近江牡蛎作为海洋重金属镉污染指示生物的研究

Studies on Crassostrea rivularis asa biological indicator of cadmium Pollution

采用更新式在自然光照和室温条件下进行了近江牡蛎（Ｃｒａｓｏｓｔｒｅａｒｉｖｕｌａｒｉｓ）对镉的累积和排出实验。近江牡蛎对海水中镉的累积是净累积型，其体内的镉含量与海水的镉浓度及暴露时间呈显著的线性正相关（Ｐ＜００１），镉从近江牡蛎体内排出的生物学半衰期为７７ｄ，近江牡蛎对镉的累积随海水盐度的升高而呈明显的下降趋势，盐度的升高有碍于其体内残留镉的排出。近江牡蛎是比较理想的海洋重金属镉污染的指示生物。

The results from the study on accumulation and elimination of Cd in Crassostrea rivularis body are as follows:The pattern of Cd absorbed by C.rivularis is net accumulation.The content of Cd in C.rivularis body is in linear direct proportion to the Cd concentration in sea water (P<0.01).The content of Cd in tissues is in linear direct proportion to the exposure time (P<0.01).The Cd accumulated by the oyster withdraws slowly and its biological half-life is 77d.The accumulation of Cd in C.rivularis body decreases with the increase of water salinity and increase of water salinity obstructs the elimination of Cd in C.rivularis tissues.As a result,this kind of oyster is a reliable biological indicator of Cd pollution.