Red tides had been sighted in Hong Kong waters over the past few days, an inter-departmental red tide working group reported today (November 10).
Staff of the Leisure and Cultural Services Department observed a red tide at Middle Bay Beach on November 8.More red tides were sighted today at Clear Water Bay First and Second Beach, Silver Mine Bay Beach, Lo So Shing Beach, Hung Shing Yeh Beach, Cheung Chau Tung Wan Beach, Kwun Yam Beach, Repulse Bay Beach, South Bay Beach, Chung Hom Kok Beach and Silverstrand Beach. Red flags were hoisted immediately. The red tides still persist.
The red tide at Silverstrand Beach was formed by Trichodesmium erythraeum while others were formed by Phaeocystis globosa.Both species are seldom found in Hong Kong waters and they are non-toxic. Though Trichodesmium erythraeum might cause itching and burning upon contact with the skin as reported elsewhere, no such reports have been recorded in Hong Kong, a spokesman for the working group said.
The Agriculture, Fisheries and Conservation Department (AFCD) immediately alerted mariculturists at Lo Tik Wan, Sok Kwu Wan, Po Toi, Cheung Sha Wan, Ma Wan, Leung Shuen Wan, Tai Tau Chau, Kai Lung Wan, Kau Sai, Ma Nam Wat, Po Toi O and Tung Lung Chau and urged them to monitor the situation closely.No associated death of fish has been reported so far.
Early detection and warning will give mariculturists sufficient time to take necessary measures. The AFCD will closely monitor the possible spread of the red tides to other areas and has also stepped up the monitoring of all fish culture zones. Water samples have been collected for analysis.
Red tide is a natural phenomenon. The AFCDs proactive phytoplankton monitoring programme will continue monitoring red tide occurrences to minimise the impact on the mariculture industry and the public.