乌江中上游鱼体含汞量的研究

The preliminary study on mercury content of fishes in middle upper reaches of Wujiang River.

以乌江中上游设置的４个采样点所采集的４种底栖性鱼类为材料，进行取样测试，研究了鱼体含汞量差异。结果表明，乌江中上游４个样点的水域底泥含汞量存在显著差异，由此造成４种底栖性鱼类肌肉含汞量在不同样点之间存在极显著性差异。其中乌江镇４种底栖性鱼类肌肉含汞量显著高于六圭河、洪家渡及六广的同种类鱼体的含汞量。在同一样点内的４种底栖性鱼类肌肉含汞量也存在明显差异，其趋势为鲤＜黑尾＜鲇＜黄颡鱼。４种底栖性鱼类肌肉含汞量与体重存在极显著相关性，且同种鱼类在不同样点中汞在鱼体内的积累与它所处的食物链营养级是相一致的，但单位体重含汞量却有明显差异。

The present study is to investigate the differences of mercury contents among four species of benthic fishes collected from four sample localities in the middle upper reaches of Wujiang River in the paper.The results show that mercury content of the bottom silt differed significantly among four sample localities,which caused the significant differences of mercury content of muscle of each fish species among four sample places.The mercury content of each fish species was higher in Wujiangzhen than those of the same species in Liuguihe,Hongjiadu and Liuguang,respectively.Mercury content of the four fishes species had a significant difference in the same sample locality,and those of Pelteobagrus fulvidraco was higher than those of Silurus asotus,those of which was in turn higher than those of Liobagrus nigricaulda and those of Cyprinus carpio was lowest.The mercury contents of muscle of four fishes species were highly correlated with fishes body weight,and those of the same fishes species were correlated with their lengths of food chains in different sample localites,but those of their weight unit were different,in addition to,the more weight,the higher mercury content.