Table_2_Metabarcoding Analyses and Seasonality of the Zooplankton Community at BATS.pdf

The diversity and specific composition of zooplankton communities have a direct effect on the ecosystem services (e.g., carbon export) and structure of ocean food webs. In areas where diversity is high, a detailed characterization of the whole community can represent a hurdle that prevents a complete understanding of those processes and interactions. One such region is the Sargasso Sea, where zooplankton diversity is among the highest in the world oceans. As a consequence, at the Bermuda Atlantic Time-series Study location, most research has focused on zooplankton biomass or on particular groups. To provide new insight into the total community composition at the BATS site, in this study the zooplankton community is investigated by means of metabarcoding of the 18S V9 hypervariable region. Day and night samples from a full year (2015) show the signature of diel vertical migration, driven by those groups with a higher representation in the metabarcoding reads. Seasonal ordination was detected after square-root transformation and, similarly to temperate regions, four seasons could be differentiated based on community composition (post-spring bloom, summer stratification, fall mixing event, and winter mixing), with no correspondence with the zooplankton biomass patterns. This community ordination showed correlation with the measured vertical flux, highlighting the need of understanding community regimes, even in theoretically stable regions such as the oligotrophic ocean, to advance in our understanding of zooplankton-mediated processes

浮游动物群落的多样性与具体组成直接影响到生态系统服务（如碳输出）以及海洋食物网的架构。在多样性较高的区域，对整个群落进行详细描述可能成为阻碍全面理解这些过程和相互作用的一道难关。大西洋中脊海便是这样的一个地区，其浮游动物多样性位居全球各大洋之最。因此，在百慕大亚特兰大时间序列研究站（BATS）的地点，大多数研究都集中在浮游动物生物量或特定群体上。为了对BATS站点的总体群落组成提供新的见解，本研究通过18S V9高度可变区域的宏条形码技术对浮游动物群落进行了研究。一年（2015年）的日夜样本揭示了昼夜垂直迁移的标志，这种迁移由在宏条形码读数中代表性较高的群体驱动。经过平方根转换后，发现了季节性排序，与温带地区相似，可以根据群落组成（春季爆发后、夏季分层、秋季混合事件和冬季混合）区分出四个季节，而与浮游动物生物量模式无关。这一群落排序与测量的垂直通量呈相关性，突显了即使在理论上稳定的区域，如寡营养海洋，也需要理解群落动态，以推进我们对浮游动物介导过程的认知。