School of Marine Sciences, Ningbo University, Ningbo 315211, China.
School of Marine Sciences, Ningbo University, Ningbo 315211, China; Zhejiang Mariculture Research Institute, Wenzhou 325005, China.
Sci Total Environ. 2018 Sep 1;635:618-628. doi: 10.1016/j.scitotenv.2018.04.142. Epub 2018 Apr 24.
The determinants of microeukaryotic biogeography in coastal waters at a regional scale remain largely unclear. The coastal northern Zhejiang (in the East China Sea) is a typical subtropical marine ecosystem with multiple environmental gradients that has been extensively perturbed by anthropogenic activities. Thus, it is a valuable region to investigate the key drivers that shape microbial biogeography. We investigated microeukaryotic communities in surface waters from 115 stations in this region using 18S ribosomal RNA gene amplicon sequencing. The microeukaryotic communities were mainly comprised of Dinoflagellata, Ciliophora, Protalveolata, Rhizaria, Stramenopiles and Cryptophyceae. The top abundant operational taxonomic units (OTUs) were highly specific for distinct habitat types, exhibiting significant environment-conditioned features; however, the cosmopolitan OTUs were not strongly correlated with the measured environmental variables. Total phosphorus and suspended particles were major environmental determinants of microeukaryotic α-diversity. Environmental variables, particularly temperature, salinity, pH and silicate concentration, were strongly associated with the microeukaryotic community composition. Overall, environmental and spatial factors explained 55.92% of community variation in total with 34.03% of the variation shared, suggesting that spatially structured environmental variations mainly conditioned the microeukaryotic biogeography in this region. Additionally, dispersal limitation, as indicated by the great pure spatial effect and distance-decay pattern, was another important factor. In summary, our results reveal that spatially structured environmental variation and dispersal limitation mainly conditioned the microeukaryotic biogeography. The results may provide useful distribution patterns of microeukaryotes to determine sources of microbes from marine ecosystems that may facilitate the utilization of coastal resources.
在区域尺度上，沿海海域微型真核生物的生物地理学决定因素在很大程度上仍不清楚。浙江北部沿海（东海）是一个典型的亚热带海洋生态系统，具有多种环境梯度，受到人类活动的广泛干扰。因此，该地区是研究塑造微生物生物地理学的关键驱动因素的宝贵区域。我们使用 18S 核糖体 RNA 基因扩增子测序技术，对该地区 115 个站点的表层水微型真核生物群落进行了调查。微型真核生物群落主要由甲藻、纤毛虫、原生动物、有孔虫、不等鞭毛类和隐藻组成。丰度最高的操作分类单元（OTUs）高度特异于不同的生境类型，表现出显著的环境条件特征；然而，广布的 OTUs 与测量的环境变量没有很强的相关性。总磷和悬浮颗粒是微型真核生物 α多样性的主要环境决定因素。环境变量，特别是温度、盐度、pH 值和硅酸盐浓度，与微型真核生物群落组成强烈相关。总的来说，环境和空间因素共解释了总群落变异的 55.92%，其中 34.03%的变异是共享的，这表明空间结构的环境变化主要控制了该地区的微型真核生物生物地理学。此外，扩散限制（由大的纯空间效应和距离衰减模式表明）也是另一个重要因素。总之，我们的结果表明，空间结构的环境变化和扩散限制主要控制了微型真核生物的生物地理学。这些结果可能为确定海洋生态系统中微生物的来源提供有用的微型真核生物分布模式，从而有助于沿海资源的利用。
