Response of microbial community of surface and deep chlorophyll maximum to nutrients and light in South China Sea

Frontiers in Marine Science

Marine Science

Han Zhang¹  Yafeng Zhang²  Wei Xie³  Suixuan Huang³  Xiuqin Wu³  Kedong Yin³  Fahui Gong³  Jun Gong³ 

[1] Dongguan Maternal and Child Health Care Hospital, Postdoctoral Innovation Practice Base of Southern Medical University, Dongguan, China;Eco-Environmental Monitoring and Research Center, Pearl River Valley and South China Sea Ecology and Environment Administration, Ministry of Ecology and Environment of the People’s Republic of China, Guangzhou, Guangdong, China;School of Marine Sciences, Sun Yat-Sen University & Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Zhuhai, China;Guangdong Provincial Key Laboratory of Marine Resources and Coastal Engineering, Zhuhai, China;

关键词: typhoon;    bloom;    phytoplankton;    flow cytometry (FCM);    high throughput sequencing;    DCM;   

DOI  :  10.3389/fmars.2023.1122765

 received in 2022-12-13, accepted in 2023-02-07,  发布年份 2023

来源: Frontiers

【 摘 要 】

In oligotrophic seas such as South China Sea, the subsurface or deep chlorophyll maximum (DCM) is always present. The surface planktonic community receives sufficient light, but is short of nutrients. The DCM layer is under light limitation, but frequent supply of nutrients. Therefore, vertical mixing becomes critical in determining their community composition and drives their changes by responding to light and nutrients. In this study, we conducted an onboard experiment by collecting seawater samples at surface and the DCM layer and adding nutrients, and incubated them under full sunlight and 10% light, and examined the diversity of bacterial and eukaryotic communities and their cell abundance using 16/18S high throughput sequencing and FCM approaches. Our study found large differences in bacterial and eukaryotic community structure and cell abundance between the surface and DCM. After 72 hours of culture, taxonomically the incubated surface water was dominated by pico-eukaryotic phytoplankton, while the incubated DCM layer water is dominated by diatoms, which suggests diatoms are the main functional group of phytoplankton bloom after a vertical mixing event. These findings indicate that phytoplankton at the DCM respond to enhanced light and frequent supplied nutrients due to vertical mixing and thus maintain primary productivity in the otherwise oligotrophic oceans.

【 授权许可】

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Copyright © 2023 Gong, Zhang, Xie, Wu, Zhang, Huang, Gong and Yin