基于食物网和环境因子的三峡水库支流鱼汞积累控制机制研究

In this study, mercury content of fishes from different regions of Xiangxi River, a major tributary of Three Gorge Reservoir (TGR), will be measured to reveal the difference of mercury bio-accumulation between these fishes. Impact to accumulation of mercury in fishes by the change of habit, food source and food web structure which are the result of the impoundment process in tributary of TGR will be studied by the stable isotope (δC13 andδN15) technique. Then the differences of mercury content and species in various food sources and the environmental factors which could influence the behavior of mercury in the reservoir will be analyzed to seek the internal mechanism of the impact to accumulation of mercury in fishes by the impoundment process. Finally scientific explanations to the current situation of mercury accumulation in fishes from the tributary of TGR will be presented, and early warning of mercury enrichment in some fishes will be provided to protect the nearby residents from the health risk of mercury uptake. Meanwhile, the new ideas of mercury bio-accumulation to TGR will be provided by the research in the tributary.

本研究拟以三峡库区支流香溪河河流区、过渡区、水库区的鱼类样品和鱼类生活密切相关的环境样品为研究对象，通过测定鱼体内汞含量，揭示香溪河不同区域鱼体内汞积累情况的差异。以稳定同位素（δC13和δN15）技术为手段，在支流尺度上，研究三峡水库成库过程通过鱼类生活习性、食物来源及食物网结构的改变对鱼体内汞积累产生的影响，并通过分析鱼类食物来源中汞的含量形态在支流不同区域的时空差异和对水库中汞的环境行为产生影响的环境因素，探寻三峡水库成库过程对库区支流鱼体内汞积累影响的内在机制。最终通过研究结果，对库区支流内鱼体内汞积累的现状提出科学的解释，并对可能出现的某些鱼类对汞的富集提出预警，避免周边居民因摄入有关鱼类而产生的健康风险。同时通过对支流香溪河的研究，为整个三峡库区内汞的生物积累研究提供新的思路。