A circumpolar study of surface zooplankton biodiversity of the Southern Ocean based on eDNA metabarcoding

Zishang Zhang; Yongchao Bao; Xiaoyue Fang; Yilin Ruan; Yue Rong; Guang Yang

doi:10.1016/j.envres.2024.119183

A circumpolar study of surface zooplankton biodiversity of the Southern Ocean based on eDNA metabarcoding

Environ Res. 2024 May 19:255:119183. doi: 10.1016/j.envres.2024.119183. Online ahead of print.

Authors

Zishang Zhang¹, Yongchao Bao², Xiaoyue Fang³, Yilin Ruan⁴, Yue Rong⁵, Guang Yang⁶

Affiliations

¹ College of Environmental and Safety Engineering, Qingdao University of Science and Technology, Qingdao, 266042, China; Key Laboratory of Marine Ecology and Environmental Sciences, Institute of Oceanology, Chinese Academy of Sciences, 7 Nanhai Road, Qingdao, 266071, China; Laboratory for Marine Ecology and Environmental Science, Qingdao National Laboratory for Marine Science and Technology, Qingdao, 266071, China; Center for Ocean Mega-Science, Chinese Academy of Sciences, 7 Nanhai Road, Qingdao, 266071, China.
² College of Environmental and Safety Engineering, Qingdao University of Science and Technology, Qingdao, 266042, China.
³ Key Laboratory of Marine Ecology and Environmental Sciences, Institute of Oceanology, Chinese Academy of Sciences, 7 Nanhai Road, Qingdao, 266071, China; College of Safety and Environmental Engineering, Shandong University of Science and Technology, Qingdao, 266590, China.
⁴ Key Laboratory of Marine Ecology and Environmental Sciences, Institute of Oceanology, Chinese Academy of Sciences, 7 Nanhai Road, Qingdao, 266071, China; Laboratory for Marine Ecology and Environmental Science, Qingdao National Laboratory for Marine Science and Technology, Qingdao, 266071, China; Center for Ocean Mega-Science, Chinese Academy of Sciences, 7 Nanhai Road, Qingdao, 266071, China; University of Chinese Academy of Sciences, Beijing, 10049, China.
⁵ College of Ocean and Earth Sciences, Xiamen University, Xiamen, 361005, China.
⁶ Key Laboratory of Marine Ecology and Environmental Sciences, Institute of Oceanology, Chinese Academy of Sciences, 7 Nanhai Road, Qingdao, 266071, China; Laboratory for Marine Ecology and Environmental Science, Qingdao National Laboratory for Marine Science and Technology, Qingdao, 266071, China; Center for Ocean Mega-Science, Chinese Academy of Sciences, 7 Nanhai Road, Qingdao, 266071, China; University of Chinese Academy of Sciences, Beijing, 10049, China. Electronic address: yangguang@qdio.ac.cn.

PMID: 38768883
DOI: 10.1016/j.envres.2024.119183

Abstract

Under pressure from climate change and fishing, the Southern Ocean ecosystems have been changing. Zooplankton plays a vital role in the food web of the Southern Ocean and is crucial for maintaining ecosystem stability. Investigating the circumpolar-scale species composition and biodiversity of zooplankton is crucial for ensuring ecosystem-based conservation and management of the Southern Ocean in a changing climate. Here, we utilized eDNA metabarcoding to assess the biodiversity of zooplankton in the surface seawater surrounding the Antarctica based on samples collected during two expeditions spanning from 2021 to 2022. The main purpose of this paper is to provide more baseline information about circumpolar zooplankton biodiversity based on the emerging eDNA metabarcoding tool. This comprehensive approach led to the identification of over 300 distinct zooplankton species, forming a diverse community dominated by Jellyfish, Mollusca and Polychaete. Surprisingly, common dominant taxonomic groups such as krill and copepods in the Southern Ocean did not show high relative abundance (reads) in surface seawater. The results of redundancy analysis (RDA) and correlation analysis highlighted that water temperature and chlorophyll a had the most significant impact on the reads and diversity of zooplankton. Notably, the influence of water temperature on zooplankton seemed to be primarily indirect, potentially mediated by its effects on primary productivity. Increasing in primary production might lead to lower zooplankton biodiversity in the Southern Ocean in future. This research underscores the effectiveness of eDNA metabarcoding as a valuable tool for monitoring zooplankton diversity in open seas. Given the ongoing changes in temperature, sea ice extent and their impact on primary production, our findings lay a crucial foundation for using eDNA techniques to establish long-term biodiversity monitoring programs across extensive marine ecosystems in the future.

Keywords: Biodiversity; Environmental factors; Southern ocean; Zooplankton; eDNA.