The Workshop on Bay of Biscay and Iberian Coast Aquaculture Overview (WKBoBICAO) was established to assemble and synthesize aquaculture related data and information and to inform the aquaculture overview for this ecoregion.The geographic extent of the Bay of Biscay and Iberian Coast ecoregion is extensive and ranges from southern Brittany in France through northern and northwestern Spain, it includes the entire coastline of Portugal (mainland) and culminates in the Gulf of Cadiz in southern Spain. It covers a wide range of habitat types and climatic conditions, which has a bearing on the types of aquaculture practiced in the ecoregion.Aquaculture is practised throughout much of the ecoregion. Both intertidal and subtidal waters are utilized in addition to terrestrial pond culture. The aquaculture production within the ecoregion is dominated by shellfish which are largely produced in France (Oysters and Mussels) and Spain (mussels). Portugal production comprises a mix of shellfish, finfish and crustacean culture and while lower in terms of tonnage produced and value than the other countries.In 2021, the aquaculture sector in the ecoregion reached 310,000 Tons produced and €775 million in value. Shellfish are the most produced in the ecoregion and contribute to almost 75% of total value. Crustacean production in Spain and shellfish and finfish production in Portugal show a clear increase since 2010, other species are static in terms of production. Spain produces the greatest tonnage but is second to France in terms of economic value. A number of other species (e.g. finfish, polychaete worms for bait) in addition macroalgae are also grown at smaller scales throughout the ecoregion.In the ecoregion, aquaculture licencing, regulation and policy are the responsibility of the member state. While overarching policy is defined at the EU level, licensing can be different in the various countries. In Portugal a single federal body is responsible for licensing. In Spain and France, regional or local authorities are responsible for issuing licences and national approvals from relevant Ministries must be sought if public waters are to be used. It is however, acknowledged that EU legislation provides an overarching framework for important regulatory aspects including assessment and monitoring, among others, of environmental (e.g. EIA), food safety and fish health considerations. However, during licencing consultation submissions from other authorities are often required in addition to challenges presented under other legislation (e.g. Natura), which can add to the complexity of the process and lead to delays in the decision-making. Marine Spatial planning, whereby specific areas are designated for aquaculture practices, has been identified as mechanism to reduce delay of licensing decisions. Yet, conflicts with other newly developing sectors (e.g. offshore renewables) is inevitable.Monitoring of shellfish culture practices are primarily focused upon food safety considerations, e.g. biotoxin and faecal coliform analysis. In addition, all species are subject to extensive animal health regulations that are wide ranging and derives primarily from EU legislation. Some persistent issues relate to ongoing bacterial (Vibrio) infections in shellfish hatcheries and mortalities associated with pathogens (e.g. OsHV-1) during grow-out. These represent a major challenge to the industry. Poor mussel recruitment in the wild is also leading to shortages of stock for on-growing.Given the dominance of shellfish culture in the ecoregion, the primary environmental effects relate to interactions with habitats and species which might be measured via assessing ecological carrying capacity. In addition to some emerging contaminants that might affect aquaculture species, aquaculture as a source of microplastics is an increasing cause of concern. The ability of shellfish to bioaccumulate nano-plastics is also considered a risk.Small production units predominate the aquaculture sector within the ecoregion. As identified elsewhere, employment in the sector in all countries is considered modest, however, the importance of these (even part-time) roles in more isolated rural areas is acknowledged.In terms of social interactions given the historical and cultural importance of shellfish farming in the ecoregion the sector has greater social licence and as such there is more a tolerance and less challenge to this sector from the wider public. It is apparent that finfish enterprises face considerably more scrutiny during licensing and subsequently. All aquaculture sectors are challenged by decreasing water quality as a result of terrestrial activities.A number of issues are identified which may affect aquaculture development and are considered common across the ecoregion. Of particular concern are the potential effects or emerging pollutants (associated with industrial development). The impact of climate change on shellfish recruitment and disease proliferation in culture stock is also a concern.