.S.B., 2000. Ultra-sound immersion
techniques to improve the efficiency of sex inversion of male
tilapia population. M.S. thesis, Asian Institute of
Technology, Pathumthani, Thailand.
Lin, C.K., M.K. Shrestha, Y. Yi, and J.S. Diana, 2001. Management to minimize the environmental impacts of pond effluent: Harvest draining techniques and effluent quality. Aquacultural Engineering, 25(2):125-135.
Yakupitiyage, A. and Y. Yi. Feeds in small-scale aquaculture. In: Utilizing Different Aquatic Environments for Small-Scale Aquaculture. (in press)
Yi, Y. and C.K. Lin, 2000. Analyses for various inputs for pond culture of Nile tilapia (Oreochromis niloticus): Profitability and possible environmental impacts. In: K.Fitzsimmons and J. Carvalho Filho (Editors), Proceedings of the Fifth International Symposium on Tilapia Aquaculture. Rio de Janeiro, Brazil, pp. 247257.
Yi, Y. and C.K. Lin, 2001. 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, 195:253-267.
Yi, Y. and C.K. Lin. Role of low-cost fertilization in inland pond aquaculture. In: Utilizing Different Aquatic Environments for Small-Scale Aquaculture. (in press)
Yi, Y., C.K. Lin, and J.S. Diana. Comparison of economic returns for various strategies of Nile tilapia (Oreochromis niloticus) pond culture. Asian Fisheries Science. (in review)
Yi, Y., C.K. Lin, and J.S. Diana. Hybrid catfish (Clarias macrocephalus ¥ C. gariepinus) and Nile tilapia (Oreochromis niloticus) culture in an integrated pen-cum-pond system: Growth performance and nutrient budgets. Aquaculture. (in review)
Yi, Y., C.K. Lin, and J.S. Diana. Recycling feeding wastes through integration of intensive and semi-intensive culture. In: Utilizing Different Aquatic Environments for Small-Scale Aquaculture. (in press)
Yi, Y., C.K. Lin, and J.S. Diana. Waste recycling in fish pond culture through integrated cage-cum-pond and pen-cum-pond culture systems. In: Proceedings of the Third World Fisheries Congress. (in review)
Bart, A.N. Seed production of farmed fish: Critical issues
for Asia. Presented to the Ag-Asia 2000 Conference
at Bangkok, Thailand, 912 November 2000.
Bart, A.N. The use of ultrasound in mass marking of fish population, drug delivery, DNA transfer and cryopreservation of fish embryos. Presented to the International Conference on Advanced Technologies in Fisheries and Marine Sciences at Nagercoli, India, 26 February 2001.
Lin, C.K. Status of aquaculture and fisheries management in Mekong Delta. Presented to the International Symposium on Mahakum Delta at Jakarta, Indonesia, 4 April 2001.
Yi, Y., C.K. Lin, and J.S. Diana. Comparison of economic return, nutrient utilization efficiency and environmental impact among different culture systems of Nile tilapia Oreochromis niloticus. Presented to Aquaculture America 2001 at Orlando, Florida, 2125 January 2001.
Fifth International Symposium on Tilapia Aquaculture at
Rio de Janeiro, Brazil, 27 September 2000. (Yi)
Third World Fisheries Congress at Beijing, China, 30 October3 November 2000. (Yi)
Ag-Asia 2000 Conference at Bangkok, Thailand, 912 November 2000. (Bart)
Aquaculture America 2001 at Orlando, Florida, 2125 January 2001. (Bart, Yi)
PD/A CRSP Annual Meeting at Orlando, Florida, 26 January 2001. (Bart, Diana, Yi)
International Conference on Advanced Technologies in Fisheries and Marine Sciences at Tamil Nadu, India, 26 February 2001. (Bart)
International Symposium on Mahakum Delta at Jakarta, Indonesia, 4 April 2001. (Lin)
Immersion protocols have been unsuccessful in consistently producing all-male tilapia at a high enough ratio for them to be commercially viable. This study explored ultrasound to improve on the results of previous immersion studies. Experiments were carried out to evaluate immersion with ultrasound as a sex-reversal procedure by 1) assessing duration of treatment (one vs. two hours) on the efficacy of hormone to sex reverse female tilapia and 2) examining the efficacy of various androgens. Due to low survival in experiment 2, experiment 3 was conducted with fewer treatments that included only two hormones (trenbolone acetateTBA and 17-methyldihydrotestosteroneMDHT) at two concentrations (100 and 250 mg l-1) and with ultrasound (cavitation level).
