Marine biodiversity is related to sustainable development and service function of marine ecosystems. The South China Sea (SCS) is an important part of the Indo-Pacific convergence zone, with high biodiversity and abundant marine resources. With the development of economic and human activities, species diversity has decreased in the SCS over recent years. However, traditional biodiversity monitoring methods have some limitations.

Recently, Prof. ZHANG Hui of the research team led by Prof. XIAN Weiwei at Institute of Oceanology, Chinese Academy of Sciences (IOCAS), conducted a comprehensive study of biodiversity in the SCS by environmental DNA (eDNA) metabarcoding.

The study was published in Environmental Research.

Researchers identified multiple trophic levels effectively from one eDNA sample. They revealed species composition, including 192 phytoplankton, 104 invertebrate, and 61 fish species from 18S rRNA gene V4 region, 18S rRNA gene V9 region, and 12S rRNA gene, respectively.

The three assemblages generally exhibited an increase in species diversity with increasing longitude in the study area in the SCS. In other words, eDNA abundance reflected the assemblage variations across longitude.

In addition, they revealed the three assemblages and its relationship with environmental factors, respectively. Canonical correspondence analysis (CCA) showed that four factors (chlorophyll a, depth, salinity, and temperature) were correlated with assemblage structure.

The study was supported by the funding from the National Natural Science Foundation of China, the Strategic Priority Research Program of the Chinese Academy of Sciences, Youth Innovation Promotion Association CAS, and National Natural Science Foundation of China.

The biodiversity of fish, phytoplankton and invertebrate based on eDNA and the relationships with environmental factors in SCS

Diao, C.Y., Jia, H., Guo, S.J., Hou, G., Xian, W.W., Zhang, H. (2022). Biodiversity exploration in autumn using environmental DNA in the South China Sea. Environmental Research. 204, 112357. https://doi.org/10.1016/j.envres.2021.112357.

ZHANG Hui

Institute of Oceanology

E-mail: zhanghui@qdio.ac.cn

(Editor: ZHANG Yiyi)