Grupo de Ecología de Sistemas Acuáticos a escala de Paisaje, Instituto de Investigaciones en Biodiversidad y Medioambiente (INIBIOMA, UNComahue- CCT Patagonia Norte CONICET), Quintral 1250, 8400, San Carlos de Bariloche, Río Negro, Argentina.
Grupo de Ecología de Sistemas Acuáticos a escala de Paisaje, Instituto de Investigaciones en Biodiversidad y Medioambiente (INIBIOMA, UNComahue- CCT Patagonia Norte CONICET), Quintral 1250, 8400, San Carlos de Bariloche, Río Negro, Argentina.
Chemosphere. 2018 Apr;197:262-270. doi: 10.1016/j.chemosphere.2018.01.048. Epub 2018 Jan 12.
Lake Nahuel Huapi (NH) is a large, ultraoligotrophic deep system located in Nahuel Huapi National Park (NHNP) and collecting a major headwater network of Northwestern Patagonia (Argentina). Brazo Rincón (BR), the westernmost branch of NH, is close to the active volcanic formation Puyehue-Cordón Caulle. In BR, aquatic biota and sediments display high levels of total Hg (THg), ranging in contamination levels although it is an unpolluted region. In this survey, Hg species and fractionation were assessed in association with dissolved organic matter (DOM) in several aquatic systems draining to BR. THg varied between 16.8 and 363 ng L, with inorganic Hg (Hg) contributing up to 99.8% and methyl mercury (MeHg) up to 2.10%. DOC levels were low (0.31-1.02 mg L) resulting in high THg:DOC and reflecting in high Hg availability for binding particles (partitioning coefficient log K up to 6.03). In streams, Hg fractionation and speciation related directly with DOM terrestrial prints, indicating coupled Hg-DOM inputs from the catchment. In the lake, DOM quality and photochemical and biological processing drive Hg fractionation, speciation and vertical levels. Dissolved gaseous Hg (Hg) reached higher values in BR (up to 3.8%), particularly in upper lake layers where solar radiation enhances the photoreduction of Hg and Hg-DOM complexes. The environmental conditions in BR catchment promote Hg binding to abiotic particles and bioaccumulation and the production of Hg, features enhancing Hg mobilization among ecosystem compartments. Overall, the aquatic network studied can be considered a "natural Hg hotspot" within NHNP.
纳韦尔瓦皮湖（NH）是一个大型的超寡营养深湖，位于纳韦尔瓦皮国家公园（NHNP），收集了西北巴塔哥尼亚的主要源头网络（阿根廷）。NH 的最西分支是里恩孔湾（BR），靠近活火山普耶韦-科登卡乌勒。在 BR，水生物群和沉积物显示出高水平的总汞（THg），尽管这是一个无污染的地区，但污染水平不同。在这项调查中，评估了与流入 BR 的几个水生系统中的溶解有机物质（DOM）相关的 Hg 物种和分馏。THg 变化范围为 16.8 至 363ng/L，其中无机汞（Hg）贡献高达 99.8%，甲基汞（MeHg）高达 2.10%。DOC 水平较低（0.31-1.02mg/L），导致 THg:DOC 很高，反映出 Hg 与颗粒结合的高可用性（分配系数 log K 高达 6.03）。在溪流中，Hg 分馏和形态与 DOM 陆地印记直接相关，表明流域中存在 Hg-DOM 输入的耦合。在湖中，DOM 质量和光化学及生物处理驱动 Hg 分馏、形态和垂直水平。溶解气态 Hg（Hg）在 BR 中达到更高的值（高达 3.8%），特别是在上湖层，那里的太阳辐射增强了 Hg 和 Hg-DOM 复合物的光还原。BR 流域的环境条件促进了 Hg 与非生物颗粒的结合以及生物积累和 Hg 的产生，这些特征增强了生态系统各部分之间 Hg 的迁移。总体而言，研究中的水网络可以被认为是 NHNP 内的一个“天然 Hg 热点”。
