Red tides sighted

     Three red tides have been sighted over the past week, an inter-departmental red tide working group reported today (February 22).
 
     All of the red tides were spotted by staff of the Leisure and Cultural Services Department. Two of the red tides were spotted on February 16 at Lido Beach in Tsuen Wan and Upper Cheung Sha Beach on Lantau Island. The other red tide was spotted on February 21 at Silver Mine Bay Beach on Lantau Island.
 
     All red tides have dissipated. No associated death of fish has been reported.
 
     A spokesman for the working group said, "The red tide at Lido Beach was formed by Noctiluca scintillans. The red tide at Upper Cheung Sha Beach was formed by Akashiwo sanguinea. The red tide at Silver Mine Bay Beach was formed by Akashiwo sanguinea, Gonyaulax polygramma and Prorocentrum triestinum. While Prorocentrum triestinum is not common in Hong Kong waters, the other three algae are commonly found in Hong Kong waters. They are all non-toxic."
 
     The Agriculture, Fisheries and Conservation Department (AFCD) urged mariculturists at the Ma Wan and Cheung Sha Wan fish culture zones to monitor the situation closely and increase aeration where necessary.
 
     Red tide is a natural phenomenon. The AFCD's proactive phytoplankton monitoring programme will continue to monitor red tide occurrences to minimise the impact on the mariculture industry and the public.