Population genetics reveals bidirectional fish movement across the Continental Divide via an interbasin water transfer

Interbasin water transfers are becoming an increasingly common tool to satisfy municipal and agricultural water demand, but their impacts on movement and gene flow of aquatic organisms are poorly understood. The Grand Ditch is an interbasin water transfer that diverts water from tributaries of the upper Colorado River on the west side of the Continental Divide to the upper Cache la Poudre River on the east side of the Continental Divide. We used single nucleotide polymorphisms to characterize population genetic structure in cutthroat trout (Oncorhynchus clarkii) and determine if fish utilize the Grand Ditch as a movement corridor. Samples were collected from two sites on the west side and three sites on the east side of the Continental Divide. We identified two or three genetic clusters, and relative migration rates and spatial distributions of admixed individuals indicated that the Grand Ditch facilitated bidirectional fish movement across the Continental Divide, a major biogeographic ...

跨流域调水正日益成为满足市政与农业用水需求的常用手段，但其对水生生物移动与基因流的影响却鲜有研究阐明。大渠（Grand Ditch）是一项跨流域调水工程，其将大陆分水岭（Continental Divide）西侧科罗拉多河上游支流的水源，调运至大陆分水岭东侧的卡什拉普德河（Cache la Poudre River）上游。本研究采用单核苷酸多态性（single nucleotide polymorphisms, SNPs）分子标记，对割喉鳟（Oncorhynchus clarkii）的种群遗传结构进行解析，并探究鱼类是否以大渠作为移动廊道。研究样本采集自大陆分水岭西侧的2个采样点与东侧的3个采样点。本研究鉴定出2至3个遗传簇，相对迁移率及遗传混合个体的空间分布均表明，大渠助力鱼类实现了跨大陆分水岭这一重要生物地理屏障的双向移动……