남해 통영 연안의 수하식 양식 굴(Crassostrea gigas)의 먹이원 규명 연구

Abstract

Using carbon and nitrogen stable isotope, we studied the seasonal change of food source for oyster cultured in long line culture system. Carbon isotope ratio of oyster showed lighter value in May (-17.42�}0.48��) and heavier value in September (-13.84�}0.09��). The different isotope ratio between cultured oyster and particle organic matter which is regarded as the main food source of oyster was the small in May and large in September. The different variation between oyster and particle organic matter showed similar trend to seasonal change of Chl-a concentration in seawater. The change of carbon isotope ratio for cultured oyster was seemed to be influenced by the variation of phytoplankton biomass. However, the result of Iso-source program in November demonstrated that macro algae occupied approximately 0.4~0.8 to oyster�fs food source, indicating lager contribution than particulate organic matter in November. We conclude that macro algae were substituted main food source in oyster farm in November.