The Arctic picoeukaryote <i>Micromonas</i> pusilla benefits synergistically from warming and ocean acidification

Abstract

15In the Arctic Ocean, climate change effects such as warming and ocean acidification (OA) are 16 manifesting faster than in other regions. Yet, we are lacking a mechanistic understanding of the 17 interactive effects of these drivers on Arctic primary producers. In the current study, one of the 18 most abundant species of the Arctic Ocean, the prasinophyte Micromonas pusilla, was exposed 19 to a range of different pCO 2 levels at two temperatures representing realistic scenarios for 20 current and future conditions. We observed that warming and OA synergistically increased 21 growth rates at intermediate to high pCO 2 levels. Furthermore, elevated temperatures shifted 22 the pCO 2 -optimum of biomass production to higher levels. Based on changes in cellular 23 composition and photophysiology, we hypothesise that the observed synergies can be explained 24 by beneficial effects of warming on carbon fixation in combination with facilitated carbon 25 acquisition under OA. Our findings help to understand the higher abundances of picoeukaryotes 26 such as M. pusilla under OA, as has been observed in many mesocosm studies. 27Biogeosciences Discuss., https://doi

Company matters: The presence of other genotypes alters traits and intraspecific selection in an Arctic diatom under climate change

“…All measurements (n = 3-4) were conducted at the respective treatment temperature. Instrument settings as well as data processing and fitting were performed as described in Hoppe, Flintrop, and Rost (2018).…”

Capacity of the common Arctic picoeukaryote Micromonas to adapt to a warming ocean

“…Micromonas is a common and often dominant member of phytoplankton communities in the Arctic (Not et al ; Lovejoy et al ; Balzano et al ; Simon et al ). Field data and short‐term acclimation experiments indicate that both warming and ocean acidification may increase the growth rate and ecological role of Micromonas in the Arctic (Lovejoy et al ; Li et al ; Hoppe et al ). There is evidence that phytoplankton may have the capacity to evolve, altering their responses to changing conditions (e.g., Schaum et al ; Walworth et al ).…”