Salinization of freshwater ecosystems threatens global aquatic biodiversity. There is a need for studies that follow populations in situ during salinization to understand the effects on species and ecosystems. We follow 170 years of Daphnia dynamics in the sediment ephippia archive of a small urban lake near St. Paul, Minnesota, to characterize effects of severe recent salinization on lake Daphnia. We found modest changes in the flux of ephippia in this lake; all three key Daphnia functional groups remained in the assemblage throughout the period of salinization. Reconstruction of the size distribution of Daphnia pulicaria demonstrated a consistent increase in body size in opposition to the expected trajectory during salinization. Our findings highlight that in hard-water lakes, the effects of salinization are nuanced and require further investigation to better understand overall impacts of salinization on hard-water lake Daphnia assemblages.

中文翻译：

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盐渍化会影响长期的水蚤组合动态吗？来自一个小硬水湖沉积物卵库的证据

淡水生态系统的盐碱化威胁着全球水生生物多样性。需要开展研究，跟踪盐碱化过程中的原地种群，以了解对物种和生态系统的影响。我们在明尼苏达州圣保罗附近的一个小城市湖泊的沉积物 ephippia 档案中跟踪了 170 年的水溞动态，以描述近期严重盐化对水溞湖的影响。我们发现这个湖中的 ephippia 流量发生了适度的变化；在整个盐渍化期间，所有三个关键的水蚤功能组都保留在组合中。水蚤大小分布的重建在盐化过程中，身体尺寸持续增加，与预期轨迹相反。我们的研究结果强调，在硬水湖泊中，盐渍化的影响是微妙的，需要进一步调查以更好地了解盐渍化对硬水湖水溞组合的总体影响。