Hong Kong marine life under threat as scientists warn of more frequent coral bleaching

City records bleaching among local reefs, with one site seeing water temperatures rising to 30.7 degrees, higher than safe level for animals

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Scientists at global NGO Reef Check Foundation and other researchers have discovered 73 per cent of corals around Sharp Island at the Hong Kong Unesco Global Geopark had bleached. Photo: Dickson Wong

Published: 7:00pm, 3 Aug 2024Updated: 11:44pm, 3 Aug 2024

Hong Kong scientists have warned local coral reefs will face more severe and frequent bleaching, with sea temperatures recently rising to as high as 30.7 degrees Celsius (87.3 Fahrenheit) and resulting in the situation becoming widespread across key marine reserves.

The city is known to be close to the northern limit of where corals can survive, as anywhere in a latitude higher than Hong Kong is generally considered inhospitable for the animals.

Frequent coral bleaching can threaten their survival, with the disappearance of reefs, which occupy just 1 per cent of the ocean floor, considered a global concern and a threat to the survival of the world’s most biodiverse habitats.

Local wildlife authorities earlier reported “different levels of coral bleaching” had been discovered in Hong Kong’s waters, citing how the average water temperature at a site in Tung Ping Chau Marine Park was 2 degrees higher in the past month compared with the same period last year.

The city’s marine biologists also discovered mass coral bleaching in other protected waters, with some sites recording levels of bleaching at more than 70 per cent of its “coral communities”.

Dickson Wong Chi-chun, a team scientist at global NGO Reef Check Foundation, said this year’s bleaching event was “very alarming” because of the higher frequency of recurrence and the greater scale of damage.