Coral Reef Bleaching Simulator

Coral reefs depend on a fragile symbiosis: coral polyps host microscopic zooxanthellae algae that photosynthesize and share sugars with their host in exchange for shelter and nutrients — the partnership behind both the reef's vivid color and most of its energy budget. This simulator models that relationship directly. Raise the water temperature and thermal stress accumulates on every colony, gradually expelling their algae and bleaching the reef from color toward white; hold it below the coral's tolerance and the reef slowly recovers. Sunlight level shapes how vividly a healthy reef glows, current speed sways coral branches and carries plankton and fish through the scene, and polyp density controls how much of the reef floor is colonized. Reef fish populations track overall reef health, echoing how bleaching events ripple outward into the wider biodiversity a healthy reef supports.