Background: As global biodiversity declines, there is an increasing need to create an educated and engaged society. Having people from all ages participate in measuring biodiversity where they live helps to create awareness. Recently, the use of environmental DNA (eDNA) for biodiversity surveys has gained momentum. Here, we test whether sampling eDNA and metabarcoding can be used for rapid urban biodiversity surveys for educational purposes. Materials & Methods: We sampled 2x1 L of water from each of 15 locations in the city of Trondheim, Norway, including a variety of freshwater, marine and brackish habitats. DNA was extracted, amplified in triplicate for the COI gene and sequenced. The obtained data were analysed on the novel mBRAVE platform, an online open access software and computing resource. Results: The water samples were collected in two days by two people and the lab analysis was completed in five days by one person. Overall, we detected the presence of 501 taxa identified as belonging to 435 species, representing 90 orders and 18 phyla. On average, only 5.4% of the taxa were shared among six replicates per site. Based on the observed diversity, three distinct clusters were detected and related to geographic distribution of sites. There were some taxa shared between the habitats, with a substantial presence of terrestrial biota. Discussion: Our results match expected patterns of biodiversity in the landscape and show that with minimal sampling effort, hundreds of species can be detected. Thus, using eDNA analysis of water is promising for rapid biodiversity surveys, and it is likely that more detailed results could be obtained by optimising field and lab methods for particular groups of interest. We recommend that rapid eDNA surveys, with openly available services and softwares, can be used to raise awareness in the importance of biodiversity.

中文翻译：

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利用水生环境DNA快速进行城市生物多样性突击

背景：随着全球生物多样性的下降，建立受过教育和参与的社会的需求日益增加。让各个年龄段的人参与测量他们所居住的生物多样性有助于提高人们的认识。最近，在生物多样性调查中使用环境DNA（eDNA）的势头越来越大。在这里，我们测试了采样eDNA和元条形码是否可以用于教育目的的快速城市生物多样性调查。材料与方法：我们从挪威特隆赫姆市的15个地点中的每个地点采样了2x1 L的水，包括各种淡水，海洋和咸淡的栖息地。提取DNA，一式三份扩增COI基因并测序。在新颖的mBRAVE平台，在线开放访问软件和计算资源上对获得的数据进行了分析。结果：两人在两天内收集了水样，一人在五天内完成了实验室分析。总体而言，我们检测到存在501个分类单元，这些分类单元属于435个物种，代表90个目和18个门。平均而言，每个站点六个副本之间仅共享5.4％的分类单元。基于观察到的多样性，检测到三个不同的群集，它们与站点的地理分布有关。栖息地之间共享一些分类单元，其中大量存在陆地生物群。讨论：我们的结果与景观中生物多样性的预期模式相符，并表明只需最少的采样工作，就可以检测出数百种。因此，对水进行eDNA分析有望用于快速的生物多样性调查，并且有可能通过针对特定兴趣群体优化现场和实验室方法来获得更详细的结果。我们建议使用公开提供的服务和软件进行快速eDNA调查，以提高人们对生物多样性重要性的认识。