The northern province of Quang Ninh has become in the country's largest pearl oyster farming centre, bringing in an average revenue of around US$4 million a year.

Pearl oyster farms in the province are mostly operated by ten companies, including two wholly foreign owned companies. They concentrate in the waters of Van Don district and Ha Long City.

These companies have reported that they are nurturing 55 million oysters in 450 ha of water, of which, 17.5 million are expected to bear pearls.

Experts predict that by the end of this year, Quang Ninh province will export around 1.1 tonne of pearls.

Pearl oyster cultivation has become another attraction of Quang Ninh province, which is already famous for Ha Long Bay, a world heritage site.