Learning from the past is not enough to survive present and future bleaching threshold temperatures

Area of Science:

• Marine Biology
• Climate Change Ecology
• Coral Reef Science

Background:

• Mass coral bleaching events are increasing due to prolonged seawater temperature anomalies.
• Coral survival depends on species-specific responses, potentially influenced by ecological and physiological memory.
• Understanding coral memory is crucial for predicting future survival strategies under climate change.

Purpose of the Study:

• To investigate the role of life-history traits, location, and season on coral responses to thermal stress.
• To simulate past, present, and future seawater temperatures in laboratory experiments.
• To assess coral survival and resilience based on accumulated thermal stress experiences.

Main Methods:

• Collected corals with diverse life-history traits from a variable and a stable site.
• Exposed corals to simulated past (29 °C), present (31 °C), and future (33 °C) bleaching threshold temperatures.
• Sampled across two seasons to evaluate seasonal influences on thermal stress response.

Main Results:

• Corals survived at 29 °C and 31 °C, but high mortality occurred in a fast-growing species at 33 °C.
• A slow-growing, temperature-resistant species showed better survival at elevated temperatures.
• Corals from the variable site and sampled during spring demonstrated enhanced resilience to thermal stress.

Conclusions:

• Life-history traits significantly influence coral responses to thermal anomalies.
• Ecological and physiological memory, shaped by location and season, plays a role in coral resilience.
• Findings provide insights into coral adaptation mechanisms for future climate change scenarios.