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

硒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争论最多的领域之一。加拿大和其他地方的金属和煤炭开采活动已被证明会导致接受其排放的水生生态系统中硒水平升高，这可能会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。更好地了解影响硒在水生生态系统中的暴露和潜在毒性效应的因素，从而制定以科学为基础的管理和监管办法，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一个综合的，多学科的方法来调查时空动态的分布，形态，命运和影响硒在北方（北方）水生生态系统接收从金属采矿作业的废水。利用实地调查、实地实验（原地无脊椎动物和鱼笼研究），围隔实验（多营养研究与部分生命周期的鱼类生物测定），和实验室实验（无脊椎动物的喂养和积累的研究，研究的后果，幼虫畸形的性能），我们打算更好地定义营养转移的硒和阈值响应跨非生物和生物区室的水生生态系统。使用国家的科学同步加速器技术，我们将定义硒（形态）的形式及其在介质和生物群中的转化，以确定形态和毒性之间的关系。我们的成果将：1）进一步硒生态毒理学领域; 2）定义与冷水栖息地相关的暴露条件和影响; 3）协助行业更好地了解存在的影响，努力走向可持续的解决方案;以及4）制定明确和可辩护的暴露阈值，以防止不利的生态影响。加拿大以前没有进行过这种程度的综合研究，其影响远远超出了这一具体研究地点。

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.