Methylmercury in freshwater fish linked to atmospheric mercury deposition
Methylmercury in freshwater fish linked to atmospheric mercury deposition
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DOI：
10.1021/es061480i
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发表时间：
2006-12-15
影响因子：
11.4
通讯作者：
Fitzgerald, William F.
中科院分区：
文献类型：
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作者：
Hammerschmidt, Chad R.;Fitzgerald, William F.
野生鱼类种群中甲基汞（MeHg）的积累与大气汞沉积之间没有联系。从横跨美国本土的监测工作中获得了鱼类中甲基汞和大气汞沉积的大型数据库。在这里，我们比较这些数据集的结果，并表明，全国范围内的平均浓度的甲基汞在一个国际性的淡水鱼，大口鲈鱼，是正相关的湿大气汞通量之间的25个国家进行了分析，跨越5倍的范围内的汞沉积。各州之间大口黑鲈甲基汞浓度的差异与平均降水深度、湿大气酸沉降或鱼类采样的水体类型（河流、湖泊、水库）的州际变化无关。有适度的相关性之间的甲基汞在低音和地表水的pH值，温度和湿大气沉积的硫酸盐。然而，当鱼和大气汞的结果相结合，在国家一级，湿大气汞沉积占约三分之二的变化，低音甲基汞之间的大多数国家，逐步多元回归分析表明，这些变量并没有改善线性模型显着。这表明，甲基汞在野生鱼类种群中的积累与大气中的汞含量有关，据估计，其中三分之二来自人类活动。
A connection between accumulation of methylmercury (MeHg) in wild fish populations and atmospheric mercury deposition has not been made. Large databases for both MeHg in fish and atmospheric mercury deposition have been assimilated from monitoring efforts spanning the contiguous United States. Here, we compare results of these data sets and show that state-wide average concentrations of MeHg in a cosmopolitan freshwater fish, the largemouth bass Micropterus salmoides, are related positively to wet atmospheric Hg fluxes among most of the 25 states that are analyzed, which span a 5-fold range in Hg deposition. Differences in largemouth bass MeHg concentrations among states are unrelated to average precipitation depth, wet atmospheric acid deposition, or interstate variations in the type of water body (river, lake, reservoir) from which the fish were sampled. There are modest correlations between MeHg in bass and surface water pH, temperature, and wet atmospheric deposition of sulfate. However, when fish and atmospheric mercury results are combined at the state level, wet atmospheric Hg deposition accounts for about two-thirds of the variation in bass MeHg among most states, and stepwise multiple regression analysis reveals that these variables do not improve the linear model significantly. This suggests the accumulation of MeHg in wild fish populations is linked to atmospheric Hg loadings, two-thirds of which are estimated to be from anthropogenic sources.