Heterotrophic plasticity and resilience in bleached corals

Area of Science:

• Marine Biology
• Coral Reef Ecology
• Climate Change Impacts

Background:

• Mass coral bleaching events, driven by rising sea temperatures, cause significant coral mortality globally.
• Increased frequency and severity of bleaching events due to global warming threaten coral reef ecosystems.
• Mechanisms of coral resilience and recovery post-bleaching are not fully understood.

Purpose of the Study:

• To investigate the role of the coral host in resilience and recovery from bleaching.
• To compare the metabolic responses of different coral species following bleaching events.

Main Methods:

• Assessed the feeding rates and carbon assimilation (CHAR) of bleached and recovering coral species (Montipora capitata, Porites compressa, Porites lobata).
• Quantified the contribution of heterotrophic feeding to meet daily metabolic energy requirements.

Main Results:

• Montipora capitata met over 100% of its daily metabolic energy needs through increased feeding and CHAR during recovery.
• Porites compressa and Porites lobata did not exhibit similar increases in feeding and CHAR.
• Coral species with higher CHAR capability demonstrated greater resilience.

Conclusions:

• The coral host's ability to increase feeding and carbon assimilation is crucial for bleaching resilience and recovery.
• Species with high CHAR capability are likely to be more resilient to future bleaching events.
• These resilient coral species may become dominant and help protect reefs from extinction.