From March 20 to 29, 2025, the vessel ANTEA docked in Lifou, Loyalty Islands, New Caledonia, for the first mission of Work Package 2 (WP2) of the MaHeWa project.
Overall Goal: To study coral resilience and enhance management capabilities against marine heatwaves, a vital challenge in the context of climate change. A scientific team explored 10 reefs across two remote sites, including key areas like Santal Bay, Cap Aimé Martin, and Chateaubriand Bay. The team comprised Gregory Lasne (Marine Biocenosis), Magalie Boussion (ENTROPIE, IRD), Riccardo Rodolfo-Metalpa (ENTROPIE, IRD), Jérémie Vidal-Dupiol (IHPE, Ifremer), and Fanny Houlbrèque (ENTROPIE, IRD).
During the mission, 305 colonies of three coral species were meticulously tagged, georeferenced, and sampled, with 3 cm fragments collected under official and customary authorizations.
Diver sampling corals
Tagged coloniesThis work is part of Module 2 of Task 2.1, “Map Coral Thermal Tolerance,” aiming to map coral tolerance to marine heatwaves (MHWs), which vary due to intrinsic factors (e.g., coral acclimatization or adaptation) and extrinsic factors (e.g., environmental conditions).
The team targeted three ecologically significant species, using (epi)genomic markers like DNA methylation variations and SNPs linked to thermal tolerance, alongside a physiological marker.
The aim is to provide local communities and managers with practical tools to quickly assess coral resistance to thermal stress and improve restoration methods, particularly at the Lifou coral farm.
Samples collected aboard ANTEA will be analyzed in Nouméa by Julien De Lorgeril (ENTROPIE, Ifremer). The data will support a doctoral project starting in November 2025 and contribute to practical outcomes, such as vulnerability maps (WP4.2) to prioritize reef protection and the selection of heat-tolerant corals for restoration projects (WP5.1).
On March 20, upon arrival in Chateaubriand Bay, 10 representatives, including PIL staff and customary authorities, joined a customary ceremony and mission presentation aboard, fostering ties with local stakeholders. This mission is a pivotal step in understanding and preserving coral ecosystems amid climate challenges.
