Brook Trout Salvelinus fontinalis have declined across their native range due to multiple anthropogenic factors, including landscape alteration and climate change. Although coldwater streams in Maryland (eastern United States) historically supported significant Brook Trout populations, only fragmented remnant populations remain, with the exception of the upper Savage River watershed in western Maryland. Using microsatellite data from 38 collections, we defined genetic relationships of Brook Trout populations in Maryland drainages. Microsatellite analyses of Brook Trout indicated the presence of five major discrete units defined as the Youghiogheny (Ohio), Susquehanna, Patapsco/Gunpowder, Catoctin, and Upper Potomac, with a distinct genetic subunit present in the Savage River (upper Potomac). We did not observe evidence for widespread hatchery introgression with native Brook Trout. However, genetic effects due to fragmentation were evident in several Maryland Brook Trout populations, resulting in erosion of diversity that may have negative implications for their future persistence. Our current study supplements an increasing body of evidence that Brook Trout populations in Maryland are highly susceptible to multiple anthropogenic stresses, and many populations may be extirpated in the near future. Future management efforts focused on habitat protection and potential stream restoration, coupled with a comprehensive assessment framework that includes genetic considerations, may provide the best outlook for Brook Trout populations in Maryland.

中文翻译：

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马里兰州溪鳟种群的遗传结构：对受威胁物种的管理意义

Brook Trout Salvelinus fontinalis由于多种人为因素，包括景观改变和气候变化，它们的原生范围已经下降。尽管马里兰州（美国东部）的冷水溪流在历史上支持了重要的布鲁克鳟鱼种群，但除了马里兰州西部的萨维奇河上游流域外，只剩下零散的残余种群。使用来自 38 个集合的微卫星数据，我们定义了马里兰州河流中布鲁克鳟鱼种群的遗传关系。对 Brook Trout 的微卫星分析表明存在五个主要的离散单元，定义为 Youghiogheny（俄亥俄州）、Susquehanna、Patapsco/Gunpowder、Catoctin 和 Upper Potomac，在 Savage River（上波托马克河）中存在一个独特的遗传亚基。我们没有观察到本地布鲁克鳟鱼广泛孵化场渗入的证据。然而，由于碎片化导致的遗传效应在几个马里兰州溪鳟种群中很明显，导致多样性的侵蚀，这可能对其未来的持久性产生负面影响。我们目前的研究补充了越来越多的证据，即马里兰州的布鲁克鳟鱼种群极易受到多种人为压力的影响，许多种群可能在不久的将来灭绝。未来的管理工作侧重于栖息地保护和潜在的河流恢复，再加上包括遗传考虑在内的综合评估框架，可能会为马里兰州的布鲁克鳟鱼种群提供最佳前景。导致多样性的侵蚀，可能对其未来的持久性产生负面影响。我们目前的研究补充了越来越多的证据，即马里兰州的布鲁克鳟鱼种群极易受到多种人为压力的影响，许多种群可能在不久的将来灭绝。未来的管理工作侧重于栖息地保护和潜在的河流恢复，再加上包括遗传考虑在内的综合评估框架，可能会为马里兰州的布鲁克鳟鱼种群提供最佳前景。导致多样性的侵蚀，可能对其未来的持久性产生负面影响。我们目前的研究补充了越来越多的证据，即马里兰州的布鲁克鳟鱼种群极易受到多种人为压力的影响，许多种群可能在不久的将来灭绝。未来的管理工作侧重于栖息地保护和潜在的河流恢复，再加上包括遗传考虑在内的综合评估框架，可能会为马里兰州的布鲁克鳟鱼种群提供最佳前景。