Corals in the waters around Xisha Qundao (Xisha Islands) in the South China Sea have been growing vigorously, thanks to China's protection and restoration efforts, including coral cultivation and transplantation and the control of harmful organisms.
The colorful corals include staghorn corals, rose-shaped corals and stony corals, exhibiting various structures and turning the seabed into an underwater fairyland.
"The coral coverage rate in the area is much larger than we expected before diving into the water. Coral reefs stretch for several kilometers and the density of corals is very high. All the corals are connected. Different kinds of corals are interwoven, covering the entire seabed," said Zhou Qinan, an underwater photographer.
However, more than a decade ago, the coral coverage rate in the waters around Xisha Qundao declined to its lowest recorded level due to overfishing and other factors.
"In fact, over the years, coral reefs around the world have been facing the impacts of global climate change and human activities. For example, seawater acidification and rising temperatures have caused coral bleaching. This is the impact of large-scale environmental changes on coral reefs. Meanwhile, on a small scale, we need to try our best to reduce the impact of human activities on coral reefs. We have engaged in the cultivation and transplantation of coral larvae on Yongxing Island, Yongle Atoll and Zhaoshu Island, and achieved good ecological effects," said Zhang Chenglong, director of the Marine Reserve Management Bureau of Sansha City of south China's Hainan Province.
So far, over 180,000 coral clusters have been cultivated on Xisha Qundao, helping to consolidate over 30,000 square meters of seabed and raising the coral coverage rate by around 10 percentage points.
The artificially cultivated corals have covered the whole seabed in the waters around the Xuande Islands, part of Xisha Qundao, with well-recovered coral reefs serving as a paradise for various marine creatures.
In addition, researchers have also kept an eye on creatures harmful to corals, such as crown-of-thorns starfish, each of which can eat two squares of corals every day.
Divers recently found five crown-of-thorns starfish in the waters around Xuande Islands.
"Next, we will take them to our lab, and measure its body length, weight and sexual maturity to analyze and confirm the population of the animal. We searched 400 square meters in the water, and found these five ones," said Yang Qingsong, an engineer of the Xisha station of the South China Sea Institute of Oceanology under the Chinese Academy of Sciences.
After examination, Yang recorded the detailed data about the captured crown-of-thorns starfish in his lab.
The starfish can spread so fast that they can eat all corals in the waters where they live within two years. Therefore, researchers also collected seawater samples to study the distribution of the starfish larvae.
According to the survey, the crown-of-thorns starfish in the waters around Xisha Qundao, are sporadically distributed to the east of Yongxing Island and around the North Island. They are small in size and not living in a large group, so their level of harm is generally controllable.
Corals grow vigorously in waters around Xisha Qundao as protection measures pay off
