The physiology of a resident Symbiodinium species often regulates the bleaching susceptibility of a coral. Therefore, a significant amount of research has focused on characterizing the physiological basis of thermal tolerance and in identifying the ecology and distribution of thermally tolerant symbiont species.
Given that the symbiotic relationship between a coral and its Symbiodinium species affects its susceptibility to bleaching, researchers have focused on uncovering the physiological factors that enable thermal tolerance and identifying the ecological habitats and geographical distribution of heat-resistant symbiont species.