Ten red tides have been sighted in Hong Kong waters in the past few days. All were formed by Prorocentrum micans which is common in Hong Kong waters and is non-toxic, an inter-departmental red tide working group says.

All except the red tides at Deep Bay and Victoria Harbour have dissipated.

The Agriculture, Fisheries & Conservation Department has stepped up red tide monitoring and informed mariculturists in fish culture zones concerned of the red tide, urging them to monitor the situation closely.

The Leisure & Cultural Services Department observed red tides at Clear Water Bay First and Second Beaches on September 3. Red flags were hoisted there until September 6 when the red tides dissipated.

Three other occurrences came to the department's attention this week, including the one at Turtle Cove Beach on September 7, and at Hairpin and Stanley Main Beaches the following day. Red flags were hoisted at these beaches until this morning when the red tides dissipated.

AFCD steps up monitoring

The rest were found at Sheung Sze Mun on September 2, Victoria Harbour and Tai Tam Bay on September 5, and Deep Water Bay and O Pui Tong Fish Culture Zone on September 8.

The red tide at Sheung Sze Mun dissipated on September 7. Those at Tai Tam Bay and O Pui Tong Fish Culture Zone dissipated today. But Deep Water Bay and Victoria Harbour are still affected by red tides.

Red tide is a natural phenomenon. The Agriculture, Fisheries & Conservation Department's phytoplankton monitoring programme will continue monitoring red tide occurrences to minimise the impact on the mariculture industry and the public.