Abstract
In April 2022, mass stranding of weedy (common) seadragons occurred, with a total of over 200 individuals washed ashore on beaches in the Sydney, Australia region, recorded by citizens. Causes of the stranding, which is unprecedented, were likely related to a series of east coast low storm events, leading to record wave heights, record coastal rainfall, and potential loss of critical food sources (schooling mysid crustaceans). A significant proportion of the local population was likely lost in this series of events, indicating a future threat to seadragons, with east coast low intensity predicted to increase under human‐caused climate change.