Department of Environmental Sciences, Rutgers University, 14 College Farm Road, New Brunswick, NJ 08901 United States.
United States Geological Survey, Upper Midwest Water Science Center, 8505 Research Way, Middleton, WI 53562 United States.
J Hazard Mater. 2019 Aug 5;375:121-129. doi: 10.1016/j.jhazmat.2019.04.074. Epub 2019 Apr 22.
Spatial redistribution of legacy mercury (Hg) contamination in the Hackensack River estuary (New Jersey, USA) was evaluated using mercury stable isotopes. Total Hg varied from 0.06 to 3.8 μg g in sediment from the tidal Hackensack River and from 15 to 154 μg g near historically contaminated sites in upper Berry's Creek, a tributary of the Hackensack River. δHg values for total Hg from Berry's Creek and Hackensack River estuaries varied over a fairly narrow range (-0.44‰ to -0.21‰), but were highest for sediment from upper Berry's Creek. Isotope mixing plots show that residual legacy mercury from upper Berry's Creek is partially diluted by a low concentration and low δHg pool of mercury associated with low organic matter content sediments similar to those in Newark Bay. Based on an isotope mixing model, we estimate that upper Berry's Creek contributes 21%-82% of the mercury in sediments in the Hackensack River estuary and its tidal tributaries, including upstream marsh habitats far from the primary source. Our results show that mercury stable isotopes can be used to track the redistribution of mercury in tidal ecosystems and highlight the potentially large areas which may be affected by legacy mercury contamination in estuaries.
利用汞稳定同位素评估了哈肯萨克河河口（美国新泽西州）中遗留汞（Hg）污染的空间再分布。潮汐哈肯萨克河沉积物中的总汞含量从 0.06 到 3.8μg/g 不等，而上贝里克里克（哈肯萨克河的一条支流）历史上受污染地区附近的总汞含量从 15 到 154μg/g 不等。贝里克里克和哈肯萨克河河口总汞的 δHg 值变化范围相当窄（-0.44‰至-0.21‰），但上贝里克里克的沉积物中最高。同位素混合图表明，上贝里克里克残留的汞主要来自于低浓度、低 δHg 的汞池，这些汞与低有机质含量的沉积物有关，类似于纽瓦克湾的沉积物。基于同位素混合模型，我们估计上贝里克里克的汞对哈肯萨克河河口及其潮汐支流的沉积物的贡献为 21%-82%，包括远离主要污染源的上游沼泽栖息地。我们的研究结果表明，汞稳定同位素可用于追踪潮汐生态系统中汞的再分布，并突出了可能受到河口汞污染影响的大面积区域。
