Environmental DNA (eDNA) analysis has become a transformative technology, but sample collection methods lack standardization and sampling at effective frequencies requires considerable field effort. Autonomous eDNA samplers that can sample water at high frequencies offer potential solutions to these problems. We present results from four case studies using a prototype autonomous eDNA sampler as part of the U.S. Geological Survey’s Rapid Environmental eDNA Assessment and Deployment Initiative & Network (READI-Net) project. These case studies involved short-term deployments of an eDNA autosampler (Smith-Root) across a range of riverine habitats with the objectives of (a) identifying what insights could be gained from high-frequency autosampling and (b) benchmarking these autosamples against manually collected samples. The high frequency autosampling revealed high temporal variability of eDNA concentrations and provided valuable insights about eDNA associations with environmental covariates, such as discharge and turbidity. Benchmarking assessments indicated autosamples had similar detection rates to manual samples and obtained similar or greater eDNA quantities. We did find minimal carryover contamination in autosampler field controls. We conclude that eDNA autosamplers have potential to improve freshwater biosurveillance by reducing logistical sampling barriers, standardizing collection methods, and clarifying the influence of environmental covariates on eDNA results.

中文翻译：

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自主 eDNA 采样器在 Lotic Waters 的现场试验


环境 DNA （eDNA） 分析已成为一项变革性技术，但样品采集方法缺乏标准化，并且以有效频率采样需要大量的现场工作。可以高频采样水的自主 eDNA 采样器为这些问题提供了潜在的解决方案。我们展示了四个案例研究的结果，这些案例研究使用了原型自主eDNA采样器，作为美国地质调查局的快速环境eDNA评估和部署计划与网络（READI-Net）项目的一部分。这些案例研究涉及在一系列河流栖息地短期部署 eDNA 自动采样器 （Smith-Root），目的是 （a） 确定可以从高频自动采样中获得哪些见解，以及 （b） 将这些自动采样与手动收集的样本进行基准测试。高频自动采样揭示了 eDNA 浓度的高时间变异性，并提供了有关 eDNA 与环境协变量（如排放和浊度）关联的宝贵见解。基准评估表明，自动样品的检出率与手动样品相似，并且获得了相似或更高的 eDNA 数量。我们确实在自动进样器现场对照中发现了极小的残留污染。我们得出结论，eDNA 自动进样器有可能通过减少物流采样障碍、标准化采集方法和阐明环境协变量对 eDNA 结果的影响来改善淡水生物监测。