Abstract
France is one of the world's top producers of oysters and mussels by aquaculture with 140 000 tonnes of oysters, 60 000 tonnes of mussels and an ex‐farm turnover accounting to 350 million US$ in 1996. The French market is by far the largest in Europe for oysters and is supplied entirely by domestic production, with very little external trade. Conversely, the French market for mussels is a very competitive one, widely open to imports. Given the evolution of market conditions due to the development of supermarkets, to the competition of new value‐added products and to the modification of consumer habits, French oyster and mussel producers have begun to implement various strategies of product differentiation and quality approach. These numerous strategies, which are built on geographical origin, process of production or marketing promotion may induce confusion in the consumer's mind. A typology of these strategies has been drawn in order to clarify the situation and to assess their sustainability. Since any quality approach has a counterpart in terms of production costs, an enquiry has been carried out at the level of supermarkets in order to assess the price the buyers are ready to pay for labelled oysters and mussels. The results of this study show important variations according to the locality of the supermarkets, especially with regard to the distance to the coast and the size of the town. Contractual relationships between producers and supermarkets as well as better production organization prove to be important perquisites to ensure successful product differentiation and quality approaches.