Coral bleaching is primarily caused by environmental stressors such as increased water temperatures, pollution, changes in salinity, and exposure to sunlight. However, the main factor contributing to coral bleaching is the warming of ocean waters due to climate change. When corals experience prolonged exposure to high temperatures, they expel the colorful algae living in their tissues, causing them to turn white and appear bleached. Without these algae, corals lose their main source of food and energy, making them more vulnerable to disease and death. Other factors like pollution and sedimentation can also contribute to coral bleaching by further stressing already weakened corals.
