Bioscience Department, Swansea University, Singleton Park, Swansea, United Kingdom.
Sci Rep. 2019 May 10;9(1):7230. doi: 10.1038/s41598-019-43570-3.
The role of river obstacles in preventing or facilitating the dispersal and establishment of aquatic invasive species is controversial. Novel detection tools like environmental DNA (eDNA) can be used for monitoring aquatic invasive species (AIS) such as the American signal crayfish (Pacifastacus leniusculus) and the Chinese mitten crab (Eriocheir sinensis), providing information on the effect of barriers on their distribution. We analysed eDNA from both water and surface sediment in three river catchments (Medway, Dee and Stour; Great Britain), with differing levels of connectivity, to determine spatial distribution of the two species, and assessed the effect of barriers on their eDNA detection. Positive eDNA detections were obtained within confirmed sites for both species in all catchments, with evidence of species overlap in the River Medway. Upstream barriers in the Medway positively influenced detection success of mitten crab lower in the catchment while detection success of signal crayfish was higher in the highly fragmented catchment (River Medway). This information on the role of river barriers on AIS distribution and eDNA detection is important for management strategies and for predicting both future dispersal and likelihood of new colonisations in previously uninvaded fragmented catchments.
河流障碍物在阻止或促进水生入侵物种的扩散和建立方面的作用存在争议。新型的检测工具，如环境 DNA（eDNA），可用于监测水生入侵物种（AIS），如美洲淡水小龙虾（Pacifastacus leniusculus）和中华绒螯蟹（Eriocheir sinensis），提供障碍物对其分布影响的信息。我们分析了来自三个具有不同连通性的河流流域（梅德韦、迪河和斯图尔；英国）的水和表面沉积物中的 eDNA，以确定这两个物种的空间分布，并评估障碍物对它们的 eDNA 检测的影响。在所有流域的确认地点都获得了这两个物种的阳性 eDNA 检测，在梅德韦河有物种重叠的证据。梅德韦河的上游障碍物对下游的中华绒螯蟹的检测成功率有积极影响，而在高度破碎化的流域（梅德韦河），信号小龙虾的检测成功率更高。关于河流障碍物对 AIS 分布和 eDNA 检测的作用的这一信息，对于管理策略以及预测以前未受入侵的碎片化流域未来的扩散和新殖民化的可能性非常重要。
