Distribution of dissolved trace elements in the Laptev Sea affected by the Lena River discharge

Abstract

This study presents new data on concentration of dissolved trace elements (DTE) in the Lena River–Laptev Sea mixing zone. Mean concentrations of some dissolved heavy metals in the mixing zone of fresh waters of the Lena River and sea waters of the Laptev Sea on the middle shelf and on the outer shelves are: 0.7± 0.05 μМ and 0.5 ± 0.04 μМ for Fe, 0.06 ± 0.01 μМ and 0.07 ± 0.01 μМ for Ni, 0.01 ± 0.003 μМ and 0.003 ± 0.002 μМ for Zn, 59.2 ± 7.4 nМ and 73.4 ± 12.8 nМ for Cu, respectively. Two major groups of DTE distribution were revealed according to their spatial behavior. The Li, V, As, Rb, Sr, Mo, U concentrations increase towards the outer shelf with increasing salinity. In contrast, mean concentrations of Al, Ti, Mn, Fe, Co decrease with increasing distance from the coast. The identified transport of freshwaters to a distance of 400 km is reflected in the distribution of DTE, which suggests that these elements are able to reach to the Central Arctic Ocean.