Press Releases

Red tide sighting report
Friday, October 17, 2003

A red tide was sighted in Hong Kong waters this week, an inter-departmental red tide working group reported today (October 17).

Staff of the Environmental Protection Department observed a patch of red tide about 10 kilometres off the eastern part of Waglan Island on October 13. It had dissipated by the following day.

"The red tide was formed by Trichodesmium thiebautii and Trichodesmium erythraeum," a spokesman for the working group said. "Trichodesmium thiebautii had not been sighted in Hong Kong waters before while Trichodesmium erythraeum is rare in Hong Kong waters.

"Recent overseas studies show that both species might contain toxins. However, no toxic effect caused by these two red tide species has been recorded in Hong Kong waters before."

The Agriculture, Fisheries and Conservation Department (AFCD) informed mariculturists in the Tung Lung, Po Toi O, Kau Sai and Leung Shuen Wan fish culture zones of the red tide and urged them to monitor the situation closely. No associated death of fish was reported.

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.