大型捕食者可通过食物网对生态系统产生直接或间接的影响。对于持久性生物可累积毒性化合物（PBT），大型捕食者是富集者，也是转运者。树岛是分布在平原沼泽的典型景观，是沼泽湿地中的生物多样性和元素循环的热点区。在我国三江平原，苍鹭（Ardea cinerea）、大白鹭（Egretta alba）、普通鸬鹚（Phalacrocorax carbo sinensis）常混群营巢于树岛。鸟类捕食驱动了汞的生物累积和转移。本研究假设鸟粪是树岛汞的主要输入源；水鸟种间取食生态位分化造成了汞迁移通道的差异。本项目通过汞输入通量研究，明确三江平原树岛土壤汞含量高的事实是否主要由鸟粪汞造成；结合定量食物网混合模型与相关物种汞含量分析，阐明食物网构成差异影响下的生物汞传输通道结构与通量变化，研究结果将为生态系统持久性生物可累积毒性化合物（PBT）防控、管理，乃至物种、生境保护提供科学依据。

Large predators have a direct or indirect impact on the ecosystem through the food web . For persistent bioaccumulative toxic Chemicals （PBT), large predator is both enricher, but also transporter . Tree Island is located in the typical landscape of the plain marsh , swamp wetland biodiversity hotspots and elements of biological cycles . In China Sanjiang Plain, herons（Ardea cinerea）, great egrets（Egretta alba）, cormorants（Phalacrocorax carbo sinensis） often nest in tree islands . Birds prey , brooding , excretion process, promote wetlands play a mercury bioaccumulation ,transpot. Tree Island soil mercury may change significantly under the long-term effects of waterfowl food webs - the fish . We hypothesized that waterbird breeding tree island is its main importer of mercury ; between clusters nesting waterbird species foraging niche differentiation/food web differences determine the spatial structure and fluxes of mercury transmission channel. This study combined quantitative food webs and mixed model analysis of associated species mercury content , clarify the structure and biological mercury flux transmission channel niche differentiation under the influence of , for the in-depth understanding of the food web PBT driven migration , distribution, and even provide a scientific basis for species habitat protection and management.