Foraminifer Shell Weight and Fragmentation: A Quantitative Study of the Influence of Temperature, [CO32-] and Dissolution on Proxies of the Marine Carbonate System

Abstract:

Quantifying the various components of the marine carbonate system is important for understanding anthropogenic ocean acidification, and the rates and magnitudes of ocean acidification/ alkalization events in Earth’s past. We performed multiple statistical analyses (factor analysis, partial correlations, multiple regression analysis and independent samples t –tests) on core top data using the Globorotalia menardii fragmentation index (MFI) in 89 core tops from across the tropical Pacific, Atlantic and Indian Oceans, the fragmentation trend of four species of foraminifers (Globorotalia truncatulinoides, G. menardii, Neogloboquadrina dutertrei and Pulleniatina obliquiloculata) in the EEP, tropical Atlantic and tropical Indian Ocean core tops, and Globorotalia menardii shell weight in a suite of 25 core tops the EEP in order to isolate the effects of surface ocean parameters such as temperature and [CO₃^2-] from dissolution in sediments. Surface ocean parameters showed no significant effect on the G. menardii fragmentation index. We found no statistically significant influence of habitat water temperature or [CO₃^2-] on foraminifer fragmentation in any of four species. While we found a strong influence of habitat water [CO₃^2-] on the size normalized shell weight proxy in N. dutertrei and Pulleniatina obliquiloculata in our previous work, we found a much reduced influence of [CO₃^2-] on the shell weight of G. menardii, which is most influenced by shell dissolution.