Marine Heatwave Response Management Workshop, March 28, 2025
On March 28, 2025, IRD in Nouméa hosted the first collective intelligence workshop as part of the MaHeWa project, dedicated to managing marine heatwaves in New Caledonia. The main objective of the day was to address two key questions: what should be done when an imminent marine heatwave is announced? and what are the seven priority themes to include in a collective strategy? More specifically, the workshop aimed to: inform stakeholders about marine heatwaves and their impacts, identify actions to implement, determine barriers and levers for intervention, and co-develop a management unit and a tailored communication plan.
Bringing together around thirty participants from diverse backgrounds—scientists, institutional representatives, civil society actors, fishing professionals, associations, and customary authorities—this day laid the groundwork for a coordinated response to this concerning environmental phenomenon.
The event began with a friendly breakfast, followed by a free-listing exercise via QR code to gather participants’ initial ideas about marine heatwaves. After a scientific introduction on current knowledge of marine heatwaves and their impacts, an icebreaker activity called “Three Things About Me” helped participants get to know each other while fostering a collaborative atmosphere.
The morning continued with the presentation of a realistic scenario in the form of a video simulating an alert bulletin announcing an imminent marine heatwave. Participants then reflected individually for 10 minutes (one idea per sticky note) on the concrete impacts of this announcement on their work and daily lives. These ideas were grouped by similarity, resulting in the emergence of six priority themes:
Communication / Theme: Develop information tools (social media, radio, posters) and tailored messages to alert populations and relevant stakeholders.
Research-Aquaculture: Deepen understanding of the impacts of marine heatwaves on ecosystems and aquaculture activities while identifying adaptive practices.
Actions to Preserve: Implement measures to protect marine ecosystems, such as reducing anthropogenic pressures or creating refuge zones.
Actions to Understand: Strengthen research and monitoring of marine heatwaves to better anticipate their occurrences and impacts.
Restore, Transfer Results: Share acquired knowledge with communities and decision-makers to promote concrete ecosystem restoration actions.
Health, Leisure, Tourism: Assess the impacts of marine heatwaves on recreational and tourism activities and propose alternatives to minimize economic and social losses.
Example of a thematic action sheet. Photo credit: J-M Boré
Each group, composed of a mix of profiles (science, institutions, civil society), identified levers, barriers, and intervention priorities, with particular attention to the feasibility of proposed measures using an Impact/Feasibility matrix.
Working group. Photo credit: J-M Boré
The afternoon focused on co-constructing a management unit and a communication plan. Participants split into subgroups to work either on establishing the unit (roles, responsibilities, organizational structure) or on communication methods (tools, channels, timelines), building on the action sheets produced in the morning.
The discussions, enriched by diverse perspectives, led to operational proposals presented in plenary during dynamic feedback sessions. The day concluded with a collective reflection on the experience through a “mood weather” activity and a group photo.
This day highlighted the value of a participatory approach. By bringing together scientific expertise, local knowledge, and operational skills, the MaHeWa workshop laid the foundation for a collective strategy to address the challenges of marine heatwaves in New Caledonia.
