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| Titel |
Influence of the Amazon River on dissolved and intra-cellular metal concentrations in Trichodesmium colonies along the western boundary of the sub-tropical North Atlantic Ocean |
| VerfasserIn |
A. Tovar-Sanchez, S. A. Sañudo-Wilhelmy |
| 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 ; 8, no. 1 ; Nr. 8, no. 1 (2011-01-28), S.217-225 |
| Datensatznummer |
250005356
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| Publikation (Nr.) |
 copernicus.org/bg-8-217-2011.pdf |
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| Zusammenfassung |
| Despite the ecological importance of Trichodesmium spp. for the global oceanic nitrogen
budget, there is limited information on their trace metal composition in
field samples. We report dissolved (<0.22 μm) metal concentrations
measured in surface waters (Ag, Cd, Co, Cu, Fe, Mo, Ni, P, Pb and V) and in
the total and the intracellular pool (Ag, Al, Cd, Co, Cu, Fe, Mn, Mo, Ni, P,
Pb, V) of Trichodesmium populations collected in the western subtropical North Atlantic
Ocean (April–May 2003) within the influence of the Amazon River plume.
Dissolved element distributions were strongly influenced by the River
discharge, with concentrations of some elements varying directly (i.e. Cd,
Mo and V) or inversely (Ag, Co, Cu, Fe, Ni, P and Pb) with surface salinity.
Intracellular metal values to phosphorous ratios (mol:mol) for Cd, Co, Cu,
Fe, Mn, Mo, Ni and V ranged from 9.0 × 10−6 for Cd to 4.4 × 10−2 for
Fe. Although total metal composition was significantly correlated with the
intracellular content in the Trichodesmium colonies for some elements (e.g., Co, Cu, V),
metal pools in the phytoplankton did not co-vary with the dissolved metal
concentrations, suggesting that water column measurements may not be good
predictors of the intracellular metal concentrations. The impact of physical
parameters and bioactive elements on biological processes such as nitrogen
fixation, carbon drawdown and biomass production in Trichodesmium colonies was explored by
using a principal component analysis test (PCA). The analysis indicated that
the biological drawdown of dissolved inorganic carbon (DIC) by
Trichodesmium seems to be influenced by the internal content of Fe, Co, Cd, and Cu, while
nitrogen fixation seems more influenced by mixed layer depth and dissolved
Fe and Ni concentrations. |
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