Red Tides Sighted in Hong Kong

Three red tides have been sighted in Hong Kong waters over the past week, an inter-departmental red tide working group reported today, April 25.

Two red tides at Pui O Beach and Silver Mine Bay Beach on Lantau Island were observed by staff of the Leisure and Cultural Services Department on April 18 and 20 respectively. Red flags were hoisted at the beaches immediately.

Another red tide was spotted by staff of the Agriculture, Fisheries and Conservation Department (AFCD) at Tolo Harbour near Tang Chau yesterday, April 24.

The red tide at Pui O Beach, Lantau Island dissipated while the other two still persist.

No associated death of fish has been reported in these occurrences so far.

"The red tide at Pui O Beach, Lantau Island was formed by Pseudo-nitzschia pungens. The one at Silver Mine Bay Beach, Lantau Island was formed by Akashiwo sanguinea whereas the one at Tolo Harbour near Tang Chau was formed by Gonyaulax polygramma. All the above algal species are commonly found in Hong Kong waters and are non-toxic," a spokesman for the working group said.

The AFCD urged mariculturists at the Cheung Sha Wan, Yim Tin Tsai, Yim Tin Tsai (East), Yung Shue Au and Lo Fu Wat fish culture zones to monitor the situation closely.

Red tide is a natural phenomenon. The AFCD's proactive phytoplankton monitoring program will continue monitoring red tide occurrences to minimize the impact on the mariculture industry and the public.