Ocean pH fluctuations affect mussel larvae at key developmental transitions

• Published in: Proceedings of the Royal Society B: Biological Sciences
• Main Authors: Kapsenberg, Lydia, Miglioli, Angelica, Bitter, Mark C., Tambutté, Eric, Dumollard, Rémi, Gattuso, Jean-Pierre
• Other Authors: National Science Foundation (US), European Commission, Department of Education (US), Università degli studi di Genova, Observatoire Océanologique de Villefranche sur Mer
• Format: Article in Journal/Newspaper
• Language: unknown
• Published: Royal Society (Great Britain) 2018
• Subjects: Ocean acidification; pH fluctuations; Mollusc; Development; Shell field; Trochophore; Genova
• Online Access: http://hdl.handle.net/10261/211328; https://doi.org/10.1098/rspb.2018.2381; https://doi.org/10.13039/501100004702; https://doi.org/10.13039/100000001; https://doi.org/10.13039/501100000780; https://doi.org/10.13039/100000138

10 pages, 4 figures, supplementary material https://dx.doi.org/10.6084/m9.figshare.c.4325828.-- Data are archived on BCO-DMO, https://www.bco-dmo.org/project/720349 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 (pHT 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 This research was funded by the US National Science Foundation (NSF; OCE-1521597 to L.K.). L.K. was also supported by the European Commission Horizon 2020 Marie Skłodowska-Curie Action (No. 747637). M.C.B. was supported by US Department of Education (Grant No. 200A150101) and NSF Graduate Research Fellowship (No. 1000198423). A.M. was supported by an Erasmus+ traineeship scholarship (University of Genova) and by the ...