Multiple carbonate system parameters independently govern shell formation in a marine mussel

• Published in: Communications Earth & Environment
• Main Authors: Aaron T. Ninokawa, Alisha M. Saley, Roya Shalchi, Brian Gaylord
• Format: Article in Journal/Newspaper
• Language: English
• Published: Nature Portfolio 2024
• Subjects: Geology; QE1-996.5; Environmental sciences; GE1-350; Ocean acidification
• Online Access: https://doi.org/10.1038/s43247-024-01440-5; https://doaj.org/article/a0c5e1abf86c4f5bbce7f286ff22e12b

Abstract Calcification is vital to marine organisms that produce calcium carbonate shells and skeletons. However, how calcification is impacted by ongoing environmental changes, including ocean acidification, remains incompletely understood due to complex relationships among the carbonate system variables hypothesized to drive calcification. Here, we experimentally decouple these drivers in an exploration of shell formation in adult marine mussels, Mytilus californianus. In contrast to models that focus on single parameters like calcium carbonate saturation state, our results implicate two independent factors, bicarbonate concentration and seawater pH, in governing calcification. While qualitatively similar to ideas embodied in the related substrate-inhibitor ratio (bicarbonate divided by hydrogen ion concentration), our data highlight that merging bicarbonate ion and hydrogen ion concentrations into a simple quotient obscures important features of calcification. Considering a dual-parameter framework improves mechanistic understanding of how calcifiers interact with complex and changing chemical conditions.