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| Titel |
Polar coralline algal CaCO3-production rates correspond to intensity and duration of the solar radiation |
| VerfasserIn |
S. Teichert, A. Freiwald  |
| 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 ; 11, no. 3 ; Nr. 11, no. 3 (2014-02-11), S.833-842 |
| Datensatznummer |
250117199
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| Publikation (Nr.) |
 copernicus.org/bg-11-833-2014.pdf |
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| Zusammenfassung |
In this study we present a comparative quantification of CaCO3
production rates by rhodolith-forming coralline red algal communities
situated in high polar latitudes and assess which environmental parameters
control these production rates. The present rhodoliths act as ecosystem
engineers, and their carbonate skeletons provide an important ecological
niche to a variety of benthic organisms. The settings are distributed along
the coasts of the Svalbard archipelago, being Floskjeret (78°18' N)
in Isfjorden, Krossfjorden (79°08' N) at the eastern coast of
Haakon VII Land, Mosselbukta (79°53' N) at the eastern coast of
Mosselhalvøya, and Nordkappbukta (80°31' N) at the northern
coast of Nordaustlandet. All sites feature Arctic climate and strong
seasonality.
The algal CaCO3 production rates were calculated from fuchsine-stained,
presumably annual growth increments exhibited by the rhodoliths and range
from 100.9 g (CaCO3) m−2 yr−1 at Nordkappbukta to 200.3 g
(CaCO3) m−2 yr−1 at Floskjeret. The rates correlate to
various environmental parameters with geographical latitude being the most
significant (negative correlation, R2 = 0.95, p = 0.0070), followed by the
duration of the polar night (negative correlation, R2 = 0.93, p = 0.0220),
the duration of the sea ice cover (negative correlation, R2 = 0.87,
p = 0.0657), and the annual mean temperature (positive correlation,
R2 = 0.48, p = 0.0301).
This points out sufficient light incidence to be the main control of the
growth of the examined coralline red algal rhodolith communities, while
temperature is less important. Thus, the ongoing global change with its
rising temperatures will most likely result in impaired conditions for the
algae, because the concomitant increased global runoff will decrease water
transparency and hence light incidence at the four offshore sites. Regarding
the aforementioned role of the rhodoliths as ecosystem engineers, the impact
on the associated organisms will presumably also be negative. |
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