Mercury geochemistry of marine sediments from the eastern Laptev Sea: The spatial distribution, levels, and contamination assessment

Twenty-seven sediment samples from the eastern Laptev Sea were analyzed for mercury and total organic carbon as well as grain-size distribution. The average total mercury (THg) concentrations in sediments are 29 ± 14 μg kg−1. A significant correlation of THg content with total organic carbon and clay and silt fractions was shown. The 210Pb-dated sediment core was used to evaluate the contamination degree and flux of THg in sediments from the eastern Laptev Sea. The average sedimentation rate for the all dated intervals was 0.17 cm/year. The THg flux increased from 20 to 28 μg/m2/year in the period of 1892–1950 to 53–59 μg/m2/year in the modern period of 2011–2015. According to various indices, the ecological risk from THg in studied sediment was low. •THg concentrations in surface sediment of the eastern Laptev Sea were 3–73 μg kg−1.•In the modern period the THg flux was from 53 to 59 μg/m2/year.•THg accumulation was associated with the warming and destruction of permafrost.•The studied sediments have low ecological risk from the mercury.