Understanding the spatial and temporal dynamics of environmental DNA for monitoring and management of priority invasive species

外来入侵物种(INN)是全球生物多样性丧失的五大驱动因素之一，生物入侵的速度正在增加。德利森贻贝(斑马贻贝、多态斑马贻贝和长尾叉尾贻贝)是英国重点监测和管理的旅店，因为它们有可能迅速传播并对生物多样性、基础设施和人类健康产生负面影响(如Karatayev等人)。2015年)。德雷森虫可以迅速地在坚硬的表面上定居，通过堵塞管道和覆盖其他人工结构，给水务行业和电力公司带来重大问题。仅在约克郡，目前从管道中移除斑马贻贝每年就要花费60万GB。及早发现是防止Inn的建立和进一步传播的关键，但对于具有微观生命阶段的物种来说，这尤其具有挑战性。环境DNA(EDNA)是一种敏感的新方法，它正开始彻底改变我们监控客栈的方式(Lawson Handley，2015；Blackman等人。2018年)。我们最近开发了针对德莱森贻贝的Edna分析方法，这种方法对成体和幼体阶段的检测都非常敏感(Blackman等人。2018年；Stroud 2018)。学生将使用这些工具来获得对德莱塞尼德埃德纳的动态的新见解，并改善对该物种的分布和影响的理解。在学生期间产生的方法和数据将是促进德莱塞尼德监测、管理和缓解的关键。目标1：了解德赖塞尼德埃德纳的时间动态，并为未来的采样活动提供信息。由于德赖塞尼德活动和种群动态的差异，以及水混合和紫外线等环境因素，EDNA的产量和降解率全年可能会有所不同。目前尚不清楚这些因素如何相互作用影响Dreissenid Edna的检测概率。学生将使用场地占有率模型来生成一年中不同时间的EDNA检测概率，确定哪些季节性变量影响检测，并为未来的采样活动提供信息。目的：了解Edna分布的空间动力学，确定哪些关键环境变量会影响Dreissenid Edna的发现概率。EDNA的检测受到环境的物理、化学和生物特性的影响(Barnes&Turner 2015)。该项目将研究环境变量(例如底物类型、DOC、叶绿素、pH等)如何影响德氏藻类的种群、EDNA产量和持久性。不同的环境变量对EDNA检测概率的影响，将通过站点占用模型来调查。目标3：使用EDNA来识别德雷塞尼德传播的关键路径和载体。识别蚊虫传播的高危媒介和途径对于制定管理计划是必不可少的，但对途径的研究往往受到现有方法在低密度下检测物种的低功率的限制。学生将使用EDNA方法来调查不同路径的相对重要性，并提供路径管理计划，还将探索使用原位检测方法进行快速、经济有效和灵敏的监测。目的：评价雷公藤对入侵生态系统结构和功能的影响。雷森虫被认为对入侵的群落有广泛的影响，对一些物种有积极的影响，但对另一些物种的影响减少(Churchill 2013；Ward&Ricciardi 2013)，但它们的影响尚未在整个生态系统层面进行全面调查。该项目将使用DNA元编码技术生成整个群落在时间和空间上的数据，与全面的环境元数据一起，将允许对德雷森学派对入侵生态系统的结构和功能的影响进行独特的洞察。

Invasive non-native species (INNS) are one of the five global drivers of biodiversity loss and the rate of biological invasions is increasing. Dreissenid mussels (zebra mussels Dreissena polymorpha and quagga mussels D. rostriformis bugensis) are INNS that are high on the UK priority list for monitoring and management, due to their potential for rapid spread and negative impacts to biodiversity, infrastructure and human health (e.g. Karatayev et al. 2015). Dreissenids can rapidly colonise hard surfaces, causing major problems for the water industry and power companies by clogging pipes and encrusting other artificial structures. In Yorkshire alone, removal of zebra mussels from pipework currently costs £600K per annum. Early detection is key to preventing establishment and further spread of INNS, but this is particularly challenging for species that have microscopic life stages. Environmental DNA (eDNA) is a sensitive new method that is starting to revolutionise how we monitor INNS (Lawson Handley 2015; Blackman et al. 2018). We have recently developed eDNA assays for Dreissenid mussels that are highly sensitive for detection of both adult and larval stages (Blackman et al. 2018; Stroud 2018). The student will use these tools to obtain novel insights into the dynamics of Dreissenid eDNA and to improve understanding of the species' distribution and impact. Methods and data generated during the studentship will be critical for facilitating Dreissenid monitoring, management and mitigation.Objective 1: to understand the temporal dynamics of Dreissenid eDNA and inform future sampling campaigns. eDNA production and degradation rates are likely to vary throughout the year due to differences in Dreissenid activity and population dynamics, and environmental factors such as water mixing and UV. How these factors interact to influence detection probability of Dreissenid eDNA is currently unknown. The studentship will use site occupancy modelling to generate eDNA detection probabilities at different times of the year, determine which seasonal variables influence detection, and inform future sampling campaigns. Objective 2: to understand the spatial dynamics of eDNA distribution and determine which key environmental variables influence the probability of detection of Dreissenid eDNA. The detection of eDNA is influenced by the physical, chemical and biological properties of the environment (Barnes & Turner 2015). The studentship will investigate how environmental variables (e.g. substrate type, DOC chlorophyll, pH etc) effect Dreissenid populations, eDNA production and persistence. The impact of different environmental variables on the probability of eDNA detection, will be investigated using site occupancy modelling.Objective 3: to use eDNA to identify key pathways and vectors for Dreissenid spread. Identification of high risk vectors and pathways for INNS spread is essential for drafting management plans, but research into pathways is often limited by the low power of current methods to detect species at low density. The studentship will use eDNA methods to investigate the relative importance of different pathways and inform a pathway management plan, and also explore the use of in situ detection methods for rapid, cost-effective and sensitive monitoring. Objective 4: to evaluate the impact of Dreissenids on the structure and function of invaded ecosystems. Dreissenids are thought to have wide-ranging impacts on invaded communities, with positive effects on some species but reductions in others (Churchill 2013; Ward & Ricciardi 2013), but their impacts have not yet been comprehensively investigated at the whole ecosystem level. The studentship will generate data over time and space on entire communities, using DNA metabarcoding, which together with comprehensive environmental metadata, will allow unique insights into impact of Dreissenids on the structure and function of invaded ecosystems.