Projected pH reductions by 2100 might put deep North Atlantic biodiversity at risk

• Published in: Biogeosciences
• Main Authors: Gehlen, Marion, Séférian, Roland, Jones, D. O. B., Roy, Tilla, Roth, R., Barry, J., Bopp, Laurent, Doney, Scott C., Dunne, John P., Heinze, Christoph, Joos, Fortunat, Orr, James C., Resplandy, Laure, Segschneider, Joachim, Tjiputra, Jerry
• Other Authors: Laboratoire des Sciences du Climat et de l'Environnement Gif-sur-Yvette (LSCE), Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ), Modelling the Earth Response to Multiple Anthropogenic Interactions and Dynamics (MERMAID), Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ), Groupe d'étude de l'atmosphère météorologique (CNRM-GAME), Institut national des sciences de l'Univers (INSU - CNRS)-Météo France-Centre National de la Recherche Scientifique (CNRS), National Oceanography Centre Southampton (NOC), University of Southampton, Laboratoire d'Océanographie et du Climat : Expérimentations et Approches Numériques (LOCEAN), Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Muséum national d'Histoire naturelle (MNHN)-Institut Pierre-Simon-Laplace (IPSL (FR_636)), École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris Diderot - Paris 7 (UPD7)-École polytechnique (X)-Centre National d'Études Spatiales Toulouse (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7)-École polytechnique (X)-Centre National d'Études Spatiales Toulouse (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Climate and Environmental Physics Bern (CEP), Physikalisches Institut Bern, Universität Bern Bern -Universität Bern Bern, Monterey Bay Aquarium Research Institute (MBARI), Monterey Bay Aquarium Research Institute, Department of Marine Chemistry and Geochemistry (WHOI), Woods Hole Oceanographic Institution (WHOI), NOAA Geophysical Fluid Dynamics Laboratory (GFDL), National Oceanic and Atmospheric Administration (NOAA), Bjerknes Centre for Climate Research (BCCR), Department of Biological Sciences Bergen (BIO / UiB), University of Bergen (UiB)-University of Bergen (UiB), Geophysical Institute Bergen (GFI / BiU), University of Bergen (UiB), Uni Research Climate, Uni Research Ltd, Max Planck Institute for Meteorology (MPI-M), Max-Planck-Gesellschaft, ANR-10-LABX-0018,L-IPSL,LabEx Institut Pierre Simon Laplace (IPSL): Understand climate and anticipate future changes(2010), European Project: 211384,EC:FP7:ENV,FP7-ENV-2007-1,EPOCA(2008), European Project: 264879,EC:FP7:ENV,FP7-ENV-2010,CARBOCHANGE(2011), European Project: 312979,EC:FP7:INFRA,FP7-INFRASTRUCTURES-2012-1,IS-ENES2(2013)
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2014
• Subjects: [SDE.BE]Environmental Sciences/Biodiversity and Ecology; [SDV.EE.BIO]Life Sciences [q-bio]/Ecology; environment/Bioclimatology; [SDU.STU.OC]Sciences of the Universe [physics]/Earth Sciences/Oceanography; North Atlantic; Ocean acidification
• Online Access: https://hal.archives-ouvertes.fr/hal-01436121; https://hal.archives-ouvertes.fr/hal-01436121/document; https://hal.archives-ouvertes.fr/hal-01436121/file/bg-11-6955-2014.pdf; https://doi.org/10.5194/bg-11-6955-2014

International audience This study aims to evaluate the potential for impacts of ocean acidification on North Atlantic deep-sea ecosystems in response to IPCC AR5 Representative Concentration Pathways (RCPs). Deep-sea biota is likely highly vulnerable to changes in seawater chemistry and sensitive to moderate excursions in pH. Here we show, from seven fully coupled Earth system models, that for three out of four RCPs over 17 % of the seafloor area below 500 m depth in the North Atlantic sector will experience pH reductions exceeding −0.2 units by 2100. Increased stratification in response to climate change partially alleviates the impact of ocean acidification on deep benthic environments. We report on major pH reductions over the deep North Atlantic seafloor (depth > 500 m) and at important deep-sea features, such as seamounts and canyons. By 2100, and under the high CO 2 scenario RCP8.5, pH reductions exceeding −0.2 (−0.3) units are projected in close to 23 % (∼ 15 %) of North Atlantic deep-sea canyons and ∼ 8 % (3 %) of seamounts-including seamounts proposed as sites of marine protected areas. The spatial pattern of impacts reflects the depth of the pH perturbation and does not scale linearly with atmospheric CO 2 concentration. Impacts may cause negative changes of the same magnitude or exceeding the current target of 10 % of preservation of marine biomes set by the convention on biological diversity, implying that ocean acidification may offset benefits from conservation/management strategies relying on the regulation of resource exploitation.