Coral Reef Health Simulator

Threats to Coral Reefs

Coral reefs cover less than 1% of the ocean floor but support over 25% of all marine life. However, they are highly sensitive to environmental changes:

• Thermal Stress (Bleaching): Corals have a symbiotic relationship with tiny algae (zooxanthellae) living in their tissues, which provide them with food and color. When water gets too warm (or too cold), corals become stressed and expel these algae, turning stark white. If temperatures don't return to normal quickly, the bleached coral will starve and die.
• Ocean Acidification: As the ocean absorbs excess CO₂ from the atmosphere, its pH drops. More acidic water reduces the availability of carbonate ions, which corals desperately need to build their hard, limestone skeletons. This causes them to grow slower and become brittle.
• Nutrient Pollution: Fertilizer runoff and untreated sewage introduce excess nutrients (nitrogen and phosphorus) into the reef. This triggers massive blooms of macroalgae that block sunlight and physically smother the slow-growing corals.