Analysis Exposes Coral Reef Damage in South China Sea
John McManus, the marine biologist of University of Miami behind the new analysis of satellite imagery, says about 10% of the shallow reefs in the Spratly Islands and 8% in the Paracels have been damaged by poaching and island building. The South China Sea is one of the most biodiverse regions in the world. It is home to 76% of the world’s coral species and 37% of the world’s reef fish. Because the reefs provide crucial habitats for fish and their larvae, widespread loss can have a major economic and social effect.
According to a new analysis of satellite imagery that was presented at the South China Sea Conference, more than 40 mi2 (104 km2) of coral reefs have been destroyed by giant clam poaching. The poachers use boat propellers to loosen the large bivalves, carving the reef and leaving it barren. And because majority of the reefs are interconnected, the damage in one place can have repercussions elsewhere.
Another 22 mi2 (58 km2) have been destroyed by island-building activities, largely by China. During the conference, the Permanent Court of Arbitration in the Hague, an international tribunal, issued a ruling in favor of the Philippines’ claim that China violated its responsibilities under the UN Convention on the Law of the Seas by engaging in large-scale environmental destruction to build artificial islands. They concluded that China was 99% responsible for the damage to the coral reefs in the Greater Spratly Islands.
Island-building allows China to strengthen its claim on the aqueous region. More than $5.3 trillion worth of international trade passes through these waters annually, making the Sea one of the world’s most important shipping routes. In the past two years, Chinese workers created more than 3,200 acres (1,300 hectares) of new land, according to Greg Poling, a South China Sea expert at the Center for Strategic Studies. All of China’s man-made islands also have military infrastructure, extending the country’s military reach.
But, island building is extremely destructive. In order to produce the sediment needed to create new land, a giant drill needs to break up the coral. That sediment is then dumped on top of another part of the reef, which becomes the base of the island. As more sediment is poured, plumes of silt and sand drift away, settling on other reefs and slowly suffocating them. Dredging to make these new ports deep enough for ships has also caused major reef damage.
But, McManus says, the damage from island building pales by comparison to the destruction caused by the clam poachers. “To know that that much has died is such a shock,” he said. “They basically plowed up these reef flats.”
In China, the giant clams are highly valuable and considered to be luxury items. The shells are carved into jewelry while their meat is eaten as a gourmet treat and aphrodisiac, reports Christina Larson for Science. Used to be abundant in the South China Sea, the clams have become few and far as Chinese fishermen travel hundreds of miles south to the Spratly Islands to get them. McManus states that 35 reefs in the Spratly Islands and six in the Paracel Islands have been damaged by the poaching with at least another 25 at risk.
“The whole thing was a big surprise,” he said while describing the scale of destruction. “Everything was thoroughly dead.”
On satellite imagery of the region, experts had noticed arcing scars. This January, reporter Victor Robert Lee published in The Diplomat that the arcs were caused by the fishermen dropping propellers onto the reef and swinging their boats from side to side to break up and loosen the clams. This practice not only kills the reefs but also ruins the entire ecosystem, which the tribunal concluded that the China was “full aware of” and “tolerated”.
Many experts, including McManus, calls on China and other Southeast Asian countries to set aside their differences and declare the region an international protected zone, the way Antarctica is managed.
“If we don’t do this, we are headed toward a major, major fisheries collapse in a part of the world where [that] will lead to mass starvation,” the expert warns during a panel in Washington organized by the Center for Strategic and International Studies.
Professor Kent Carpenter of Old Dominion University, another coral expert that was consulted by the tribunal, reluctantly said, “There is no hope for many of these reefs to recover in the coming decades or centuries.”
Visiting fellow at the Asia-Pacific Center at Fudan University in Shanghai Ashley Townsend summarizes the issue as this.
“Environmental degradation and depletion of endangered species by Chinese activities and island construction… essentially has been a background story to what’s been happening in the South China Sea. Now there is a strong legal grounding” to criticize China on its environmental stewardship and open a “second front. There’s a capacity to … leverage global environmental activist networks to make this not just an issue about sovereignty and geopolitics but about the health and well-being of the global commons. That’s more likely under the ruling.”
Tracking Hawksbill Sea Turtles May Yield Crucial Information
Hawksbill sea turtles, named for their pointed beaks, are on the edge of extinction. Their populations are only 10% of what they were a century ago, according to Richard Hamilton, the Nature Conservancy’s Melanesia program director. The Sea Turtle Conservancy estimates that there are between 20,000 and 23,000 nesting females worldwide. This makes them the most critically endangered of all seven species of sea turtles.
Found in the tropical and subtropical waters of the Atlantic, Pacific, and Indian Oceans, the turtles face seemingly insurmountable threats: a thriving illegal trade in their shells, poaching of their eggs, hunting for their meat, beach erosion and human development at their nesting sites, and degradation of coral reefs where they forage.
The largest rookery in the South Pacific is the Arnavons, four forested bumps within the Solomon Islands. It supports between 300 and 600 nesting females annually with a total nesting population of 2,000 to 4,000.
According to Hamilton, poaching in the Solomons has been getting worse. It is legal for local people to harvest hawksbills for subsistence, but national law bans the sale of any turtle product and international trade in hawksbills is also banned.
In response to the increased poaching, the Nature Conservancy and local conservation officers from the Arnavon Community Marine Conservation Area launched the first hawksbill sea turtle satellite tagging program.
“While turtle tagging has been done before, a comprehensive hawksbill satellite program has never been done in the Arnavons, which is a crucial breeding ground for this critically endangered species,” commented Hamilton. “This new data will show whether the current Arnavons boundaries are sufficient to protect nesting turtles, and where they migrate between nesting years.”
In April, during the peak nesting season, scientists tagged 10 hawksbills with GPS trackers. After about a year later, the adhesive will disintegrate, allowing the trackers to fall off. And because turtles nest year-round and nesting areas may change year to year, the Conservancy is also planning to tag an additional ten per year in 2017 and 2018.
Although two females were later killed by poachers, data from the other eight have already provided insight on hawksbill movement, nesting, and feeding habitats.
Some key findings include:
Hawksbill sea turtles island-hop. Satellite tagging revealed that individuals nested on beaches in two main areas on Kerehikapa and Sikopo Islands. The bulk of the nesting now occurs on Sikopo Island, likely due to rising sea levels and storm surges that have eroded Kerehikapa’s beaches. The number of rangers has been doubled, from three to six, on both islands to protect the nesting sites.
One particularly important find is that during the two-week period of laying clutches of eggs, the turtles spend nearly all their time within the protected area boundaries of the Arnavons, making it critical to keep the poachers out.
Lastly, the data proves that migration patterns vary extremely. While two of the tagged turtles remained in the Solomon Islands, another is currently in Papua New Guinea and three are heading to the Great Barrier Reef in Australia (about 1,300 miles or 2,092 kilometers away). Those returning to northern and central parts of the Great Barrier Reef will find a very different habitat, due to coral bleaching that occurred over the summer. The turtles’ wide range of foraging grounds shows that they are a shared cultural and biological treasure that need both local and global action to address poaching and climate change impacts.
Hamilton hopes to expand the turtle-tagging program to better understand “legal or illegal harvest rates, or on what is sustainable”. This information will make it easier to nip illegal exports and get better enforcement. But also, the local people need to be informed about the turtles with the community being involved “in everything from naming the tagged turtles to monitoring the beaches”.