CUHK coral hub as city's first indoor facility for propagated corals

Today is the International Day of Climate Action. The Chinese University of Hong Kong officially opens its new coral restoration hub, marking Hong Kong's first indoor facility dedicated to sexually propagated corals, now cultivating over 4,500 baby corals.

The Super El Nino effect warms up the sea but also poses a critical threat to corals that are highly sensitive to temperature changes. Four years ago, Hong Kong's coral reefs experienced the most widespread and severe bleaching on record.

At the Chinese University of Hong Kong's newly unveiled Coral Academy -- Hub for Coral Restoration, Resilience and Education, these vibrantly coloured specks are not fish food. They are indeed baby corals -- among the over 4,500 baby corals across four species now hosted in the hub -- tasked with an important mission.

Assistant Professor, School of Life Sciences, CUHK APPLE CHUI PUI-YI: "You cannot restore reefs without a sustainable source of corals. Our solution is right behind the stores. The first and only indoor coral nursery dedicated to sexual propagation in Hong Kong."

The team is researching how selective propagation, as well as the use of beneficial microbes and probiotics can enhance corals' heat resistance.

APPLE CHUI: "Instead of cloning exact copies of coral over and over, we breed corals from eggs and sperm, meaning that the coral babies that we have -- each one of them, they are genetically unique. So, in warming oceans, the genetic diversity is nature's insurance policy."

And the corals' journey doesn't end in the lab. Since 2019, the team, partnering with the Agriculture, Fisheries and Conservation Department, has supplied corals to 29 schools.

Acting Director of Agriculture, Fisheries and Conservation Department PATRICK LAI CHUEN-CHI: "The government will continue to advance and expand collaborative efforts to conserve Hong Kong's marine ecosystem and biodiversity."

Some corals eventually return to the wild -- more than 500 corals have been transplanted to Tolo Harbour and the Tolo Channel after maturity. CUHK says a batch of corals released into the wild recorded a survival rate of nearly 90% after 4 years and even reproduced a new generation of juvenile corals.