Contents of five trace elements in different tissues of four species of mussels in Lake Chaohu and their spatial variation

Abstract

蚌类在湿地生态系统元素的富集与转化过程中发挥重要作用.以巢湖常见扭蚌（Arconaia lanceolata）、三角帆蚌（Hyriopsis cumingii）、褶纹冠蚌（Cristaria plicata）和圆顶珠蚌（Unio douglasiae）为对象，分析其内脏团、外套膜（包含鳃，下同）和斧足中5种微量元素（Cu、Zn、As、Cd、Pb）的含量.结果表明：5种元素在4种蚌体内均有检出，除Zn在圆顶珠蚌组织间表现为外套膜>内脏团>斧足外，4种蚌体组织间5种微量元素含量均表现为内脏团 > 外套膜 > 斧足；4种蚌类各微量元素平均含量均表现为Zn > Cu > As > Pb > Cd；Cu和Pb在4种蚌类中的平均含量表现为扭蚌 > 褶纹冠蚌 > 圆顶珠蚌 > 三角帆蚌，扭蚌各组织中Pb含量是其他3种蚌类的2.62~6.99倍，Zn的各平均含量表现为圆顶珠蚌 > 扭蚌 > 三角帆蚌 > 褶纹冠蚌，As表现为圆顶珠蚌 > 三角帆蚌 > 褶纹冠蚌 > 扭蚌，Cd表现为扭蚌 > 圆顶珠蚌 > 三角帆蚌 > 褶纹冠蚌，Cd在圆顶珠蚌和扭蚌中的含量是三角帆蚌和褶纹冠蚌的2.75~6.08倍.不同种类之间微量元素含量的差异大于同一种类微量元素含量的空间差异.微量元素污染较重的河口区蚌体组织具有较高的微量元素含量，污染较轻的河口中蚌体组织各微量元素含量也相对较低，表明蚌类可作为巢湖水体微量元素污染监测的指示生物.4种蚌类中Pb、Cd、As含量均未超出国家食品安全标准的限定值.;Mussels play an important role in the enrichment and transformation of elements in wetland ecosystems. In this study, Arconaia lanceolata, Hyriopsis cumingii, Cristaria plicata, and Unio douglasiae were used to analyze the content of five trace elements (Cu, Zn, As, Cd, Pb) in different tissues (visceral mass, mantle containing gills, foot ). The results showed that all five elements were detected in four species of mussels. The average content of each element in the tissues of the four species of mussels was visceral mass > mantle > foot, except for the average content of Zn in the tissues of U. douglasiae was shown as mantle > visceral mass > foot. The average content of each trace element in the four species of mussels was Zn>Cu>As>Pb>Cd; The average contents of Cu and Pb in the four species of mussels were expressed as A. lanceolata > C. plicata > U. douglasiae > H. cumingii. The content of Pb in the tissues of A. lanceolata was 2.62-6.99 times of the other three mussels. The average content of Zn is expressed as U. douglasiae > A. lanceolata > H. cumingii > C. plicata, As is expressed as U. douglasiae > H. cumingii > C. plicata > A. lanceolata, Cd appears as A. lanceolata > U. douglasiae > H. cumingii > C. plicata, the content of Cd in U. douglasiae and A. lanceolata is 2.75-6.08 times of H. cumingii and C. plicata. The difference in the content of trace elements between different species is greater than the spatial difference in the content of trace elements of a certain kind. Mussels in the estuary of Lake Chaohu, where the trace element is polluted heavily, have a higher content of trace elements and the contents of trace elements in tissues in estuaries with less pollution are also relatively low, indicating that mussels can be used as indicator organisms for monitoring of trace element pollution in Lake Chaohu. The contents of Pb and Cd in the four mussels did not exceed the limit of the national food safety standards, but the safety risks caused by As accumulation in H. cumingii and U. douglasiae were not excluded, and large quantities of food were not recommended.