Resilience to ocean acidification: decreased carbonic anhydrase activity in sea anemones under high pCO(2) conditions

• Published in: Marine Ecology Progress Series
• Main Authors: Ventura, Patricia, Jarrold, Michael D., Merle, Pierre-Laurent, Barnay-Verdier, Stephanie, Zamoum, Thamilla, Rodolfo-Metalpa, Riccardo, Calosi, Piero, Furla, Paola
• Other Authors: Symbiose Marine (SM), Evolution Paris Seine, Université des Antilles et de la Guyane (UAG)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Université Nice Sophia Antipolis (. - 2019) (UNS), COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Centre National de la Recherche Scientifique (CNRS)-Université des Antilles et de la Guyane (UAG)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Université Nice Sophia Antipolis (. - 2019) (UNS), COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Centre National de la Recherche Scientifique (CNRS), French Ministere de l'Enseignement superieur et de la Recherche 513-EDSFA021-2013, EU-FP7 MedSeA project 265103, NERC OA Research Programme Grant, NSERC Discovery Grant
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2016
• Subjects: Dissolved inorganic carbon uptake; Carbonic anhydrase; Ocean acidification; Plasticity; CO2 vent; Anemonia viridis; [SDV.BID.EVO]Life Sciences [q-bio]/Biodiversity/Populations and Evolution [q-bio.PE]
• Online Access: https://hal.archives-ouvertes.fr/hal-01546163; https://doi.org/10.3354/meps11916

International audience Non-calcifying photosynthetic anthozoans have emerged as a group that may thrive under high carbon dioxide partial pressure (pCO(2)) conditions via increased productivity. However, the physiological mechanisms underlying this potential success are unclear. Here we investigated the impact of high pCO(2) on the dissolved inorganic carbon (DIC) use in the temperate sea anemone Anemonia viridis. We assessed the impacts of long-term exposure to high pCO(2), i.e. sampling in situ natural CO2 vents (Vulcano, Italy), and short-term exposure, i.e. during a 3 wk controlled laboratory experiment. We focused on photo-physiological parameters (net photosynthesis rates, chlorophyll a content and Symbiodinium density) and on carbonic anhydrase (CA) activity, an enzyme involved in the energy-demanding process of DIC absorption. Long-term exposure to high pCO(2) had no impact on Symbiodinium density and chlorophyll a content. In contrst, short-term exposure to high pCO(2) induced a significant reduction in Symbiodinium density, which together with unchanged net photosynthesis resulted in the increase of Symbiodinium productivity per cell. Finally, in both in situ long-term and laboratory short-term exposure to high pCO(2), we observed a significant decrease in the CA activity of sea anemones, suggesting a change in DIC use (i.e. from an HCO3- to a CO2 user). This change could enable a shift in the energy budget that may increase the ability of non-calcifying photosynthetic anthozoans to cope with ocean acidification.