Red tides sighted
Friday, March 24, 2023
Thirteen red tides have been sighted over the past week, the Inter-departmental Red Tide Working Group reported today (March 24).
The first two red tides were spotted by staff of the Marine Department on March 21 at the southern waters of Lamma Island and Stanley Bay, Hong Kong Island. On the same day, staff of the Agriculture, Fisheries and Conservation Department (AFCD) spotted two red tides at Sham Wan Fish Culture Zone and Wong Chuk Kok Hoi (including Wong Wan Fish Culture Zone) respectively, and staff of the Leisure and Cultural Services Department (LCSD) spotted a red tide at Repulse Bay Beach, Hong Kong Island. On March 22, LCSD staff spotted three red tides at Deep Water Bay Beach, Chung Hom Kok Beach and South Bay Beach on Hong Kong Island. On the same day, a member of the public and staff of the Environmental Protection Department spotted two red tides in the waters off Tseung Kwan O Waterfront Park and Deep Water Bay, Hong Kong Island, respectively. On March 23, LCSD staff spotted two red tides at Turtle Cove Beach and St Stephen's Beach, Hong Kong Island. A red tide was spotted by LCSD staff today at Stanley Main Beach, Hong Kong Island.
The red tide at the southern waters of Lamma Island has dissipated while the other 12 red tides persist. No fish deaths associated with the red tides have been found as of today.
A spokesman for the working group said, "The red tides at Sham Wan Fish Culture Zone and Wong Chuk Kok Hoi (including Wong Wan Fish Culture Zone) were formed by Gonyaulax polygramma, while the other 11 red tides were formed by Noctiluca scintillans. Both algal species are common in Hong Kong waters and non-toxic."
The AFCD urged mariculturists at Lo Tik Wan, Sok Kwu Wan, Po Toi, Sham Wan, Wong Wan, Tap Mun, Kau Lau Wan, O Pui Tong, Kat O, Sai Lau Kong, Ap Chau, Sha Tau Kok and Tung Lung Chau 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.