Abstract

In Korea, Longline oyster farms are located near shipping routes, where continuous artificial waves are generated by the movement of ships, causing physical stress, known as the "tumbling" phenomenon, which has been reported to result in reduced growth. Therefore, to develop suitable suspended cutchless oyster farming techniques in the korea, the relationship between physical impacts and the growth of suspended cutchless oysters was investigated. The oysters in the 0 m and 1 m experimental groups showed higher growth in terms of condition index and flesh weight in April compared to other groups. Cutchless oysters in the suspended group exhibited relatively higher whole and flesh weights throughout the period, confirming faster growth compared to hanging cultured oysters. Shell height growth was recorded in the following order 3 m depth group, 1 m depth group, hanging cultured oysters and the 0 m depth group. This slow growth in the 0 m depth group appears to be due to damage to the shell edges caused by physical impacts. However, whole weight was similar in both the 1 m and 3 m depth groups, with the 0 m depth group showing relatively lower growth, apparently due to physical stress. This study confirmed shell edge damage and partial growth retardation of individual suspended oysters caused by physical impacts as a function of depth.