Wealthy nations’ drastic increase in construction sand consumption contributes to erosion of estuaries
Patrick Barkham The Guardian 31 Aug 18;
The secretive trade of coastal sand to wealthy countries such as China is seriously damaging the wildlife of poorer nations whose resources are being plundered, according to a new study.
Sand and gravel are the most extracted groups of materials worldwide after water, with sand used in the concrete and asphalt of global cities. China consumed more sand between 2011 and 2013 than the US did during the entire 20th century. India has more than tripled its annual use of construction sand since 2000.
But coastal sand is also being used to make wealthy countries larger via land reclamation projects, and the cost to poorer nations is revealed in a presentation to the Royal Geographical Society’s annual conference.
Research by Melissa Marschke and Laura Schoenberger of the University of Ottawa highlights that the dredging of coastal sand from Cambodia is causing the loss of mangrove swamps, coastal erosion, and damaging local fishing. They also allege that the sheer scale of the multimillion dollar trade of sand must be illegal, given that the volumes permitted for import are being exceeded.
Singapore is built on sand: its land area has grown by more than a fifth since its independence in 1965 from 581 sq km to 719 sq km in 2015, according to the researchers. Between 2007 and 2017, Singapore imported more sand from Cambodia than any other country.
Sand worth US$752m was imported by Singapore from Cambodia between 2007 and 2016, according to UN data.
Cambodia is not the only place experiencing vast sand extraction. A study recently estimated that 236m cubic metres of sand were extracted from Poyang Lake in China, causing its water levels to drop dramatically. Sand miners have destroyed at least two dozen islands in Indonesia since 2005. The UK obtains about one fifth of its sand from the seabed.
Cambodian figures claim that the total export worth for the same time period was just $5m but Singapore trade statistics show that 80.22m metric tons of sand was imported from Cambodia, compared with the 2.77m metric tons Cambodia claims was exported to Singapore.
Schoenberger, a postdoctoral fellow, told the conference: “The volume of sand that has been leaving Cambodia over the last ten years is absolutely illegal; way beyond the government’s permitted limits.
“Small amounts of sand can be legally exported, but Singaporean import figures reveal that this Cambodian resource is clearly, and rapidly, disappearing. It appears that someone with high level connections in the Cambodian government is making a lot of money.”
Desert sand is too rounded by the wind to make good concrete but coastal sand can be rinsed with freshwater to clean it of salt before use in construction. Coastal sand is also a key ingredient in land reclamation projects such as China’s expansion into the South China Sea.
Schoenberger and Marschke interviewed villagers and sand dredgers in Cambodia and found that most dredgers were entrepreneurs with small boats who extracted the sand in estuaries and close to coastal fisheries, damaging local crab and fish stocks.
According to Marschke, associate professor at the University of Ottowa, the noise and sediment disturbance causes grouper fish to relocate and drives crabs from the area. Subsequent erosion of mangroves destroys vital fish and crab breeding grounds and damages a natural sea defence for coastal communities.
“Sand mining is contributing to the erosion of estuaries, the collapse of riverbanks and loss of mangroves,” said Marschke. “The removal of vast quantities of sand will definitely impact upon coastal erosion.”
Following petitions and protests by local people and an influential campaign by Cambodian group Mother Nature, the Cambodian government banned coastal sand mining in 2017. But the researchers cast doubt on whether the ban is being upheld or will endure in the face of relentless global demand for sand. Singapore’s land area in 2030 is predicted to be 30% larger than in 1965.
Marschke said: “We need to realise that sand is a finite resource and we are overusing it and if we don’t start to manage it properly it has huge implications.”
Schoenberger said the issue of rich nations buying poor nations’ sands was “a huge social justice question”.
She added: “What does it mean for a wealthy country to grow out into the sea and up into the sky at the expense of the physical biomaterial of poor countries?
“Sand is not a renewable resource within human timescales.”
