Establishing environmental DNA (eDNA) monitoring for causal analysis of amphibian occupancy and aquatic ecosystem risk assessment

建立环境 DNA (eDNA) 监测，用于两栖动物占用的因果分析和水生生态系统风险评估

• 批准号: 463602-2014
• 负责人: Murray, Dennis
• 金额: $ 14.56万
• 依托单位: Trent University
• 依托单位国家: 加拿大
• 项目类别: Strategic Projects - Group
• 财政年份: 2017
• 资助国家: 加拿大
• 起止时间: 2017-01-01 至 2018-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=641852
• 关键词: Establishing; environmental; DNA; eDNA; monitoring

Across Canada, freshwater wetlands are rapidly declining in number and quality, and there is an urgent need to understand the causes of their decline and develop protocols for their effective monitoring and assessment. Amphibians are important components of aquatic ecosystems but worldwide their populations are declining, and in Canada several species are listed at-risk or are absent from apparently suitable habitat. Amphibian declines and local extinctions likely are related to deterioration of their aquatic habitat, including mortality associated with water-borne pathogens (chytrid fungus, ranavirus) acting either directly or interactively with other environmental stressors (e.g., climate, contaminants, habitat loss). However, the precise cause of most amphibian declines is poorly known due to inadequate population monitoring combined with weak causal relationships between numerical trends and environmental stressors; such trends may portend changes in freshwater quality and aquatic system services. Capitalizing on new animal survey methods using environmental DNA (eDNA), and improved landscape mapping and modeling techniques, this work will provide a rigorous assessment of the causes of observed amphibian occurrence patterns. Specifically, we will: 1) Establish water-based sampling protocols for detecting and quantifying amphibians and their primary pathogens (chytrid fungus, ranavirus) in a Canadian context; 2) Use land cover and environmental variables (moisture regimes, contaminants) associated with field-collected data to develop models for amphibian and pathogen occupancy, and assess their utility as bioindicators of wetland quality; and 3) Develop modelsestablishing likely causal links between amphibian occupancy and environmental stressors. This research will be among the first to adopt a comprehensive and multivariate approach to understand amphibian occupancy and wetland quality. These advances will lead to robust understanding of the relationship between amphibian populations and environmental stressors, and contribute to the development of state-of-the-art and truly 'world class' freshwater monitoring systems.

在加拿大各地，淡水湿地的数量和质量正在迅速下降，迫切需要了解其下降的原因，并制定有效监测和评估的协议。两栖动物是水生生态系统的重要组成部分，但在世界范围内，它们的数量正在下降，在加拿大，有几个物种被列为处于危险之中，或者没有明显合适的栖息地。两栖类的减少和局部减少可能与其水生栖息地的恶化有关，包括与水媒病原体（壶菌，蛙病毒）直接或与其他环境压力因子（例如，气候、污染物、栖息地丧失）。然而，大多数两栖动物下降的确切原因知之甚少，由于人口监测不足，加上数量趋势和环境压力之间的因果关系薄弱，这种趋势可能预示着淡水质量和水生系统服务的变化。利用新的动物调查方法，使用环境DNA（eDNA），并改进景观制图和建模技术，这项工作将提供一个严格的评估观察到的两栖动物发生模式的原因。具体而言，我们将：1）建立检测和量化两栖动物及其主要病原体的水基采样协议（壶菌，蛙病毒）在加拿大的背景下; 2）使用土地覆盖和环境变量（湿度状况、污染物）与实地收集的数据相关联，以建立两栖动物和病原体占据的模型，并评估其作为湿地质量生物指标的效用;和3）开发模型，建立可能的因果关系之间的关系，两栖动物的占用和环境压力。这项研究将是第一个采用全面和多元的方法来了解两栖动物的占用和湿地质量。这些进展将导致对两栖动物种群与环境压力之间关系的深入了解，并有助于发展最先进和真正“世界级”的淡水监测系统。