EXAMINATION ON MORTALITY FACTORS OF OYSTER CRASSOSTREA GIGAS AND INFERENCE OF MECHANISM OF THE MORTALITY

Abstract

 Global warming and eutrophication caused by human activity and variations in social needs for foods have been deteriorated environments of oyster farm. Various surveys in response to environmental contaminations have not yet been conducted sufficiently, because aquaculture technology has been developed mainly with emphasis on the quality and increased production of oysters. i.e., the cause of mass mortality of oyster has not been elucidated. In this study, we hypothesized the mechanism of oyster mortality on the basis of previous study. In addition, mortality conditions were confirmed by surveys on quality of water and sediment during field experiments. As a result, the mechanism of oyster mortality that we assumed was well consistent with results of filed investigation conducted in oyster farm.