Coral reefs cover less than 1% of the ocean floor, yet they support approximately 25% of all known marine species. Tiny animals called coral polyps built these underwater ecosystems over thousands of years. Reefs serve as nurseries for young fish, hunting grounds for predators, and shelters for countless organisms. Scientists estimate that coral reefs provide food and income for about 500 million people worldwide, mostly in developing coastal nations.

Despite their importance, coral reefs are disappearing at an alarming rate. Scientists estimate that the world has already lost about half of its coral reef cover since the 1950s. The main threat is rising ocean temperatures caused by climate change. When water gets too warm, corals expel the colorful algae living in their tissues and turn white. This process is called bleaching. Without these algae, corals lose their main food source and often die.

Ocean acidification poses another serious threat. As the ocean absorbs carbon dioxide from the atmosphere, seawater becomes more acidic. The acid makes it harder for corals to build their calcium carbonate skeletons, and the whole reef structure grows weaker. Pollution from farm runoff and harmful fishing practices add even more stress. Together, these pressures are pushing many reefs past the point of recovery.

Conservation efforts offer some hope. In marine protected areas, fishing is restricted, and damaged reefs have shown they can partly recover when given time. Scientists are growing heat-resistant coral varieties in laboratories and moving them onto damaged reefs. Some communities have built sustainable tourism programs that fund reef protection while providing local jobs. However, researchers stress that local efforts alone will not be enough. Without action on climate change, even the best conservation work cannot save the world's coral reefs.