What Through identifying novel light handling strategies in nature and resolving the function of green fluorescent pigments in corals, this work will provide the very basis for novel bio-inspired photonics approaches. Why I will investigate the biophotonic properties of symbiotic reef-building corals. Although light is the prime controlling factor of the coral-algal symbiosis, the fundamental optical properties of corals remain to be resolved. The successful outcome will advance our understanding of coral ecophysiology and will allow us to predict the energy efficiency of corals. How The work describes a highly interdisciplinary approach combining marine biology with biomedical optics in order to push the frontiers of marine science research.