Photosynthesis and calcification in the articulated coralline alga Ellisolandia elongata (Corallinales, Rhodophyta) from intertidal rock pools

• Published in: European Journal of Phycology
• Main Authors: Egilsdottir, Hronn, Olafsson, Jon, Martin, Sophie
• Other Authors: Faculty of Earth Sciences, University of Iceland Reykjavik, Marine Research Institute, Ecogéochimie et Fonctionnement des Ecosystèmes Benthiques (EFEB), Adaptation et diversité en milieu marin (AD2M), Station biologique de Roscoff Roscoff (SBR), Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Station biologique de Roscoff Roscoff (SBR), Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2015
• Subjects: calcification; Corallina elongata; coralline algae; Ellisolandia elongata; irradiance; P-E curve; photosynthesis; tidal pool; [SDE.BE]Environmental Sciences/Biodiversity and Ecology; Ocean acidification
• Online Access: https://hal.sorbonne-universite.fr/hal-01281671; https://hal.sorbonne-universite.fr/hal-01281671/document; https://hal.sorbonne-universite.fr/hal-01281671/file/Egilsdottir_2016_Photosynthesis_and.pdf; https://doi.org/10.1080/09670262.2015.1101165

International audience Calcifying coralline algae are functionally important in many ecosystems but their existence is now threatened by global climate change. The aim of this study is to improve our understanding of coralline algal metabolic functions and their interactions by assessing the respiration, photosynthesis and calcification rates in an articulated (geniculate) coralline alga, Ellisolandia elongata. Algal samples selected for this case study were collected from an intertidal rock-pool on the coast of Brittany (France). Physiological rates were assessed in summer and winter by measuring the concentration of oxygen, dissolved inorganic carbon and total alkalinity fluxes at five irradiance levels and in the dark using incubation chambers. Respiration, photosynthetic and calcification rates were strongly affected by seasonal changes. Respiration increased with temperature, being ten-fold higher in summer than in winter. Photosynthetic parameters of the photosynthesis-irradiance (P-E) curve, Pgmax, Pnmax and Ek, were two- to three-fold higher in summer relative to winter. Photoinhibition was observed under high irradiance indicating an acclimation of E. elongata to low irradiance levels. Parameters of the calcification-irradiance (G-E) curve, Gmax and Ek, were approximately two-fold higher in summer compared with winter. In summer, calcification rates were more strongly inhibited under high irradiance than photosynthetic rates, suggesting a dynamic relationship between these metabolic processes. By inhabiting intertidal rock pools, E. elongata exhibits tolerance to a dynamic physico-chemical environment. Information on respiration, photosynthesis and calcification rates in a calcifying coralline alga inhabiting such dynamic environments in terms of pH and temperature is important in order to better understand how ocean acidification and warming will affect coralline algae in the future.