Two red tides have been sighted in Hong Kong waters in the past few days, the inter-departmental red tide working group says.

Marine Police staff observed a red tide stretching from Steep Island to Fat Tong Mun and another from Ham Tin Wan to Tai Long Wan on November 14.

Both red tides dissipated the following day.

The red tides were formed by Trichodesmium erythraeum which is rare in Hong Kong waters. Though it might cause itching and burning upon contact with the skin as reported elsewhere, no such reports have been recorded in Hong Kong.

The Agriculture, Fisheries & Conservation Department has informed mariculturists in Tung Lung Chau and Po Toi O fish culture zones of the red tide and urged them to monitor the situation closely.