Research output per year
Research output per year
I. Brinkmann, S. Ni, M. Schweizer, V. E. Oldham, N. B. Quintana Krupinski, K. Medjoubi, A. Somogyi, M. J. Whitehouse, C. M. Hansel, C. Barras, J. M. Bernhard, H. L. Filipsson
Research output: Contribution to journal › Article › peer-review
Hypoxia is of increasing concern in marine areas, calling for a better understanding of mechanisms leading to decreasing dissolved oxygen concentrations ([O2]). Much can be learned about the processes and implications of deoxygenation for marine ecosystems using proxy records from low-oxygen sites, provided proxies, such as the manganese (Mn) to calcium (Ca) ratio in benthic foraminiferal calcite, are available and well calibrated. Here we report a modern geochemical data set from three hypoxic sites within the Santa Barbara Basin (SBB), USA, where we study the response of Mn/Caforam in the benthic foraminifer Nonionella stella to variations in sedimentary redox conditions (Mn, Fe) and bottom-water dissolved [O2]. We combine molecular species identification by small subunit rDNA sequencing with morphological characterization and assign the SBB N. stella used here to a new phylotype (T6). Synchrotron-based scanning X-ray fluorescence (XRF) imaging and Secondary Ion Mass Spectrometry (SIMS) show low Mn incorporation (partition coefficient DMn < 0.05) and limited proxy sensitivity of N. stella, at least within the range of dissolved [O2] (2.7–9.6 μmol/l) and Mnpore-water gradients (2.12–21.59 μmol/l). Notably, even though intra- and interspecimen Mn/Ca variability (33% and 58%, respectively) was only partially controlled by the environment, Mn/Caforam significantly correlated with both pore-water Mn and bottom-water [O2]. However, the prevalent suboxic bottom-water conditions and limited dissolved [O2] range complicate the interpretation of trace-elemental trends. Additional work involving other oxygenation proxies and samples from a wider oxygen gradient should be pursued to further develop foraminiferal Mn/Ca as an indicator for hypoxic conditions.
Original language | English |
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Article number | e2020PA004167 |
Journal | Paleoceanography and Paleoclimatology |
Volume | 36 |
Issue number | 11 |
DOIs | |
Publication status | Published - 2021 Nov |
Research output: Thesis › Doctoral Thesis (compilation)
Brinkmann, I. (Research student), Filipsson, H. (Supervisor), Bernhard, J. M. (Supervisor), Barras, C. (Supervisor) & Schweizer, M. (Supervisor)
2018/06/01 → 2022/12/31
Project: Dissertation
Filipsson, H. (PI), Brinkmann, I. (Research student), Bernhard, J. M. (Researcher), Barras, C. (Researcher), Schweizer, M. (Researcher), Geslin, E. (Researcher) & Ni, S. (Research student)
The Royal Physiographic Society in Lund, Swedish Research Council
2017/12/01 → 2022/12/31
Project: Dissertation
Filipsson, H. (First/primary/lead supervisor)
Activity: Examination and supervision › Supervision of PhD students