Investigation of stressors on freshwater mussel populations

地球上淡水贻贝种类最多的地方是北美；不幸的是，它们是最危险的生物之一。例如，在加拿大发现的53种淡水贻贝中，安大略省南部有42种，其中13种被列为受威胁或濒危物种。监测淡水贻贝种群的传统方法是资源和劳动密集型的（例如，定时搜索和样方调查）。也可能需要5到10年的时间才能确定种群数量的显著下降。例如，渔业和海洋部监测被列为濒临灭绝的淡水贻贝种群，但由于监测一个物种和濒危贻贝物种的数量需要大量资源，他们只能每五年轮流评估一个特定地点的种群。这就需要一种更快速的非致命性诊断工具来评估处于危险中的淡水贻贝种群的健康状况。因此，我的研究计划的最终研究问题是，代谢组的变化是否会成为淡水贻贝种群中压力的有效非致死指标。我的研究计划的三个短期目标集中在了解导致实验室培养和野生种群的血淋巴代谢组变化的因素。1)研究加拿大原产淡水贻贝血淋巴代谢组的变化2)研究不同应激源下淡水贻贝血淋巴代谢组的变化。3)研究安大略省五大湖流域野生淡水贻贝物种血淋巴代谢组的变化。了解代谢组变化的基本驱动因素对于表征淡水贻贝种群中使用代谢组作为应激指标的统计能力至关重要。之所以选择血淋巴作为靶组织，是因为可以去除代谢组学分析所需的体积，而不会对单个贻贝产生不利影响。非致死终点的开发将允许对受威胁和濒危淡水贻贝物种的压力源进行直接评估，而不会对自然种群产生影响。长期目标是应用我们所学到的知识，完成这三个短期目标，扩大血淋巴代谢组学分析的使用，以调查栖息地改变（例如，温度、营养输入、总悬浮固体等）和微生物对淡水贻贝健康的影响。希望我们能够开发出一种诊断工具，使我们能够以非致命性的方式收集濒危种群的健康数据，从而有助于制定和监测恢复和重新引入计划。

The greatest diversity of freshwater mussels on the planet is found in North America; unfortunately, they are one of the most imperiled group of organisms. For example, the southern portion of the province of Ontario contains 42 of the 53 freshwater mussel species found in Canada, and 13 of these species are classified as threatened or endangered. The traditional approach to monitoring freshwater mussel populations is resource and labour intensive (e.g., timed searches and quadrat survey). It can also take 5 to 10 years before the significant decline of a population is identified. For example, the Department of Fisheries and Oceans monitor freshwater mussel populations classified as at risk of extinction, but due to the large amount of resources required to monitor one species and the number of imperiled mussel species, they are only able to assess populations at a specific site on a five-year rotation. This generates the need for a more rapid non-lethal diagnostic tool to assess the health of a population of at-risk freshwater mussel species. Consequently, the ultimate research question for my program of study is whether changes in the metabolome will be an effective non-lethal measure of stress within freshwater mussel populations. The three short-term objectives of my research program focus on understanding factors that contribute to variation in the hemolymph metabolome of laboratory-cultured and wild populations. 1) Investigate the variation in the metabolome present in the hemolymph of freshwater mussel species native to Canada2) Investigate changes in the hemolymph metabolome of freshwater mussel species under various types of stressors.3) Investigate the variation in the hemolymph metabolome of wild freshwater mussel species in the Great Lakes basin of Ontario.Understanding basic drivers of variation in the metabolome is critical to characterizing the statistical power of using the metabolome as an indicator of stress in a freshwater mussel population. Hemolymph has been chosen as the target tissue because the volume required for metabolomic analyses can be removed without having an adverse effect on the individual mussel. The development of a non-lethal endpoint would allow for a direct assessment of stressors on threatened and endangered freshwater mussel species without having an impact on natural populations. The long-term objective is the apply what we have learnt accomplishing these three short-term objectives to expand the use of metabolomic analyses of hemolymph to investigate the effect of habitat alteration (e.g., temperature, nutrient inputs, total suspended solids, etc.) and microbiological threats on the health of freshwater mussels. The hope is that we can develop a diagnostic tool that will allow us to non-lethally collect data on the health of endangered populations, which could then aid in the development and monitoring of recovery and reintroduction plans.