Oyster growing pollutes rivers Farmers in Long Hoa Commune in HCM City's Can Gio District are using old tyres and iron mesh to cultivate oysters, which is polluting the environment.   An oyster farm in Long Hoa Commune, HCM City's Can Gio District. Local households use old tyres and iron mesh to make floating oyster cultivation cages on the commune's rivers and canals, causing environmental pollution.  Long Hoa, which is one of the largest oyster cultivation areas in Can Gio District, and home to more than 100 households that farm oysters in the rivers and canals, including rivers Ha Thanh and Rach Lo. The households use hundreds of thousands of old tyres and thousands of metres of iron mesh to make floating oyster cultivation cages on the commune's rivers and canals. However, at this time of year, farmers are more likely to see their oysters dying rather than thriving. Farmer Pham Van Son in Long Hoa's Long Thanh Hamlet, said three tonnes of his oyster stock, which he had cultivated in 70 iron wire mesh cages, had died. Another farmer, Nguyen Hai Ly, who has 200 oyster cages in Dong Tranh Hamlet, said this year's death rate had been higher than in previous years, due to prolonged cold weather. However, the official agencies have not yet formally investigated the reasons behind the death of the oysters in Long Hoa. A few years ago, the oyster breeding area in Long Son Commune in Vung Tau City became a victim of ecological pollution. At the time, local agencies found that using old tyres and fibro sheets to raise oysters was one of the causes of the pollution. Oyster farmers traditionally used bamboo or wooden stakes to breed oysters. However, using old tyres and fibro sheets for oysters to cling onto is a cheaper alternative to using bamboo or wooden stakes, which accounts for its sudden popularity. Along a two kilometre section of river from Ha Thanh Bridge to the April 30 beach in Long Hoa, there are about 6,000 oyster cages and hundreds of thousands of old tyres used to cultivate oysters. Farmers now breed oysters in much larger quantities but have not taken care to protect the environment from the pollution this causes, according to Ly. Previously when oysters died, farmers would bury them further in land. However now they are forced to throw the dead oysters into the river because the quantities are so vast, that it's impossible to dispose of them on land. This part of the river is now so over-loaded with dead and rotting oysters, that locals have complained of its smell. "If pollution continues, oyster farmers will lose it all," Ly said. Earlier this year, the Can Gio District People's Committee ordered the relevant agencies to manage oyster farmers better. Truong Tien Trien, chairman of the Long Hoa People's Committee, said farmers had been entering into the industry with no prior experience or training, and that it was still largely unregulated. The Long Hoa People's Committee had petitioned Can Gio authorities to issue more stringent policies on breeding oysters, he said. Oyster farming often brings high profits for farmers as overheads are low, thanks to the fact that oysters feed off foods naturally available in rivers and canals. Farmers only have to invest in baby oysters and raising cages to set up business, which means there are low barriers to entry. This, and the high profit margins, is what is attracting people to the industry. VNS