Rising Marine Heatwaves: Assessing the Current Dynamics and Health Status of Paramuricea clavata (Risso, 1826) Populations in the Upper Mesophotic Zone of the French Mediterranean

Marine heatwaves (MHWs) have been intensifying in frequency and magnitude, posing significant threats to marine biodiversity, particularly to sessile benthic species such as the red gorgonian, Paramuricea clavata. This study examines the status of P. clavata populations in the upper mesophotic zone (30 m – 60 m) of the French Mediterranean, a depth range that may offer partial refuge from MHW events. By analyzing data from more than 40 populations, we evaluate the health, density, and growth dynamics of these populations in the context of rising temperature anomalies and anthropogenic pressures. The findings provide insights into the vulnerability of mesophotic ecosystems and underscore the need for targeted conservation strategies in collaboration with Marine Protected Areas to mitigate the impacts of climate change on these critical habitats and support sustainable management initiatives.