Global pollution of mercury (Hg) threatens ecosystem and human health. We measured total Hg (THg) and monomethylmercury (MMHg) concentrations in filter-feeding blackfly (Simulium spp.) larvae in the inflows and the outflows of six boreal lakes with no Hg point source pollution. THg in the larvae ranged from 0.03 to 0.31 mg kg⁻¹ dw and MMHg between 0.02 and 0.25 mg kg⁻¹ dw. The proportion of MMHg in the larvae was 74 ± 0.16% and ranged from 43 to 98% of THg, the highest proportions being comparable to those typically found in aquatic predatory insects and fish. We compared the larvae MMHg concentrations to river water quality, catchment land-use, and to size-adjusted lake pike THg data. Two of the investigated catchments have been affected by a multimetal biomine since 2008 and were characterized by higher conductivity and higher urban land-use activity. Larvae THg and MMHg concentrations were higher in the lake inflows than in outflows and associated with water conductivity and catchment land-use activity. Lake pike THg concentrations were highly correlated to lake outflow blackfly larvae MMHg concentrations. Our data illustrate that blackfly larvae take up high percentage of THg that is MMHg, which in turn is available for higher consumers in aquatic and terrestrial food webs.

中文翻译：

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黑蝇幼虫（Simulium spp。）可以增强北方食物网中甲基汞的生物放大作用

汞的全球污染威胁着生态系统和人类健康。我们测得的总汞（THG）和monomethylmercury（毫米汞柱）浓度滤食性蚋（蚋在流入spp。）的幼虫和六个寒带湖泊的无汞点源污染的流出。幼虫中的THg为0.03至0.31 mg kg ^-1 dw，MMHg为0.02至0.25 mg kg ^-1dw。幼虫中MMHg的比例为THg的74±0.16％，范围为THg的43％至98％，最高比例与水生掠食性昆虫和鱼类中常见的比例相当。我们将幼体MMHg浓度与河流水质，集水区土地利用以及大小调整后的湖泊派克THg数据进行了比较。自2008年以来，两个受调查流域受到了多金属生物矿的影响，其特点是电导率较高，城市土地利用活动较高。湖泊流入物中的幼虫THg和MMHg浓度高于流出物中，并且与水的电导率和集水区土地利用活动有关。梭子鱼THg的浓度与湖水流出粉虱幼虫MMHg的浓度高度相关。我们的数据表明，black蝇幼虫占THg的比例很高，也就是MMHg，