Investigation of temporal and spatial distribution, fate and biological effects of selenium in a boreal aquatic ecosystem

硒（Se）在水生系统中的毒性，特别是对鱼类的毒性，是目前北美水生生态毒理学中最具争议和研究密集的领域之一。加拿大和其他地方的金属和煤炭开采活动已被证明导致其排放的水生生态系统中硒水平升高，这可能影响鱼类种群的可持续性以及生态系统结构和功能的完整性。更好地了解影响水生生态系统中硒的接触和潜在毒理学影响的因素，从而制定基于科学的管理和监管办法，符合加拿大环境管理和科学领导的利益。这个为期三年的项目的总体目标是使用综合的、多学科的方法来调查硒在北部（北方）水生生态系统中分布、物种形成、命运和影响的时空动态，这些生态系统接收来自金属采矿作业的废水。通过实地调查、实地实验（无脊椎动物和鱼类圈养研究）、中观实验（鱼类部分生命周期生物分析的多营养研究）和实验室实验（无脊椎动物摄食和积累研究、幼虫畸形对生产性能影响的研究），我们打算更好地定义硒的营养转移以及水生生态系统中非生物和生物隔间的响应阈值。利用最先进的同步加速器技术，我们将定义硒（物种形成）的形式及其在媒介和生物群中的转化，目的是确定物种形成与毒性之间的关系。本研究结果将：1)进一步推进硒生态毒理学研究；2)确定与冷水生境有关的暴露条件和影响；3)帮助行业更好地了解在努力实现可持续解决方案的过程中存在的影响；4)制定明确的、可防御的暴露阈值，以防止不利的生态影响。这种程度的整合和范围的研究以前从未在加拿大进行过，其国家和国际影响远远超出了这个特定的研究地点。

The toxicity of selenium (Se) in aquatic systems, particularly to fishes, is currently one of the most debated and research intensive areas of aquatic ecotoxicology in North America. Metal and coal mining activities in Canada and elsewhere have been shown to cause elevated levels of selenium in aquatic ecosystems receiving their discharges, which can impact the sustainability of fish populations and the integrity of ecosystem structure and function. It is in the interest of Canada's environmental stewardship and scientific leadership to better understand factors influencing exposure and potential toxicological effects of Se in aquatic ecosystems, thereby developing a science-based management and regulatory approach. The overall objective of this three year project is to use an integrative, multidisciplinary approach to investigate temporal and spatial dynamics of the distribution, speciation, fate and effects of Se in a northern (boreal) aquatic ecosystem receiving effluent from a metal mining operation. Using field surveys, field experiments (in situ invertebrate and fish caging studies), mesocosm experiments (multi-trophic studies with partial life-cycle fish bioassays), and laboratory experiments (invertebrate feeding and accumulation studies, studies examining the consequences of larval deformities on performance) we intend to better define the trophic transfer of Se and thresholds for response across abiotic and biotic compartments of an aquatic ecosystem. Using state-of-the science synchrotron technology, we will define the form of Se (speciation) and its transformation across media and biota with the goal of determining relationships between speciation and toxicity. Our results will: 1) further the field of Se ecotoxicology; 2) define conditions of exposure and effects associated with coldwater habitats; 3) assist industry to better understand effects that exist in an effort to move towards sustainable solutions; and 4) develop clear and defensible exposure thresholds for preventing adverse ecological impacts. A study of this level of integration and scope has not been conducted in Canada before and has national and international implications far beyond this specific study site.