An Electrochemical Approach to Understanding Coral Bleaching

Coral bleaching, a worsening crisis driven by climate change, occurs when the symbiotic relationship between corals and intracellular dinoflagellate algae deteriorates. The dinoflagellates supply the corals with photosynthetically fixed carbon while receiving nutrients and protection in return, however, elevated temperatures can disrupt this symbiosis, leading to the expulsion of the dinoflagellates and resulting in 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.