Two-hour treatments with ultrasound resulted in a significantly higher percentage of males (92%) than one-hour (73%) treatments. Ultrasound treatment resulted in significantly higher percentages of males (94%) compared to treatments without ultrasound (89%). Two of the three replicates of the TBA-250 mg l-1 treatment in the third experiment resulted in 100% males and also in the highest percentage of males (98%). Variability within and between treatments with ultrasound was significantly lower (91 to 98%) than treatments with no ultrasound (83 to 94%). While there was no concentration effect, treatment of fry in TBA-250 mg l-1 and ultrasound resulted in significantly higher percentages of males (98.5%) than treatment with MDHT and ultrasound (90.5%). This study thus demonstrated the potential of a short-term immersion protocol using ultrasound to more predictably produce all-male tilapia seed.
An experiment was conducted in nine 200-m2 fertilized earthen ponds at the Asian Institute of Technology, Thailand, from January to September 2000. This experiment was designed to assess the recovery of pond mud nutrient by lotus (Nelumbo nucifera), to assess pond mud characteristics after lotus-fish co-culture, and to compare fish growth with and without lotus integration. There were three treatments in triplicate: A) lotus-tilapia together; B) tilapia alone; and C)lotus alone. Seedlings (0.39 ± 0.09 kg) of Thai lotus variety were transplanted to ponds of treatments A and C at a density of 25 seedlings pond-1, while sex-reversed all-male Nile tilapia (Oreochromis niloticus) fingerlings (8.6 to 10.3 g) were stocked at 2 fish m-2 in ponds of treatments A and B when the water depth had been increased to 50 cm due to increasing lotus height. Ponds stocked with tilapia (treatments A and B) were fertilized weekly with urea and triple superphosphate (TSP) at a rate of 28 kg nitrogen and 7 kg phosphorus ha-1 wk-1 after tilapia stocking. There was no fertilization in ponds of treatment C.
Lotus co-cultured with tilapia or cultured alone in
ponds was able to effectively take up nutrients from old pond
mud (about 300 kg N and 43 kg P ha-1
yr-1) and resulted in the reduction of nutrients in mud by about 2.4 t N and
1 t P ha-1 yr-1. There were no significant differences in lotus growth performance between treatments A and C, while Nile tilapia cultured alone grew significantly better than when co-cultured with lotus. The partially budget analysis indicates that lotus cultured alone generated the highest net return, and lotus contributed the largest portion of net income in lotus-tilapia co-culture. The present experiment has demonstrated the effectiveness of nutrient removal from old pond mud by lotus and the feasibility of rotation and co-culture of lotus and Nile tilapia technically and economically. Both systems can recycle nutrients effectively within ponds and are environmentally friendly culture systems.
An experiment was conducted in eighteen 200-m2 fertilized earthen ponds at the Asian Institute of Technology, Thailand, from March through October 2000. This experiment was designed to assess the efficiency of snakehead (Channa striata) in controlling recruitment of mixed-sex Nile tilapia (Oreochromis niloticus) in ponds and to assess growth and production characteristics of Nile tilapia in monoculture and polyculture with snakehead. There were six treatments: A)monoculture of sex-reversed all-male tilapia; B) monoculture of mixed-sex tilapia; C) polyculture of snakehead and mixed-sex tilapia at 1:80 ratio; D) polyculture of snakehead and mixed-sex tilapia at 1:40 ratio; E) polyculture of snakehead and mixed-sex tilapia at 1:20 ratio; F) polyculture of snakehead and mixed-sex tilapia at 1:10 ratio. Sex-reversed and mixed-sex Nile tilapia were stocked at 2 fish m-2 at sizes of 10.5 to 11.6 g and 7.2 to 8.1 g, respectively.
Results show that snakehead were able to completely control Nile tilapia recruitment at all tested predator:stocked-prey ratios, and the best predator:stocked-prey ratio was 1:80. The addition of snakehead into Nile tilapia ponds did not result in significantly greater tilapia growth, but it significantly lowered total net and gross yields of adult plus recruited tilapia. Snakehead growth was density-dependent, decreasing significantly with increasing stocking densities. While snakehead biomass gain was not significantly different at stocking densities from 0.025 to 0.1 fish m-2, the gain was significantly lower at a stocking density of 0.2 fish m-2. The present experiment demonstrates that snakehead are able to control Nile tilapia recruitment completely and provide an alternative technique for Nile tilapia culture.
