Mercury (Hg) is a toxic pollutant, widespread in northeastern US ecosystems. Resource managers’ efforts to develop fish consumption advisories for humans and to focus conservation efforts for fish-eating wildlife are hampered by spatial variability. Dragonfly larvae can serve as biosentinels for Hg given that they are widespread in freshwaters, long-lived, exhibit site fidelity, and bioaccumulate relatively high mercury concentrations, mostly as methylmercury (88% ± 11% MeHg in this study). We sampled lake water and dragonfly larvae in 74 northeastern US lakes that are part of the US EPA Long-Term Monitoring Network, including 45 lakes in New York, 43 of which are in the Adirondacks. Aqueous dissolved organic carbon (DOC) and total Hg (THg) were strongly related to MeHg in lake water. Dragonfly larvae total mercury ranged from 0.016–0.918 μg/g, dw across the study area; Adirondack lakes had the minimum and maximum concentrations. Aqueous MeHg and dragonfly THg were similar between the Adirondack and Northeast regions, but a majority of lakes within the highest quartile of dragonfly THg were in the Adirondacks. Using landscape, lake chemistry, and lake morphometry data, we evaluated relationships with MeHg in lake water and THg in dragonfly larvae. Lakewater DOC and lake volume were strong predictors for MeHg in water. Dragonfly THg Bioaccumulation Factors (BAFs, calculated as [dragonfly THg]:[aqueous MeHg]) increased as lake volume increased, suggesting that lake size influences Hg bioaccumulation or biomagnification. BAFs declined with increasing DOC, supporting a potential limiting effect for MeHg bioavailability with higher DOC.

汞 (Hg) 是一种有毒污染物，广泛存在于美国东北部的生态系统中。空间变异性阻碍了资源管理者为人类制定鱼类消费建议并重点保护食鱼野生动物的努力。蜻蜓幼虫可以作为汞的生物哨兵，因为它们广泛存在于淡水中，寿命长，表现出地点保真度，并且生物累积浓度相对较高，主要为甲基汞（本研究中为 88% ± 11% MeHg）。我们对属于美国 EPA 长期监测网络一部分的美国东北部 74 个湖泊的湖水和蜻蜓幼虫进行了采样，其中包括纽约的 45 个湖泊，其中 43 个位于阿迪朗达克山脉。水中溶解有机碳（DOC）和总汞（THg）与湖水中的甲基汞密切相关。研究区域内蜻蜓幼虫的总汞含量为 0.016–0.918 μg/g, dw；阿迪朗达克湖泊的浓度最低和最高。阿迪朗达克和东北地区的水体甲基汞和蜻蜓 THg 相似，但蜻蜓 THg 最高四分之一范围内的大多数湖泊都位于阿迪朗达克山脉。利用景观、湖泊化学和湖泊形态测量数据，我们评估了湖水中的甲基汞和蜻蜓幼虫中的 THg 的关系。湖水 DOC 和湖水体积是水中甲基汞的有力预测因子。蜻蜓 THg 生物累积因子（BAF，计算公式为 [蜻蜓 THg]:[水性 MeHg]）随着湖泊容量的增加而增加，表明湖泊大小影响汞生物累积或生物放大。 BAF 随着 DOC 的增加而下降，这支持了 DOC 较高时对 MeHg 生物利用度的潜在限制作用。