Mercury contamination in aquatic ecosystems under a changing environment:Implications for the Three Gorges Reservoir  

作　　者：WANG Feiyue ZHANG JinZhong 

机构地区：[1]Center for Earth Observation Science,Department of Environment and Geography,and Department of Chemistry,University of Manitoba [2]Key Laboratory of Eco-Environments in Three Gorges Reservoir Region,Ministry of Education,College of Resources and Environment,Southwest University

出　　处：《Chinese Science Bulletin》2013年第2期141-149,共9页

基　　金：supported by the Natural Science and Engineering Council(NSERC) of Canada (F.W.);the National High Technology Research and Development Program of China (2012AA101405)

摘　　要：Mercury is one of the primary contaminants of global concern.As anthropogenic emissions of mercury are gradually placed under control,evidence is emerging that biotic mercury levels in many aquatic ecosystems are increasingly driven by internal biogeochemical processes,especially in ecosystems that have been undergoing dramatic environmental changes.Here we review the unique properties of mercury that are responsible for the exceptional sensitivity of its biogeochemical cycles to changes in climatic,geochemical,biological and ecological processes.We show that,due to rapid climate warming,a shift from sources-driven to processes-driven mercury bioaccumulation is already happening in the Arctic marine ecosystem.We further suggest that such a shift might also be operating in the Three Gorges Reservoir due to changes in these biogeochemical processes induced by the damming.As a result,the effectiveness of mercury emission control is expected to be followed by long delays before ensuing reduction is seen in food-web levels,making it all the more pressing to control and reduce mercury emissions to the reservoir.Long-term monitoring and targeted studies are urgently needed to understand how biotic mercury levels in the reservoir are responding to changes in mercury emissions and in biogeochemical processes.Mercury is one of the primary contaminants of global concern. As anthropogenic emissions of mercury are gradually placed under control, evidence is emerging that biotic mercury levels in many aquatic ecosystems are increasingly driven by internal biogeo- chemical processes, especially in ecosystems that have been undergoing dramatic environmental changes. Here we review the unique properties of mercury that are responsible for the exceptional sensitivity of its biogeochemical cycles to changes in climat- ic, geochemical, biological and ecological processes. We show that, due to rapid climate warming, a shift from sources-driven to processes-driven mercury bioaccumulation is already happening in the Arctic marine ecosystem. We further suggest that such a shift might also be operating in the Three Gorges Reservoir due to changes in these biogeochemical processes induced by the damming. As a result, the effectiveness of mercury emission control is expected to be followed by long delays before ensuing reduction is seen in food-web levels, making it all the more pressing to control and reduce mercury emissions to the reservoir. Long-term monitoring and targeted studies are urgently needed to understand how biotic mercury levels in the reservoir are re- sponding to changes in mercury emissions and in biogeochemical processes.

关 键 词：水生生态系统 三峡库区 汞污染 生物地球化学过程 环境影响 汞排放控制 生物地球化学循环 海洋生态系统 

分 类 号：X820.3[环境科学与工程—环境工程]