Can reef-building corals keep evolutionary pace with global warming?

A project undertaken at The University of Wollongong, and supervised by Emily Howells

Additional Participant:           Dr David Abrego, University of Wollongong

Coral reefs are among the most biodiverse ecosystems on the planet and the services they provide to the environment, economies and societies are valued at trillions of dollars per year. Their evolutionary success is attributed to productive symbioses between coral animals, beneficial algae and bacteria which grow the living foundation of the ecosystem. However, coral symbioses are very sensitive to changes in their environment, and are negatively impacted by the effects of climate warming. Anomalously warm temperatures cause coral bleaching, a severe stress response involving symbiosis breakdown, coral starvation and death. Warm water bleaching events have contributed to significant losses of coral from all ocean basins and coral reefs have recently experienced their third global die-off due to rising sea temperatures. The future persistence of corals depends on whether rates of adaptation can keep pace with climate warming.

Our project will provide timely knowledge on the potential for Australian coral populations to adapt to climate warming based on their standing genetic variation. We will undertake breeding experiments and genomic profiling to identify heat tolerant phenotypes and the underlying genotypes upon which natural selection acts. Population genomics will then be used to measure the abundance of heat tolerant genotypes within and among reefs, and if they are increasing over time. Our research focusses on populations of the common brain coral Platygyra daedalea (Figure 1) on the Great Barrier Reef and in Western Australia. The findings are expected to improve predictions of coral reef futures and inform the best management strategies for their conservation.


Figure 1. Platygyra daedalea (right) is commonly found on shallow near shore reefs in the Indo-Pacific