我国东部湿地典型鸟类的甲基汞富集、代谢及传输作用

甲基汞具有超强生物富集性、是毒性最强的有机金属污染物之一。全球汞污染已对食物链顶端生物的生存和健康构成危害。本项目针对高汞负荷地区陆生鸟类甲基汞暴露水平和风险不清、鸟类甲基汞/汞代谢过程不明这一当前核心科学问题开展研究。拟在我国东部典型淡水湿地，从食物链、居留型和食性的角度开展典型鸟类甲基汞富集、代谢与生境汞的野外调查研究，从食物链的角度分析我国东部典型鸟类的甲基汞富集特征，揭示鸟类各组织器官中甲基汞富集、代谢与生境汞的关系；利用模式鸟的稳定汞同位素模拟实验，发展鸟的汞/甲基汞代谢参数化模型；结合野外调查和模型，评估候鸟迁徙导致的跨区域甲基汞迁移及其风险传输。本项研究立足汞生物地球化学的科学前沿，独辟蹊径，以揭示汞污染的生态风险和探索汞循环的新机制。项目实施也有助于提高对全球汞污染防治的认识，有益于野生鸟类保护。

Methylmercury (MeHg) is a highly toxic organic metal pollutant with tremendous bioaccumulation and biomagnification in food webs. Enhanced global Hg pollution has posed a great threat to the survival and health of organisms at the top of the food chain. This project aims at the current core scientific issues of unclear exposure levels and risks of MeHg and unclear metabolism processes of MeHg and Hg in terrestrial birds in high Hg load regions. The main objectives of this project are (1) to carry out the field investigation of Hg in typical fresh water wetlands in eastern China and explore the MeHg enrichment in typical birds from the perspective of food chain, habitation and feeding habits; (2) to analyze the enrichment characteristics of MeHg in typical birds in wetlands of eastern China from the perspective of food chain; (3) to reveal the relationship between the enrichment and metabolism of MeHg in various tissues and organs of birds and the Hg loads in their habitats; (4) to parameterize the metabolism of Hg in birds based on the oral dosage experiment with spiked food of 198Hg2+ and Me202Hg; (5) to identify and evaluate the trans-regional migration of MeHg and its risk transfer as a result of migration of migratory birds based on the field surveys and models. Based on the scientific frontier of biogeochemistry of Hg, this project develops a new method to reveal the ecological risk of Hg pollution and explore the mechanism of Hg cycle in birds. The implementation of this project will improve our understanding of global Hg pollution control, and it is also beneficial to wild bird conservation.