Testing planktic foraminiferal shell weight as a surface water [CO32−] proxy using plankton net samples

• Published in: Geology
• Main Authors: Beer, Christopher J., Schiebel, Ralf, Wilson, Paul-A.
• Other Authors: National Oceanography Centre Southampton (NOC), University of Southampton, Laboratoire de Planétologie et Géodynamique - Angers (LPG-ANGERS), Laboratoire de Planétologie et Géodynamique UMR 6112 (LPG), Université d'Angers (UA)-Université de Nantes - UFR des Sciences et des Techniques (UN UFR ST), Université de Nantes (UN)-Université de Nantes (UN)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université d'Angers (UA)-Université de Nantes - UFR des Sciences et des Techniques (UN UFR ST), Université de Nantes (UN)-Université de Nantes (UN)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2010
• Subjects: [SDU]Sciences of the Universe [physics]; ice core
• Online Access: https://univ-angers.hal.science/hal-03277996; https://doi.org/10.1130/G30150.1

International audience Planktic foraminiferal size-normalized weight (SNW) has been used as a proxy for both past changes in deepwater dissolution and surface ocean [CO2- 3], the latter potentially providing a way to evaluate paleoatmospheric pCO2 variations beyond the ice core records. Here we examine the relationship between SNW in modern planktic foraminifera and surface water [CO2- 3] in the Arabian Sea using a suite of samples obtained from plankton net casts in surface waters having a large range in their carbon chemistry. Our results reveal substantial interspecies-and intraspecies-specific variations in the strength, gradient, and even sign of this relationship, indicating that [CO2- 3] does not exert a dominant control on foraminiferal test weight. Similarly, foraminiferal abundance data do not lend support to the hypothesis that SNW responds to optimal growth conditions. Further work is needed, perhaps in laboratory cultures, to determine those environmental factors that are simply correlated with SNW and those that exert control.