Journal cover Journal topic
Biogeosciences An interactive open-access journal of the European Geosciences Union
Journal topic
Volume 15, issue 14
Biogeosciences, 15, 4353-4365, 2018
https://doi.org/10.5194/bg-15-4353-2018
© Author(s) 2018. This work is distributed under
the Creative Commons Attribution 4.0 License.
Biogeosciences, 15, 4353-4365, 2018
https://doi.org/10.5194/bg-15-4353-2018
© Author(s) 2018. This work is distributed under
the Creative Commons Attribution 4.0 License.

Research article 18 Jul 2018

Research article | 18 Jul 2018

The Arctic picoeukaryote Micromonas pusilla benefits synergistically from warming and ocean acidification

Clara Jule Marie Hoppe1,2, Clara M. Flintrop1,3, and Björn Rost1 Clara Jule Marie Hoppe et al.
  • 1Marine Biogeosciences, Alfred Wegener Institute – Helmholtz Centre for Polar and Marine Research, 27570 Bremerhaven, Germany
  • 2Norwegian Polar Institute, 9296 Tromsø, Norway
  • 3MARUM, 28359 Bremen, Germany

Abstract. In the Arctic Ocean, climate change effects such as warming and ocean acidification (OA) are manifesting faster than in other regions. Yet, we are lacking a mechanistic understanding of the interactive effects of these drivers on Arctic primary producers. In the current study, one of the most abundant species of the Arctic Ocean, the prasinophyte Micromonas pusilla, was exposed to a range of different pCO2 levels at two temperatures representing realistic current and future scenarios for nutrient-replete conditions. We observed that warming and OA synergistically increased growth rates at intermediate to high pCO2 levels. Furthermore, elevated temperatures shifted the pCO2 optimum of biomass production to higher levels. Based on changes in cellular composition and photophysiology, we hypothesise that the observed synergies can be explained by beneficial effects of warming on carbon fixation in combination with facilitated carbon acquisition under OA. Our findings help to understand the higher abundances of picoeukaryotes such as M. pusilla under OA, as has been observed in many mesocosm studies.

Publications Copernicus
Download
Short summary
Responses of the Arctic microalgae Micromonas pusilla to different pCO2 levels were investigated at two temperatures. We observed that warming and ocean acidification (OA) synergistically increased growth rates. Furthermore, elevated temperature shifted the pCO2 optimum of biomass production to higher levels. This seem to be caused by more efficient photosynthesis under warmer and more acidic conditions. Our findings explain the dominance of picoeukaryotes frequently observed in OA experiments.
Responses of the Arctic microalgae Micromonas pusilla to different pCO2 levels were investigated...
Citation
Share