Living In Hong Kong News Newsletter

Crimson Tide: 6 reports of Toxic Algal Bloom/HAB in Hong Kong this week

water pollution hong kong toxic algal bloom HAB red tide
Toxic algal bloom at Wong Shek Water Sports Centre


Whoa, this one isn’t for the kids! Spotted at Repulse Bay beach today, toxic algal bloom AKA HAB is appearing on our shores. Although not the traditional type of water pollution we usually fear, this is enough to make us say ‘yikes!’.

According to the Agricultural, Fisheries and Conservation Department (AFCD), six (that’s half a dozen, folks!) red tides have been reported in Hong Kong waters over the past week.

Harmful Algal Bloom (HAB) snapshot at Repulse Bay – thanks, Alexis Kwong Alvarez!

What is “Red Tide”? Red tides occur naturally when microscopic algae color waters pink via the pigment of the algal cells. Harmful Algal Bloom (HAB), or toxic algal bloom, happens when the “red tide” of particular algal species are harmful to fish, seafood, and even humans, starve water animals of oxygen and further contaminate the living species that enter the water during a toxic algal bloom.

So when the Hong Kong AFCD spots the crimson tide and tests show that it is indeed harmful, it is ill advised to fish in these waters, to go swimming, or to consume fish or shellfish that originates from these water sources.

Image credits: Hong Kong AFCD and Alexis Kwong Alvarez

Red tide at Hoi Hai Marine Park