AbstractMarine protected areas (MPAs) are a crucial component of international biodiversity conservation commitments, yet are increasingly affected by climate change. No synthesis or analysis exists of the specific on‐the‐ground management actions that have been taken by MPA managers in response to climate change. Here, we extract, evaluate, classify, and analyze adaptation responses from 646 existing, English‐language MPA management plans preselected for their consideration of climate change. Our synthesis documents 213 unique management actions, of which only a fraction (4.7%) were on‐the‐ground adaptative measures directed at enhancing biodiversity conservation; in contrast, almost half (45.5%) were monitoring measures. Our analysis highlights the apparent paucity of documented management actions addressing the challenging task of limiting climate change impacts on biodiversity within MPAs—a “biodiversity adaptation gap”. By compiling a community resource of adaptation approaches that can be further expanded and disseminated, we hope to contribute to the effort to adapt MPA networks to climate change.