Red tides sighted
Friday, March 31, 2023
Four red tides have been sighted over the past week, the Inter-departmental Red Tide Working Group reported today (March 31).
The first red tide was spotted by staff of the Agriculture, Fisheries and Conservation Department (AFCD) on March 27 at Tolo Harbour near Wu Kai Sha. On March 28, a red tide was spotted at Three Fathoms Cove (including Yung Shue Au Fish Culture Zone) by a mariculturist. On March 30, staff of the Leisure and Cultural Services Department spotted a red tide at Silverstrand Beach, Sai Kung. On the same day, AFCD staff spotted a red tide at Double Haven. The four red tides persist and no associated fish deaths have been reported as of today.
A spokesman for the working group said, "The red tide at Silverstrand Beach, Sai Kung, was formed by Noctiluca scintillans, while the other three red tides were formed by Gonyaulax polygramma. Both algal species are common in Hong Kong waters and non-toxic."
The AFCD urged mariculturists at Yim Tin Tsai, Yim Tin Tsai (East), Yung Shue Au, Lo Fu Wat, Ma Nam Wat, Kau Sai, Kai Lung Wan, Tai Tau Chau, Leung Shuen Wan, Tiu Cham Wan and Po Toi O 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.