The symbiosis between reef-building corals and photosynthesizing dinoflagellates is the building block of the coral reef system, since corals acquire up to 90% of their nutritional needs from this interaction. Increasing temperature can trigger the disruption of this symbiosis and lead to coral death. This process is called coral bleaching and global warming has increased coral bleaching frequency and severity worldwide. Corals differ in their susceptibility to bleaching due to their morphotype and associated symbiont. Branching corals usually grow faster, but are more vulnerable to bleaching than massive corals. Coral symbionts differ in their thermal tolerance and majorly determine the bleaching threshold of the coral. Corals can harbor a single dominant symbiont type, called specialist, or over one symbiont dominant type, considered generalist. Generalist corals can shuffle their symbionts toward more thermotolerant types, while specialist corals rely on the evolution in thermotolerance of their symbiont populations. Although it is known that coral morphotype and symbiotic strategy are two relevant functional attributes that indicate reef vulnerability to climate change, we still lack a theoretical framework addressing how the rate of increasing temperatures would affect different coral reefs and how critical transitions may occur, thus hindering our understanding of the system and management decisions. In this project, I will use mathematical models to investigate the impact of different global warming scenarios on coral reefs worldwide by incorporating regional differences and the eco-evolutionary aspect of coral symbiosis. By considering the fundamental differences in the dominant coral morphotype and symbiotic strategies among Indo-Pacific, Caribbean and South Atlantic coral reefs, we will bring new and more realistic insights on the vulnerability of coral reefs to suffer critical transitions worldwide.
News published in Agência FAPESP Newsletter about the scholarship: