Coral Polyp Photosynthesis–Irradiance Curve

This simulator zooms into a single coral polyp to model the everyday engine of a reef: the endosymbiosis between the coral animal and its photosynthetic algae, Symbiodinium. A live 3D cutaway shows sunlight photons striking the algae-laden gastrodermis, triggering oxygen bubbles and translocated sugars that feed the coral host, while a real photosynthesis-irradiance curve — including saturation and photoinhibition — drives every number on screen. Adjust irradiance, water temperature and symbiont density to see the P–I curve shift, watch the oxygen and carbon-translocation flux respond, and see how the resulting photosynthetic surplus scales light-enhanced calcification, the same mechanism reef corals use to build their skeletons faster during the day than at night.