2022/03/25
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Press Releases

Red tides sighted
Friday, March 25, 2022

Five red tides have been sighted over the past week, the Inter-departmental Red Tide Working Group reported today (March 25).

Staff members of the Marine Department spotted two red tides on March 19 at the waters off Tsuen Wan West and the northern waters of Chek Lap Kok. On March 20, staff of the Leisure and Cultural Services Department spotted red tides at Golden Beach, Cafeteria New Beach and Cafeteria Old Beach, Tuen Mun, respectively. The five red tides have dissipated and no associated fish deaths have been reported as of today.

A spokesman for the working group said, "The red tides at the waters off Tsuen Wan West and the northern waters of Chek Lap Kok were formed by Noctiluca scintillans, while the other three red tides were formed by Heterosigma akashiwo. Noctiluca scintillans is non-toxic, while Heterosigma akashiwo might produce neurotoxins and kill fish by damaging their gills, according to overseas literature. The two algae are commonly found in Hong Kong waters."

The Agriculture, Fisheries and Conservation Department (AFCD) urged mariculturists at Ma Wan fish culture zone 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.

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