New Zealand mussel exporters are seeing a rapid increase in demand in China.
But they are also having to be extra vigilant against attempts by traders to adulterate their product.
The Sanford Seafood says the United States, Australia and South Korea are still the dominant markets for New Zealand mussel exports, but sales to China are growing by more than 30-percent a year.
Sanford is part of a co-operative of four seafood companies marketing Pure New Zealand Green Shell Mussels.
Managing director Eric Barratt said they have been attracting a lot of interest at recent trade shows in China.
But, he said, protecting the brand and the product is a constant challenge.