Chemical and structural variations of bivalve shells at the micrometer scale - taking sclerochronology to the next level

• Applicant: Professor Dr. Bernd R. Schöne
• Subject Area: Palaeontology ; Oceanography
• Term: from 2019 to 2023
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 415854995

• Final Report Year: 2024

Final Report Abstract

The cooperation project between Germany and Japan assessed the use of trace and minor elements (TMEs) of bivalve shells as environmental proxies. Driven by previous observations according to which the incorporation of TMEs into mollusk shells is strongly affected by non-environmental fractionation processes, it was explored if the quantification and mathematical removal of vital effects would enable or improve the usability and robustness of TMEs as environmental proxies. Thus, combined analyses of the shell element chemistry (LA-ICP-MS), ultrastructure (SEM) as well as ontogenetic age and growth rate (δ18O, increment width) were conducted, predominantly in field and lab-grown specimens of Arctica islandica. Results of this project contributed significantly to the understanding of how paleoenvironmental conditions can be reconstructed from shell TMEs. Aside from the need to conduct a combined analysis of chemical, ultrastructural and physiological properties, measurements need to be confined to the iOSL or oOSL as well as a single ultrastructure category. Specifically, this study shed new light on the long-debated use of Sr/Cashell as a temperature proxy. The analytical strategies explored here for the ocean quahog, A. islandica, should be tested with other species in future research projects.

Publications

• Advances of sclerochronology research in the last decade. Palaeogeography, Palaeoclimatology, Palaeoecology, 570, 110371.
  Peharda, Melita; Schöne, Bernd R.; Black, Bryan A. & Corrège, Thierry
  
• Reading the diaries of life – Current advances in sclerochronological research. Palaeogeography, Palaeoclimatology, Palaeoecology, 570, 110373.
  Peharda, Melita; Schöne, Bernd R.; Black, Bryan A. & Corrège, Thierry
  
• Importance of Weighting High-Resolution Proxy Data From Bivalve Shells to Avoid Bias Caused by Sample Spot Geometry and Variability in Seasonal Growth Rate. Frontiers in Earth Science, 10.
  Schöne, Bernd R.; Marali, Soraya; Mertz-Kraus, Regina; Butler, Paul G.; Wanamaker, Alan D. & Fröhlich, Lukas
  
• Strong Coupling between Biomineral Morphology and Sr/Ca of Arctica islandica (Bivalvia)—Implications for Shell Sr/Ca-Based Temperature Estimates. Minerals, 12(5), 500.
  Brosset, Cornélia; Höche, Nils; Shirai, Kotaro; Nishida, Kozue; Mertz-Kraus, Regina & Schöne, Bernd R.
  
• Can element chemical impurities in aragonitic shells of marine bivalves serve as proxies for environmental variability?. Chemical Geology, 616, 121215.
  Schöne, Bernd R.; Marali, Soraya; Jantschke, Anne; Mertz-Kraus, Regina; Butler, Paul G. & Fröhlich, Lukas
  
• Data for "Sr/Ca in shells of laboratory-grown bivalves (Arctica islandica) serves as a proxy for water temperature – Perspectives for (paleo)environmental research?" [Data set]. Zenodo.
  Brosset, C., Höche, N., Witbaard, R., Nishida, K., Shirai, K., Mertz-Kraus, R. & Schöne, B. R.
  
• Shell microstructures (disturbance lines) of Arctica islandica (Bivalvia): a potential proxy for severe oxygen depletion. Frontiers in Marine Science, 10.
  Höche, Nils; Zettler, Michael L.; Huang, Xizhi & Schöne, Bernd R.
  
• Sr/Ca in shells of laboratory-grown bivalves (Arctica islandica) serves as a proxy for water temperature – implications for (paleo)environmental research?. Frontiers in Marine Science, 10.
  Brosset, Cornélia; Höche, Nils; Witbaard, Rob; Nishida, Kozue; Shirai, Kotaro; Mertz-Kraus, Regina & Schöne, Bernd R.