Effects of high CO2 and warming on a Baltic Sea microzooplankton community. (2nd November 2015)

• Record Type: Journal Article
• Authors: Horn, Henriette G.; Boersma, Maarten; Garzke, Jessica; Löder, Martin G. J.; Sommer, Ulrich; Aberle, Nicole
• Is Part Of: ICES journal of marine science. Volume 73:Number 3(2016)
• Page Start: 772
• Page End: 782
• Publication Date: 2015-11-02
• Subjects: CO2 -- global warming -- heterotrophic protists -- mesocosm experiment -- ocean acidification -- protozooplankton; Ocean -- Periodicals; Fisheries -- Periodicals; Fishes -- Periodicals; Marine biology -- Bibliography -- Periodicals; 551.4605
• DOI: 10.1093/icesjms/fsv198
• Languages: English
• ISSNs: 1054-3139

Abstract

Abstract: Global warming and ocean acidification are among the most important stressors for aquatic ecosystems in the future. To investigate their direct and indirect effects on a near-natural plankton community, a multiple-stressor approach is needed. Hence, we set up mesocosms in a full-factorial design to study the effects of both warming and high CO2 on a Baltic Sea autumn plankton community, concentrating on the impacts on microzooplankton (MZP). MZP abundance, biomass, and species composition were analysed over the course of the experiment. We observed that warming led to a reduced time-lag between the phytoplankton bloom and an MZP biomass maximum. MZP showed a significantly higher growth rate and an earlier biomass peak in the warm treatments while the biomass maximum was not affected. Increased p CO2 did not result in any significant effects on MZP biomass, growth rate, or species composition irrespective of the temperature, nor did we observe any significant interactions between CO2 and temperature. We attribute this to the high tolerance of this estuarine plankton community to fluctuations in p CO2, often resulting in CO2 concentrations higher than the predicted end-of-century concentration for open oceans. In contrast, warming can be expected to directly affect MZP and strengthen its coupling with phytoplankton by enhancing its grazing pressure.