Near-future pH conditions severely impact calcification, metabolism and the nervous system in the pteropod Heliconoides inflatus

• Published in: Global Change Biology
• Main Authors: Moya, Aurelie, Howes, Ella L, Lacoue-Labarthe, Thomas, Forêt, Sylvain, Hanna, Bishoy, Medina, Mónica, Munday, Philip L, Ong, Jue-Sheng, Teyssié, Jean-Louis, Torda, Gergely, Watson, Sue-Ann, Miller, David J, Bijma, Jelle, Gattuso, Jean-Pierre
• Other Authors: ARC Centre of Excellence for Coral Reef Studies (CoralCoE), James Cook University (JCU), Laboratoire d'océanographie de Villefranche (LOV), Observatoire océanologique de Villefranche-sur-mer (OOVM), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS), Alfred-Wegener-Institut, Helmholtz-Zentrum für Polar- und Meeresforschung (AWI), LIttoral ENvironnement et Sociétés - UMRi 7266 (LIENSs), Université de La Rochelle (ULR)-Centre National de la Recherche Scientifique (CNRS), Marine Environment Laboratories Monaco (IAEA-MEL), International Atomic Energy Agency Vienna (IAEA), Australian National University (ANU), Pennsylvania State University (Penn State), Penn State System, Australian Institute of Marine Science Townsville (AIMS Townsville), Australian Institute of Marine Science (AIMS), Sciences Po (Sciences Po)
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2016
• Subjects: calcification; GABAA receptor; gene expression; global change biology; nervous system; ocean acidification; pteropods; respiration; RNA sequencing; [SDE.BE]Environmental Sciences/Biodiversity and Ecology; Ocean acidification
• Online Access: https://hal.sorbonne-universite.fr/hal-01346620; https://hal.sorbonne-universite.fr/hal-01346620/document; https://hal.sorbonne-universite.fr/hal-01346620/file/Moya_2016_Near%E2%80%90future_pH.pdf; https://doi.org/10.1111/gcb.13350

International audience Shelled pteropods play key roles in the global carbon cycle and food webs of various ecosystems. Their thin external shell is sensitive to small changes in pH, and shell dissolution has already been observed in areas where aragonite saturation state is ~1. A decline in pteropod abundance has the potential to disrupt trophic networks and directly impact commercial fisheries. Therefore, it is crucial to understand how pteropods will be affected by global environmental change, particularly ocean acidification. In this study, physiological and molecular approaches were used to investigate the response of the Mediterranean pteropod, Heliconoides inflatus, to pH values projected for 2100 under a moderate emissions trajectory (RCP6.0). Pteropods were subjected to pHT 7.9 for 3 days, and gene expression levels, calcification and respiration rates were measured relative to pHT 8.1 controls. Gross calcification decreased markedly under low pH conditions, while genes potentially involved in calcification were up-regulated, reflecting the inability of pteropods to maintain calcification rates. Gene expression data imply that under low pH conditions, both metabolic processes and protein synthesis may be compromised, while genes involved in acid–base regulation were up-regulated. A large number of genes related to nervous system structure and function were also up-regulated in the low pH treatment, including a GABAA receptor subunit. This observation is particularly interesting because GABAA receptor disturbances, leading to altered behavior, have been documented in several other marine animals after exposure to elevated CO2. The up-regulation of many genes involved in nervous system function suggests that exposure to low pH could have major effects on pteropod behavior. This study illustrates the power of combining physiological and molecular approaches. It also reveals the importance of behavioral analyses in studies aimed at understanding the impacts of low pH on marine animals.