Data from: Population genetic analysis of white sturgeon (Acipenser transmontanus) in the Fraser River

White sturgeon (Acipenser transmontanus) in the Fraser River are listed as imperiled (the second highest possible rating) by the British Columbia Conservation Data Centre. A difficulty in trying to protect this species in the Fraser River and elsewhere is the lack of knowledge regarding their population biology. Variation in the mitochondrial DNA control region and at four microsatellite loci was examined in order to characterize white sturgeon samples from throughout the Fraser River mainstem and from a major tributary, the Nechako River. Samples from the adjacent Columbia River were analyzed for comparison. In contrast to previous work, present data indicate that white sturgeon population structure in this region reflects post-glacial dispersal more than it does recent anthropogenic effects. The data divided the Fraser into four biogeographic regions: (i) the lower Fraser, below Hell’s Gate; (ii) the middle Fraser, between Hell’s Gate and river km 553; (iii) the upper Fraser, above the Nechako confluence; and (iv) the Nechako River. These four groups are concordant with those suggested by tag and recapture and catch per unit effort data, and are separated by what have been identified as barriers to white sturgeon migration. Based on concordance between these different types of data, it is argued that the four groups identified here merit evolutionarily significant unit (ESU) status.

弗雷泽河（Fraser River）中的高首鲟（Acipenser transmontanus）已被不列颠哥伦比亚省保护数据中心（British Columbia Conservation Data Centre）列为濒危（为该机构评级体系中第二高的濒危等级）。在弗雷泽河及其他区域开展该物种保护工作所面临的一大难点，在于学界对其种群生物学认知的匮乏。本研究对采集自弗雷泽河干流全段及主要支流尼查科河（Nechako River）的高首鲟样本，展开了线粒体DNA控制区（mitochondrial DNA control region）及4个微卫星位点（microsatellite loci）的变异分析，以完成样本特征刻画；同时对邻近的哥伦比亚河（Columbia River）的样本进行了分析以作为对照。与既往研究结论不同，本次研究数据显示，该区域高首鲟的种群结构更多反映了冰期后扩散的影响，而非近期人为活动的作用。本次数据将弗雷泽河划分为4个生物地理区域：(i) 下游弗雷泽河段（地狱门（Hell’s Gate）以下区域）；(ii) 中游弗雷泽河段（地狱门至河公里标553之间区域）；(iii) 上游弗雷泽河段（尼查科河汇流处以上区域）；(iv) 尼查科河。上述4个类群与标记重捕（tag and recapture）数据及单位捕捞努力量渔获量（catch per unit effort）数据所提出的类群相一致，且各类群之间被已证实的高首鲟洄游障碍所分隔。基于不同类型数据间的一致性，本研究认为本次所界定的4个类群均应被认定为进化显著单元（evolutionarily significant unit, ESU）。