Université de Lorraine, CNRS, LIEC, F-57000, Metz, France.
Université de Lorraine, CNRS, LIEC, F-57000, Metz, France.
J Environ Manage. 2021 Aug 1;291:112726. doi: 10.1016/j.jenvman.2021.112726. Epub 2021 May 4.
Ultramafic sediments exhibit high levels of geogenically-derived and potentially toxic metals, with Ni, Cr and Co often exceeding benchmark values. As yet, a holistic understanding of the bioavailability, mobility, potential ecotoxicity and trophic transfer of trace elements in both benthic and pelagic food chains in aquatic ultramafic environments (UME) is lacking. We investigated potential environmental health issues due to metal contamination by jointly implementing chemical, ecological and toxicological tools, along the Albanian shoreline of Lake Ohrid. It is an aquatic system of worldwide importance, representative of temperate UME with a legacy of Ni and Cr contamination from mining activities. Levels of Ni, Cr, Cd, Cu, Co, Fe, Mn and Zn were determined in waters, sediments and native biota. The potential environmental mobility of sediment-bound elements was further assessed using CaCl, EDTA and acetic acid extractions. Whole-sediment ecotoxicity tests were also carried out using ostracods and chironomids, according to standardized procedures. Despite Ni and Cr concentrations above the sediment quality guidelines for probable effect levels, we did not observe ecotoxic effects in laboratory tests. However, these elements were bioavailable to native organisms under field conditions, especially to benthic primary producers in direct contact with sediments (up to 139 mg Cr kg and 785 mg Ni kg). Although biomagnification was not observed, further investigations of metal translocation, metabolism and elemental trophic transfer along benthic food webs appears to be a general research priority in the management of temperate UME. The present study shows that proper management of temperate UME requires not only the integration of data from different lines of evidence, but also laboratory vs. field approaches to understand the subtler, long-term effects of increased elemental body burdens in native organisms.
超镁铁质沉积物中含有高水平的原生和潜在有毒金属，其中镍（Ni）、铬（Cr）和钴（Co）常常超过基准值。迄今为止，对于水生超镁铁质环境（UME）中底栖和浮游食物链中痕量元素的生物利用度、迁移性、潜在生态毒性和营养转移，我们还缺乏全面的了解。我们通过联合使用化学、生态和毒理学工具，沿阿尔巴尼亚奥赫里德湖的湖岸线，调查了由于金属污染而可能产生的环境健康问题。这是一个具有全球重要性的水生系统，是具有镍和铬采矿活动污染遗留问题的温带 UME 的代表。我们测定了水、沉积物和本地生物群中 Ni、Cr、Cd、Cu、Co、Fe、Mn 和 Zn 的含量。还使用 CaCl、EDTA 和乙酸提取进一步评估了沉积物中结合元素的潜在环境迁移能力。根据标准化程序，还使用介形虫和摇蚊进行了全沉积物生态毒性测试。尽管 Ni 和 Cr 浓度高于可能产生影响水平的沉积物质量指南值，但我们在实验室测试中没有观察到生态毒性效应。然而，在野外条件下，这些元素对本地生物是可利用的，尤其是直接与沉积物接触的底栖初级生产者（高达 139mg Cr kg 和 785mg Ni kg）。尽管没有观察到生物放大作用，但进一步调查金属转移、代谢和元素营养转移沿底栖食物网的情况，似乎是管理温带 UME 的一般研究重点。本研究表明，要对温带 UME 进行妥善管理，不仅需要整合来自不同证据来源的数据，还需要采用实验室与野外相结合的方法，以了解增加原生生物体内元素负荷的更微妙、长期影响。
