The main cause of coral bleaching is elevated water temperatures, often linked to climate change. When corals experience thermal stress, they expel the symbiotic algae, known as zooxanthellae, that live within their tissues and provide them with energy through photosynthesis. This loss of algae not only affects the coral’s color—leading to the "bleached" appearance—but also compromises their health and survival. Prolonged bleaching can lead to coral death, disrupting the entire marine ecosystem that depends on healthy coral reefs. Other stressors, like pollution and ocean acidification, can exacerbate bleaching events.