长江水系河流与水库中鲤鱼的元素含量特征

CHARACTERISTICS OF ELEMENT CONTENTS IN CARP (Cyprinus carpio L.) FROM THE CHANGJIANG RIVER

针对长江三峡水库蓄水后引起水库汞活化效应对生态与环境的影响问题，系统地分析了长江水系水库与河流鲤鱼肌肉的Ａｓ、Ｃｄ、Ｃｕ、Ｆｅ、Ｈｇ、Ｍｎ、Ｐｂ、Ｓｅ、Ｍｎ、Ｐｂ、Ｓｅ、Ｎａ、Ｍｇ等元素含量的分布特征。并以丹江口水库－汉江、陈村水库－青弋江为例，用多元分析证明水库与河流的鲤鱼肌肉中Ａｓ、Ｓｅ、Ｈｇ、Ｃｄ等元素含量存在显著差异，同时指出水库汞活化效应引起的鱼体汞含量增加是该元素的一种生物地球化学现象，并利用同一水系水库与河流鲤鱼汞元素含量的比值Ｒ作为定量描述水库汞活化效应的指标。逐步回归分析指出，所研究的长江流域１３个水库的Ｒ值与其水库集水面积Ａ、径流量Ｑ和库容Ｖ满足下列二元回归方程：Ｒ＝２．７５５８－０．５３２９×Ａ／Ｑ－０．３３０８／ＶＰ＜０．０１利用此经验方程对三峡水库不同水域的汞活化效应进行了预测。

The paper reports the preliminary results of an investigation on contents of As,Cd, Cu, Hg,Mn,Pb,Se,Zn,Na, K, Fe,Mg in cap(Cyprinus carpio L.) from the Changjiang River water system. The marked difference between contents of elements in fish from a river and a reservoir was identified by using the multivariable analysis,for example, in the Danjiangkou Reservoir Hanjiang River and the Taipinghu Reservoir Qingyijiang River. Contents of Hg and Cd in fish from the reservoir are higher than those from the river, but the opposite is true for As and Se. The results of the multiple regression analysis show that there is a good correlation among R , V, A and Q , and that R may be estimated by the following regression equation: R=2.7558 - 0.532 9AQ -1 - 0.330 8V -1 P < 0.01 R is the ratio of Hg content of fish in the reservior to that in the river within the same water system. V is volume of the reservoir, A and Q are the drainage area and rain runoff within the basin respectively. Using the equation, we predict that the bioconcentration of fish mercury in the Three-Gorge Reservoir will increase after impoundng, contents of fish mercury will be 1.4～ 2.5 times of existing contents, and there will be possibility off fish mercury exceeding 0.3 ppm which is the maximum content allowed by the Food Hygiene Law of the People's Republic of China.