Gattuso J.-P., Payri C. E., Pichon M., Delesalle B., Canon C. & Frankignoulle M., in press. Organic production, calcification and air-sea CO2 fluxes of a macroalgal-dominated coral reef community (Moorea, French Polynesia). Journal of Phycology.




Abstract

Community metabolism and air-sea CO2 fluxes were investigated in July 1992 on a fringing reef at Moorea (French Polynesia). The benthic community was dominated by macroalgae (85% substratum cover) and comprised of Phaeophyceae (Padina tenuis Bory, Turbinaria ornata (Turner) J. Agardh and Hydroclathrus clathratus Bory (Howe)), Chlorophyta (Halimeda incrassata f. ovata J. Agardh (Howe) and Ventricaria ventricosa J. Agardh (Olsen et West)) as well as several Rhodophyta (Actinotrichia fragilis Forskål (Börgesen) and several species of encrusting coralline algae). Algal biomass was 171 g dry weight m-2. Community gross production (Pg), respiration (R ) and net calcification (G ) were measured in an open-top enclosure. Pg and R were respectively 248 and 240 mmol CO2 m-2 d-1 and there was a slight net dissolution of CaCO3 (0.8 CO2 m-2 d-1). This site was a sink for atmospheric CO2 (10 ± 4 CO2 m-2 d-1) and the analysis of data from the litterature suggests that this is a general feature of algal-dominated reefs. Measurement of air-sea CO2 fluxes in open water close to the enclosure demonstrated that changes in small scale hydrodynamics can lead to misleading conclusions. Net CO2 evasion to the atmosphere was measured on the fringing reef due to changes in current pattern which drove water from the barrier reef (a CO2 source) to the study site.


Last modified: 20/12/05 at 16:15 by Jean-Pierre Gattuso
[JPG Home page] [Group Home page] [Email]

Browse Happy logo Made with a Mac