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Marine Heatwaves

Understanding the Threats They Pose to Overseas Territories in the Pacific; Co-developing Decision Support Tools and Adaptation Solutions

(Coordination: Sophie Cravatte (IRD), Catherine Sabinot (IRD), Guillaume Mitta (IFREMER))

About MaHeWa

Marine heatwaves are prolonged episodes of extreme ocean temperatures that can have devastating effects on marine ecosystems, such as massive coral bleaching, coastal species mortality, and toxic algal blooms. The intensity and frequency of marine heatwaves are expected to increase in the future, posing a growing threat to island societies that heavily rely on marine resources.

MaHeWa is an interdisciplinary project funded for four years (2024–2028) by the French National Research Agency (ANR) as part of the Priority Research Program “Ocean and Climate: An Ocean of Solutions.”

This project brings together a consortium of climatologists, oceanographers, biologists, anthropologists, and economists from France and overseas institutes and universities. These teams collaborate to make significant advances in understanding the characteristics and impacts of marine heatwaves on socio-ecological systems in Pacific Overseas Territories.

MaHeWa has 2 main objectives

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1Enhancing Knowledge: Assessing the Risks of Marine Heatwaves to Socio-ecosystems

MaHeWa will study:

  • The characteristics of past and future marine heatwaves around these territories and in lagoons with contrasting geomorphologies, as well as the physical processes driving them.
  • The sensitivity and adaptability of coral reefs, the vulnerability of mariculture species, and the impact of marine heatwaves on the risk of ciguatera poisoning.
  • The socio-economic resilience of these territories to marine heatwaves, exploring how “risk cultures” designed to address extreme events are constructed, transformed, and negotiated. The project will also produce biocultural risk indicators.
2Co-developing Solutions to Mitigate Risks

Throughout the project, MaHeWa will facilitate close collaboration between scientists and the project’s partner territorial managers responsible for health and marine resources.

  • Together, they will co-create decision support tools: short-term marine heatwave alert systems, health alert networks, and long-term vulnerability maps, along with crisis management action plans and public policies on environmental and health issues.
  • Together, they will test innovative, nature-based solutions to counter habitat degradation and ensure food security, focusing on thermotolerance markers and enhancing species resilience.
  • MaHeWa will engage the public through innovative activities in close collaboration with local associations.

News

Mahewa
Argo Floats Have Arrived in Nouméa!

Innovative Tools for Understanding Marine Heatwaves

We are thrilled to announce the arrival of 5 Argo floats in New Caledonia as part of the MaHeWa-OO project (LEFE/GMMC). These high-precision instruments will enable monitoring of the vertical structure of marine heatwaves around New Caledonia.

Continue reading Argo Floats Have Arrived in Nouméa!
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Official Launch of the MaHeWa Project on Marine Heatwaves

A Kick-Off Meeting to Present Project Actions and Objectives on November 27th, in the Presence of the ANR
The MaHeWa project, focused on research and management of Marine Heatwaves (MHWs) in the Pacific, has officially secured funding from the French National Research Agency (ANR) under the PPR Ocean and Climate program (France 2030). The first launch meeting, or “kick-off meeting,” will be held on Wednesday, November 27, to outline the goals and main action lines of this innovative initiative.

Continue reading Official Launch of the MaHeWa Project on Marine Heatwaves
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Field visit with our local partners on the lagoon coast

Field visit with our local partners on the lagoon coast affected by erosion of the Ouvéa atoll in New Caledonia, April 12, 2023.