Fish stocking programs have been implemented to mitigate the blockage of original riverbeds by the construction of hydropower dams, which affects the natural migration of fish populations. However, this method raises concerns regarding the genetic rescue of the original populations of migratory fish species. We investigated the spatial distribution of genetic properties, such as genetic diversity, population structure, and gene flow (migration), of the Neotropical migratory fish Prochilodus costatus in the Três Marias dam in the São Francisco River basin, Brazil, and examined the possible effects of fish stocking programs on P. costatus populations in this region. In total, 1,017 specimens were sampled from 12 natural sites and a fish stocking program, and genotyped for high‐throughput sequencing at 8 microsatellite loci. The populations presented low genetic variability, with evidence of inbreeding and the presence of only four genetic pools; three pools were observed throughout the study region, and the fourth was exclusive to one area in the Paraopeba River. Additionally, we identified high unidirectional gene flow between regions, and a preferred migratory route between the Pará River and the upper portion of the São Francisco River. The fish stocking program succeeded in transposing the genetic pools from downstream to upstream of the Três Marias dam, but, regrettably, promoted genetic homogenization in the upper São Francisco River basin. Moreover, the data show the fragility of this species at the genetic level. This monitoring strategy could be a model for the development of conservation and management measures for migratory fish populations that are consumed by humans.

中文翻译：

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gr游鱼类的遗传评价：对养护和放养计划的影响

实施了鱼类放养计划，以减轻因修建水力发电大坝而对原始河床的阻塞，从而影响鱼类种群的自然迁移。但是，这种方法引起了对迁徙鱼类原始种群的基因拯救的关注。我们调查了巴西圣弗朗西斯科河盆地TrêsMarias大坝中新热带迁徙鱼类Prochilodus costatus遗传特性的空间分布，例如遗传多样性，种群结构和基因流（迁移），并研究了可能的影响对虾的鱼类放养计划该地区的人口。总共从12个自然地点和鱼类放养程序中取样了1,017个标本，并对8个微卫星基因座进行了高通量测序的基因型。种群的遗传变异性低，具有近交和仅存在四个遗传库的证据；在整个研究区域中观察到了三个水池，​​第四个水池是Paraopeba河中一个地区专用的。此外，我们确定了区域之间的高单向基因流动，以及在帕拉河和圣弗朗西斯科河上部之间的首选迁徙路线。鱼类放养计划成功地将遗传资源从特雷斯·玛丽亚斯大坝的下游转移到上游，但遗憾的是，促进了圣弗朗西斯科河上游流域的遗传同质化。此外，数据显示了该物种在遗传水平上的脆弱性。该监测战略可以成为发展人类食用的fish游鱼类种群养护和管理措施的典范。