Horn Henriette G, Sander Nils, Stuhr Annegret, Algueró-Muñiz María, Bach Lennart T, Löder Martin G J, Boersma Maarten, Riebesell Ulf, Aberle Nicole
Alfred-Wegener-Institut Helmholtz-Zentrum für Polar- und Meeresforschung, Biologische Anstalt Helgoland, Helgoland, Germany.
GEOMAR Helmholtz Centre for Ocean Research Kiel, Kiel, Germany.
PLoS One. 2016 Nov 28;11(11):e0165800. doi: 10.1371/journal.pone.0165800. eCollection 2016.
Ocean acidification is considered as a crucial stressor for marine communities. In this study, we tested the effects of the IPCC RPC6.0 end-of-century acidification scenario on a natural plankton community in the Gullmar Fjord, Sweden, during a long-term mesocosm experiment from a spring bloom to a mid-summer situation. The focus of this study was on microzooplankton and its interactions with phytoplankton and mesozooplankton. The microzooplankton community was dominated by ciliates, especially small Strombidium sp., with the exception of the last days when heterotrophic dinoflagellates increased in abundance. We did not observe any effects of high CO2 on the community composition and diversity of microzooplankton. While ciliate abundance, biomass and growth rate were not affected by elevated CO2, we observed a positive effect of elevated CO2 on dinoflagellate abundances. Additionally, growth rates of dinoflagellates were significantly higher in the high CO2 treatments. Given the higher Chlorophyll a content measured under high CO2, our results point at mainly indirect effects of CO2 on microzooplankton caused by changes in phytoplankton standing stocks, in this case most likely an increase in small-sized phytoplankton of <8 μm. Overall, the results from the present study covering the most important part of the growing season indicate that coastal microzooplankton communities are rather robust towards realistic acidification scenarios.
海洋酸化被认为是海洋群落面临的一个关键压力源。在本研究中，我们在瑞典古尔马尔峡湾的一个长期中宇宙实验中，测试了政府间气候变化专门委员会（IPCC）RCP6.0世纪末酸化情景对自然浮游生物群落的影响，该实验从春季水华持续到仲夏情况。本研究的重点是微型浮游动物及其与浮游植物和中型浮游动物的相互作用。微型浮游动物群落以纤毛虫为主，特别是小型的斯氏虫属，除了最后几天异养甲藻数量增加的时候。我们没有观察到高二氧化碳对微型浮游动物群落组成和多样性的任何影响。虽然纤毛虫的丰度、生物量和生长速率不受高二氧化碳的影响，但我们观察到高二氧化碳对甲藻丰度有积极影响。此外，在高二氧化碳处理中，甲藻的生长速率显著更高。鉴于在高二氧化碳条件下测得的叶绿素a含量较高，我们的结果表明，二氧化碳对微型浮游动物的影响主要是间接的，是由浮游植物现存生物量的变化引起的，在这种情况下最有可能是<8μm的小型浮游植物增加。总体而言，本研究涵盖生长季节最重要部分的结果表明，沿海微型浮游动物群落对现实的酸化情景相当稳健。
