The red tide was sighted by Marine Department staff at Sham Tseng Public Pier on 14 May and still persists. No associated death of fish has been reported by mariculturists so far.
"The red tide was formed by Thalassiosira pseudonana, which is common in Hong Kong waters and non-toxic," a spokesman for the working group said.
The Agriculture, Fisheries and Conservation Department (AFCD) urged mariculturists at Ma Wan and Cheung Sha Wan to monitor the situation closely.
