Effect of elevated CO 2 on the dynamics of particle-attached and free-living bacterioplankton communities in an Arctic fjord

• Published in: Biogeosciences
• Main Authors: Sperling, M., Piontek, J., Gerdts, G., Wichels, A., Schunck, H., Roy, A.-S., La Roche, J., Gilbert, J., Nissimov, J. I., Bittner, Lucie, Romac, Sarah, Riebesell, U., Engel, A.
• Other Authors: Biologische Anstalt Helgoland, Alfred-Wegener-Institut, Helmholtz-Zentrum für Polar- und Meeresforschung (AWI), Helmholtz Centre for Ocean Research Kiel (GEOMAR), Argonne National Laboratory Lemont (ANL), Plymouth Marine Laboratory (PML), Plymouth Marine Laboratory, 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), Evolution des Protistes et Ecosystèmes Pélagiques (EPEP), 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), Institute for Atmosphere and Environment, University of Frankfurt, European Community 211384, EU EraNet BiodivErsA program BioMarKs, Helmholtz Graduate School for Polar and Marine Research (POLMAR)
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2013
• Subjects: [SDV]Life Sciences [q-bio]; [SDE]Environmental Sciences; Arctic; Svalbard; Kongsfjord*; Kongsfjorden; Ocean acidification; Phytoplankton
• Online Access: https://hal.archives-ouvertes.fr/hal-01258225; https://hal.archives-ouvertes.fr/hal-01258225/document; https://hal.archives-ouvertes.fr/hal-01258225/file/bg-10-181-2013.pdf; https://doi.org/10.5194/bg-10-181-2013

International audience In the frame of the European Project on Ocean Acidification (EPOCA), the response of an Arctic pelagic community (<3 mm) to a gradient of seawater pCO(2) was investigated. For this purpose 9 large-scale in situ mesocosms were deployed in Kongsfjorden, Svalbard (78 degrees 56.2' N, 11 degrees 53.6' E), in 2010. The present study investigates effects on the communities of particle-attached (PA; >3 mu m) and free-living (FL; <3 mu m > 0.2 mu m) bacteria by Automated Ribosomal Intergenic Spacer Analysis (ARISA) in 6 of the mesocosms, ranging from 185 to 1050 mu atm initial pCO(2), and the surrounding fjord. ARISA was able to resolve, on average, 27 bacterial band classes per sample and allowed for a detailed investigation of the explicit richness and diversity. Both, the PA and the FL bacterioplankton community exhibited a strong temporal development, which was driven mainly by temperature and phytoplankton development. In response to the breakdown of a picophytoplankton bloom, numbers of ARISA band classes in the PA community were reduced at low and medium CO2 (similar to 185-685 mu atm) by about 25 %, while they were more or less stable at high CO2 (similar to 820-1050 mu atm). We hypothesise that enhanced viral lysis and enhanced availability of organic substrates at high CO2 resulted in a more diverse PA bacterial community in the post-bloom phase. Despite lower cell numbers and extracellular enzyme activities in the post-bloom phase, bacterial protein production was enhanced in high CO2 mesocosms, suggesting a positive effect of community richness on this function and on carbon cycling by bacteria.