Introduction

The marketing of bivalve molluscs is consolidating its position as a strategic asset within the European Blue Economy. In this competitive transnational ecosystem, the five countries involved in the OPTIMA project – Italy, France, Spain, Greece and Ireland – have complex supply chain architectures, 90% of which are supported by micro- enterprises with fewer than ten employees, which act as irreplaceable socio-economic pillars for coastal communities. Access and positioning in today's markets require the implementation of advanced differentiation strategies, where certifications of origin, measurable sustainability and technological innovation act as value catalysts. France represents the benchmark paradigm in this respect, with an annual production of over 80,000 tonnes of oysters enhanced through a widespread application of territorial marketing based on the adoption of stringent protection marks, such as the PGI Marennes Oléron and the Label Rouge. It favours a disintermediation model in which over 50% of volumes are allocated through direct sales channels, maximising company margins.

This approach contrasts with the hyper-productive model of Spain, a true continental giant with around 250,000 tonnes of mussels farmed on bateas in the Galician rías; in this context, the strategic use of the "Mejillón de Galicia" PDO has a dual function: on the one hand, it is an identity branding tool, and on the other, it is a fundamental protective trade barrier to stem the competitive pressure of low-cost non-EU production, such as that from Chile.

This strategy is accompanied by a powerful canning industry, capable of processing fresh produce and production surpluses, significantly extending their shelf-life. Within the Mediterranean basin, Italy, the leader in terms of clam and mussel farming volumes, is reorienting its marketing levers towards ecological integrity and local excellence, highlighting an exponential growth in organic certifications, driven by about seventy operators active in the lagoons of Veneto and Emilia-Romagna, and capitalising on absolute unique features such as the PDO of the Cozza di Scardovari.

Competitiveness in this case is strongly linked to food safety: in Italy, Spain and France, the infrastructure of shipping and purification centres (CSM) and the strict hygienic and sanitary classification of water are sine qua non requirements for access to large-scale retail trade. In terms of production that is structurally oriented towards export, Greece has historically sent between 80% and 90% of its mussel biomass to Iberian and Italian processing centres.

Despite a delay in the implementation and use of quality marks and certifications, and a bureaucratic impasse linked to the establishment of Allocated Zones for Aquaculture (AZA), the Greek sector is repositioning its offer by adopting international food safety and sustainability standards, such as ISO 22000, IFS and ASC certifications, in order to directly penetrate the lucrative Northern European markets and counter the critical issues linked to unauthorised supply chains. Similarly projected onto international markets, but with a diametrically opposed niche positioning, is the Irish sector, which takes advantage of the exceptional trophic status and purity of its coastal waters to minimise post-harvest treatments; institutionally supported by the government's Origin Green sustainability programme, Irish products – in particular oysters marketed under the "Irish Rock Oysters" brand – are successfully entering the Asian market segment. To support and validate these complex commercial narratives, the entire European supply chain is accelerating the digital transition: the implementation of blockchain platforms and smart labels now guarantees unequivocal traceability that increases consumer confidence, while the experimentation with Integrated Multitrophic Aquaculture (IMTA) systems opens up new interconnected production paradigms.

In the near future, the strategic marketing horizon for European shellfish farming lies in the monetisation and communication of ecosystem services: promoting bivalves not only as a high-quality, very low-impact protein source, but as true "environmental engineers" capable, on the one hand, of building natural reefs in which biodiversity thrives, and on the other, of ensuring active biofiltration and carbon sequestration in their shells, is the right way to reach the undecided, increase product acceptability and ensure the expansion of the sector.