MANILA—Protected by their country’s navy, Chinese fishing boats devastated mile upon mile of pristine coral in Philippine waters, using their propellers as blades to hack out giant clams buried in the reefs. Other threatened species that fell prey to Chinese poaching on an industrial scale, with official connivance: turtles, sharks, eels and oysters. And all of this, according to the unanimous ruling of an international tribunal in The Hague, was just the prelude to an even greater catastrophe—China’s dredging of seven massive islands in the Spratlys chain on top of the already traumatized reef systems that form a critical link in the fragile ecology of the South China Sea. ‘The Tribunal has no doubt that China’s artificial island-building activities on the seven reefs in the Spratly Islands have caused devastating and long-lasting damage to the marine environment.’ —Tribunal at the Permanent Court of Arbitration, July 12 The headline-grabbing part of the verdict, which stretches to nearly 500 pages, is its categorical striking down of China’s historic claims over almost the entire South China Sea within a “nine-dash” line. Yet the section that describes China’s obliteration of reefs is by far the most damning. It is a portrait of destructive power, unconstrained by international law, public opinion in the region, or seafaring tradition. The judges came up with a detailed description, backed by reams of scientific evidence, of how coercive Chinese policies now imperil the livelihoods of some of the region’s most vulnerable communities who live on the edge of hunger—those that make a living from the sea. Even though Obama administration officials harp constantly on the Chinese threat to navigation and overflight, that danger is theoretical, for now at least. China hasn’t yet interfered with commercial shipping or aviation. If it did, China itself would be the most notable casualty since it is the world’s largest trader. Ecological devastation, on the other hand, is all too real. Some 270 million people inhabit coastal areas of Southeast Asia; millions depend directly on the sea, many through fishing. China isn’t the only country that has made life precarious for these groups. Marine stocks in the South China Sea are severely depleted as a result of overfishing, practices like dynamite and cyanide fishing, as well as coastal pollution. Likewise, damage to reefs, where the cycle of marine life in the oceans begins, has been under way for years. Here comes China with the world’s largest fishing fleet, rapidly expanding navy and growing territorial ambition, exacerbating a crisis that condemns fishing villages in littoral states like the Philippines to poverty. According to one scientific report published in 2013, coral cover on atolls and archipelagoes in disputed areas of the South China Sea—six governments, including China and the Philippines, contest ownership—has declined from around 60% to 20% within the past 10 to 15 years. The situation off China’s coast is even more dire: Coral abundance has declined by at least 80% over the past 30 years on its fringing reefs, the report says. The tribunal verdict cites research by John McManus, a marine biologist at the University of Miami, who says the propeller harvesting of giant clams “exceeded anything I had previously seen in four decades of investigating coral reef degradation.” It quotes Sebastian C.A. Ferse, a coral-reef ecologist at the Leibniz Center for Tropical Marine Ecology in Bremen, Germany, as saying the artificial islands have destroyed complex reef systems formed over millennia and they won’t recover for decades, perhaps centuries. It is possible, he warns, that the demolition could have a “cascading effect” across the South China Sea, which covers 1.4 million square miles. ‘China cares about protecting the ecological environment of relevant islands, reefs and waters more than any other country, organization or people in the world.’ —Hong Lei, Chinese Foreign Ministry spokesman in May China outright dismisses evidence that it is presiding over the environmental rape of a stretch of water that it increasingly treats like its own private lake. “China cares about protecting the ecological environment of relevant islands, reefs and waters more than any other country, organization or people in the world,” a Foreign Ministry spokesman said in May. China has rejected the tribunal’s verdict. The commander of the People’s Liberation Army Navy vowed that China would press ahead with building artificial islands in the Spratlys. Construction “is reasonable, justified and lawful,” Wu Shengli said, according to the official Xinhua News Agency. If ever there was an issue for Southeast Asian countries to tackle, as a regional group, this is it. Yet over the weekend, a statement that followed a meeting of foreign ministers of the Association of Southeast Asian Nations managed to avoid reference to the tribunal’s ruling altogether. China is a signatory to the United Nations Convention on the Law of the Sea—whose rules on the preservation of marine life it has blatantly flouted, according to the tribunal—but insists on negotiations with neighbors one by one to settle issues in the South China Sea. With a multiparty solution off the table, what’s ahead for the coral reefs? China can double down on its defiant island-building, or quietly comply with the ruling of The Hague. To gauge where one of the world’s most important marine areas is headed, don’t listen to the bluster of China’s admirals, focus instead on what its fishing boats and dredgers are doing.