Red tides sighted
Thursday, April 4, 2019
Three red tides have been sighted over the past week, an inter-departmental red tide working group reported today (April 4).
Two of the red tides were spotted by staff of the Leisure and Cultural Services Department on March 30 at Anglers' Beach, Tsuen Wan, and Ma Wan Tung Wan Beach. Another red tide was spotted by a mariculturist at Tolo Harbour including the Yim Tin Tsai and Yim Tin Tsai (East) fish culture zones on the same day.
All red tides have dissipated and no associated death of fish has been reported so far.
A spokesman for the working group said, "The red tides at Anglers' Beach and Ma Wan Tung Wan Beach were formed by Mesodinium rubrum. The red tide at Tolo Harbour was formed by Heterosigma akashiwo. Mesodinium rubrum is non-toxic, while Heterosigma akashiwo might be capable of producing toxins which are harmful to fish according to overseas studies. Both algae are commonly found in Hong Kong waters."
The Agriculture, Fisheries and Conservation Department (AFCD) urged mariculturists at Ma Wan, Yim Tin Tsai, Yim Tin Tsai (East), Yung Shue Au and Lo Fu Wat 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 monitoring red tide occurrences to minimise the impact on the mariculture industry and the public.