Assessment of Mercury Flux to Bottom Sediments in High-Altitude Small Lakes of the Altai Mountains (Ukok Plateau, Altai Republic)
V.I. Malov1,2, V.D. Strakhovenko1,2, M.A. Gustaitis1,2, E.A. Ovdina1, G.I. Malov1
1V.S. Sobolev Institute of Geology and Mineralogy, Siberian Branch of the Russian Academy of Sciences, Novosibirsk, Russia
2Novosibirsk National Research State University, Novosibirsk,Russia
Keywords: Mercury; mercury flux; Hg; Altai; bottom sediments; lakes
Abstract
This study presents the results of a comprehensive assessment of mercury content in bottom sediments of four high-altitude lakes on the Ukok Plateau (Altai, Russia): Zerlyukol-Nur, Krasnoye, Tyoply Klyuch, and Argamdzhi. The aim was to quantify mercury concentrations and evaluate its fluxes in sediments as indicators of global atmospheric pollution. Mercury levels range from 28 to 130 ng g⁻¹, with an average of 57.4 ± 21.4 ng g⁻¹, corresponding to background values for high-mountain lakes of the Northern Hemisphere. Elevated concentrations in the upper layers of three lakes reflect post-industrial contamination, whereas this trend is absent in Tyoply Klyuch, likely due to a thermal endogenous influence. Sedimentation rates of 0.18, 0.9 cm yr⁻¹ yield mercury fluxes of 3.9, 9.1 ng cm⁻² yr⁻¹, comparable to those reported for the southern Himalayas but lower than levels in industrially active regions. The findings indicate that the Ukok Plateau remains isolated from direct pollution sources and highlight its value as a background indicator area for evaluating transboundary mercury transport. This work fills a data gap on Hg distribution in remote high-mountain ecosystems and refines global mercury-cycling models.
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