Ocean pH fluctuations affect mussel larvae at key developmental transitions

• Published in: Proceedings of the Royal Society B: Biological Sciences
• Main Authors: Kapsenberg, L., Miglioli, A., Bitter, M., C., Tambutté, E., Dumollard, R., Gattuso, Jean-Pierre
• Other Authors: Laboratoire d'océanographie de Villefranche (LOV), Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Institut de la Mer de Villefranche (IMEV), Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Università degli studi di Genova = University of Genoa (UniGe), University of Chicago, Centre Scientifique de Monaco (CSM), Laboratoire de Biologie du Développement de Villefranche sur mer (LBDV), Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Institut de la Mer de Villefranche (IMEV), Sciences Po (Sciences Po)
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2018
• Subjects: ocean acidification; pH fluctuations; mollusc; shell field; development; trochophore; [SDV.BDD.EO]Life Sciences [q-bio]/Development Biology/Embryology and Organogenesis; [SDV.EE.BIO]Life Sciences [q-bio]/Ecology; environment/Bioclimatology; [SDU.STU.OC]Sciences of the Universe [physics]/Earth Sciences/Oceanography; [SDU.ENVI]Sciences of the Universe [physics]/Continental interfaces; environment; [SDU.OCEAN]Sciences of the Universe [physics]/Ocean; Atmosphere; [SDE.ES]Environmental Sciences/Environment and Society; [SDE.MCG]Environmental Sciences/Global Changes; Ocean acidification
• Online Access: https://hal.sorbonne-universite.fr/hal-02123964; https://hal.sorbonne-universite.fr/hal-02123964/document; https://hal.sorbonne-universite.fr/hal-02123964/file/rspb.2018.2381.pdf; https://doi.org/10.1098/rspb.2018.2381

International audience Coastal marine ecosystems experience dynamic fluctuations in seawater carbonate chemistry. The importance of this variation in the context of ocean acidification requires knowing what aspect of variability biological processes respond to. We conducted four experiments (ranging from 3 to 22 days) with different variability regimes (pH T 7.4-8.1) assessing the impact of diel fluctuations in carbonate chemistry on the early development of the mussel Mytilus galloprovincialis. Larval shell growth was consistently correlated to mean exposures, regardless of variability regimes, indicating that calcification responds instantaneously to seawater chemistry. Larval development was impacted by timing of exposure, revealing sensitivity of two developmental processes: development of the shell field, and transition from the first to the second larval shell. Fluorescent staining revealed developmental delay of the shell field at low pH, and abnormal development thereof was correlated with hinge defects in D-veligers. This study shows, for the first time, that ocean acidification affects larval soft-tissue development, independent from calcification. Multiple developmental processes additively underpin the teratogenic effect of ocean acidification on bivalve larvae. These results explain why trochophores are the most sensitive life-history stage in marine bivalves and suggest that short-term variability in carbonate chemistry can impact early larval development.