Mercury in lakes and lake fishes on a conservation-industry gradient in Brazil.
Mercury in lakes and lake fishes on a conservation-industry gradient in Brazil.
复制标题
巴西湖泊和湖泊鱼类中的汞处于保护产业梯度中。
DOI：
10.1016/j.chemosphere.2004.12.047
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发表时间：
2005
期刊：
影响因子：
8.8
通讯作者：
V. T. Kütter
中科院分区：
文献类型：
--
作者：
N. Mirlean;S. Larned;Vladimir Nikora;V. T. Kütter
淡水食物网中的汞污染可能是严重和持久的，淡水鱼是人类汞污染的主要来源。北方的研究表明，淡水鱼积累汞的主要途径是食物网，大气沉积是汞进入淡水系统的主要途径。大气沉积水平与汞排放源的接近程度密切相关。这些命题尚未在南半球得到检验。在这项研究中，我们测量了在巴西南部的三个湖泊中的汞含量，并评估了汞在降水，湖水，沉积物和鱼类组织中的关系，在网站接近（工业和郊区）和远离（保护区）的汞排放源。我们还评估了鱼类中的汞与其营养习性之间的关系。沉积物和湖水中的汞浓度在湖泊之间没有变化。相比之下，在研究湖泊的降水中的汞增加接近工业来源。汞在鱼体组织中的含量一般沿着同一梯度增加，但也随营养水平和偏好深度带而变化。这些封闭湖泊的大气汞沉积可能与鱼类的汞浓度直接相关，其中水面摄食的食鱼物种的汞浓度最高。
Mercury contamination in freshwater food webs can be severe and persistent, and freshwater fish are a major source of mercury contamination in humans. Northern hemisphere studies suggest that the primary pathway by which freshwater fish accumulate mercury is the food web, and that atmospheric deposition is the primary route by which mercury enters freshwater systems. Levels of atmospheric deposition are closely linked to proximity to sources of mercury emissions. These propositions have not been tested in the southern hemisphere. In this study, we measured mercury levels at three lakes in southern Brazil and assessed relationships between mercury in precipitation, lake water, sediment and fish tissues at sites close to (industrial and suburban areas) and distant from (protected conservation area) sources of mercury emissions. We also assessed relationships between mercury in fish species and their trophic habits. Mercury concentrations in sediment and lake water did not vary among lakes. In contrast, mercury in precipitation at the study lakes increased with proximity to industrial sources. Mercury in fish tissue generally increased along the same gradient, but also varied with trophic level and preferred depth zone. Atmospheric mercury deposition to these closed lakes may be directly linked to concentrations in fish, with surface-feeding piscivorous species attaining the highest concentrations.