This paper investigates the potential of Geographical Indications to enhance the environmental sustainability of bivalve aquaculture, with a focus on the Protected Designation of Origin (PDO) granted to the bouchot mussel of the bay of Mont Saint-Michel (BMSM). First, a retrospective analysis of the PDO application process was carried out to provide insight into specific environmental and regulatory issues facing mussel farming in the BMSM (e.g. common resource management). Second, further assessment relied on a comparative analysis with other public labelling strategies developed by mussel farmers, notably emerging organic certification. This involved setting up an ad-hoc analysis grid to evaluate different dimensions of sustainability, namely economic, environmental and governance. The discussion then addresses the potential of PDO to promote sustainable mussel farming with respect to the current trends in food/mussel labelling in the market and to the increasing demand for environmental preservation in marine and coastal areas. It also emphasises the overlap between different EU labelling schemes that questions their consistency and legibility, particularly for bivalve aquaculture. In conclusion, the system of quality linked to origin has provided an appropriate framework for supporting the implementation of sustainable bouchot mussel farming in the BMSM, thanks to the relevance and inclusiveness of the PDO labelling process and institutional support. Next, to strengthen the legitimacy of the PDO to guarantee the environmental sustainability of farming methods and increase protection on the market, more adaptive management of the PDO label is recommended.