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

传统的水生群落调查方法往往成本高、破坏性大、效率低。加拿大联邦政府每年在涉及2500多人的环境监测活动上的支出超过5亿美元(根据加拿大环境与可持续发展专员2011年12月的报告进行估计)。各行业在环境监测方面的额外支出为3亿美元。例如，我们的工业合作伙伴WSP加拿大公司每年花费约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的分子方法(EDNA)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。到目前为止，人们非常注意改进基于EDNA的技术，以准确捕获环境中释放的DNA并对其进行排序，并准确确定存在的物种。然而，我们仍然缺乏关于Edna的“行为”的信息--它是如何产生、运输和退化的。这些过程影响了从分子样本中准确确定物种存在的机会。例如，很少有研究考察湖泊中季节性水运动的作用，以及这如何影响埃德纳的分布。我们建议在夏季水成层的月份以及在春季和秋季水的周转期间采样一水硬铝质湖泊。我们将对水柱进行采样，以创建Edna深度剖面，并将使用湖鲑鱼的无线电遥测标记来验证该方法。这项拟议的研究将有助于我们理解埃德纳的“生态”及其在Lentic系统中的分布。此外，这项研究将通过考虑季节性水分运动如何影响DNA分子的分布，帮助WSP计划Edna采样活动。我们的结果也将适用于任何进行全面EDNA抽样运动的人，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.