Mercury in the sediments of freshwater lakes in Ny-Ålesund, Arctic V. G. Gopikrishna & V. M. Kannan & M. B. Binish & M. Abdul Shukkur & K. P. Krishnan & Mahesh Mohan Received: 14 February 2020 /Accepted: 19 July 2020 # Springer Nature Switzerland AG 2020 Abstract Mercury and its speciation in aquatic ecosys- tems 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 collect- ed 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 var- ious 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. Keywords Pollution . Metal . Svalbard . Methylation . Fractionation Introduction The pristine environment of the Arctic has served as a sink for various contaminants in the past (Bard 1999; Ariya et al. 2004; Dastoor and Durnford 2014; Moskovchenko et al. 2017). Metals like mercury, lead, and other organic contaminants have reached Arctic by long-range transport and have been deposited in the cryosphere (Cheng and Schroeder 2000; Zaborska et al. 2017; Mohan et al. 2019). Moreover, local sources, such as coal power plants, weathering of rocks, and tourism, are responsible for contamination of the Arctic environment (Poissant et al. 2008; Zhang et al. 2015; Gamberg et al. 2015). However, recent climatic varia- tions have transformed the Arctic into a source of these contaminants (Douglas and Blum 2019). The enhanced rate of release of elements from the cryosphere is due to the influence of increased average temperature and rate of melting of contaminant flow (ACIA 2004; Gamberg et al. 2015; Halbach et al. 2017; Mohan et al. 2018). Metals mainly reach the Arctic through atmospheric and oceanic transport (Jia et al. 2012; Zaborska et al. Environ Monit Assess (2020) 192:538 https://doi.org/10.1007/s10661-020-08511-y Electronic supplementary material The online version of this article (https://doi.org/10.1007/s10661-020-08511-y) contains supplementary material, which is available to authorized users. V. G. Gopikrishna : V. M. Kannan : M. B. Binish : M. Abdul Shukkur : M. Mohan (*) School of Environmental Sciences, Mahatma Gandhi University, Kottayam, Kerala 686560, India e-mail: maheshmohan@mgu.ac.in K. P. Krishnan National Centre for Polar and Ocean Research, Vasco da Gama, Goa 403802, India