An Electrochemical Approach to Understanding Coral Bleaching

Coral bleaching is a growing catastrophe resulting from climate change. Coral animals rely on symbiosis with intracellular dinoflagellate algae. The dinoflagellates provide the host with photosynthetically fixed carbon, and receive other nutrients and physical protection in return. This symbiosis breaks down under some conditions, including raised temperatures, resulting in expulsion of the dinoflagellates and bleaching.

All photosynthetic microorganisms exhibit exoelectrogenesis, where electrons from photosynthesis are exported extracellularly. The project will develop electrochemical approaches for measuring exoelectrogenesis by the dinoflagellate Symbiodinium, the genus whose members form symbiosis with corals. It will study how external stresses may disturb photosynthesis, affecting redox signalling via exoelectrogenesis. Several mutant cell lines are available in which photosynthesis has been directly compromised; these will be included in the study. Overall, the project will provide direct indications of how disturbance of photosynthesis affects the redox exchange between dinoflagellates and their hosts.