Responses of a coral reef shark acutely exposed to ocean acidification conditions

• Published in: Coral Reefs
• Main Authors: Rummer, Jodie, Bouyoucos, Ian, Mourier, Johann, Nakamura, Nao, Planes, Serge
• Other Authors: James Cook University (JCU), Centre de recherches insulaires et observatoire de l'environnement (CRIOBE), Université de Perpignan Via Domitia (UPVD)-École Pratique des Hautes Études (EPHE), Université Paris Sciences et Lettres (PSL)-Université Paris Sciences et Lettres (PSL)-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'Excellence CORAIL (LabEX CORAIL), Institut de Recherche pour le Développement (IRD)-Université des Antilles et de la Guyane (UAG)-École des hautes études en sciences sociales (EHESS)-École Pratique des Hautes Études (EPHE), Université Paris Sciences et Lettres (PSL)-Université Paris Sciences et Lettres (PSL)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Université de La Réunion (UR)-Université de la Polynésie Française (UPF)-Université de la Nouvelle-Calédonie (UNC)-Institut d'écologie et environnement-Université des Antilles (UA), MARine Biodiversity Exploitation and Conservation (UMR MARBEC), Institut de Recherche pour le Développement (IRD)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS), This research was funded by the Australian Research Council (ARC; PDE150101266), the L’Oréal-United Nations Educational, Scientific and Cultural Organisation (UNESCO) Women in Science Foundation, an Institut des Récifs Coralliens du Pacifique Fellowship (J.L.R.), an ARC Super Science Fellowship (J.L.R.), a James Cook University Postgraduate Research Scholarship (I.A.B.), an Institute for Research and Development postdoctoral fellowship (J.M.), and the ARC Centre of Excellence for Coral Reef Studies (J.L.R., I.A.B).
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2020
• Subjects: Acid–base; Blacktip reef shark; Haematology; Climate change; Oxygen uptake rates; Physiology; [SDE]Environmental Sciences; Ocean acidification
• Online Access: https://hal.science/hal-03368786; https://hal.science/hal-03368786/document; https://hal.science/hal-03368786/file/s00338-020-01972-0.pdf; https://doi.org/10.1007/s00338-020-01972-0

International audience Anthropogenic ocean acidification (OA) is a threat to coral reef fishes, but few studies have investigated responses of high-trophic-level predators, including sharks. We tested the effects of 72-hr exposure to OA-relevant elevated partial pressures of carbon dioxide (pCO2) on oxygen uptake rates, acid–base status, and haematology of newborn tropical blacktip reef sharks (Carcharhinus melanopterus). Acute exposure to end-of-century pCO2 levels resulted in elevated haematocrit (i.e. stress or compensation of oxygen uptake rates) and blood lactate concentrations (i.e. prolonged recovery) in the newborns. Conversely, whole blood and mean corpuscular haemoglobin concentrations, blood pH, estimates of standard and maximum metabolic rates, and aerobic scope remained unaffected. Taken together, newborn blacktip reef sharks appear physiologically robust to end-of-century pCO2 levels, but less so than other, previously investigated, tropical carpet sharks. Our results suggest peak fluctuating pCO2 levels in coral reef lagoons could still physiologically affect newborn reef sharks, but studies assessing the effects of long-term exposure and in combination with other anthropogenic stressors are needed.