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Titel |
Response of halocarbons to ocean acidification in the Arctic |
VerfasserIn |
F. E. Hopkins, S. A. Kimmance, J. A. Stephens, R. G. J. Bellerby, C. P. D. Brussaard, J. Czerny, K. G. Schulz, S. D. Archer |
Medientyp |
Artikel
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Sprache |
Englisch
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ISSN |
1726-4170
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Digitales Dokument |
URL |
Erschienen |
In: Biogeosciences ; 10, no. 4 ; Nr. 10, no. 4 (2013-04-08), S.2331-2345 |
Datensatznummer |
250018187
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Publikation (Nr.) |
copernicus.org/bg-10-2331-2013.pdf |
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Zusammenfassung |
The potential effect of ocean acidification (OA) on seawater halocarbons in
the Arctic was investigated during a mesocosm experiment in Spitsbergen in
June–July 2010. Over a period of 5 weeks, natural phytoplankton communities
in nine ~ 50 m3 mesocosms were studied under a range of
pCO2 treatments from ~ 185 μatm to ~ 1420 μatm. In general, the response of halocarbons to pCO2 was
subtle, or undetectable. A large number of significant correlations with a
range of biological parameters (chlorophyll a, microbial plankton community,
phytoplankton pigments) were identified, indicating a biological control on
the concentrations of halocarbons within the mesocosms. The temporal
dynamics of iodomethane (CH3I) alluded to active turnover of this
halocarbon in the mesocosms and strong significant correlations with
biological parameters suggested a biological source. However, despite a
pCO2 effect on various components of the plankton community, and a
strong association between CH3I and biological parameters, no effect of
pCO2 was seen in CH3I. Diiodomethane (CH2I2) displayed a
number of strong relationships with biological parameters. Furthermore, the
concentrations, the rate of net production and the sea-to-air flux of
CH2I2 showed a significant positive response to pCO2. There
was no clear effect of pCO2 on bromocarbon concentrations or dynamics.
However, periods of significant net loss of bromoform (CHBr3) were
found to be concentration-dependent, and closely correlated with total
bacteria, suggesting a degree of biological consumption of this halocarbon
in Arctic waters. Although the effects of OA on halocarbon concentrations
were marginal, this study provides invaluable information on the production
and cycling of halocarbons in a region of the world's oceans likely to
experience rapid environmental change in the coming decades. |
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