This paper warrants selection as a highlight due to its comprehensive synthesis of ocean alkalinity enhancement (OAE) impacts on marine calcifiers, offering essential insights for understanding potential ecological risks of this climate mitigation approach. By leveraging data from 96 studies and capturing responses across eleven biological groups, the paper establishes a predictive framework for biological responses to OAE. This work addresses a critical gap in OAE research, providing a precautionary guideline that can inform future studies, guide regional applications, and communicate risks to stakeholders.