Global warming is one of the main causes of coral bleaching. Coral bleaching occurs when the symbiotic algae (zooxanthellae) that live within coral tissue are expelled or die off. The algae are responsible for providing corals with much of their energy requirements. When corals are subjected to prolonged periods of high sea surface temperatures, the symbiotic relationship between the coral and the algae can break down, and the algae may be expelled or die off. The coral then turns white or "bleaches," which makes it more susceptible to disease and mortality. Warmer water temperatures due to global warming are one of the primary drivers of coral bleaching events worldwide. As ocean temperatures continue to rise, the frequency and severity of coral bleaching events are likely to increase, with potentially devastating consequences for coral reef ecosystems and the many species that depend on them.