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

水体中硒的毒性，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、研究最多的领域之一。加拿大和其他地方的金属和煤炭开采活动已被证明导致接受其排放的水生生态系统中的硒水平升高，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。为了加拿大的环境管理和科学领导，更好地了解影响水生态系统中硒暴露的因素和潜在的毒理影响，从而制定一种以科学为基础的管理和监管办法，符合加拿大的利益。这一为期三年的项目的总体目标是采用综合、多学科的方法来研究北部(北方)水生生态系统中Se的分布、形态、去向和影响的时空动态。通过实地调查、实地实验(现场无脊椎动物和鱼类笼养研究)、中游实验(部分生命周期鱼类生物测定的多营养研究)和实验室实验(无脊椎动物摄食和积累研究，研究幼虫畸形对性能的影响)，我们打算更好地确定Se的营养转移和跨越非生物和生物生态系统的反应阈值。使用最先进的同步加速器技术，我们将定义Se(形态形成)的形式及其在介质和生物群中的转化，目的是确定形态形成与毒性之间的关系。我们的成果将：1)进一步研究硒生态毒理学领域；2)确定与冷水栖息地相关的暴露条件和影响；3)帮助工业更好地了解为走向可持续解决方案而存在的影响；以及4)制定明确和可防御的暴露阈值，以防止不利的生态影响。关于这种融合程度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.