Atmospheric carbon dioxide (CO2) emissions are continuously increasing due to the growing anthropogenic activities, causing a rise in the sea-surface partial pressure of CO2 (pCO2). This change in turn leads to decreased ocean pH, named ocean acidification, and affects the carbonate-silicate cycle. Such modification of seawater chemistry also affects the physiology and behaviour of marine organisms, impacting their metabolism, growth and development during vulnerable early-life stages. Among them, the embryo of the cephalopod cuttlefish develops for ~2 months) in encapsulated eggs with harsh conditions of hypoxia and hypercapnia, potentially worsen by the environmental ocean acidification. In this study, the development and the growth of early-life stages of Sepia officinalis were followed during the whole embryonic developmental period up to 10 days post-hatchling juveniles. Embryos and juveniles were exposed to five elevated pCO2 conditions controlled with a continuous pH-stat system (pH 8.08; 7.82; 7.65; 7.54; 7.43). Metabolites were determined in ready-to-hatch embryos, just hatched embryos and 10 d-old juveniles, using a 1H nuclear magnetic resonance (NMR) spectroscopy as a platform for untargeted metabolomics analysis. Consistent with previous studies, our results showed longer embryonic development and decreased hatching success at the lowest pH, but no effect on juvenile weight upon hatching. Metabolomics analysis revealed a metabolic depression in embryos reared at pH 7.43, non-monotonic changes to pH in 10 d-old juveniles, and no clear pH effect in newly hatched juvenile cuttlefish, likely due to the metabolic stress associated with hatching. Those results reveal possible effect of ocean acidification on the cuttlefish recruitment.

Minet A., Melvin S., Taylor A., Lefrancois C., Bustamante P., Metian M. & Lacoue-Labarthe T., 2022. Metabolic effect of ocean acidification on common cuttlefish Sepia officinalis early stages. ResearchGate. Article.