Comeau S. auteur aut IRD Cornwall C. E. auteur aut IRD Shlesinger T. auteur aut IRD Hoogenboom M. auteur aut IRD Mana R. auteur aut IRD McCulloch M. T. auteur aut IRD Rodolfo-Metalpa Riccardo auteur aut IRD text journalArticle eng text/pdf born digital access Coral reefs are iconic ecosystems with immense ecological, economic and cultural value, but globally their carbonate-based skeletal construction is threatened by ocean acidification (OA). Identifying coral species that have specialised mechanisms to maintain high rates of calcification in the face of declining seawater pH is of paramount importance in predicting future species composition, and growth of coral reefs. Here, we studied multiple coral species from two distinct volcanic CO2 seeps in Papua New Guinea to assess their capacity to control their calcifying fluid (CF) chemistry. Several coral species living under conditions of low mean seawater pH, but with either low or high variability in seawater pH, were examined and compared with those living in 'normal' (non-seep) ambient seawater pH. We show that when mean seawater pH is low but highly variable, corals have a greater ability to maintain constant pH(cf) in their CF, but this characteristic was not linked with changes in abundance. Within less variable low pH seawater, corals with limited reductions in pH(cf) at the seep sites compared with controls tended to be more abundant at the seep site than at the control site. However, this finding was strongly influenced by a single species (Montipora foliosa), which was able to maintain complete pH(cf) homeostasis. Overall, although our findings indicate that there might be an association between ecological success and greater pH(cf) homeostasis, further research with additional species and at more sites with differing seawater pH regimes is required to solidify inferences regarding coral ecological success under future OA. specialized abundance calcification calcifying fluid coral coral reefs dissolved inorganic carbon ocean acidification Papua New Guinea PAPOUASIE NOUVELLE GUINEE 034 021 [Early access] [13 p.] 2022 1354-1013 https://www.documentation.ird.fr/hor/fdi:010084245 10.1111/gcb.16093 1354-1013 [F B010084245] https://www.documentation.ird.fr/hor/fdi:010084245 https://www.documentation.ird.fr/intranet/publi/2022-03/010084245.pdf Accès réservé (Intranet de l'IRD) IRD - Base Horizon / Pleins textes 2022-03-09 2025-02-24 fdi:010084245 fre