Hong Kong fish farmers claim proliferation of red tides is worst ‘unnatural disaster’ to hit industry in years

On April 1, a thick brownish-white froth floating off Shek O beach caused a stir among residents and tourists. Smartphones at the ready, they flocked to the shoreline to capture the morbid spectacle, braving the putrid stench.

Scenes like these are common in Hong Kong come springtime. Algal blooms, also known as “red tides”, are a natural phenomenon, according to the Agriculture, Fisheries and Conservation Department (AFCD).

Peaking between March and June, the department has received more than 80 reports of red tide this year, six of which have been confirmed as actual cases.

Red tide season appears to have struck early, too. According to the Post’s review of data from the department’s red tide monitoring network, Hong Kong has seen 29 days with red tide sightings in the first three months of the year, more than any year in the same period over the last decade.

While formations of algal blooms are indeed completely natural, scientists believe their frequency and persistence are anything but.

“They are correct when they say they are formed naturally by natural organisms. But it’s their abundance and occurrence, which is extremely unnatural,” said ecologist Dr David Baker, an assistant professor at the University of Hong Kong Swire Institute of Marine Science.