An experiment was conducted at the Asian Institute of Technology, Thailand, to investigate effects of fertilization rates and salinity levels on the growth of sex-reversed, Thai red tilapia (Oreochromis sp.). The experiment was designed to test two fertilization rates (28 kg nitrogen and 7 kg phosphorus ha-1 wk-1, N:P = 4:1; and 14 kg N and 7 kg P ha-1 wk-1, N:P = 2:1) and three salinity levels (10, 20, and 30). An additional treatment using optimized fertilization rates (28 kg N and 7 kg P ha-1 wk-1, N:P = 4:1) in freshwater ponds served as a control. Red tilapia fingerlings (20.2 to 23.7 g size) were stocked at 2.4 fish m-2 in 5-m2 cement tanks with soil bottoms. They were cultured for 160 days.
Growth performance of red tilapia was better in brackish water than in fresh water. Growth of red tilapia in brackish water was inversely related to the salinity levels (r = 0.63, P< 0.05), decreasing significantly with increasing salinity. Best growth performance was achieved in the treatment with N:P ratio of 4:1 at 10 salinity. The highest net economic return was achieved in the treatment with N:P ratio of 2:1 at 10 salinity, and all treatments had positive returns.
Preliminary trials using a single species of marine phytoplankton showed that growth of red tilapia fed with Chaetoceros sp. and Thalassiosira sp. was significantly better than those fed with Tetraselmis sp. and Chlorella sp., and the former two resulted in a significantly higher protein utilization efficiency than the latter two. The prey ingestion rate of red tilapia for Chaetoceros sp. and Thalassiosira sp. was significantly higher than that for Tetraselmis sp. and Chlorella sp.
An experiment was conducted at the Asian Institute of Technology, Thailand, to investigate effects of feeding regimes on growth of sex-reversed Thai red tilapia (Oreochromis sp.). There were five different supplemental feeding regimes: 0, 25, 50, 75, and 100% of satiation. Red tilapia fingerlings (33.2 to 33.4 g size) were stocked at 62.5 fish m-3 in fifteen 0.8-m3 net cages suspended in a 200-m2 earthen pond and cultured for 90 days. The pond was maintained at 10 salinity and fertilized weekly at rates of 4kg N and 1kg P ha-1 d-1. Growth performance of red tilapia was significantly better in the feeding treatments than in the non-feeding treatment. Red tilapia growth and average feeding rate increased, but the Feed Conversion Ratio (FCR) and net economic return decreased with increasing percentages of satiation feeding levels from 25 to 100%. Considering low FCR, good growth and yield performance, high economic return, and potential for growing to greater size, 50% satiation feeding was the most efficient feeding rate.
This study was conducted at the Asian Institute of Technology from January to June 2001 to summarize the PD/A CRSP work on Nile tilapia (Oreochromis niloticus) pond culture in Thailand and thus to develop a manual of fertilization and supplemental feeding strategies for small-scale Nile tilapia culture in ponds. The manual consists of eight sections. Section 1 gives a brief introduction to PD/A CRSP work and Nile tilapia culture; section 2 introduces pond preparation; section 3 examines different sources of pond inputs and quality; sections 4 and 5 focus on fertilization and supplemental feeding strategies, respectively; section 6 presents methods to control overpopulation of Nile tilapia; section 7 introduces pond management; and section 8 gives a simple economic analysis to select the suitable strategy. The aims of the manual are to provide simple guidelines of fertilization, supplemental feeding, and pond management for small-scale Nile tilapia pond culture and to provide simple extension and training materials to extension workers, trainers, and well-educated farmers. We expect that small-scale fish farmers in Asian countries, especially in Southeast and South Asia, will benefit from this manual to produce Nile tilapia through effectively using organic and inorganic fertilizers and feeds to increase fish production, achieve higher economic returns, and reduce environmental impacts.
This activity was conducted from January to June 2001. Through this activity, a new link between the PD/A CRSP and a Bangladesh institution has been established. The potential PD/A CRSP collaborators in Bangladesh were identified, including an academic institution, Bangladesh Agricultural University, and three nongovernmental organizations (NGOs), namely Bangladesh Rural Advancement Committee (BRAC), Caritas and PROSHIKA. The needs in aquaculture research in Bangladesh were also identified with a priority to optimize the fertilization regimes in pond culture. This report describes the potential site, current status of aquaculture development in Bangladesh, and the potential role of the PD/A CRSP. The establishment of collaboration with academic institutions and NGOs in Bangladesh will provide great opportunities for extending research and impacts of the PD/A CRSP to Bangladesh and South Asia, which is a potential site of the project in the future. Bangladesh researchers, NGO and government extension staff, and fish farmers will benefit from the experiences, research results, and approaches of the PD/A CRSP through the collaboration.
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