Methylmercury Bioaccumulation in Stream Food Webs Declines with Increasing Primary Production.
Methylmercury Bioaccumulation in Stream Food Webs Declines with Increasing Primary Production.
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随着初级生产的增加，河流食物网中的甲基汞生物累积量下降。
DOI：
10.1021/acs.est.5b00911
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发表时间：
2015
影响因子：
11.4
通讯作者：
J. Oris
中科院分区：
文献类型：
--
作者：
D. Walters;D. Raikow;C. R. Hammerschmidt;M. G. Mehling;A. Kovach;J. Oris
相反的假说认为，增加初级生产力应导致或多或少的污染物积累在流食物网。我们进行了一项实验，以评估初级生产力的影响，在流消费者的甲基汞积累。我们改变了16条人工溪流的光照，在溪流之间产生了生产率梯度（产氧量=0.048-0.71 mg O2 L（-1）d（-1））。两级食物网建立浮游植物/滤食性蛤，附着生物/放牧蜗牛，叶/切碎端足类（Hyalella azteca）。浮游植物和附着生物的生物量，沿着从水柱中去除甲基汞，生产力显着增加，但甲基汞浓度在这些初级生产者下降。蛤蜊和蜗牛中的甲基汞浓度也随着生产力的下降而下降，消费者浓度与初级生产者中的甲基汞浓度密切相关。异养生物量的叶片，甲基汞在叶片中，和甲基汞在Hyalella流生产力无关。我们的研究结果支持这一假设，即污染物的生物积累下降流初级生产通过机制的水华稀释（甲基汞负担每细胞减少藻类水华），扩展模式的污染物积累记录在湖泊中的湖泊，以lotic系统。
Opposing hypotheses posit that increasing primary productivity should result in either greater or lesser contaminant accumulation in stream food webs. We conducted an experiment to evaluate primary productivity effects on MeHg accumulation in stream consumers. We varied light for 16 artificial streams creating a productivity gradient (oxygen production =0.048-0.71 mg O2 L(-1) d(-1)) among streams. Two-level food webs were established consisting of phytoplankton/filter feeding clam, periphyton/grazing snail, and leaves/shredding amphipod (Hyalella azteca). Phytoplankton and periphyton biomass, along with MeHg removal from the water column, increased significantly with productivity, but MeHg concentrations in these primary producers declined. Methylmercury concentrations in clams and snails also declined with productivity, and consumer concentrations were strongly correlated with MeHg concentrations in primary producers. Heterotroph biomass on leaves, MeHg in leaves, and MeHg in Hyalella were unrelated to stream productivity. Our results support the hypothesis that contaminant bioaccumulation declines with stream primary production via the mechanism of bloom dilution (MeHg burden per cell decreases in algal blooms), extending patterns of contaminant accumulation documented in lakes to lotic systems.
影响因子：
11.4
作者：
Chen, CY;Folt, CL
通讯作者：
Folt, CL