In the developed countries, especially in the European Union, demand for seafood products has increased very quickly (faster than that of meat products). This growth may be explained by the recurring problems of animal health impacts on other products (bovine spongiform encephalopathy (BSE), avian influenza (bird flu)...) and to the impacts of the environmental problems (dioxins...) which are less prevalent in seafood products. In addition, seafood products profit from an increasingly positive image positioned on the axis of nutrition- health. The enhancement of the markets is influenced more and more by the retailing channel (hyper and supermarkets). Indeed, France profits from being a pioneer in retailing, (more than 70% of the seafood market is through retailers) who can be seen as axis of development with other sectors and in other countries. To satisfy the demand, the national platforms of the retailers rely upon imported products to supplement their supplies from local fishermen and fish farmers. These local actors must adapt to the constraints imposed by the platforms, which constitutes a major innovation in the contractual relationship with the hyper and supermarket stores. The international context weighs heavily in the determination of these constraints. This paper deals with this framework of the new forms of contractualisation between the actors imposed by the evolution of the international context. It also describes the implications in term of setting in market and marketing strategies. Lastly, it takes into account the emergence characteristics of new food buying behaviours.