Watching Corals Grow: China's solutions for coral reef restoration

The coral reefs are at risk of disappearing.

Chinese scientists say the fragile ecosystem is under threat from ocean warming, crown-of-thorn starfish and human activities. They are growing coral in labs and in the open sea.

"Once the coral reef ecosystem disappears, nearly one-third of marine life will lose their habitat," says Zhang Yuyang, associate research fellow of the South China Sea Institute of Oceanology of the Chinese Academy of Sciences.

The institute began coral cultivation in the South China Sea in 2009. It was Zhang's first time working in the Xisha Islands, also known as the Paracels. Over the past 15 years, Zhang has been monitoring the progress in all their testing areas.

Coral can be cultivated through sexual reproduction, by collecting eggs and sperm. Zhang's institute does this in the lab, and then replants the baby corals in natural habitats. Progress is slow; a baby coral grows only one centimeter a year.

A more efficient method is what's called the nursery. In 2017, Zhang Yuyang's team set up nursery frames in waters near Zhaoshu Island. They placed broken coral fragments on them. Those fragments then established themselves and were transplanted onto the nearby reefs. The coral coverage has increased from less than 10 percent to over 30 percent.

"Now the corals have reached sexual maturity. They release eggs and sperm for reproduction. The eggs and sperm are dispersed into the surrounding areas, facilitating the recovery of corals around them," says Zhang Yuyang.

Zhang Yuyang emphasizes the interconnections of the South China Sea's ecosystem. China can't do it alone, but that won't stop him from trying to green the blue.

"My dream is to restore the coral reefs of our country to a higher level so that future generations will be able to appreciate the beautiful ecosystem. I don't want them to only see coral reefs in books or films, and then tell them we once had a beautiful, vibrant underwater ecosystem, but it's gone now."