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| Titel |
Sediment DSi and DIP fluxes under simulated redox conditions |
| VerfasserIn |
Love-Raoul Nteziryayo, Åsa Danielsson |
| Konferenz |
EGU General Assembly 2017
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| Medientyp |
Artikel
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| Sprache |
en
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 19 (2017) |
| Datensatznummer |
250138318
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| Publikation (Nr.) |
 EGU/EGU2017-1294.pdf |
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| Zusammenfassung |
| The Baltic Sea is one of the most eutrophic water bodies in the world. This eutrophication of
the Baltic Sea has resulted in the expansion of areas of hypoxic bottom waters. Hypoxia is
known to cause the release of dissolved inorganic phosphorus (DIP) from sediment. It is
largely assumed that dissolved silica (DSi) reacts in an analogous way in hypoxic conditions.
From sediment incubation experiments, we found that P reacts faster to oxygen changes than
Si. Here we show that DSi and DIP behave differently to changing oxygen concentrations in
the bottom waters, and that the adsorption and de-sorption on Fe oxihydroxides may
control the release of P more efficiently than of Si. The results showed that DSi
fluxes were higher under oxic conditions (2.21±0.28 mmol Si m−2d−1) than under
hypoxic conditions (1.36±0.29 mmol Si m−2d−1). The opposite was observed
for P fluxes (0.06 ±0.01 and 0.10±0.09 mmol P m−2d−1) under oxic respective
hypoxic conditions). Our results indicate that the increase of hypoxic conditions in
coastal areas may directly cause the decrease of Si fluxes from sediment and thereby
contribute to the diminishing Si concentrations observed in the Baltic Sea waters. |
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