South China's reefs on the brink of extinction

Problems

• South China Sea has lost more than 80% of its coral reefs in the past 30 years

  High-resolution satellite images of the South China Sea have revealed the massive and rapid destruction of some of the world's most biodiverse coral reefs, as China attempts to turn pristine habitats into military outposts. Professor John McManus, a leading marine biologist who analyzed the images, commented that the loss of thousands of acres of reef in recent years is the fastest rate of the final defeat of coral reef area in human history.
  
  Over the past 30 years, coral islands and reefs in southern waters have shrunk by 80%. Scientists are now trying to rebuild polyp colonies, but even in the best-case scenario, this will take hundreds of years. So far, everything goes to the fact that the most beautiful places on the planet can finally turn into lifeless underwater deserts.
  
  "Our generation has a temporary responsibility to pass these extraordinarily diverse and incredibly beautiful coral reef atolls on to future generations," says McManus. Six countries -- China, Vietnam, Malaysia, the Philippines, Taiwan, and Brunei -- are vying for ownership of more than 250 islands, reefs, and sandbanks in the South China Sea. The islands are largely uninhabited, but rapid reclamation is threatening ecosystems that are key to maintaining the world's fish stocks and biodiversity. The development of the islands is expanding.

• China's military conflict hurts coral reefs

  Recent photos have shown that China is building a third airstrip on reclaimed land, giving it even more options in the area. In the struggle for territorial claims, rival countries have mined sand on the reefs to build airstrips, military posts, and even small towns. Corals sank into the sand, and marine ecosystems were destroyed. A decade-long dispute erupted into a separate armed conflict, and tensions reached unprecedented levels. Satellite images provided by the Asian Maritime Transparency Initiative at the Center for Strategic and International Studies show China at the forefront of this political standoff. Photographs taken over the past decade of the four main islands that China is reclaiming - Fiery Cross Reef, Subi Reef, Mischief Reef, and Johnson Reef - show an alarming rate of destruction.
  
  "The picture of Mischief Reef is particularly disturbing," says McManus, a marine biology and fisheries specialist at the University of Miami. The reef covers about 45 m², not counting the dense coral that extends dozens of meters in depth. "Sand and silt destroyed by dredgers cover most of the lagoon and settle over most of the remaining reef. The sand kills virtually any benthic organisms on which it settles in large quantities and clogs the gills of most fish. I don't expect any fish to survive in this lagoon, except in very southern areas," he says.
  
  The images give an idea of the extent of the underwater devastation. You can see that the recovered silt is formed as strands rather than plumes. That's because millions of tiny polyps on the coral reef are reacting to the dredging by releasing large amounts of mucus in a desperate attempt to remove the sediment, McManus says. The slime mixes with the silt, forming bright white strands hundreds of meters long. In the lagoon, the slime mixes with the decomposing bodies of organisms. The sand, which will smell horribly rotten for months, will have a very low oxygen content, preventing the fish from settling. Much of this damage is irreparable and irretrievable.

• Underwater predators are destroying coral reefs

  Zhang Yuyang, a researcher at the Institute of Oceanology says coral colonies in the South China Sea are dying too fast. Some coral reefs and islands are already completely extinct, others are on the verge of extinction. And the situation is only getting worse.
  
  Starfish is one of the causes of coral extinction. The underwater predator feeds on defenseless polyps. Since 2006, red stars have become a real headache for ecologists. The only thing that can help is the artificial creation of colonies. Or, as oceanologists say, reef restoration. Zhang Yuyan talked about a kind of coral farm in the city of Sansha. Here they grow bricks for underwater construction. They first gather live young corals from the sea and then place them on an artificial platform in the form of these bricks. When polyps reach a certain age, they will be returned to their natural environment. But this process is too long - corals grow only one centimeter per year and die much faster. Polyp colonies give life to surrounding areas. If reefs disappear, fish will leave the area and the locals will have nothing to catch and nothing to feed themselves. Incidentally, not starfish are the corals' worst enemy, but man and his economic activities. Several thousand tourists visited Sansha last year. On the one hand, their money could have served the environment, but on the other hand, the increase in tourist traffic is negatively affecting the environment.

• Poaching and fishing threaten reef existence

  Experts said coral poaching could threaten the existence of some reefs and islets in the South China Sea.
  At a celebration of the International Day for Biological Diversity, Wang Xiaoqiang, deputy director of the State Oceanic Research Administration, said the biodiversity and biome of the South China Sea have suffered from destruction and degeneration.
  
  "Since the 1970s, 80 percent of the coral reefs in the area have been lost, and the area of mangroves lost could be about 73 percent. The overall situation is dire," Wang said at an event organized by the China Biodiversity Conservation Organization in Beijing.
  
  The Green Development Foundation found severe damage to coral reefs near the Yongle Islands, part of the Sisha Islands, during an expedition in the South China Sea. In addition to the rampant illegal coral market that has destroyed coral reef ecosystems, overfishing of giant clams has also led to reef destruction, analysts said.
  
  The China Coast Guard warned in 2015 that the price of red coral in China had increased by 30 percent annually for the past 10 years, with a booming illegal industry stretching from poaching, mining, and processing to red coral sales.
  
  "In 2013 and 2014, giant clams began to be sold as artwork after being carved, leading to over-exploitation. Although only one species of giant clam is listed as a protected species in China, it is difficult for fishermen to notice the difference. Consequently, great damage has been done to all giant clam species in the area," Chen Hui, secretary-general of the Hainan Marine Environmental Protection Association, told the Global Times.
  
  The misguided government support and promotion of the giant clam industry in Tanmen, Hainan province, has accelerated the process, with many local fishermen flocking to Xisha, Nansha, and Zhongsha Islands. According to Lin Hongming, a senior engineer at the Hainan Institute for Planning and Design of Construction Projects, some fishermen even reached the South Pacific Ocean.