Authors: Chengding Li Qianggong Zhang Shichang Kang Yongqin Liu Jie Huang Xiaobo Liu Junming Guo Kang Wang Zhiyuan Cong
Publish Date: 2015/04/24
Volume: 22, Issue: 16, Pages: 12490-12500
Abstract
Mercury Hg in aquatic ecosystems is of great concern due to its toxicity bioaccumulation and magnification in the food web The Tibetan Plateau TP is endowed with the highest and largest lakes on earth whereas Hg distribution and behavior in lake waters are least known In this study surface water samples from 38 lakes over the TP were collected and determined for the total Hg THg concentrations Results revealed a wide range of THg concentrations from 1 ng to 403 ng L−1 THg in lake waters exhibited an increasing trend along the southeast to northwest transect over the TP Strong positive correlations were observed between THg concentrations and salinity and salinityrelated environmental variables especially for total dissolved solids TDS and some of the major ions such as Na+ K+ and Cl− suggesting the enrichment of Hg in saline lakes The largescale geographical pattern of climatic and environmental factors shows a decreasing precipitation and an increasing evaporation northwards and westwards and thereby induces gradientenhanced enrichment of soluble substances in lake waters which are likely to complex more Hg in northwestern TP Our study provides the first comprehensive baseline data set of Hg in Tibetan lake waters and highlights the concurrent high Hg and salinity representing valuable references and fundamental rules in further understanding the behavior and fate of Hg in lakes over the TP and perhaps highaltitude regions beyondThis work was supported by the National Natural Science Foundation of China 41101064 41371088 and 41225002 and the “Strategic Priority Research Program B” of the Chinese Academy of Sciences XDB03030504 The authors thank the 2010 and 2011 Expedition Team to Tibetan lakes
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