Abstract：
Marine phytoplankton are widely used to monitor the state of the water column due to their rapid changes in response to environmental conditions. In this study, we aimed to investigate the coastal phytoplankton assemblages, including bloom-forming species using high-throughput sequencing of 18S rRNA genes targeting the V4 region and their relationship with environmental variables along the Istanbul coasts of the Sea of Marmara. A total of 118 genera belonging to six phyla were detected. Among them, Dinoflagellata (36) and Bacillariophyta (26) were represented with the highest number of genera. According to the relative abundance of DNA reads, the most abundant taxa were Dinoflagellata_phylum (18.1%), Emiliania (8.4%), Biecheleria (8.4), and Noctiluca (8.1%). The ANOSIM test showed that there was a significant temporal difference in the assemblages, while the driving environmental factors were pH, water temperature, and salinity. According to the TRIX index, the trophic state of the coasts was highly mesotrophic and eutrophic. In addition, 45 bloom-forming and HAB taxa were detected and two species of Noctiluca and Emiliania, which frequently cause blooms in the area, were recorded in high abundance. Our results provide insight into the phytoplankton assemblages along the urbanized coastlines by analysing the V4 region of 18S rRNA. This data can support future studies that use both traditional methods and metabarcoding, employing various primers and targeting different genes and regions.
摘要：
海洋浮游植物由于其响应环境条件的快速变化而被广泛用于监测水柱的状态。在这项研究中,我们的目的是调查沿海浮游植物的组合，包括使用针对V4区域的18SrRNA基因的高通量测序形成水华的物种，以及它们与马尔马拉海伊斯坦布尔沿海的环境变量的关系。共检测到属于六个门的118属。其中,鞭毛（36）和芽孢杆菌（26）的属数量最高。根据DNA读数的相对丰度，最丰富的类群是鞭毛虫门(18.1%)，艾米丽尼亚（8.4%），比切莱亚（8.4），和夜光(8.1%)。ANOSIM测试表明，组合之间存在显着的时间差异，而驱动环境因素是pH，水温,和盐度。根据TRIX指数，海岸的营养状态是高度中营养和富营养化的。此外,检测到45种水华形成和HAB类群，以及两种Noctiluca和Emiliania，这经常导致该地区的开花，记录的丰度很高。通过分析18SrRNA的V4区域，我们的结果为城市化海岸线上的浮游植物组合提供了见解。这些数据可以支持使用传统方法和元编码的未来研究，采用各种引物和靶向不同的基因和区域。
