Analysis of Current Distribution around a Scaled-down Abalone System to determine the cause of mass mortality of abalone, Haliotis discus hannai (Ino, 1952)

Abstract

This study is aimed at figuring out the reasons of the mass mortality of abalone and the increase in its mortality rate in the sea cage. The study suggests that lack seawater circulation in an abalone aquaculture cage is an important culprit for it. We analyzed the current distribution around a 1/20 scaled-down abalone unit cage of 4 rows and 10 columns by fluid flow visualization technique (PIV : Particle Image Velocimetry). The speed of current in the model cage definitely slowed down in the first column of a unit cage. We also observed currents going down to the bottom of a water tank from the unit cages placed in the middle. The speed of wakes behind inside the row in the middle was slower than that outside the row. Water velocity inside and outside a real abalone cage at Nowha Island adjacent to Wan Island was measured to verify results from the tank test. The speed of current in front of the cage by 2 m was 0.11 m/sec while it was only 0.0009 m/sec inside the cage. It had similar findings with those of a tank test.

The Effects of Fed Artificial Diet and Seaweed Diet on Growth and Body Composition of Juvenile Abalone, Haliotis discus hannai by Land-based Tank Immediate Culture Types

“…. 그러나 최 근 해상가두리에서 양성중인 전복의 폐사량이 점차 증가되고 있으며 이러한 원인으로 부유토사 (Lee, 2008), 유속감소 (Shon et al, 2010), 패각 천공성 다모류 감염 (Won et al, 2013), 조류소통 (Cha et al, 2014) (Kim et al, 2013 (NFRDI, 2008;Shon et al, 2003). 특히 해상가두리 중간육성과의 약 30% 이상의 일간성장율 차이는 (Kim et al, 2013) (Jeong et al, 1994a), 먹이별 사육효과 (Jeong et al, 1994b), 순환여과시스템 내 사육온도와 성장효 과 (Park et al, 1995) 및 적정 사육밀도 (Park et al, 1995;Shon et al, 2003) (Lee et al, 1997;Kim et al, 2013), 사육밀도…”

The Growth and Survival Rate of Juvenile Abalone, Haliotis discus hannai at Different Intermediate Culture Type in Net Cage or Indoor Tank

“…, 패각 천공성 다모류 감염 (Won et al, 2013), 조류 소통 (Cha et al, 2014 (Shon et al, 2003). (Jeong et al, 1994a), 먹이별 사육효과 (Jeong et al, 1994b), 순환 여과시스템 내 사육온도와 성장효과 (Park et al, 1995) 및 적정 사육밀도 (Shon et al, 2003;Park et al, 2008), 사육 시스템 종류별 성장 비교 (Moon et al, 2006) 등 실용적인 시스템개발과 사육조건 등을 중심으로 연구가 수행되었다.…”