Marine heatwaves pose severe risks to marine ecosystems, including coral reefs, coastal habitats, and species dependent on stable ocean temperatures. Coral bleaching and habitat loss can disrupt biodiversity, while food-web disruptions may impact fisheries and human communities reliant on marine resources. Harmful algal blooms triggered by heatwaves can further degrade water quality and harm marine life. These events also weaken ecosystems' ability to recover from future stressors, amplifying the long-term risks associated with climate change.