|Farmers in the southern province of Dong Nai said they disagree with the contention that a low oxygen content in water caused the death of roughly 200 tonnes of fish in Dong Nai River recently. — Photo tuoitre.vn
DONG NAI (VNS) — Farmers in the southern province of Dong Nai said they disagree with the contention that a low oxygen content in water caused the death of roughly 200 tonnes of fish in Dong Nai River recently.
Surveys from the Environmental Protection Bureau under Dong Nai Province's Department of Natural Resources and Environment showed that the decline of dissolved oxygen content caused the deaths, local authorities have said.
Analysis showed that the concentration of dissolved oxygen in the water early this month was between 1.51mg/l to 1.92 mg/l while the required ratio was 4 mg/l.
According to Vo Niem Tuong, head of the Environmental Protection Bureau, the high density of fish and the narrow distance between cages affected the living environment of the fish.
Food that had been in cages a long time created bacteria, which also contributed to the reduction of oxygen, he said.
Fish breeders do not use professional standards and only use techniques based on their personal experience, environmental officials said.
The Dong Nai Province's Veterinary Bureau, however, agreed with the farmers that the cause of the death of fish was polluted water discharged from factories, and not the farmers' breeding methods.
Bureau officials said that they had told farmers in the past to breed fewer fish in cages, and the farmers had followed their instructions.
Farmers said that water pollution was the cause but noted that the authorities did not mention this factor in their report.
Tran Van Tinh, whose five tonnes of fish died during the incident, told Nguoi Lao Dong (The Labourer) newspaper that he had invested billions of dong to operate a fish farm. He lost most of his money after the fish died.
Vu Dinh Doanh, who was able to save half of his fish, said the authorities' conclusion was groundless, based on his years of experience in breeding fish. If fish died in such large numbers, it would have happened before as well, he said.
In addition, feed for the fish is expensive, so he would not waste it, he added.
Several households in the village said that when their fish died, the fish living in the wild also died, so the breeding method was not the reason for the deaths.
"We know that at the end of each year, enterprises in nearby industrial parks clean their factories. The untreated waste water causes polluted water. We expect the Police Department against Environmental Crime to clarify this issue," Nguyen Van Duong, one of the farmers facing serious losses after the incident, was quoted as saying in the paper.
The farmers said there were dozens of pipes discharging waste water from factories to the river.
Police officials have also begun investigating the incident.
On January 3-5, fish in many fish farms unexpectedly died. The total amount was more than 200 tonnes, causing heavy losses to 150 fish-breeding households in Hiep Hoa Commune.
According to the Dong Nai Province's Department of Agriculture and Rural Development, the density of fish cages in the area exceeds the planned density.
There are a total of 272 fish cages owned by 215 households.
The Department of Agriculture and Rural Development, which has asked the Department of Natural Resources and Environment to strengthen monitoring of water quality in recommended areas, said it would improve inspection and strictly punish acts of environmental pollution.
In a related development, the Ba Ria – Vung Tau Province's Department of Agriculture and Rural Development has worked with the provincial Judicial Department to help farmers in Long Son Commune in Vung Tau city to complete procedures to proceed with a lawsuit against 14 enterprises in Tan Thanh District for creating pollution in the Cha Va River, causing serious losses to their fish farms.
Earlier, the provincial government had organised a meeting between the enterprises and farmers.
It was estimated that the pollution level was 76 per cent and total required compensation was VND13 billion (US$578,000). — VNS