Kiser Tim, Hansen James, Kennedy Brian
Eastern Washington Field Office, US Fish and Wildlife Service, Spokane, WA 99206, USA.
Arch Environ Contam Toxicol. 2010 Aug;59(2):301-11. doi: 10.1007/s00244-009-9457-x. Epub 2010 Jan 26.
Metals contamination from mining activities is a persistent problem affecting aquatic ecosystems throughout mining districts in the western USA. The Gold Creek drainage in northern Idaho has a history of mining within its headwaters and contains elevated sediment concentrations of As, Cd, Cu, Pb, and Zn. To determine system-wide impacts of increased metals, we measured concentrations of metals in water, sediment, and benthic macroinvertebrate tissues and related them to whole-body fish tissues and histopathological alterations in native salmonids. Water concentrations were higher than those in reference areas, but were below water quality criteria for protection of aquatic biota for most of the study area. Sediment and benthic macroinvertebrate tissue concentrations for all metals were significantly higher at all sites compared with the reference site. Fish tissues were significantly higher for all metals below mine sites compared with the reference site, but only Cd and Pb were higher in fish tissues in the furthest downstream reach in the Gold Creek Delta. Metals concentrations in benthic macroinvertebrate tissues and fish tissues were strongly correlated, suggesting a transfer of metals through a dietary pathway. The concentrations within sediments and biota were similar to those reported in other studies in which adverse effects to salmonids occurred. We observed histopathological changes in livers of bull trout, including inflammation, necrosis, and pleomorphism. Our study is consistent with other work in which sediment-driven exposure can transfer up the food chain and may cause adverse impacts to higher organisms.
采矿活动造成的金属污染是一个长期存在的问题，影响着美国西部矿区的水生生态系统。爱达荷州北部的金溪排水区上游有采矿历史，沉积物中砷、镉、铜、铅和锌的浓度升高。为了确定金属含量增加对整个系统的影响，我们测量了水、沉积物和底栖大型无脊椎动物组织中的金属浓度，并将其与本地鲑鱼的全身组织以及组织病理学变化相关联。研究区域大部分地区的水体浓度高于参考区域，但低于保护水生生物的水质标准。与参考站点相比，所有站点的沉积物和底栖大型无脊椎动物组织中所有金属的浓度均显著更高。与参考站点相比，矿场下方所有金属在鱼类组织中的含量均显著更高，但在金溪三角洲最下游河段的鱼类组织中，只有镉和铅的含量更高。底栖大型无脊椎动物组织和鱼类组织中的金属浓度高度相关，表明金属通过饮食途径转移。沉积物和生物群中的浓度与其他对鲑鱼产生不利影响的研究报告中的浓度相似。我们观察到公牛鳟肝脏出现组织病理学变化，包括炎症、坏死和多形性。我们的研究与其他研究一致，即沉积物驱动的暴露可沿食物链向上转移，并可能对高级生物造成不利影响。
