First Successful Mission to Map Coral Thermal Tolerance in Lifou

From March 20 to 29, 2025, the vessel ANTEA docked in Lifou, in the Loyalty Islands subdivision of New Caledonia, for the first mission of Work Package 2 (WP2) of the MaHeWa project.

Overall Objective: To study coral resilience and enhance our management capabilities in the face of marine heatwaves, a critical issue in the context of climate change. A scientific team set out to explore 10 reefs across two distant sites, including key areas such as Santal Bay, Cap Aimé Martin, and Chateaubriand Bay. The team consisted of Gregory Lasne (Marine Biocenosis), Magalie Boussion (ENTROPIE, IRD), Riccardo Rodolfo-Metalpa (ENTROPIE, IRD), Jérémie Vidal-Dupiol (IHPE, Ifremer), and Fanny Houlbrèque (ENTROPIE, IRD).

During this mission, 305 colonies of three coral species were carefully tagged, georeferenced, and sampled, with 3 cm fragments collected under official and customary authorizations.

Part of Module 2 of Task 2.1 “Map coral thermal tolerance,” this work aims to map coral tolerance to marine heatwaves, which varies due to internal (adaptation) and external (environmental) factors. The team studied three key species using genetic and physiological markers.

Samples collected aboard ANTEA will be analyzed in the lab and support a doctoral project starting in November 2025. This will help create vulnerability maps to prioritize reef protection and select heat-tolerant corals for ecological restoration.

On March 20, upon arrival in Chateaubriand Bay, 10 representatives, including PIL staff and customary authorities, joined a customary ceremony and mission presentation aboard, strengthening ties with local stakeholders. This mission is a key step in understanding and preserving coral ecosystems amid climate challenges.