Zhonglin Maa, Paraskevi Marab, Lei Sua, Long Wangc, Huifang Lid, Rui Zhangc,e, Virginia P. Edgcombb, Jiangtao Lia*
aState Key Laboratory of Marine Geology, Tongji University, Shanghai 200092, China
b Department of Geology and Geophysics, Woods Hole Oceanographic Institution, Woods Hole, MA, USA
c Institude for Advanced Study, Shenzhen University, Shenzhen 518060, China
d School of Marine Science and Fisheries, Jiangsu Ocean University, Lianyungang 222005, China
E Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Zhuhai, 519082, China
*Correspondence: Jiangtao Li, jtli@tongji.edu.cn
Abstract: Sinking of organic matter represents an essential mechanism for sequestration of carbon that is exported from the ocean surface to deeper depths. While recent studies have highlighted the important role of microorganisms in the biological pump, the impact of sinking particles on the vertical connectivity of microbial communities has received limited attention. In this study, we present the microbial profile of sinking particles in the northern slope and the central basin of the marginal South China Sea (SCS) using an in-line size-fractionated water filtration and Illumina high-throughput 16S rRNA amplicon sequencing. We investigate the microbial community composition within organic particles of different size fractions (30, 5, 3, 0.22 μm), and we reveal significant differences in the microbial community structure between these two distinct areas of SCS. The vertical connectivity of microbial communities in the slope and the central basin of SCS shows distinct patterns of microbial dispersal along the water column that occurs via the sinking of organic particles. We find that the microbial communities have different abundances on the different examined particle size fractions and which highlights the role of sinking particles in shaping microbial lifestyles along the water column. Our study underscores the influence of environmental variations on the vertical connectivity of microorganisms and provides additional insights into the marine biological pump under different environmental conditions.
Full article:https://doi.org/10.1016/j.gloplacha.2024.104497
