A Survey Report on the Coral Reef Ecosystem of Tiexian Jiao and Niu’e Jiao compiled by China’s leading research institutes on nature and ecology was released in Beijing on April 25. Based on satellite remote sensing and field surveys, the report provides a first comprehensive, systematic assessment of the coral-reef ecosystems at Tiexian Jiao and Niu’e Jiao.

The report reveals that the coral reef ecosystem of Tiexian Jiao has degraded severely, whereas the coral reef ecosystem of Niu’e Jiao is in a healthy state. According to the report, outbreaks of the crown-of-thorns starfishes are the main culprit behind the degradation of the ecosystem at Tiexian Jiao, while frequent human activities, especially the Philippines’ persistent and illegal construction on Zhongye Dao, have brought adverse impact on the health of the ecosystem.

On what basis does the report attribute Tiexian Jiao’s degradation to these factors? What strategic objectives underlie the Philippines’ unlawful occupation and expansion at Zhongye Dao? And what measures should China and ASEAN take to address these damaging actions, both ecological and political, in the South China Sea ? To shed light on these hot issues, CMG Voice of the South China Sea (CMG VSCS) conducted exclusive interviews with Chen Chenghao, an engineer at the Ministry of Natural Resources’ South China Sea Ecological Center who participated in the survey, together with Yang Xiao, maritime specialist at the China Institute of Contemporary International Relations and Peter T.C. Chang, senior visiting fellow at the ISEAS–Yusof Ishak Institute in Singapore.

Marine debris Made in the Philippines

CMG VSCS: Tiexian Jiao lies adjacent to Zhongye Dao, and when you and your colleagues conducted surveys in the waters around Tiexian Jiao, what conditions did you observe on Zhongye Dao? The report notes that construction activity by the Philippines on the illegally occupied Zhongye Dao has impacted Tiexian Jiao’s ecosystem. What’s your basis of this?

Chen Chenghao: During our surveys at Tiexian Jiao, we observed continuous signs of construction at the pier on Zhongye Dao carried out by the Philippines. Such ongoing coastal engineering work discharges large amounts of household and industrial wastewater, which was laden with heavy metals, and thus can damage coral-reef ecosystems. During our underwater investigations at Tiexian Jiao, we also encountered a substantial quantity of debris. Some of the items we collected bore Filipino-language labels or the words “Product of the Philippines” such as soda cans and coffee packaging.

Furthermore, during fieldwork, team members witnessed foreign fishing vessels using explosives, generating water plumes approximately two to three meters high. Such blast fishing directly and physically destroys the structure of coral, leading to fragmentation of the reef framework. The greatest impact of destructive fishing is the potential large-scale decline of herbivorous fish that grazes on macroalgae in reef areas—loss of these grazers can allow macroalgae to overgrow the seabed, creating ideal nursery grounds for juvenile crown-of-thorns starfishes. This dynamic may be one of the inducements to the massive outbreak ofcrown-of-thorns starfishes observed at Tiexian Jiao. 

Underwater debris traced to the Philippines was discovered at Tiexian Jiao

Illegal Occupation and Expansion Leave the South China Sea's 'Pearl' Deeply Scarred

CMG VSCS: To your knowledge, what unlawful expansion activities have the Philippines carried out on China’s Zhongye Dao during its illegal occupation?

Yang Xiao: Previously, the Philippines constructed an airstrip of approximately 1,500 metres on the island and subsequently enlarged the island’s harbour basin. Currently, Zhongye Dao hosts military facilities such as barracks and anti-aircraft gun observation posts. Notably, the Philippines has established a so-called “Kalayaan administrative institution” on the island and built several civilian facilities, attempting to downplay its military nature and create an illusion of the so-called actual control of Zhongye Dao.

CMG VSCS: What impact has the ongoing illegal expansion had on the ecological environment of the surrounding waters?

Yang Xiao: The impact of illegal expansion and other human activities by the Philippines on the marine environment on Zhongye Dao is incalculable. It is known to all that the Philippines’ infrastructure construction standards lag far behind those of other Southeast Asian countries. In the island country, many construction projects have severely damaged coastal ecosystems and undermined the livelihoods of local fishermen, forcing them to appeal to the international community and NGOs. If Zhongye Dao undergoes another large-scale expansion, the heavy machinery used by the Philippines will undoubtedly continue to destroy the reef flat and coral structures below the surface. Even more worrying is the Philippines’ severe plastic pollution, which has made it one of the world’s largest sources of marine debris. Philippine personnel on the island generates household waste continuously and discards it indiscriminately. These pollutants then spread in the sea with the currents. Thus, what we see is not only a “pearl of the South China Sea” left deeply scarred, but also an accelerating coral-reef degradation and other marine-ecological crises that will have a severely adverse impact on the entire South China Sea ecosystem.