Crown-of-thorns starfish (aka COTS) contribute to large losses of hard coral on the Great Barrier Reef. Disturbances such as marine heatwaves and more severe cyclones because of climate change are placing increased pressures on the Reef. With little relief in sight, this makes efforts to control the starfish outbreaks at the local or regional level even more important.

Crown-of-thorns starfish are native to the Great Barrier Reef but can occur in plague proportions. Where numbers are high they consume vast amounts of living coral, dramatically reducing coral cover.

 

For nearly 40 years, AIMS has monitored crown-of-thorns starfish on the Great Barrier Reef. Now, we are developing innovative approaches to strengthen monitoring efforts and improve efficiency.

They have up to 21 arms, hundreds of toxin-tipped thorns, a taste for coral, and can occur in plague proportions. No wonder crown-of-thorns starfish have a formidable reputation on the Great Barrier Reef.

Outbreaks of crown-of-thorns starfish are responsible for extensive loss of reef-building corals on the Great Barrier Reef and elsewhere. Scientists and managers work together to understand outbreaks and develop new ways to control them.
 

Competition and overgrowth by algae is among the primary hazards faced by tiny coral spat (young coral) during their first months in aquaculture or on the reef. Overcoming their low survival during this early life phase represents one of the greatest barriers to upscaling reef restoration. 

This project investigates the potential for the application of non-toxic antifoulant coatings on coral deployment devices to reduce competition by algae and maximise coral recruit growth and survival. 

As reefs experience increasing loss of coral cover due to a variety of environmental events and stressors, genetic diversity in those affected populations continues to be lost. For coral species to be able to adapt to environmental stressors like climate change, genetic diversity is the key. 

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.  

Coral nutrition

In the field, corals obtain sugars (their ‘fast food’) from their symbiotic algae. But most other nutrients are obtained when they feed on live plankton. However, in land-based coral aquaculture settings, these sources of nutrition are not normally available

This project is exploring technological and methodological options to automate, and upscale, the sexual propagation of corals in an aquaculture setting.