Marine environmental protection is an important part of marine governance. International treaties, including the United Nations Convention on the Law of the Sea, contain a number of provisions on the protection of the marine environment, and there are many relevant rules in general international law, including customary international law.

The South China Sea is the common home of China and ASEAN countries. According to Article 6 of the Declaration on the Conduct of Parties in the South China Sea, the parties concerned may explore or carry out cooperation in the field of marine environment protection before the dispute over territorial sovereignty and maritime jurisdiction in the South China Sea is fully and permanently resolved. Over the past 20 years, China and ASEAN countries have built platforms and mechanisms to achieve results in environmental protection and conservation of biological resources in the South China Sea.

This cooperation has played an important role in avoiding the continuous and rapid deterioration of the ecosystem and biodiversity in the South China Sea, which is conducive to the regional marine environmental governance of the coastal countries in the semi-enclosed sea and has created favorable conditions for the countries concerned to dilute the negative effects of the disputes and enhance mutual trust. Through these cooperation practices, we can not only hear the voices and echoes of the coastal countries in the South China Sea for deepening cooperation in regional marine environmental protection and fishery resource conservation, but also feel that China and ASEAN countries still have a relatively deep civil foundation and increasingly urgent practical needs in translating consensus into practical actions.

However, environmental cooperation in the South China Sea under the declaration framework has not always been smooth – the complex and difficult disputes over territory and maritime jurisdiction, the intensification of maritime frictions due to US interference and provocations by individual parties, and the continuous influence of zero-sum games and Cold War ideology on the South China Sea issue – are all reasons why the stability of maritime cooperation in low-sensitive areas is not high enough. Policy is only one side of the problem, and the shortcomings of some countries in their ability to protect the marine environment also constrain their willingness to deepen regional cooperation in the South China Sea.

In terms of conservation, a report released by the Asia Foundation has pointed out that about 64 percent of Southeast Asia's fishery resources are at medium to high risk of overfishing, and the Philippines is one of the most problematic countries: in addition to overfishing, destructive fishing practices such as using sodium cyanide to stun fish, using explosives or grenades to create explosions in the sea to kill fish, and using bottom trawling nets to drag seagrass beds or coral reefs have also exacerbated the marine biodiversity crisis in the Philippines.

In terms of dumping, according to a recent report by Asia News, the Philippines has few competitors in dumping plastic waste into the sea, and it is difficult to find a remedy, with more than 20,000 square kilometers of the Coral Triangle alone directly polluted. A report from the University of Oxford also shows that the Philippines contributes one-third to the world's 80 percent of ocean plastic from Asian rivers. Interpol’s "30 Days at Sea" report on marine pollution crimes also mentioned that the Philippines has seriously polluted the marine environment by dumping farm waste in its coastal waters.

In terms of oil pollution prevention and control, countries in the region are facing common challenges, and emergency response capabilities also need to be improved urgently. In February last year, a Philippine oil tanker sank off the coast of Mindoro Island, leaking about 800,000 liters of industrial oil.

Pollutants have been detected in the coastal waters of more than 60 nearby villages, and the coast is also covered with black sludge. Marine scientists at the University of the Philippines say about 360 square kilometers of coral reefs, mangroves and seagrass beds are contaminated with oil, and the damage caused will take a long time to recover. There are a large number of merchant ships and fishing vessels sailing through the South China Sea every year, but countries in the region have not yet formed a scientific, smooth and efficient cooperation or coordination mechanism for oil pollution prevention and control, and there is no corresponding emergency plan. If a similar incident were to occur in the South China Sea, the impact on the marine environment and the damage to ecosystems could be equally devastating.

As the largest coastal state in the South China Sea, China's efforts to protect the marine environment in the South China Sea over the years have paid off significantly. According to Bulletin of Marine Ecology and Environment Status of China released by China's Ministry of Ecology and Environment, in 2022, the sea area with water quality failing to meet the Seawater Quality Standard Grade I was 9,540 square kilometers, falling by 2120 square kilometers compared with that in the previous year. The water quality of the offshore oil/gas exploration zones in the South China Sea met Seawater Quality Standard Grade I. Nearly 50 species of live coral reefs in the Xisha Qundao were monitored, with a coral coverage of 19.6 percent and nearly 120 species of coral reef fish, indicating that the coral reef ecosystem was in a healthy status.

In the face of changes in the international and regional situation, China has made unremitting efforts to promote cooperation in low-sensitivity areas while safeguarding its legitimate rights and interests in the South China Sea. Despite the provocative nature of the Philippines' policy in the South China Sea, China has remained patient, shown goodwill, and persuaded with good words, and has put forward cooperation initiatives on fisheries, marine environmental protection, and marine plastic waste management, which are highly in line with the Philippines' practical needs to improve its own marine governance capabilities.

The plastic waste in Manila Bay, the oil-water mixture in Mindoro Island, and the coral that died due to cyanide in the Calamian Islands many years ago are in fact a reminder to the coastal countries of the South China Sea that only a clean and beautiful South China Sea can truly benefit all parties and future generations.

Ding Duo is deputy director and associate research fellow, at the Research Center for Ocean Law and Policy at the National Institute for South China Sea Studies.

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