Data and R codes from: Exploring the effect of 195 years-old locks on species movement: Landscape genetics of painted turtles in the Rideau Canal, Canada

Aquatic systems have been extensively altered by human structures (e.g., construction of dams/canals) and these have major impacts on the connectivity of wildlife populations through the loss and isolation of suitable habitats. Habitat loss and isolation affect gene flow and influence the persistence of populations in time and space by restricting movements. Isolation can result in higher inbreeding, lower genetic diversity, and greater genetic structure, which may render populations more vulnerable to environmental changes, and thus to extinction. Given the ubiquity and the persistence of dams and canals in space and time, it is crucial to understand their effects on the population genetics of aquatic species. Here, we documented the genetic diversity and structure of painted turtle (<em>Chrysemys picta</em>) populations in the Rideau Canal, Ontario, Canada. More specifically, we used 13 microsatellites to evaluate the influence of locks on genetic variation in 822 painted turtles from 22 sites evenly distributed along the 202-km canal. Overall, we found low, but significant, genetic differentiation suggesting that some dispersal is occurring throughout the canal. In addition, we showed that locks contribute to the genetic differentiation observed in the system. Clustering analysis revealed two distinct genetic groups whose boundary is associated with a series of six locks. Our results illustrate how artificial waterways, such as canal systems, can influence population genetic structure. We highlight the importance of adopting management plans that can mitigate the impacts of human infrastructure and preserve gene flow across the landscape to maintain viable populations.水生生态系统已被人类工程设施（如大坝、运河的修建）广泛改造，这类活动通过适宜栖息地的丧失与隔离，对野生动物种群的连通性造成显著负面影响。栖息地的丧失与隔离会限制生物移动，进而影响基因流，并最终作用于种群在时空维度上的存续能力。种群隔离会导致近交程度升高、遗传多样性降低以及遗传结构分化加剧，这会使种群对环境变化的抵御能力更弱，进而增加灭绝风险。鉴于大坝与运河在时空尺度上的广泛分布与长期存续，明确其对水生物种种群遗传学的影响至关重要。本研究以加拿大安大略省里多运河（Rideau Canal）的锦龟（*Chrysemys picta*）种群为研究对象，对其遗传多样性与种群遗传结构进行了系统调查。具体而言，本研究针对沿202公里运河均匀分布的22个采样点的822只锦龟，利用13个微卫星（microsatellite）分子标记，评估了船闸对其遗传变异的影响。整体而言，本研究检测到了显著但程度较低的遗传分化，表明整个运河系统内仍存在一定程度的个体扩散。此外，研究结果证实船闸是导致该系统出现遗传分化的重要因素之一。聚类分析结果显示，该种群存在两个显著分化的遗传类群，其类群边界与连续分布的6座船闸高度相关。本研究结果清晰阐明了运河系统这类人工水道对种群遗传结构的塑造作用。本研究强调，制定能够减轻人类工程设施负面影响、维持跨景观尺度基因流的管理方案，对维持种群存续能力具有重要意义。