수평망식 굴양식의 입식 시기에 따른 성장 비교

Abstract

In order to investigate the effect of stocking time on the growth performances, the oyster, in a density of 100 individuals per bag, introduced into rack culture farm on Wando tidal flat at three different time, April 2011 (APR-11), June 2012 (JUN-12) and November 2012 (NOV-12), respectively. In APR-11 and NOV-12, the growth of oysters was, with an initial size of 20 g in total weight and 3-5 cm in shell height, reached to commercial size over 80 g in total weight within 6-8 months. Regardless of stocking time, the crash season from summer mortality began in June, which difference between air and surface seawater temperature become increasing. Age or size dependent mortality was observed by 20-30% for 1-year-old oysters (APR-11), and 70-80% for 2-year-old oysters (NOV-12), respectively. Because of the stresses from transfer handling in hot summer season and direct impact of typhoons in 2012, JUN-12 did not reached to commercial size throughout the experimental period. Our data indicated that stocking time is one of the most important cultural practices for strategic approach to achieve the successful oyster farming of rack culture. In Wando, to avoid disastrous mortality, it is not recommend for 2 year old oysters to be exposed by oversummering for more growth.