Marine heatwaves are increasing in frequency and intensity, causing mass mortality events and severe welfare harm to fish, marine mammals and seabirds.
Marine heatwaves cause acute mass suffering and death at unprecedented scale. Fish killed by thermal shock die slowly as oxygen-depleted warm water suffocates them. Seabirds feeding emaciated chicks during prey shortfalls cause both adult and chick welfare harm. Climate mitigation is the only effective intervention.