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Titel |
Emission of atmospherically significant halocarbons by naturally occurring and farmed tropical macroalgae |
VerfasserIn |
E. C. Leedham, C. Hughes, F. S. L. Keng, S.-M. Phang, G. Malin, W. T. Sturges |
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. 6 ; Nr. 10, no. 6 (2013-06-03), S.3615-3633 |
Datensatznummer |
250018273
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Publikation (Nr.) |
copernicus.org/bg-10-3615-2013.pdf |
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Zusammenfassung |
Current estimates of global halocarbon emissions highlight the tropical
coastal environment as an important source of very short-lived (VSL) biogenic
halocarbons to the troposphere and stratosphere, due to a combination of
assumed high primary productivity in tropical coastal waters and the
prevalence of deep convective transport, potentially capable of rapidly
lifting surface emissions to the upper troposphere/lower stratosphere.
However, despite this perceived importance, direct measurements of tropical
coastal biogenic halocarbon emissions, notably from macroalgae (seaweeds),
have not been made. In light of this, we provide the first dedicated study of
halocarbon production by a range of 15 common tropical macroalgal species and
compare these results to those from previous studies of polar and temperate
macroalgae. Variation between species was substantial; CHBr3 production
rates, measured at the end of a 24 h incubation, varied from 1.4 to
1129 pmol g FW−1 h−1 (FW = fresh weight of sample). We used
our laboratory-determined emission rates to estimate emissions of CHBr3
and CH2Br2 (the two dominant VSL precursors of stratospheric
bromine) from the coastlines of Malaysia and elsewhere in South East Asia
(SEA). We compare these values to previous top-down model estimates of
emissions from these regions and, by using several emission scenarios, we
calculate an annual CHBr3 emission of 40 (6–224 Mmol Br−1 yr),
a value that is lower than previous estimates. The contribution of tropical
aquaculture to current emission budgets is also considered. Whilst the
current aquaculture contribution to halocarbon emissions in this regional is
small, the potential exists for substantial increases in aquaculture to make
a significant contribution to regional halocarbon budgets. |
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