Substantial Limitations of Ocean Alkalinity Enhancement in Mitigating the Negative Impacts of Ocean Acidification on Marine Calcifiers.

ABSTRACT: Ocean Alkalinity Enhancement (OAE) is increasingly considered as a marine carbon dioxide removal (mCDR) strategy with the potential cobenefit of mitigating ocean acidification (OA), but this remains poorly constrained. Here, we evaluate these biological cobenefits for 27 marine calcifiers whose calcification has declined under OA, by quantifying both historical OA-driven calcification losses and the potential of OAE to reverse them under scenarios with and without air-sea equilibration. Regression models describing calcification as a function of TA-DIC reveal substantial declines since preindustrial times, particularly in linear responders (mean 22%, range 7-44%), such as gastropods and pteropods, while threshold responders show minimal decline (∼3%). A realistic addition of 50 μmol kg

SUBMITTER: van de Mortel H 

PROVIDER: S-EPMC12810250 | biostudies-literature | 2026 Jan

REPOSITORIES: biostudies-literature