Mercury and its speciation in aquatic ecosystems have been assessed globally. Even though previous studies were limited to Arctic freshwater lakes, they are highly significant in the context of the changing climate. The present study is based on sediment samples collected from three Arctic freshwater lakes over a period of 4 years (2015–2018). The samples were analysed for total mercury (THg), methyl mercury (MHg), and various mercury fractions. The observed mean THg and MHg concentrations were 22.23 ng/g and 0.41 ng/g respectively; these values were comparable with those for other Arctic freshwater lakes. The mercury content significantly varied among the years as well as among the lakes. Changes in snowdrift and meltwater inputs, which are the major sources of water for the lakes, may have influenced the sediment mercury content along with geographical location and increased productivity. The results of MHg indicated the susceptibility of lake sediments to methylation. The major fractions observed were the organo-chelated form of mercury, followed by the elemental and water-soluble forms. These results indicate the availability of mercury for methylation. Hence, it is necessary to conduct more studies on the influence of climate change, mercury release through permafrost melting, and atmospheric deposition.

中文翻译：

---

北极Ny-Ålesund淡水湖泊沉积物中的汞。

全球对汞及其在水生生态系统中的形态进行了评估。尽管先前的研究仅限于北极淡水湖泊，但在气候变化的背景下它们仍然具有重要意义。本研究基于四年（2015-2018年）期间从三个北极淡水湖收集的沉积物样本。分析了样品中的总汞（THg），甲基汞（MHg）和各种汞组分。观察到的平均THg和MHg浓度分别为22.23 ng / g和0.41 ng / g；这些数值与其他北极淡水湖泊的数值相当。多年来，各湖泊之间的汞含量差异很大。飘雪和融水输入量的变化，这是湖泊的主要水源，可能已经影响了沉积物中的汞含量以及地理位置和生产力的提高。MHg的结果表明湖泊沉积物易于甲基化。观察到的主要部分是汞的有机螯合形式，其次是元素形式和水溶性形式。这些结果表明汞可用于甲基化。因此，有必要对气候变化，永久冻土融化释放的汞以及大气沉积的影响进行更多的研究。