Data from: Understanding admixture patterns in supplemented populations: a case study combining molecular analyses and temporally explicit simulations in Atlantic salmon

Genetic admixture between wild and introduced populations is a rising concern for the management of endangered species. Here we use a dual approach based on molecular analyses of samples collected before and after hatchery fish introduction in combination with a simulation study to get insight into the mechanisms of admixture in wild populations. Using 17 microsatellites we genotyped pre- and post-stocking samples from four Atlantic salmon populations supplemented with non-native fish to estimate genetic admixture. We also used individual-based temporally explicit simulations based on realistic demographic and stocking data to predict the extent of admixture. We found a low admixture by hatchery stocks within pre-stocking samples but moderate to high values in post-stocking samples (from 12 % to 60 %). The simulation scenarios best fitting the real data suggested a 10 to 25 times lower survival of stocked fish relative to wild individuals. Simulations also suggested relatively high dispersal rates of stocked and wild fish, which may explain some high levels of admixture in weakly stocked populations and the persistence of indigenous genotypes in heavily stocked populations. This study overall demonstrates that combining genetic analyses with simulations can significantly improve the understanding of admixture mechanisms in wild populations.

野生种群与引种种群间的遗传渐渗（genetic admixture）已成为濒危物种管理领域日益受到关注的问题。本研究采用双轨研究策略：一方面对孵化场养殖鱼类放流前后采集的样本开展分子遗传学分析，另一方面结合模拟研究，旨在阐明野生种群的遗传渐渗机制。本研究选取4个经外来养殖鱼补充放流的大西洋鲑（Atlantic salmon）种群，利用17个微卫星标记（microsatellites）对其放流前后的样本进行基因分型，以估算遗传渐渗水平。同时，基于真实的种群动态与放流数据，构建基于个体的时间显性模拟模型，以预测遗传渐渗的发生程度。研究结果显示，放流前样本中养殖种群的遗传渐渗比例较低，但放流后样本的渐渗比例可达12%至60%，呈现中等至高水平。与真实数据拟合度最高的模拟场景表明，放流养殖鱼的存活率较野生个体低10至25倍。模拟结果还显示，养殖与野生鱼类均具有较高的扩散速率，这可部分解释低放流强度种群中较高的遗传渐渗水平，以及高放流强度种群中本土基因型的留存现象。综上，本研究证实，将分子遗传学分析与模拟研究相结合，可显著提升对野生种群遗传渐渗机制的认知水平。