Interdisciplinary Center of Marine and Environmental Research (CIIMAR/CIMAR), University of Porto, Terminal de Cruzeiros do Porto de Leixões, Av. General Norton de Matos s/n, 4450-208, Matosinhos, Portugal.
Institut des Sciences Analytiques et de Physico-Chimie pour l'Environnement et les Matériaux, CNRS/UNIV PAU & PAYS ADOUR, UMR5254, Mira, 64000, Pau, France.
Environ Sci Pollut Res Int. 2018 Jun;25(18):17371-17382. doi: 10.1007/s11356-018-1925-2. Epub 2018 Apr 13.
The concentrations of dissolved and particulate inorganic mercury (IHg(II)) and methylmercury (MeHg) from the contaminated Laranjo Bay (main freshwater discharge from the Antuã River) were measured by species-specific isotope dilution during six sampling campaigns at high and at low tide. Different effective riverine concentrations were calculated, based on salinity profiles, for specific hydrological conditions. The export fluxes of total Hg and MeHg (324 and 1.24 mol year, respectively) from the bay to the rest of the Aveiro Lagoon are much higher than the input fluxes from the Hg source (3.9 and 0.05 mol year) and from the Antuã River (10.4 and 0.10 mol year). Resuspension of contaminated sediments from Laranjo Bay is crucial for the transport of both IHg(II) and MeHg. Methylation and/or selective enrichment into biogenic particles is responsible for the mobilization of MeHg. Sorption of dissolved IHg(II) onto suspended particles limits its export flux. This is one of the rarest examples where both speciation fluxes and partitioning of mercury are studied in a contaminated coastal environment. Despite the lower fraction of total MeHg (relative to total Hg), the contaminated lagoon may have an impact on coastal areas, particularly if change in the lagoon geometry occurs, due to sea level rise.
在六个高、低潮采样期间，通过种特异性同位素稀释法测量了受污染的拉兰霍湾（安图亚河的主要淡水排放口）中溶解态和颗粒态无机汞（IHg(II)）和甲基汞（MeHg）的浓度。基于盐度剖面，针对特定的水文条件计算了不同的有效河流浓度。从海湾到阿韦罗泻湖其他地区的总汞和 MeHg 的出口通量（分别为 324 和 1.24 mol 年）远高于汞源（3.9 和 0.05 mol 年）和安图亚河（10.4 和 0.10 mol 年）的输入通量。拉兰霍湾受污染沉积物的再悬浮对于 IHg(II)和 MeHg 的传输至关重要。甲基化和/或选择性富集到生物颗粒中是 MeHg 迁移的原因。溶解态 IHg(II)被悬浮颗粒吸附限制了其输出通量。这是在受污染的沿海环境中研究汞形态通量和分配的罕见示例之一。尽管总 MeHg（相对于总汞）的比例较低，但由于海平面上升导致泻湖几何形状发生变化，受污染的泻湖可能会对沿海地区产生影响。
