Feature: Flourishing underwater garden of Colombo Port City shows China’s green footprint in Sri Lanka

by Xinhua writer Chen Dongshu
COLOMBO, Dec. 5 (Xinhua) — The 3.7-km breakwater of Sri Lanka’s Colombo Port City, while stretching out like an arm to embrace the coastal area from high above, resembles a flourishing garden teeming with corals and fish when viewed from underwater.
Piyal de Silva, a 60-year-old former commander of the Sri Lankan Navy, runs a diving school called “Coral Wall” inside the Port City. As a diving enthusiast since his youth, he first discovered this thriving marine ecosystem in 2019.
Back then, as a major project under the Belt and Road Initiative (BRI), the Colombo Port City just completed land reclamation. While diving nearby one day, Piyal discovered that coral was spreading and growing on the blocks of the breakwater.
Piyal said Sri Lanka’s coral reefs had been severely impacted by ecological degradation and the tsunami, making it rare for him to encounter such a large coral reef in the area in recent years.
“I felt surprised and excited to discover the coral, and I was sure a large and beautiful coral reef would grow here in a few years,” he said.
After Piyal told the Port City about his discovery and coral nursery plan, the Port City authorities gave immediate support by providing all the needed materials. They also invited experts from the Chinese Academy of Sciences to conduct underwater surveys and guide coral cultivation.
In June 2023, experts from the South China Sea Institute of Oceanology, Chinese Academy of Sciences, and international academic institutions such as Sri Lanka’s University of Ruhuna, conducted a joint workshop and field survey of the coral reefs.
The results showed that the breakwater area contained 73 coral species, with an average coverage of 24.36 percent and a maximum coverage of 60 precent in some areas. A total of 114 fish species, including endangered species like the humphead wrasse, were also found in this area.
Corals have specific ecological requirements, and the project under China’s BRI has created favorable conditions for their growth in Sri Lanka.
Experts believe that the breakwater’s unique design, improved through Chinese technology, provides an ideal surface for coral attachment. Its stepped structure creates varying water depths, allowing corals to thrive under suitable conditions of depth and light.
After multiple studies using digital and physical models, the design of the Port City can achieve a complete renewal of the internal and external water areas every 10 days. The flow of water can bring in nutrients and oxygen, preventing the long-term accumulation of pollutants at high concentrations.
Since 2024, the Colombo Port City has collaborated with Chinese and Sri Lankan research institutions to further enhance the underwater garden, including adding 68 coral nursery groups, cultivating over 5,000 coral plants, and organizing open days and marine conservation volunteer activities to continuously enhance the research and conservation efforts for coral ecosystems in Sri Lanka.
It has been ten years since construction began on Colombo Port City, which is now evolving into a vibrant new town. This development spans an area roughly the size of 377 standard football fields reclaimed from the sea, featuring landmarks such as the marina, pedestrian pathways, and the marina footbridge, which have all become popular entertainment destinations for the people of Colombo.
Local children often see Piyal, who feeds fish every morning and gathers them in front of his “Coral Wall” to share stories about the underwater garden.
Zhao Lei, general manager of the project management department in CHEC (China Harbor Engineering Co.) Port City Colombo (Private) Ltd., said that the Port City’s design phase established the overall goals of environmental protection, energy conservation, material savings, and emission reduction. Through third-party professional institutions’ full-process environmental assessment, “zero pollution and zero accidents” have been achieved.
“The Port City will continue to actively assume ecological responsibility for underwater afforestation and build a smart, livable, and environmentally friendly city of the future,” said Zhao.
“I have always been a practitioner of building a maritime community with a shared future. Thanks to the Chinese standards, technologies, and solutions adopted by the Port City project, they have made outstanding contributions to the protection of Sri Lanka’s marine biodiversity and ecological environment,” said Piyal. ■