An oyster farm in northern coastal Quang Ninh province’s Van Don district (Photo: VNA)

Quang Ninh (VNA) - The northern coastal province of Quang Ninh has asked local authorities to urgently examine and determine the reason for the mass oyster deaths in Tien Yen district.

Reports from Tien Yen district’s People’s Committee showed that since early March, the deaths have wiped out 75 percent of 7,200 tonnes oysters raised in the district, causing a loss of some 82 billion VND (3.6 million).

Apart from Tien Yen district mass oyster deaths are also being recorded in Quang Yen town, Van Don district and Mong Cai city.

Nguyen Huu Giang, Director of the provincial Department of Agriculture and Rural Development, said the department had asked specialised units to inspect and collect information on the reason for the oyster deaths.

It had also asked the General Department of Fisheries, the northern Environmental Monitoring and Aquatic Disease Centre and the Veterinary Authority Zone 2 to participate and determine measures to stabilise production activities of those affected, he said.

Currently, water samples of the affected area have shown two different results.

Results of the water analysis of the northern Environmental Monitoring and Aquatic Disease Centre, which took place on April 21, revealed that as many as 13 indicators of the aquatic environment are within the permitted level.

Although the salinity was rather high – between 29 and 30 percent of the water – it was within the permitted level and would not have impacted the aquaculture.

However, according to results of the Veterinary Authority Zone 2, all three samples of water were positive for Vibrio parahaemolyticus and Vibrio vulnificus bacteria.

Giang said the province would not yet announce an epidemic, as regulated by the Ministry of Agriculture and Rural Development in 2016. Currently, the ministry’s Circular 04/2016/TT stipulates that affected localities must announce an epidemic only when the oyster deaths are because the marine creatures have been infected with a parasite named Perkinsus.

The department has sent more inspection teams to take samples for further tests to get accurate results.-VNA