Mn/Ca, Mg/Ca and Sr/Ca ratios of multiple chambers of specimens of Ammonia tepida from Lake Grevelingen
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| Autores principales: | , , , , , , , , |
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| Formato: | Dataset Open Access |
| Lenguaje: | en |
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PANGAEA
2018
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| _version_ | 1867169124438769664 |
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| author | Petersen, Jassin Barras, Christine Bézos, Antoine La, Carole de Nooijer, Lennart Jan Meysman, Filip J R Mouret, Aurélia Slomp, Caroline P Jorissen, Frans J |
| author_facet | Petersen, Jassin Barras, Christine Bézos, Antoine La, Carole de Nooijer, Lennart Jan Meysman, Filip J R Mouret, Aurélia Slomp, Caroline P Jorissen, Frans J |
| collection | Datos científicos de ciencias marinas y ambientales |
| contents | The adaptation of some benthic foraminiferal species to low-oxygen conditions provides the prospect of using the chemical composition of their tests as proxies for bottom water oxygenation. Manganese may be particularly suitable as such a geochemical proxy because this redox element is soluble in reduced form (Mn2+) and hence can be incorporated into benthic foraminiferal tests under low-oxygen conditions. Therefore, intra- and inter-test differences in foraminiferal Mn/Ca ratios may hold important information about short-term variability in pore water Mn2+ concentrations and sediment redox conditions. Here, we studied Mn/Ca intra- and inter-test variability in living individuals of the shallow infaunal foraminifer Ammonia tepida sampled in Lake Grevelingen (the Netherlands) in three different months of 2012. The deeper parts of this lake are characterized by seasonal hypoxia/anoxia with associated shifts in microbial activity and sediment geochemistry, leading to seasonal Mn2+ accumulation in the pore water. Earlier laboratory experiments with similar seawater Mn2+ concentrations as encountered in the pore waters of Lake Grevelingen suggest that intra-test variability due to ontogenetic trends (i.e. size-related effects) and/or other vital effects occurring during calcification in A. tepida (11-25% relative SD, RSD) is responsible for part of the observed variability in Mn/Ca. Our present results show that the seasonally highly dynamic environmental conditions in the study area lead to a strongly increased Mn/Ca intra- and inter-test variability (average of 45% RSD). Within single specimens, both increasing and decreasing trends in Mn/Ca ratios with size are observed. Our results suggest that the variability in successive single-chamber Mn/Ca ratios reflects the temporal variability in pore water Mn2+. Additionally, active or passive migration of the foraminifera in the surface sediment may explain part of the observed Mn/Ca variability. |
| format | Dataset Open Access |
| id | pangaea_https___doi_org_10_1594_PANGAEA_885145 |
| institution | PANGAEA |
| language | en |
| publishDate | 2018 |
| publisher | PANGAEA |
| record_format | pangaea |
| spellingShingle | Mn/Ca, Mg/Ca and Sr/Ca ratios of multiple chambers of specimens of Ammonia tepida from Lake Grevelingen Petersen, Jassin Barras, Christine Bézos, Antoine La, Carole de Nooijer, Lennart Jan Meysman, Filip J R Mouret, Aurélia Slomp, Caroline P Jorissen, Frans J Chamber number; DATE/TIME; DEPTH, sediment/rock; GCUWI; Gravity corer, UWITEC; Lake_Grevelingen_S2; Laser-ablation inductively coupled plasma mass spectrometer (LA-ICP-MS); Magnesium/Calcium ratio; Manganese/Calcium ratio; Number of specimens; Strontium/Calcium ratio; The Netherlands The adaptation of some benthic foraminiferal species to low-oxygen conditions provides the prospect of using the chemical composition of their tests as proxies for bottom water oxygenation. Manganese may be particularly suitable as such a geochemical proxy because this redox element is soluble in reduced form (Mn2+) and hence can be incorporated into benthic foraminiferal tests under low-oxygen conditions. Therefore, intra- and inter-test differences in foraminiferal Mn/Ca ratios may hold important information about short-term variability in pore water Mn2+ concentrations and sediment redox conditions. Here, we studied Mn/Ca intra- and inter-test variability in living individuals of the shallow infaunal foraminifer Ammonia tepida sampled in Lake Grevelingen (the Netherlands) in three different months of 2012. The deeper parts of this lake are characterized by seasonal hypoxia/anoxia with associated shifts in microbial activity and sediment geochemistry, leading to seasonal Mn2+ accumulation in the pore water. Earlier laboratory experiments with similar seawater Mn2+ concentrations as encountered in the pore waters of Lake Grevelingen suggest that intra-test variability due to ontogenetic trends (i.e. size-related effects) and/or other vital effects occurring during calcification in A. tepida (11-25% relative SD, RSD) is responsible for part of the observed variability in Mn/Ca. Our present results show that the seasonally highly dynamic environmental conditions in the study area lead to a strongly increased Mn/Ca intra- and inter-test variability (average of 45% RSD). Within single specimens, both increasing and decreasing trends in Mn/Ca ratios with size are observed. Our results suggest that the variability in successive single-chamber Mn/Ca ratios reflects the temporal variability in pore water Mn2+. Additionally, active or passive migration of the foraminifera in the surface sediment may explain part of the observed Mn/Ca variability. |
| title | Mn/Ca, Mg/Ca and Sr/Ca ratios of multiple chambers of specimens of Ammonia tepida from Lake Grevelingen |
| topic | Chamber number; DATE/TIME; DEPTH, sediment/rock; GCUWI; Gravity corer, UWITEC; Lake_Grevelingen_S2; Laser-ablation inductively coupled plasma mass spectrometer (LA-ICP-MS); Magnesium/Calcium ratio; Manganese/Calcium ratio; Number of specimens; Strontium/Calcium ratio; The Netherlands |
| url | https://doi.org/10.1594/PANGAEA.885145 |