Success Stories In Asian Aquaculture - Library - Network of ...

7 Striped Catfish Aquaculture in Vietnam: A Decade of Unprecedented Development141varied from 22.2 to 29.5% (dry weight basis) compared to 17.9–22.6% in commercialpellet feeds (Phuong 1988) . It is hard to determine the exact amount of pelletedfeeds used for striped catfish culture in the Mekong Delta, but an approximate estimationis that 1.2–1.5 million t were used in the year 2007.7.7.4 Advantage of Water SourcesStriped catfish culture is based on the advantage of the availability of a plentifulwater supply from the Mekong River. The environmental management of stripedculture models is largely dependednt on river water. Mekong is a large river withhigh water flow, especially during flood season that a large water volume convergefrom upper reaches and sweeps away waste matters from cages and pens, and this isa noticeable advantage contributing to the development of these culture models.Pond culture environment has total ammonia nitrogen (TAN), nitrite (NO 2− ), andphosphorus (PO 4 3− ), BOD and H 2S much higher than the recommended levels(Giang et al. 2008) due to high stocking density. However, high rate of waterexchange is the main method applied to improve pond water quality. In theory, treatmentis required for water supply and waste water, but this is absolutely impossiblein practice. Striped catfish ponds contain a large volume of water and land used forcatfish ponds is very expensive, and thus, it is impractical and inapplicable to havesettlement and treatment ponds in catfish farms.7.7.5 High Economic ReturnsHigh economic return is an attractive reason for the involvement of investors incatfish farming. Most recent striped catfish farmers are investors from other sectors.Striped catfish farming requires high level of investment for land, infrastructuralbuilding, and operating costs (mainly feed and seed) (Table 7.1 ). The productioncost and net profit per unit of fish harvest are relatively lower than for other species.However, total net profit per ha is much higher than other farmed species becauseof higher productivity. The production cost has been increasing over time. Phuonget al. (2007) reported that the production cost (US $/kg) in 2006 was 0.59, whichis lower than that of 0.70 in 2008 (Hien 2008) . Hien (2008) also stated that 11.6%of farms encountered a financial loss in 2008. The losses in catfish farming recentlyhave been mainly due to the reduction of prices.7.7.6 Traditional Practices and Farmer InnovationsAs mentioned earlier, striped catfish culture has a long historical practice in theMekong Delta. The farmers in Dong Thap and An Giang Provinces, which are closeto the Cambodian border, have a long tradition of catching wild fry and nursing