Red tides sighted
Friday, February 5, 2021
Seven red tides have been sighted over the past week, an inter-departmental red tide working group reported today (February 5).
Staff of the Environmental Protection Department and the Marine Department spotted the first and second red tides on January 29 at Victoria Harbour and Tuen Mun Ferry Pier respectively. On January 31, members of the public spotted the third red tide at West Lamma Channel. On February 1, staff of the Leisure and Cultural Services Department spotted the fourth and fifth red tides at Stanley Main Beach, Hong Kong Island, and Approach Beach, Tuen Wan, respectively. On February 2, staff of the Agriculture, Fisheries and Conservation Department (AFCD) spotted the sixth red tide at Ma Wan Fish Culture Zone. The seventh red tide was spotted by mariculturist at Deep Bay yesterday (February 4).
Apart from the third and seventh red tides, which still persist, the other five red tides have dissipated. No fish deaths associated with the seven red tides have been reported as at today.
A spokesman for the working group said, "The second red tide was formed by Noctiluca scintillans, while the fourth and seventh red tides were formed by Akashiwo sanguinea. Both algae are commonly found in Hong Kong waters and are non-toxic. The other four red tides were formed by Phaeocystis globosa, which is commonly found in Hong Kong waters as well. According to overseas literature, Phaeocystis globosa can produce foam that may cause harmful effects to fish."
The AFCD urged mariculturists at Ma Wan, Cheung Sha Wan, Lo Tik Wan, Sok Kwu Wan and Po Toi fish culture zones and related oyster farmers at Deep Bay 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.