Assessing biodiversity in Hong Kong western waters using environmental DNA approach

The freshwater outflow of Pearl River renders the seawater in the western Hong Kong low in salinity, turbid and fast flowing, compared to their counterpart in eastern waters. The poor visibility in the western waters hinder the biodiversity survey by typical visual census method. In the present study, the biodiversity of Hong Kong western waters was examined using molecular technique - Environmental DNA (eDNA). Five sites in western waters were selected, from which seawater and sediment samples were collected for eDNA analyses. Polymerase Chain Reaction (PCR) amplification of genetic marker cytochrome c oxidase subunit I (COI) for all samples were conducted and sequenced by next generation sequencing (Illumina MiSeq). The results of blast-searching sequences obtained against online database showed that many major groups of marine organisms such as decapoda, porifera, mollusca, and scleractinia, could be detected by eDNA approach. However, a large quantity of DNA remained unknown in identity. Further study will be sought to test if eDNA is effective in revealing biodiversity in marine environment. Copyright © 2019 ICMPE-9.