Inter- and intraspecific phenotypic plasticity of three phytoplankton species in response to ocean acidification

• Published in: Biology Letters
• Main Authors: Hattich, Giannina S.I., Listmann, Luisa, Raab, Julia, Ozod-Seradj, Dorthe, Reusch, Thorsten B.H., Matthiessen, Birte
• Format: Article in Journal/Newspaper
• Language: English
• Published: 2017
• Subjects: Ocean acidification
• Online Access: https://research.abo.fi/en/publications/c5e6b579-0818-4d3c-987a-c6aec52bd22c; https://doi.org/10.1098/rsbl.2016.0774; http://www.scopus.com/inward/record.url?scp=85011949649&partnerID=8YFLogxK

Phenotypic plasticity describes the phenotypic adjustment of the same genotype to different environmental conditions and is best described by a reaction norm. We focus on the effect of ocean acidification on inter-and intraspecific reaction norms of three globally important phytoplankton species (Emiliania huxleyi, Gephyrocapsa oceanica and Chaetoceros affinis). Despite significant differences in growth rates between the species, they all showed a high potential for phenotypic buffering (similar growth rates between ambient and high CO 2 conditions). Only three coccolithophore genotypes showed a reduced growth in high CO 2 . Diverging responses to high CO 2 of single coccolithophore genotypes compared with the respective mean species responses, however, raise the question of whether an extrapolation to the population level is possible from single-genotype experiments. We therefore compared the mean response of all tested genotypes with a total species response comprising the same genotypes, which was not significantly different in the coccolithophores. Assessing species reaction norms to different environmental conditions on short time scale in a genotype-mix could thus reduce sampling effort while increasing predictive power.