Roger Williams University, Department of Marine Biology, One Old Ferry Road, Bristol, RI 02809, USA.
Mar Pollut Bull. 2012 Apr;64(4):807-19. doi: 10.1016/j.marpolbul.2012.01.013. Epub 2012 Feb 7.
Total mercury (Hg) and methylmercury (MeHg) were analyzed in near surface sediments (0-2 cm) and biota (zooplankton, macro-invertebrates, finfish) collected from Narragansett Bay (Rhode Island/Massachusetts, USA) and adjacent embayments and tidal rivers. Spatial patterns in sediment contamination were governed by the high affinity of Hg for total organic carbon (TOC). Sediment MeHg and percent MeHg were also inversely related to summer bottom water dissolved oxygen (DO) concentrations, presumably due to the increased activity of methylating bacteria. For biota, Hg accumulation was influenced by inter-specific habitat preferences and trophic structure, and sediments with high TOC and percent silt-clay composition limited mercury bioavailability. Moreover, hypoxic bottom water limited Hg bioaccumulation, which is possibly mediated by a reduction in biotic foraging, and thus, dietary uptake of mercury. Finally, most biota demonstrated a significant positive relationship between tissue and TOC-normalized sediment Hg, but relationships were much weaker or absent for sediment MeHg. These results have important implications for the utility of estuarine biota as subjects for mercury monitoring programs.
总汞（Hg）和甲基汞（MeHg）在纳拉甘塞特湾（美国罗得岛州/马萨诸塞州）及其邻近的港湾和潮汐河流中采集的近地表沉积物（0-2 厘米）和生物群（浮游动物、大型无脊椎动物、鱼类）中进行了分析。沉积物污染的空间格局受汞对总有机碳（TOC）的高亲和力控制。沉积物中的 MeHg 和 MeHg 百分比也与夏季底层水溶解氧（DO）浓度呈反比关系，这可能是由于甲基化细菌活性增加所致。对于生物群，Hg 的积累受到种间栖息地偏好和营养结构的影响，并且 TOC 和淤泥-粘土成分高的沉积物限制了汞的生物利用度。此外，缺氧的底层水限制了 Hg 的生物积累，这可能是由于生物觅食减少，从而减少了汞的饮食摄入。最后，大多数生物群的组织与 TOC 归一化沉积物 Hg 之间存在显著的正相关关系，但沉积物 MeHg 的相关性较弱或不存在。这些结果对将河口生物群作为汞监测计划的研究对象具有重要意义。
