Ocean Acidification and the End-Permian Mass Extinction: To What Extent does Evidence Support Hypothesis?

• Published in: Geosciences
• Main Authors: Kershaw, Stephen, Crasquin, Sylvie, Li, Yue, Collin, Pierre-Yves, Forel, Marie-Béatrice
• Other Authors: Institute for the Environment Uxbridge, Brunel University London Uxbridge, Centre de recherche sur la Paléobiodiversité et les Paléoenvironnements (CR2P), Muséum national d'Histoire naturelle (MNHN)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS), Telecom Bretagne - Rennes, Télécom Bretagne, Biogéosciences UMR 6282 (BGS), Université de Bourgogne (UB)-Centre National de la Recherche Scientifique (CNRS), State Key Laboratory of Geological Processes and Mineral Resources Wuhan (GPMR), China University of Geosciences Wuhan (CUG)
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2012
• Subjects: ocean acidification; end-Permian extinction; microbialite; ocean buffer; stylolite; [SDU.STU.PG]Sciences of the Universe [physics]/Earth Sciences/Paleontology; Ocean acidification
• Online Access: https://mnhn.hal.science/mnhn-01725594; https://mnhn.hal.science/mnhn-01725594/document; https://mnhn.hal.science/mnhn-01725594/file/2012bKershawetal.pdf; https://doi.org/10.3390/geosciences2040221

International audience Ocean acidification in modern oceans is linked to rapid increase in atmospheric CO 2 , raising concern about marine diversity, food security and ecosystem services. Proxy evidence for acidification during past crises may help predict future change, but three issues limit confidence of comparisons between modern and ancient ocean acidification, illustrated from the end-Permian extinction, 252 million years ago: (1) problems with evidence for ocean acidification preserved in sedimentary rocks, where proposed marine dissolution surfaces may be subaerial. Sedimentary evidence that the extinction was partly due to ocean acidification is therefore inconclusive; (2) Fossils of marine animals potentially affected by ocean acidification are imperfect records of past conditions; selective extinction of hypercalcifying organisms is uncertain evidence for acidification; (3) The current high rates of acidification may not reflect past rates, which cannot be measured directly, and whose temporal resolution decreases in older rocks. Thus large increases in CO 2 in the past may have occurred over a long enough time to have allowed assimilation into the oceans, and acidification may not have stressed ocean biota to the present extent. Although we acknowledge the very likely occurrence of past ocean acidification, obtaining support presents a continuing challenge for the Earth science community. OPEN ACCESS Geosciences 2012, 2 222