The French public debates on maritime spatial planning: an innovative public consultation to disseminate knowledge on offshore wind energy and marine biodiversity?

France initiated in 2023 a revision of its maritime spatial planning policy objectives at national level (the National Strategy for the Sea and the Coast) and regional level (four Maritime Spatial Plans - MSP plans - for 4 maritime regions). MSP plans are the key documents for implementing French maritime policy. Through them, the French government intends to integrate several public policies linked to the sustainable blue economy: “contributing to the sustainable development of maritime economy sectors (offshore energy, maritime transport, fishing, aquaculture...) and preserving the marine and coastal environment, including resilience to the impacts of climate change”. At the same time, the French government speeds up the implementation of offshore wind farms and strictly marine protected areas in order to meet EU targets. Ambitious targets have been set at national and regional level which will be incorporated into the new MSP plans.Public consultation, a legal requirement is at the heart of the process. Several public participation tools are used bringing together stakeholders and citizens. Public debates are one of the most emblematic. Conducted by an independent authority (the National Commission of Public Debate - CNDP), the aim of public debates is not to reach a general agreement on a specific project, but to inform stakeholders and citizens about all the issues relating to the project and give them a space to ask questions and debate.Four public debates associated with the revision of the objectives of the four MSP plans were organised simultaneously by the CNDP over a six-month period between November 2023 and April 2024. They addressed more specifically two main questions:Identifying areas for the development of offshore wind farms to reach 45 GW installed by 2050, including a mapping for each region (with maritime and land areas for the installation of offshore renewable energy production facilities); Identify strictly marine protected areas for 10% of the waters under French jurisdiction, including a map of these areas in each region. Various tools were used. Some are traditional tools (a website, online and in-person meetings, a platform for collecting written contributions, etc.), others are more innovative (streaming using Twitch and YouTube, a digital tool for finding out about MSP issues, participatory mapping workshops on offshore wind power and marine biodiversity protection, etc.).Using the example of public debates organized in the Mediterranean and Brittany regions, the aim of this paper is to analyze the dissemination of knowledge between all audiences (stakeholders, citizens, researchers, maritime sectors, public authorities). On the basis of the participatory tools, materials, resources and players mobilized during the public debates, we investigate: (i) how the knowledge presented in the debate is structured and what it reveals about our relationship with the marine environment; (ii) how information is mobilized to inform the public with the aim of building, through public debate, the legitimacy of decisions linked to maritime planning; (iii) the effectiveness of the approach developed by the CNDP for these MSP public debates compared with other public participation formats, such as citizens' conventions.