Resilience of cold-water coral holobionts to thermal stress

• Published in: Proceedings of the Royal Society B: Biological Sciences
• Main Authors: Chapron, Leila, Galand, Pierre, Pruski, Audrey, Peru, Erwan, Vétion, Gilles, Robin, Sarah, Lartaud, Franck
• Other Authors: Laboratoire d'Ecogéochimie des environnements benthiques (LECOB), Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Observatoire océanologique de Banyuls (OOB), Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2021
• Subjects: [SDV]Life Sciences [q-bio]; Lophelia pertusa
• Online Access: https://hal.archives-ouvertes.fr/hal-03819819; https://doi.org/10.1098/rspb.2021.2117

International audience <jats:p> Cold-water corals are threatened by global warming, especially in the Mediterranean Sea where they live close to their upper known thermal limit (i.e. 13°C), yet their response to rising temperatures is not well known. Here, temperature effects on <jats:italic>Lophelia pertusa</jats:italic> and <jats:italic>Madrepora oculata</jats:italic> holobionts (i.e. the host and its associated microbiome) were investigated. We found that at warmer seawater temperature (+2°C), <jats:italic>L. pertusa</jats:italic> showed a modification of its microbiome prior to a change in behaviour, leading to lower energy reserves and skeletal growth, whereas <jats:italic>M. oculata</jats:italic> was more resilient. At extreme temperature (+4°C), both species quickly lost their specific bacterial signature followed by lower physiological activity prior to death. In addition, our results showing the holobionts' negative response to colder temperatures (−3°C), suggest that Mediterranean corals live close to their thermal optimum. The species-specific response to temperature change highlights that global warming may affect dramatically the main deep-sea reef-builders, which would alter the associated biodiversity and related ecosystem services. </jats:p>