Effect of CO2, nutrients and light on coastal plankton. II. Metabolic rates

Abstract

AB Aquatic Biology Contact the journal Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout the JournalEditorsTheme Sections AB 22:43-57 (2014) - DOI: https://doi.org/10.3354/ab00606 Theme Section: Environmental forcing of aquatic primary productivity Effect of CO2, nutrients and light on coastal plankton. II. Metabolic rates J. M. Mercado1,*, C. Sobrino2, P. J. Neale3, M. Segovia4, A. Reul4, A. L. Amorim1, P. Carrillo5, P. Claquin6, M. J. Cabrerizo5, P. León1, M. R. Lorenzo4, J. M. Medina-Sánchez7, V. Montecino8, C. Napoleon6, O. Prasil9, S. Putzeys1, S. Salles1, L. Yebra1 1Centro Oceanográfico de Málaga, Instituto Español de Oceanografía, Puerto Pesquero s/n, 29640 Fuengirola, Málaga, Spain 2Department of Ecology and Animal Biology, Faculty of Sciences, University of Vigo, 36310 Vigo, Spain 3Smithsonian Environmental Research Center, Edgewater, Maryland 21037, USA 4Department of Ecology, Faculty of Sciences, University of Málaga, 29071 Málaga, Spain 5Instituto del Agua, Universidad de Granada, Granada, Spain 6Université Caen Basse-Normandie, BIOMEA FRE3484 CNRS, 14032 Caen Cedex, France 7Departamento de Ecología, Facultad de Ciencias, Universidad de Granada, Granada, Spain 8Departamento de Ciencias Ecológicas, Facultad de Ciencias, Universidad de Chile, Santiago, Chile 9Laboratory of Photosynthesis, CenterAlgatech, Institute of Microbiology ASCR, 37981 Trĕboň, Czech Republic *Corresponding author: jesus.mercado@ma.ieo.es ABSTRACT: We conducted a microcosm experiment aimed at studying the interactive effects of high CO2, nutrient loading and irradiance on the metabolism of a planktonic community sampled in the Western Mediterranean near the coast of Málaga. Changes in the metabolism of phytoplankton and bacterioplankton were observed for 7 d under 8 treatment conditions, representing the full factorial combinations of 2 levels each of CO2, nutrient concentration and solar radiation exposure. The initial plankton sample was collected at the surface from a stratified water column, indicating that phytoplankton were naturally acclimated to high irradiance and low nutrient concentrations. Nutrient addition combined with high irradiance resulted in a significant increase in primary production. Nitrate uptake by phytoplankton was also stimulated under high nutrient conditions. High nutrients, high irradiance and the combination of low CO2 and high irradiance positively affected bacterial production. Light was the main factor affecting the respiration rates of the community, which were higher at the high light level. After 7 d of incubation, nutrient loading was the only factor that significantly affected the amount of particulate organic carbon (POC) accumulated in the microcosms. Therefore, the changes in metabolic rates produced at high CO2 had no effect on net production of particulate organic matter. If these results are extrapolated to the natural environment, it could be hypothesized that high levels of CO2 will have a limited impact on biological pump activity in the northern Alboran Sea since it is assumed that POC export towards deeper layers determines the potential for carbon sequestration. KEY WORDS: Acidification · Bacterioplankton · Nutrients · Phytoplankton · Primary productivity · Respiration · UVR Full text in pdf format PreviousNextCite this article as: Mercado JM, Sobrino C, Neale PJ, Segovia M and others (2014) Effect of CO2, nutrients and light on coastal plankton. II. Metabolic rates. Aquat Biol 22:43-57. https://doi.org/10.3354/ab00606 Export citation RSS - Facebook - Tweet - linkedIn Cited by Published in AB Vol. 22. Online publication date: November 20, 2014 Print ISSN: 1864-7782; Online ISSN: 1864-7790 Copyright © 2014 Inter-Research.