Data from: Patterns of intra- and inter-population genetic diversity in Alaskan coho salmon: implications for conservation

Little is known about the genetic diversity of coho salmon in Alaska, although this area represents half of the species' North American range. In this study, nine microsatellite loci were used to genotype 32 putative coho salmon populations from seven regions of Alaska. The primary objectives were to estimate and evaluate the degree and spatial distribution of neutral genetic diversity within and among populations of Alaskan coho salmon. Genetic analysis yielded four results that provide insight into forces influencing genetic diversity in Alaskan coho salmon and have important conservation implications: 1) significant population differentiation was found within each region; 2) the degree of differentiation (FST = 0.099) among populations was as large or larger than that reported for other Pacific salmon species in Alaska; 3) phenetic clustering of populations showed weak geographic concordance; 4) strong genetic isolation by distance was only apparent at the finest geographic scale (within a drainage). These results suggest that coho salmon populations are small relative to populations of other Pacific salmon, and the genetic diversity within and among coho salmon populations is influenced primarily by genetic drift, and not gene flow. Resource management and conservation actions affecting coho salmon in Alaska must recognize that the populations are generally small, isolated, and probably exhibit local adaptation to different spawning and freshwater rearing habitats. These factors justify managing and conserving Alaskan coho salmon at a fine geographic scale.

尽管阿拉斯加地区占该物种北美分布范围的一半，但目前学界对阿拉斯加银大麻哈鱼（coho salmon）的遗传多样性认知仍较为匮乏。本研究采用9个微卫星位点（microsatellite loci），对来自阿拉斯加7个区域的32个疑似银大麻哈鱼种群进行基因分型。本研究的核心目标为评估并解析阿拉斯加银大麻哈鱼种群内部及种群间的中性遗传多样性水平与空间分布模式。通过遗传分析得到四项结果，可为解析影响阿拉斯加银大麻哈鱼遗传多样性的驱动因素提供参考，同时具备重要的保护生物学意义：1）各区域内部均存在显著的种群遗传分化；2）种群间的遗传分化程度（FST=0.099）与阿拉斯加其他太平洋鲑属鱼类的报道值相当，甚至更高；3）种群的表型聚类结果与地理分布的关联性较弱；4）仅在最精细的地理尺度（流域内部）中，才呈现出显著的距离隔离遗传模式。上述结果表明，相较于其他太平洋鲑属鱼类种群，阿拉斯加银大麻哈鱼的种群规模更小，其种群内部及种群间的遗传多样性主要受遗传漂变影响，而非基因流。针对阿拉斯加银大麻哈鱼的资源管理与保护举措，需充分认识到其种群普遍规模较小、且彼此隔离，同时可能对不同产卵场与淡水育幼栖息地存在局部适应性分化。上述因素证明，需在精细地理尺度下开展阿拉斯加银大麻哈鱼的管理与保护工作。