Protist Interactions and Seasonal Dynamics in the Coast of Yantai, Northern Yellow Sea of China as Revealed by Metabarcoding

Abstract

Facilitated by the high-throughput sequencing (HTS) technique, the importance of protists to aquatic systems has been widely acknowledged in the last decade. However, information of protistan biotic interactions and seasonal dynamics is much less known in the coast ecosystem with intensive anthropic disturbance. In this study, year-round changes of protist community composition and diversity in the coastal water of Yantai, a city along the northern Yellow Sea in China, were investigated using HTS for the V4 region of 18S rDNA. The interactions among protist groups were also analyzed using the co-occurrence network. Data analyses showed that Alveolata, Chlorophyta, and Stramenopiles are the most dominant phytoplanktonic protists in the investigated coastal area. The community composition displayed strong seasonal variation. The abundant families Dino-Group-I-Clade-1 and Ulotri-chales_X had higher proportions in spring and summer, while Bathycoccaceae exhibited higher ratios in autumn and winter. Alpha diversities (Shannon and Simpson) were the highest in autumn and the lowest in spring (ANOVA test, P < 0.05). Nutrients (SiO 4 2− , PO 4 3− ), total organic carbon (TOC), and pH seemed to drive the variation of alpha diversity, while temperature, PO 4 3− and TON were the most significant factors influencing the whole protist community. Co-variance network analyses reveal frequent co-occurrence events among ciliates, chlorophytes and dinoflagellate, suggesting biotic interactions have been induced by predation, parasitism and mixotrophy.

Cultivation of different seaweed species and seasonal changes cause divergence of the microbial community in coastal seawaters

“…PCoA and NMDS analyses also confirmed the diversity of microbiota distributed independently in different periods (Supplementary Figure 3). This observation was similar to previous studies that have highlighted remarkable seasonal diversity and dynamics in marine microbes (Gilbert et al, 2010;Egge et al, 2015;Fu et al, 2020).…”

The community of Marine Alveolate parasites in the Atlantic inflow to the Arctic Ocean is structured by season, depth and water mass

“…DG-I-Clade 1 is the most diverse clade within Dino-Group-I, and has been retrieved from a wide range of marine habitats (Groisillier et al 2006). It was found to be particularly abundant in spring and summer in a metabarcoding study of a temperate coastal environment (Yellow Sea, China, Fu et al 2020). In metaPR 2 , DG-I-Clade 1 has a wide latitudinal distribution, and is most abundant in euphotic zone samples (Table S3).…”

Culture-Independent Single-Cell PacBio Sequencing Reveals Epibiotic Variovorax and Nucleus Associated Mycoplasma in the Microbiome of the Marine Benthic Protist Geleia sp. YT (Ciliophora, Karyorelictea)

“…Abundance analysis and the primary classification of the 16S rRNA gene were performed according to Fu et al [ 46 ]. In short, chimeras were identified and eliminated by the Vsearch program integrated with QIIME v.1.8.0 [ 47 ], combined with manual examination using blastN against an NCBI database.…”