Recovery of fish populations in response to major infrastructure investments at municipal wastewater treatment plants

最近有报道称，各种令人担忧的污染物被排放到环境中，这加剧了人们对加拿大各地废水潜在影响的担忧。这些不同的化学物质有可能破坏内分泌系统的正常功能，损害鱼类和其他生物的繁殖和发育。尽管世界范围内对这一问题进行了大量的研究，但废水处理厂排放物下游所观察到的影响的化学物质和机制大部分仍未确定。该提案将研究安大略省格兰德河污水处理厂的主要工艺升级对哨兵鱼类的影响。先前对该流域虹鲷（Etheostoma caeruleum）的研究已经发现了不利的生物学影响，包括基因表达改变、双性人（睾丸-卵子）的发生、生殖生理（如性腺大小和类固醇产生减少）、生殖性能（如受精成功）和群落组合的改变。这样就有了一个多年的基线，以便在今后几年实施升级时进行比较。本研究将比较在同一流域内的几个污水处理厂的工艺变化后，鱼类在这些多层生物组织中的反应。这将有助于评估不同端点如何在时间和空间上对污水质量的重大变化作出反应。它将促进我们对污染物（包括内分泌干扰化合物）的命运的理解，以及导致不良后果的不同水平的生物组织之间的联系，这是评估风险的关键终点。了解这些过程和联系对于制定流域累积效应预测评估框架至关重要。该研究将应用和评估新兴监测工具/方法（例如下一代测序）的有效性，这些工具/方法将使许多部门的水资源管理人员能够评估和优先考虑未来的压力源和补救方案。

Concern over the potential impacts of wastewater across Canada has been heightened by recent reports of a variety of emerging contaminants of concern being released into the environment. These diverse chemicals have the potential to disrupt the normal function of endocrine systems and impair reproduction and development in fish and other organisms. Although considerable research has been focused on this issue worldwide, the chemicals and mechanisms responsible for the effects observed downstream of wastewater water treatment plant outfalls remains mostly undetermined. This proposal will examine the impact of major process upgrades at wastewater treatment plants in the Grand River, Ontario, on a sentinel fish species. Previous studies on rainbow darter (Etheostoma caeruleum) in this watershed have identified adverse biological impacts including altered gene expression, the occurrence of intersex (testis-ova), alterations in reproductive physiology (e.g. reduced gonad size and steroid production), reproductive performance (e.g., fertilization success) and community assemblages. Thus there is a multiyear baseline from which to make comparisons as upgrades are implemented over the next several years. This research will compare the responses in fish across these multiple levels of biological organization after process changes at several wastewater treatment plants within the same watershed. This will allow assessment of how various endpoints respond temporally and spatially to major changes in effluent quality. It will advance our understanding of the fate of contaminants (including endocrine disrupting compounds) and the linkages among various levels of biological organization leading to adverse outcomes that are key endpoints in assessing risk. Understanding of these processes and linkages are central to the development of predictive cumulative effects assessment frameworks for watersheds. The research will apply and assess the validity of emerging monitoring tools/approaches (e.g. next generation sequencing) that will allow water managers in many sectors to assess and prioritize stressors and remedial options for the future.