Monitoring changes in eukaryotic microbial communities is critical for understanding ecosystem dynamics, trophic interactions and the impacts of climate change. Long-term time series are an important tool for monitoring changes in ecological communities, but time series from a single location may not be representative of regional dynamics. In the German Bight, the Helgoland Roads time series is such a long-term series. Here, we consider the spatial dynamics of the eukaryotic microbes as an indicator of the representativeness of the Helgoland Roads site for the coastal German Bight, which is located in the North Sea. The eukaryotic microbial community in the German Bight was analysed at Helgoland Roads and two coastal stations (Cuxhaven and Wilhelmshaven) between March and October 2016 using metabarcoding. In addition, an oceanographical model was used to check for potential hydrological connectivity between the stations during the sampling period. Our results showed that the communities were different at the three stations. Helgoland was dominated by dinoflagellates, whereas the coastal stations had more diverse communities. Furthermore, differences were observed in the dinoflagellate and diatom communities between the three stations. Lagrangian particle tracking applied to the model results, showed limited connectivity between Helgoland and the coastal stations in 2016. The differences between Helgoland and the coastal stations were correlated with the different hydrological regimes and associated nutrient contents. Our observations suggest the presence of different eukaryotic microbial communities separated by complex hydrological conditions in the coastal German Bight.

中文翻译：

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德国湾真核微生物群落的空间动态

监测真核微生物群落的变化对于了解生态系统动态、营养相互作用和气候变化的影响至关重要。长期时间序列是监测生态群落变化的重要工具，但单一地点的时间序列可能不能代表区域动态。在 German Bight 中，Helgoland Roads 时间序列就是这样一个长期序​​列。在这里，我们将真核微生物的空间动态视为位于北海沿岸德国湾的 Helgoland Roads 站点代表性的指标。2016 年 3 月至 10 月期间，在 Helgoland Roads 和两个沿海站点（Cuxhaven 和 Wilhelmshaven）使用元条形码分析了德国湾的真核微生物群落。此外，在采样期间，使用海洋学模型检查站之间潜在的水文连通性。我们的结果表明，三个站点的社区是不同的。黑尔戈兰以甲藻为主，而沿海站点的群落更为多样化。此外，在三个站点之间的甲藻和硅藻群落中观察到差异。应用于模型结果的拉格朗日粒子跟踪显示，2016 年黑尔戈兰与沿海站之间的连通性有限。黑尔戈兰与沿海站之间的差异与不同的水文状况和相关的营养成分有关。