Cu、Pb、Zn和Cd对东海原甲藻的生态毒性效应

Ecotoxicological effect of Cu, Pb, Zn and Cd on Prorocentrum donghaiense Lu

采用现场调查、现场培养实验和模型分析的方法,研究长江口及邻近海域重金属Cu、Pb、Zn、Cd对东海原甲藻的生态毒性效应.结果表明,东海原甲藻在重金属浓度较低时处于非检测毒性生长状态,在重金属浓度较高时处于毒性生长状态,毒性效应随重金属浓度的升高而增大,重金属离子与生物活性离子的竞争吸附是造成2种不同生长状态的原因.建立非检测毒性效应模型,获得Cu、Pb、Zn、Cd对东海原甲藻的非检测毒性浓度（NDEC）分别为4.1,45.2,131.7,138.9μg/L.2003年5月调查海区溶解态Cu、Pb、Zn、Cd浓度范围分别为1.0～5.8,0.10～0.57,3.8～7.5,0.01～0.05μg/L,Cu浓度超过其NDEC的面积达49%,估计造成东海原甲藻生物量降低5%,浓度最高的海区降低24%,Pb、Zn、Cd等对东海原甲藻的NDEC高于调查海区的浓度,不会对其生长造成影响.

Ecotoxicological effects of Cu, Pb, Zn, Cd on Prorocentrum donghaiense Lu in the Changjiang estuary and adjacent sea area were studied, adopting the technologies of field survey, in situ incubation and modeling analysis. The Prorocentrum donghaiense Lu was in no detected toxic growth state when heavy metal concentration was relatively low, in toxic growth state when heavy metal concentration was relatively high. Toxic effect increased with enhancing of heavy metal concentration. The competitive adsorption of heavy metal ion with bioactive ion was the cause of creating two different growth states. The modeled no detected toxic concentrations （NDEC） of Cu, Pb, Zn, Cd on Prorocentrum donghaiense Lu were 4.1, 45.2, 131.7, 138.9 μg/L respectively. In May 2003, the dissolved Cu, Pb, Zn, Cd concentration ranges were 1.0-5.8, 0.10-0.57, 3.8-7.5, 0.01-0.05 μg/L respectively in the studied area. About 49% of the total studied area had a Cu level exceeding NDEC, leading to an average of 5% decrease of the biomass of Prorocentrum donghaiense Lu and up to 24% decrease in the highest Cu level area. Field concentrations of Pb, Zn, and Cd were lower than the modeled NDEC so that they had no significant influence on the Prorocentrum donghaiense Lu.