Marine heatwaves caused by climate change are becoming more frequent and intense, causing mass mortality events and chronic stress in marine species globally.
Marine heatwaves cause both acute suffering through direct thermal stress and chronic welfare compromise through ecosystem disruption. Animals unable to thermoregulate or relocate experience physiological stress at temperatures outside their tolerance range, followed by starvation as prey collapses. Colony-breeding seabirds are particularly vulnerable as they cannot move breeding sites but face local prey depletion. The frequency of these events makes recovery between heatwaves impossible for many populations.