Publication Date:
2012-11-29
Description:
The production of the marine trace gas dimethyl sulfide (DMS) provides 90% of the marine biogenic sulfur in the atmosphere where it affects cloud formation and climate. The effects of increasing anthropogenic CO 2 and the resulting warming and ocean acidification on trace gas production in the oceans are poorly understood. Here we report the first measurements of DMS-production and data on growth, DMSP and DMS concentrations in pH-stated cultures of the phytoplankton haptophyte Emiliania huxleyi . Four different environmental conditions were tested: ambient, elevated CO 2 (+CO 2 ) elevated temperature (+T), and elevated temperature and CO 2 (+TCO 2 ). In comparison to the ambient treatment, average DMS-production was about 50% lower in the +CO 2 treatment. Importantly, temperature had a strong effect on DMS-production and the impacts outweighed the effects of a decrease in pH. As a result, the +T and +TCO 2 treatments showed significantly higher DMS-production of 36.2±2.58 and 31.5±4.66 μmol · L -1 cell volume (CV) · h -1 in comparison to the +CO 2 treatment (14.9±4.20 μmol · L -1 CV · h -1 ). Since the cultures were aerated with an air/CO 2 mixture, DMS was effectively removed from the incubation bottles so that concentration remained relatively low (3.6 to 6.1 mmol · L -1 CV). Intracellular DMSP has been shown to increase in E. huxleyi as a result of elevated temperature and/or elevated CO 2 and our results are in agreement with this finding: the ambient and +CO 2 treatments showed 125±20.4 and 162±27.7 mmol · L -1 CV, whereas +T and +TCO 2 showed significantly increased intracellular DMSP concentrations of 195±15.8 and 211±28.2 mmol · L -1 CV, respectively. Growth was unaffected by the treatments, but cell diameter decreased significantly under elevated temperature. These results indicate that DMS-production is sensitive to CO 2 and temperature in E. huxleyi . Hence, global environmental change that manifests in ocean acidification and warming may not result in decreased DMS as suggested by earlier studies investigating the effect of elevated CO 2 in isolation. © 2012 Blackwell Publishing Ltd
Print ISSN:
1354-1013
Electronic ISSN:
1365-2486
Topics:
Biology
,
Energy, Environment Protection, Nuclear Power Engineering
,
Geography
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