汞在新建水库食物网中的迁移特征与生物富集

The risk of increased mercury concentration in fish is an important issue in environmental impact assessment of newly constructed reservoirs in high mercury zone of the world. The upper reach of Yangtze River and southwestern region in our country locate at high mercury zone. Many reservoirs were under construction. Mercury may threat human health by biomagnification of food web transferring. Thus, it is essential to study bioaccumulation and migration of mercury in food web of newly constructed reservoir. In the previous studies on the migration of mercury in food web of the whole ecosystem after reservoir formation, the definition of trophic levels in food webs mostly based on traditional.classification methods. The classification of trophic level is discontinuous and lacks quantitative techniques. This project quantitative establishs trophic structure of food web in a newly constructed reservoir and analyzes the long-term source of biological nutritions, by using nitrogen and carbon stable isotope techniques, and establishs the quatitative relationship between bioaccumulation and the nutrient transfer of food web, and analyzes bioaccumation rates of mercury and methylmercury in the food web, and studies migration and biacumulaiton of mercury in a newly constructed reservoir food web.

新建水库中鱼类汞含量升高的风险是国际上高汞背景值地区水库环境影响评价中的重要内容。我国长江上游和西南地区处于高汞背景区域，在水库大量修建的情况下，汞经过生物放大作用在食物网中传递，有可能对人类健康产生威胁。因此，有必要对水库形成后汞在整个水库生态系统食物网中的迁移富集路径进行系统研究。目前在有关水库形成后汞在食物网中迁移富集路径的研究中，食物网中营养级的界定大多基于传统分类方法，营养级的分级具有不连续性，缺乏定量化的技术手段。本项目通过碳、氮稳定性同位素技术技术的介入，定量地构建新建水库食物网营养结构，跟踪生物富集来源，据此建立生物富集与食物网营养传递的定量关系，分析汞及甲基汞比例在食物网的生物放大速率，研究重金属汞在新建水库食物网中迁移富集路径。

新建水库中鱼类汞含量升高的风险是国际上高汞背景值地区水库环境影响评价中的重要内容。我国长江上游和西南地区处于高汞背景区域，在水库大量修建的情况下，汞经过生物放大作用在食物网中传递，有可能对人类健康产生威胁。因此，有必要对水库形成后汞在整个水库生态系统食物网中的迁移富集路径进行系统研究。目前在有关水库形成后汞在食物网中迁移富集路径的研究中，食物网中营养级的界定大多基于传统分类方法，营养级的分级具有不连续性，缺乏定量化的技术手段。本项目通过碳、氮稳定性同位素技术的介入，定量地构建新建水库食物网营养结构，跟踪生物富集来源，据此建立生物富集与食物网营养传递的定量关系，分析汞及甲基汞比例在食物网的生物放大速率，研究重金属汞在新建水库食物网中迁移富集路径。