52 JUNE 2018 • WORLD AQUACULTURE • WWW.WAS.ORG Furthermore, spinal abnormality rate of fish in the experimental diet plus 500 mg/kg vitamin C treatment was significantly lower than that in the commercial feed treatment, but survival, cannibalism, and FCR were not significantly different. Outcomes Based largely on the results of our AquaFish project, in June 2016, the Government of Cambodia lifted the decade-old ban on snakehead fish farming following a request from the Ministry of Agriculture to allow farmers to fish. The statement said the decision to legalize snakehead farming again would be accompanied by forthcoming conditions and advice for farmers and it would help farmers sustainably manage and maintain their farms and keep fish stocks healthy. Currently Cambodia has identified aquaculture as one among the most important three pillars of the country’s fisheries development. The government’s Strategic Planning Framework for Fisheries for 2010 to 2019 considers expanding the farming of fish and other aquatic animals as “essential” given the limited capacity of natural resources to sustain the country’s growing population. In general, to support the growth of small-, medium- and largescale freshwater aquaculture, government spending on aquaculture has been budgeted at more than US$16 million under the 10-year framework. Recently, aquaculture extension is one of the national policies under the Strategic Plan Framework for the fisheries sector. Due to advances in controlled reproduction and weaning techniques, the number of hatcheries in Vietnam has increased considerably (Fig. 6) from slightly more than 50 in 2006, when this project began, to about 150 in 2016. Although about 30 hatcheries stopped operating between 2016 and 2017, the quantity of fingerlings increased from 148 to 170 million from 2016 to 2017. The reasons that the number of hatcheries decreased are: 1) small-scale hatcheries shifted to produce other species of fingerlings or closed due to competition with large hatcheries, 2) large-scale hatcheries provided the majority of fingerlings and their cost per fingerling is cheaper and 3) the cost of snakehead fish production decreased in 2017 so that some hatcheries also temporarily stopped produce fingerlings. Although the number of broodstock is not increasing markedly, the production of fingerlings is, indicating that hatchery efficiency is improving. The number of Vietnamese households devoted to each type of snakehead production has not markedly increased over the last few years (Fig. 7). Regarding environmental improvement, Hien et al. (2016a) showed that better pond water quality results when pelleted diets are used, compared to trash fish, which likely contributes to the improved profits seen with pelleted feed. Perhaps more important, usage of small fish from the wild for snakehead culture in Vietnam has been reduced (Fig. 8) and use of small freshwater fish in particular has been reduced. As small-fish usage has decreased, the number of commercial feed mills making snakehead feed has increased from five in 2010 to more than 20 today and total commercial feed production has approximately doubled. Finally, and perhaps most important, the snakehead ban in Cambodia was lifted in June 2016. Nonetheless, some research and considerable outreach must be done in Cambodia to implement a viable snakehead industry. Notes This research was funded by the AquaFish Innovation Lab under USAID CA/LWA No. EPP-A-00-06-00012-00 and by US and Host Country partners. The AquaFish accession number is 1482. The opinions expressed herein are those of the author(s) and do not necessarily reflect the views of the AquaFish Innovation Lab or the U.S. Agency for International Development. Tran Thi Thanh Hien and Pham Minh Duc, College of Aquaculture and Fisheries, Can Tho University, Can Tho, Vietnam Nen Phanna, Hap Navy, Chheng Phen and So Nam, Inland Fishery Research and Development Institute, Phnom Penh, Cambodia Robert Pomeroy, Department of Environmental and Agricultural Economics and Connecticut Sea Grant, University of Connecticut, Avery Point, Groton, CT, USA David A. Bengtson, Department of Fisheries, Animal and Veterinary Sciences, University of Rhode Island, Kingston, RI, USA References Enterria, A., M. Slocum, D.A. Bengtson, P.D. Karayannakidis and C.M. Lee. 2011. Partial replacement of fish meal with plant protein sources singly and in combination in diets for summer flounder (Paralichthys dentatus). Journal of the World Aquaculture Society 42:753-765. FIGURE 6. Snakehead fish hatchery development in Vietnam. The number for 2020 is an estimate. FIGURE 7. Number of Vietnamese households culturing snakehead in earthen ponds or in hapas or lined-tanks. The 2020 numbers are estimates.
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