Journal cover Journal topic
Biogeosciences An interactive open-access journal of the European Geosciences Union
Journal topic
Volume 10, issue 1
Biogeosciences, 10, 161-180, 2013
https://doi.org/10.5194/bg-10-161-2013
© Author(s) 2013. This work is distributed under
the Creative Commons Attribution 3.0 License.

Special issue: Arctic ocean acidification: pelagic ecosystem and biogeochemical...

Biogeosciences, 10, 161-180, 2013
https://doi.org/10.5194/bg-10-161-2013
© Author(s) 2013. This work is distributed under
the Creative Commons Attribution 3.0 License.

Research article 11 Jan 2013

Research article | 11 Jan 2013

Temporal biomass dynamics of an Arctic plankton bloom in response to increasing levels of atmospheric carbon dioxide

K. G. Schulz1, R. G. J. Bellerby2,3,4, C. P. D. Brussaard5, J. Büdenbender1, J. Czerny1, A. Engel1, M. Fischer1, S. Koch-Klavsen1, S. A. Krug1, S. Lischka1, A. Ludwig1, M. Meyerhöfer1, G. Nondal6, A. Silyakova2,3, A. Stuhr1, and U. Riebesell1 K. G. Schulz et al.
  • 1Helmholtz Centre for Ocean Research (GEOMAR), Düsternbrooker Weg 20, 24105 Kiel, Germany
  • 2Uni Bjerknes Centre, Allégaten 55, 5007 Bergen, Norway
  • 3Bjerknes Centre for Climate Research, Allégaten 55, 5007 Bergen, Norway
  • 4Geophysical Institute, University of Bergen, Allégaten 70, 5007, Norway
  • 5Royal Netherlands Institute for Sea Research (NIOZ), P.O. Box 59, 1790 AB Den Burg (Texel), The Netherlands
  • 6Norwegian Institute for Water Research (NIVA), Thormøhlensgaten 53D, 5006 Bergen, Norway

Abstract. Ocean acidification and carbonation, driven by anthropogenic emissions of carbon dioxide (CO2), have been shown to affect a variety of marine organisms and are likely to change ecosystem functioning. High latitudes, especially the Arctic, will be the first to encounter profound changes in carbonate chemistry speciation at a large scale, namely the under-saturation of surface waters with respect to aragonite, a calcium carbonate polymorph produced by several organisms in this region. During a CO2 perturbation study in Kongsfjorden on the west coast of Spitsbergen (Norway), in the framework of the EU-funded project EPOCA, the temporal dynamics of a plankton bloom was followed in nine mesocosms, manipulated for CO2 levels ranging initially from about 185 to 1420 μatm. Dissolved inorganic nutrients were added halfway through the experiment. Autotrophic biomass, as identified by chlorophyll a standing stocks (Chl a), peaked three times in all mesocosms. However, while absolute Chl a concentrations were similar in all mesocosms during the first phase of the experiment, higher autotrophic biomass was measured as high in comparison to low CO2 during the second phase, right after dissolved inorganic nutrient addition. This trend then reversed in the third phase. There were several statistically significant CO2 effects on a variety of parameters measured in certain phases, such as nutrient utilization, standing stocks of particulate organic matter, and phytoplankton species composition. Interestingly, CO2 effects developed slowly but steadily, becoming more and more statistically significant with time. The observed CO2-related shifts in nutrient flow into different phytoplankton groups (mainly dinoflagellates, prasinophytes and haptophytes) could have consequences for future organic matter flow to higher trophic levels and export production, with consequences for ecosystem productivity and atmospheric CO2.

Publications Copernicus
Special issue
Download
Citation
Share