caa a22 4500 445819944 CHVBK 20180317145241.0 cr unu---uuuuu 170323e20111201xx s 000 0 eng 10.1007/s00338-011-0786-7 doi (NATIONALLICENCE)springer-10.1007/s00338-011-0786-7 Is the response of coral calcification to seawater acidification related to nutrient loading? [Elektronische Daten] [Anne Chauvin, Vianney Denis, Pascale Cuet] The effect of decreasing aragonite saturation state (ΩArag) of seawater (elevated pCO2) on calcification rates of Acropora muricata was studied using nubbins prepared from parent colonies located at two sites of La Saline reef (La Réunion Island, western Indian Ocean): a back-reef site (BR) affected by nutrient-enriched groundwater discharge (mainly nitrate), and a reef flat site (RF) with low terrigenous inputs. Protein and chlorophyll a content of the nubbins, as well as zooxanthellae abundance, were lower at RF than BR. Nubbins were incubated at ~27°C over 2h under sunlight, in filtered seawater manipulated to get differing initial pCO2 (1,440-340μatm), ΩArag (1.4-4.0), and dissolved inorganic carbon (DIC) concentrations (2,100-1,850μmolkg−1). Increasing DIC concentrations at constant total alkalinity (AT) resulted in a decrease in ΩArag and an increase in pCO2. AT at the beginning of the incubations was kept at a natural level of 2,193±6μmolkg−1 (mean±SD). Net photosynthesis (NP) and calcification were calculated from changes in pH and AT during the incubations. Calcification decrease in response to doubling pCO2 relative to preindustrial level was 22% for RF nubbins. When normalized to surface area of the nubbins, (1) NP and calcification were higher at BR than RF, (2) NP increased in high pCO2 treatments at BR compared to low pCO2 treatments, and (3) calcification was not related to ΩArag at BR. When normalized to NP, calcification was linearly related to ΩArag at both sites, and the slopes of the relationships were not significantly different. The increase in NP at BR in the high pCO2 treatments may have increased calcification and thus masked the negative effect of low ΩArag on calcification. Removing the effect of NP variations at BR showed that calcification declined in a similar manner with decreased ΩArag (increased pCO2) whatever the nutrient loading. Springer-Verlag, 2011 Calcification nationallicence Coral nationallicence Aragonite saturation state nationallicence Acidification nationallicence Nutrient enrichment nationallicence Acropora muricata nationallicence Chauvin Anne Laboratoire d'Ecologie Marine (ECOMAR), Université de La Réunion, 15 Avenue René Cassin, BP 7151, 97715, Saint-Denis, Messag Cedex 9, La Réunion, France aut Denis Vianney Laboratoire d'Ecologie Marine (ECOMAR), Université de La Réunion, 15 Avenue René Cassin, BP 7151, 97715, Saint-Denis, Messag Cedex 9, La Réunion, France aut Cuet Pascale Laboratoire d'Ecologie Marine (ECOMAR), Université de La Réunion, 15 Avenue René Cassin, BP 7151, 97715, Saint-Denis, Messag Cedex 9, La Réunion, France aut Coral Reefs Springer-Verlag 30/4(2011-12-01), 911-923 0722-4028 30:4<911 2011 30 338 https://doi.org/10.1007/s00338-011-0786-7 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s00338-011-0786-7 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Chauvin Anne Laboratoire d'Ecologie Marine (ECOMAR), Université de La Réunion, 15 Avenue René Cassin, BP 7151, 97715, Saint-Denis, Messag Cedex 9, La Réunion, France aut NATIONALLICENCE 700 1- Denis Vianney Laboratoire d'Ecologie Marine (ECOMAR), Université de La Réunion, 15 Avenue René Cassin, BP 7151, 97715, Saint-Denis, Messag Cedex 9, La Réunion, France aut NATIONALLICENCE 700 1- Cuet Pascale Laboratoire d'Ecologie Marine (ECOMAR), Université de La Réunion, 15 Avenue René Cassin, BP 7151, 97715, Saint-Denis, Messag Cedex 9, La Réunion, France aut NATIONALLICENCE 773 0- Coral Reefs Springer-Verlag 30/4(2011-12-01), 911-923 0722-4028 30:4<911 2011 30 338 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer