Data And Scripts For Predictable Ecological Response To Rising Co2 Of A Community Of Marine Phytoplankton

• Main Authors: Pardew, Jacob, Pimentel, Macarena Blanco, Low-Décarie, Etienne
• Format: Dataset
• Language: English
• Published: Zenodo 2018
• Subjects: CO2, competition coefficient, global change, primary producers, taxonomic group , marine, phytoplankton; Ocean acidification
• Online Access: https://dx.doi.org/10.5281/zenodo.1172665; https://zenodo.org/record/1172665

Rising atmospheric CO 2 and ocean acidification are fundamentally altering conditions for life of all marine organisms, including phytoplankton. Differences in CO 2 related physiology between major phytoplankton taxa lead to differences in their ability to take up and utilise CO 2 . These differences may cause predictable shifts in the composition of marine phytoplankton communities in response to rising atmospheric CO 2 . We report an experiment in which 7 species of marine phytoplankton, belonging to 4 major taxonomic groups (cyanobacteria, chlorophytes, diatoms and coccolithophores) were grown at both ambient (500 µatm) and future (1000 µatm) CO 2 levels. These phytoplankton were grown as individual species, as cultures of pairs of species and as a community assemblage of all seven species in two culture regimes (high-nitrogen batch cultures and lower-nitrogen semi-continuous cultures, though not under nitrogen limitation). All phytoplankton species tested in this study increased their growth rates under elevated CO 2 independent of the culture regime. We also find that, despite species-specific variation in growth response to high CO 2 , the identity of major taxonomic groups provides a good prediction of changes in population growth and competitive ability under high CO 2 . The CO 2 -induced growth response is a good predictor of CO 2 -induced changes in competition (R 2 >0.93) and community composition (R 2 >0.73). This study suggests that it may be possible to infer how marine phytoplankton communities respond to rising CO 2 levels from the knowledge of the physiology of major taxonomic groups, but that these predictions may require further characterisation of these traits across a diversity of growth conditions. These findings must be validated in the context of limitation by other nutrients. Also, in natural communities of phytoplankton, numerous other factors that may all respond to changes in CO2, including nitrogen fixation, grazing and variation in the limiting resource will likely complicate this prediction.