Mercury is a persistent, biomagnifying contaminant that can cause negative behavioral, immunological, and reproductive effects in wildlife and human populations. We examined the role of wetland water-management on mercury bioaccumulation in songbirds and ducks at Kellys Slough National Wildlife Refuge Complex, near Grand Forks, North Dakota USA. We assessed mercury concentrations in blood of wetland-foraging songbirds (80 common yellowthroats [Geothlypis trichas] and 14 Nelson’s sparrows [Ammospiza nelsoni]) and eggs of upland-nesting ducks (28 gadwall [Mareca strepera], 19 blue-winged teal [Spatula discors], and 13 northern shoveler [S. clypeta]) across four wetland water-management classifications. Nelson’s sparrow blood mercury concentrations were elevated (mean: 1.00 µg/g ww; 95% CL: 0.76–1.31) and similar to those reported 6 years previously. Mercury in songbird blood and duck eggs varied among wetland water-management classifications. Songbirds and ducks had 67% and 49% lower mercury concentrations, respectively, when occupying wetlands that were drawn down with water flow compared to individuals occupying isolated-depressional wetlands with no outflow. Additionally, songbirds within impounded and partially drawn-down wetland units with water flow had mercury concentrations that were 26–28% lower, respectively, than individuals within isolated-depressional wetlands with no outflow. Our results confirm that mercury concentrations in songbirds at Kellys Slough continue to be elevated and suggest that water-management could be an important tool for wetland managers to reduce bioaccumulation of mercury in birds.

汞是一种持久的生物放大污染物，可对野生动植物和人类造成不良的行为，免疫和生殖影响。我们在美国北达科他州格兰德福克斯附近的凯利斯劳国家野生动物保护区检查了湿地水管理对鸣禽和鸭子中汞生物积累的作用。我们评估了湿地觅食鸣禽（80只常见的黄喉[ Geothlypis trichas ]和14纳尔逊的麻雀[ Ammospiza nelsoni ]）和高地鸭子的蛋（28只gadwall [ Mareca strepera ]，19只蓝翅蓝绿色的小鸭[ Spatula] discors ]和13个北方用铲子[ S. clypeta]）进行四个湿地水管理分类。尼尔森的麻雀血中汞浓度升高（平均值：1.00 µg / g重量； 95％CL：0.76-1.31），与六年前报告的相似。在湿地水管理分类中，鸣禽血液和鸭卵中的汞有所不同。相较于没有隔离流出的低气压湿地，鸣禽和鸭子在被水流吸引的湿地中的汞含量分别低67％和49％。此外，在有水流的蓄水和部分下放的湿地单元中的鸣禽，其汞浓度分别比没有泄水的偏低洼地湿地中的个体低26-28％。