사육수 비교환방식을 이용한 포장 사육지에서의 흰다리새우, Litopenaeus vannamei (Boone, 1931)의 초고밀도양식

Abstract

Shrimp farming is the most important mariculture industry on the west coast of South Korea. However, it has suffered from mass mortality due to viral disease outbreaks and coastal pollution due to water discharge. This study developed an intensive shrimp culture method for outdoor ponds, without water exchange, which minimizes the chance of viral transmission from the environment, reduces coastal pollution by water discharge and enhances shrimp production. A culture trial was conducted in two high-density polyethylene (HDPE)-lined ponds with a <TEX>$550\;m^2$</TEX> surface area. The ponds were stocked with postlarvae of Litopenaeus vannamei, the major farmed shrimp species in Korea, on July 10, 2007, and cultured for 90 days with no water exchange. The stocking density of the postlarvae (B.W. 0.0015 g) was <TEX>$272\;ind./m^2$</TEX>, which is eight times higher than in traditional pond culture in Korea. At harvest, the total production of ponds 1 and 2 was 1,362kg (<TEX>$2.48\;kg/m^2$</TEX>) and 1,282 kg (<TEX>$2.33\;kg/m^2$</TEX>), respectively. This is 20~22 times higher than the mean farmed shrimp production (<TEX>$0.112\;kg/m^2$</TEX>) in Korea and about eight times higher than in traditional ponds with a good harvest. Although there was no water exchange throughout the culture period, the mean concentrations of unionized ammonia and nitrite-nitrogen were as low as 0.038 and 6.0 mg/L, respectively. The feed conversion rate (FCR) was 1.38, which is 20~45% lower than that of traditional pond cultures. The high efficiency of the diet in this study is thought to be due to a well-managed feeding strategy and well-developed bioflocs used as diet additions for the shrimp. The final body weight of the shrimp at harvest was low (12.2~12.5 g), compared with that of traditional pond culture. This may have resulted from the combination of a short culture period, high density of shrimp, and low temperature. This study suggests that a super-intensive shrimp pond culture method using biofloc technology with no water exchange can minimize viral transmission via water exchange, reduce coastal pollution, and enhance shrimp production.