FN Archimer Export Format PT J TI Combined effects of global climate change and nutrient enrichment on the physiology of three temperate maerl species BT AF Qui-Minet, Zujaila Nohemy Coudret, Jérôme Davoult, Dominique Grall, Jacques Mendez‐Sandin, Miguel Cariou, Thierry Martin, Sophie AS 1:1;2:1;3:1;4:2;5:1;6:3;7:1; FF 1:;2:;3:;4:;5:;6:;7:; C1 Sorbonne Universités CNRS UMR 7144 Adaptation et Diversité en Milieu Marin Station Biologique de Roscoff Roscoff ,France Université de Bretagne Occidentale IUEM Plouzané , France Sorbonne Universités CNRS, FR2424 Station Biologique de Roscoff Roscoff , France C2 UNIV PARIS SORBONNE, FRANCE UBO, FRANCE CNRS, FRANCE SI BREST SE OBSERVATOIRE_IUEM IN DOAJ IF 2.392 TC 18 UR https://archimer.ifremer.fr/doc/00595/70722/68955.pdf https://archimer.ifremer.fr/doc/00595/70722/68956.pdf LA English DT Article BO Albert Lucas DE ;calcification;maerl;nitrate;ocean acidification;ocean warming;phosphate;photosynthesis;respiration AB Made up of calcareous coralline algae, maerl beds play a major role as ecosystem engineers in coastal areas throughout the world. They undergo strong anthropogenic pressures, which may threaten their survival. The aim of this study was to gain insight into the future of maerl beds in the context of global and local changes. We examined the effects of rising temperatures (+3°C) and ocean acidification (−0.3 pH units) according to temperature and pH projections (i.e., the RCP 8.5 scenario), and nutrient (N and P) availability on three temperate maerl species (Lithothamnion corallioides, Phymatolithon calcareum, and Lithophyllum incrustans) in the laboratory in winter and summer conditions. Physiological rates of primary production, respiration, and calcification were measured on all three species in each treatment and season. The physiological response of maerl to global climate change was species‐specific and influenced by seawater nutrient concentrations. Future temperature–pH scenario enhanced maximal gross primary production rates in P. calcareum in winter and in L. corallioides in both seasons. Nevertheless, both species suffered an impairment of light harvesting and photoprotective mechanisms in winter. Calcification rates at ambient light intensity were negatively affected by the future temperature–pH scenario in winter, with net dissolution observed in the dark in L. corallioides and P. calcareum under low nutrient concentrations. Nutrient enrichment avoided dissolution under future scenarios in winter and had a positive effect on L. incrustans calcification rate in the dark in summer. In winter conditions, maximal calcification rates were enhanced by the future temperature–pH scenario on the three species, but P. calcareum suffered inhibition at high irradiances. In summer conditions, the maximal calcification rate dropped in L. corallioides under the future global climate change scenario, with a potential negative impact on CaCO3 budget for maerl beds in the Bay of Brest where this species is dominant. Our results highlight how local changes in nutrient availability or irradiance levels impact the response of maerl species to global climate change and thus point out how it is important to consider other abiotic parameters in order to develop management policies capable to increase the resilience of maerl beds under the future global climate change scenario. PY 2019 PD DEC SO Ecology And Evolution SN 2045-7758 PU Wiley VL 9 IS 24 UT 000500738500001 BP 13787 EP 13807 DI 10.1002/ece3.5802 ID 70722 ER EF