Warming but not enhanced CO2 quantitatively and qualitatively affects phytoplankton biomass

• Main Authors: Paul, Carolin, Matthiessen, Birte, Sommer, Ulrich
• Format: Conference Object
• Language: English
• Published: 2014
• Subjects: Ocean acidification
• Online Access: https://oceanrep.geomar.de/id/eprint/25918/; https://oceanrep.geomar.de/id/eprint/25918/1/Carolin%20Paul_E%C3%96N_Poster%20_%20JASM%202014.pdf

We investigated the impacts of ocean acidification and future warming on the quantity and nutritional quality of a natural phytoplankton autumn bloom in a mesocosm experiment. Since the effects of CO2-enrichment and temperature have usually been studied in isolation, we were also interested in the interactive effects of both aspects of climate change. In that way we used a factorial design with two temperature and two acidification levels for our mesocosm experiment with a Baltic Sea phytoplankton community. Our results report a significant influence of warming as average and maximal phytoplankton carbon decreased significantly with increasing temperature. Additionally fatty acid composition changed with increasing temperature and biomass. Impacts of CO2 or synergetic effects of warming and acidification could not be detected. Nevertheless our analyses suggest that biological effects of warming on Baltic Sea phytoplankton are considerable and will influence the food cycle in case of food quantity as well as quality.