Data from: Exploring the impact of multidecadal environmental changes on the population genetic structure of a marine primary producer

Many marine protists form resting stages that can remain viable in coastal sediments for several decades. Their long-term survival offers the possibility to explore the impact of changes in environmental conditions on population dynamics over multidecadal time scales. Resting stages of the phototrophic dinoflagellate Pentapharsodinium dalei were isolated and germinated from five layers in dated sediment cores from Koljö fjord, Sweden, spanning ca. 1910–2006. This fjord has, during the last century, experienced environmental fluctuations linked to hydrographic variability mainly driven by the North Atlantic Oscillation. Population genetic analyses based on six microsatellite markers revealed high genetic diversity and suggested that samples belonged to two clusters of subpopulations that have persisted for nearly a century. We observed subpopulation shifts coinciding with changes in hydrographic conditions. The large degree of genetic diversity and the potential for both fluctuation and recovery over longer time scales documented here, may help to explain the long-term success of aquatic protists that form resting stages.诸多海洋原生生物可形成休眠体（resting stages），此类休眠体能够在沿岸沉积物中保持数十年的活性。这类休眠体的长期存活特性，为研究数十年尺度下环境条件变化对种群动态的影响提供了可行途径。研究人员从瑞典科尔约峡湾（Koljö fjord）的定年沉积物岩心的五个层位中，分离并萌发了光合甲藻（phototrophic dinoflagellate）*Pentapharsodinium dalei*的休眠体，这些层位的沉积时间跨度约为1910年至2006年。在过去一个世纪中，该峡湾经历了与水文变化相关的环境波动，而此类水文变化主要由北大西洋涛动（North Atlantic Oscillation）驱动。基于6个微卫星标记（microsatellite markers）的群体遗传分析结果显示，本次研究的样本具有较高的遗传多样性，且可划分为两个亚种群簇，这两个亚种群已存续近一个世纪。研究人员观察到，亚种群的转变与水文条件的变化相吻合。本研究记录的高遗传多样性，以及较长时间尺度下种群波动与恢复的潜力，或有助于解释形成休眠体的水生原生生物何以实现长期存续。