VietNamNet Bridge – Over 100 households farming in Son Tra District's Man Quang Bay suffered a devastating blow to their seafood harvest when a dozen hectares of oyster farms were wiped out suspectedly due to water pollution.

Tran Thi Hoa, 70, stands over dead oysters at her farm in Man Quang Bay in central Da Nang City. An estimated 1,000 tonnes of oysters died en masse during the past week, on farms of over 100 households.

An estimated 1,000 tonnes of oyster have died over the past five days since fishermen made the first discovery last Monday.

It's the first major loss of harvest that locals have seen in 20 years.

Tran Thi Xi, 54, who lost 3 tonnes of oyster, said polluted water would be a main reason for shellfish dying en masse.

"Oysters rarely die of an illness. Water at the bay would likely have been polluted by waste from Tho Quang seafood processing zone which is just 1km away," Xi said.

She said the water on the farm turned foul five days ago and oysters began to die.

Xi's husband added: "A stink across a large area woke me up at midnight and I found that oysters had become rotten by the next morning. I thought they might have died from an illness, but the smell from the bay water continues. We struggled to save the oyster farm, but we failed."

Nguyen Dieu, director of the city's natural resources and environment department, said experts have been examining water samples from the area. "We're trying to establish the cause of the oyster deaths. The city warned two years ago that local people should not farm at the bay because of the low quality water," he said.

"The department and the district administration will solve the problem soon."

In 2010, the city invested VND10 billion ($476,000) to build a centralised waste water treatment station for Tho Quang seafood processing zone with a capacity of 3,000 cubic metres per day.

However the station only treats around half the volume waste water discharged by the 15 companies in the area.

In August, the city also fined five companies from the seafood processing zone for wrongful disposal of untreated waste.

Tran Thi Hoa, 70, said her family was plunged into debt when their 10 tonnes of oysters died just one month before harvest time.

"I invested VND320 million ($15,000) to breed oysters from February and would have collected around VND1 billion ($48,000) next month. But now I've lost it all," she groaned.

"Meanwhile, I have to pay back a VND100 million ($4,700) loan, which matures next month."

Oyster farming has been a major source of income for over 700 people living in the coastal district, providing a monthly income of around VND7 million ($330) per capita in recent years.

"The 2,000sq.m farm used to produce a net profit of VND300 million ($14,000) each year. Oysters often grow well in the area, even though the climate has changed dramatically in recent years," said Huynh Thi Vinh.

Vinh, 41, had to carry away 10 tonnes of rotten oyster and clean the farm for the next crop.

"I would have earned VND500 million ($24,000) from next month's crop, but all I've got now are piles of shells. It's the worst harvest I've seen in the decades since we started farming here," Vinh added.

Source: VNS