Developing and testing metabarcoding approaches to describe the vertebrate diversity within aquatic habitats

调查水生群落的传统方法往往成本高昂、破坏性强且效率低下。加拿大联邦政府每年在环境监测活动上花费超过5亿美元，涉及2500多人（根据加拿大环境与可持续发展专员2011年12月的报告估计）。工业在环境监测上额外花费了3亿美元。例如，我们的工业合作伙伴WSP Canada Inc.每年花费约75万美元监测受影响栖息地的鱼类群落。基于从环境样本中分离的DNA （eDNA）的分子方法可以大大降低水生生态系统评估的成本，特别是在评估稀有和濒危物种时。迄今为止，人们已将大量注意力放在改进基于edna的技术上，以准确地捕获和测序环境中释放的DNA，并准确地确定存在的物种。然而，我们仍然缺少关于eDNA“行为”的信息——它是如何产生、运输和降解的。这些过程影响从分子样品中准确确定物种存在的机会。例如，很少有研究检查湖泊中季节性水运动的作用以及这如何影响eDNA的分布。我们建议在水体分层的夏季和春秋两季水体周转期间取样。我们将对水柱取样以创建eDNA深度剖面，并将使用湖鳟鱼的无线电遥测标记验证该方法。这项研究将有助于我们了解eDNA的“生态学”及其在生物系统中的分布。此外，通过考虑季节性水运动如何影响DNA分子分布，本研究将帮助科进计划eDNA采样活动。我们的结果也将适用于任何进行全面的eDNA采样活动的人，如学术界，工业界和政府

Traditional methods for surveying aquatic communities are often costly, destructive and ineffective. The Canadian federal government spends more than $500M per year on environmental monitoring activities which involve more than 2500 people (estimate based on December 2011 report of the Canadian Commissioner of the Environment and Sustainable Development). Industries spend an additional $300M on environmental monitoring. For example, our industrial partner, WSP Canada Inc. spends about $750,000 per year to monitor fish communities in impacted habitats. Molecular methods based on DNA isolated from environmental samples (eDNA) can considerably lower the costs of aquatic ecosystem assessment, particularly when assessing rare and endangered species. To date, significant attention has been placed on refining eDNA-based techniques to accurately capture and sequence the DNA released in the environment and to accurately determine the species present. However, we are still missing information on the "behaviour" of eDNA - how it is created, transported and degraded. These processes influence the chance of accurately determining species presence from molecular samples. For example, few studies have examined the role of seasonal water movements in lakes and how this influences the distribution of eDNA. We propose to sample dimictic lakes during summer months when water is stratification and during spring and autumn water turnover. We will sample the water column to create an eDNA depth profile and will validate the method using radio-telemetry tagging of lake trout. The proposed study will contribute to our understanding of the "ecology" of eDNA and its distribution within lentic systems. Moreover, this study will help WSP plan eDNA sampling campaigns, by taking into consideration how seasonal water movements influences the distribution of DNA molecules. Our results will be also applicable to anyone undertaking a comprehensive eDNA sampling campaign, such as academics, industry and government.**