Estuarine water column methylmercury (MeHg) is an important driver of mercury (Hg) bioaccumulation in pelagic organisms and thus it is necessary to understand the sources and processes affecting environmental levels of MeHg. Increases in water column MeHg concentrations can ultimately be transferred to fish consumed by humans, but despite this, the sources of MeHg to the estuarine water column are still poorly understood. Here we evaluate MeHg sources across 4 estuaries and 10 sampling sites and examine the distributions and partitioning of sediment and water column MeHg across a geographic range (Maine to New Jersey). Our study sites present a gradient in the concentrations of sediment, pore water and water column Hg species. Suspended particle MeHg ranged from below detection to 187 pmol g^− 1, dissolved MeHg from 0.01 to 0.68 pM, and sediment MeHg from 0.01 to 109 pmol g^− 1. Across multiple estuaries, dissolved MeHg correlated with Hg species in the water column, and sediment MeHg correlated with sediment total Hg (HgT). Water column MeHg did not correlate well with sediment Hg across estuaries, indicating that sediment concentrations were not a good predictor of water MeHg concentrations. This is an unexpected finding since it has been shown that MeHg production from inorganic Hg^2 + within sediment is the primary source of MeHg to coastal waters. Additional sources of MeHg regulate water column MeHg levels in some of the shallow estuaries included in this study.

河口水柱甲基汞（MeHg）是中上层生物体内汞（Hg）生物积累的重要驱动力，因此有必要了解影响MeHg环境水平的来源和过程。水柱中甲基汞浓度的增加最终可以转移到人类食用的鱼中，但是尽管如此，人们对河口水柱中甲基汞的来源仍知之甚少。在这里，我们评估了4个河口和10个采样点的MeHg来源，并研究了从地理范围（缅因州到新泽西州）的沉积物和水柱MeHg的分布和分配。我们的研究地点呈现出沉积物，孔隙水和水柱汞物种浓度的梯度。悬浮颗粒的MeHg范围从低于检测到187 pmol g ^{− 1}，溶解的MeHg从0.01到0.68 pM，沉淀的MeHg从0.01到109 pmol g ^-1。在多个河口中，溶解的MeHg与水柱中的Hg种类相关，而沉积物MeHg与沉积物总Hg（HgT）相关。水柱中的甲基汞与跨河口的沉积物汞没有很好的相关性，表明沉积物浓度不是水中甲基汞浓度的良好预测指标。这是一个出乎意料的发现，因为已经表明，沉积物中无机Hg ^{2 +}产生的MeHg是向沿海水域产生MeHg的主要来源。甲基汞的其他来源可调节本研究中某些浅河口中水柱的甲基汞含量。