Ocean temperatures are getting warmer and hot temperatures can kill corals and degrade reefs. Throughout the 2023 Great Barrier Reef mass spawning season we are trialling two interventions – artificial selection and selective breeding – that aim to breed corals that are tolerant to high temperatures. Tolerant corals might be used to restore reefs threatened by climate change.
Selective breeding and artificial selection are both types of assisted evolution – approaches which aim to accelerate the rate of adaptation and produce offspring with comparatively high thermal tolerance.
Selective breeding
We can harness the natural reproductive cycle of corals to breed corals for reef restoration and adaptation initiatives. Selectively breeding temperature-tolerant corals involves:
1. Finding and collecting heat-tolerant parent corals.
2. Supporting the parent corals to naturally spawn.
3. Collecting the spawn (eggs and sperm) of the parent corals.
4. Crossing the spawn of the parent corals to enhance the chances of producing resilient offspring.
This year, we are taking a rapid, mobile temperature stress test out to sea and using it to identify resilient and sensitive corals. We will collect and cross the parents to generate experimental lines of coral offspring. The performance of these offspring will be tested and compared using heat stress tests in the laboratory and in the ocean to assess the efficacy of selective breeding.
Artificial selection
Artificial thermal stress can be applied to a bulk pool of coral larvae that could be fatal to sensitive larvae and generate a relatively resilient pool of surviving larvae; this process is termed artificial selection.
This year, we are using the capabilities of the National Sea Simulator to generate pools of coral larvae and assess whether artificial selection might be used to generate enhanced coral stock for reef restoration.
The corals we produce this year will be tested in the ocean,and will provide vital information regarding the potential for generating enhanced coral stock for reef restoration initiatives.
Researchers
Dr Annika Lamb (AIMS)
Cary Morgans (AIMS)
Guy McCutchan (AIMS)
Dr Richard Edmunds (AIMS)
Prof. Madeleine van Oppen (AIMS and University of Melbourne)
Dr Line Bay (AIMS)
This research is supported by:
The Reef Restoration and Adaptation Program funded by the Partnership between the Australian Government's Reef Trust and the Great Barrier Reef Foundation
This page was updated in November 2023
