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Titel |
Seasonal distribution of dissolved inorganic carbon and net community production on the Bering Sea shelf |
VerfasserIn |
J. T. Mathis, J. N. Cross, N. R. Bates, S. Bradley Moran, M. W. Lomas, C. W. Mordy, P. J. Stabeno |
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 ; 7, no. 5 ; Nr. 7, no. 5 (2010-05-28), S.1769-1787 |
Datensatznummer |
250004783
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Publikation (Nr.) |
copernicus.org/bg-7-1769-2010.pdf |
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Zusammenfassung |
In order to assess the current state of net community production (NCP) in
the southeastern Bering Sea, we measured the spatio-temporal distribution
and controls on dissolved inorganic carbon (DIC) concentrations in spring
and summer of 2008 across six shelf domains defined by differing
biogeochemical characteristics. DIC concentrations were tightly coupled to
salinity in spring and ranged from ~1900 μmoles kg−1 over
the inner shelf to ~2400 μmoles kg−1 in the deeper waters
of the Bering Sea. In summer, DIC concentrations were lower due to dilution
from sea ice melt, terrestrial inputs, and primary production.
Concentrations were found to be as low ~1800 μmoles kg−1
over the inner shelf. We found that DIC concentrations were drawn down 30–150 μmoles kg−1
in the upper 30 m of the water column due to
primary production and calcium carbonate formation between the spring and
summer occupations. Using the seasonal drawdown of DIC, estimated rates of
NCP on the inner, middle, and outer shelf averaged 28 ± 9 mmoles C m−2 d−1.
However, higher rates of NCP (40–47 mmoles C m−2 d−1) were observed in the "Green Belt" where the greatest confluence
of nutrient-rich basin water and iron-rich shelf water occurs. We estimated
that in 2008, total NCP across the shelf was on the order of ~96 Tg C yr−1.
Due to the paucity of consistent, comparable productivity data,
it is impossible at this time to quantify whether the system is becoming
more or less productive. However, as changing climate continues to modify
the character of the Bering Sea, we have shown that NCP can be an important
indicator of how the ecosystem is functioning. |
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