Iron and manganese in Antarctic bivalves: Indicators of change in near-shore biogeochemistry?
This thesis focuses on the assimilation of Fe and Mn by the Antarctic bivalve Laternula elliptica and their incorporation into the carbonate shell, to survey a potential suitability of Fe and Mn contents in the bivalve shell as proxies for the melt water driven sediment load into the coastal environ...
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| Format: | Thesis |
| Language: | unknown |
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2013
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| Online Access: | http://oops.uni-oldenburg.de/1823/ http://oops.uni-oldenburg.de/1823/1/poiiro13.pdf |
| Summary: | This thesis focuses on the assimilation of Fe and Mn by the Antarctic bivalve Laternula elliptica and their incorporation into the carbonate shell, to survey a potential suitability of Fe and Mn contents in the bivalve shell as proxies for the melt water driven sediment load into the coastal environment of King George Island (Antarctic Peninsula). This thesis shows that Fe and Mn are not suited as proxies: No high spatial (temporal) resolution analyses in the chondrophore (part of the shell) were possible due to low Fe and Mn contents in seasonal growth layers. The chondrophore exists of up to 3 different CaCO3 polymorphs (calcite, aragonite, vaterite), which affect the metal incorporation differently. Potential environmental influences on element incorporation into the shell matrix are readily overprinted by a strong physiological influence. Iron precipitated from pore water appears as main assimilation source by L. elliptica. |
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