Stem the red tide: researchers say human pollution is behind algal blooms and government should take charge
A wave of harmful red tides killed off 220 tonnes of fish across mariculture zones, mostly in the Tolo Harbour area this year
Hydrologist Jimmy Jiao and his team are perhaps the few scientists in Hong Kong who can make the claim to have carried out field work in the presence of a deity.
A 76-metre tall statue of Kwun Yum, the Buddhist goddess of mercy, towers over their research site – a mosquito-infested corner of Ting Kok village in Plover Cove – casting a watchful eye over Tolo Harbour.
Traversing thick mangroves and mudflats, Jiao’s research team have been on a quest to find an often neglected source of pollution which they believe may be driving outbreaks of algal bloom, also known as red tides, to counter a government narrative that they are a completely “natural” phenomenon.
Jiao, a professor at the University of Hong Kong’s earth sciences department, and his colleague Luo Xin of the Shenzhen Research Institute, have put forth a straightforward hypothesis – groundwater discharges under sea level are loading nutrient pollution into the harbour, feeding algal blooms and causing them to proliferate.
“If you want to fix the problem [of red tides], then you can’t ignore this,” Jiao said. “We don’t have a single information source or monitoring point for groundwater and this is very strange for a developed society.”