An important consideration when implementing species management is preserving genetic variation, which is fundamental to the long-term persistence of populations and adaptive potential of the species. The European water vole Arvicola amphibius is of high conservation importance in the United Kingdom due to its documented decline in both distribution and abundance. Conservation strategies for this species include protecting source populations, increasing habitat availability and connectivity, non-native predator control and reintroduction. We used mtDNA control region sequences and eight microsatellite markers from samples collected from 12 localities in southeast England, to determine how genetic variation is structured amongst regional water vole populations and to what extent population structure has been influenced by reintroductions. We found high haplotype diversity (h) across native populations in the southeast region and evidence that divergent lineages had been introduced to the region. We detected significant structure between watersheds with mtDNA from native populations and evidence of finer scale structure between populations within watersheds with both mtDNA and microsatellites. We suggest that management strategies should aim to conserve genetic diversity at a population level and that watersheds are a practicable unit for prioritising management within regions. We propose that introductions to restore or augment water voles within watersheds should consider the genetic composition of regional populations and highlight that genetic data has an important role in guiding future conservation options that secure adaptive potential in the face of future environmental change.

实施物种管理时的重要考虑因素是保存遗传变异，这对于种群的长期持久生存和物种的适应潜力至关重要。欧洲水田鼠Arvicola两栖类由于其分布和丰度均有下降，因此在英国具有很高的保护重要性。该物种的保护策略包括保护源种群，增加栖息地的可利用性和连通性，非本地捕食者的控制和再引入。我们使用了mtDNA控制区序列和来自英格兰东南部12个地区的样本中的8个微卫星标记，来确定区域水田鼠种群之间的遗传变异结构以及种群结构在多大程度上受到了再引入的影响。我们发现高单倍型多样性（^ h）在东南地区的原住民中迁移，并证明该地区引入了不同的血统。我们检测到了来自本地种群的mtDNA的流域之间的重要结构，并证明了同时具有mtDNA和微卫星的流域内的种群之间的尺度结构更精细。我们建议管理策略应旨在在种群水平上保护遗传多样性，并且分水岭是在区域内优先进行管理的可行单位。我们建议在流域内恢复或增加水田鼠的介绍中应考虑区域种群的遗传组成，并强调遗传数据在指导未来的保护方案中起着重要作用，以确保面对未来环境变化时的适应潜力。