Building Reef Resilience

The Great Barrier Reef — the jewel in the crown of coral reefs worldwide — is facing an uncertain future.
Most Australians are now aware that the greatest threat to the Reef is climate change. Rising ocean temperatures are driving mass coral bleaching events, while ocean acidification weakens the very skeletons corals rely on to grow. Combating climate change requires a coordinated global response, and while action is underway, it is happening far too slowly. Time, unfortunately, is not on the Reef’s side.
Yet all is not lost. While the Reef cannot be saved by local action alone, there is much Australia can do right now to buy the Reef time. The key lies in building reef resilience — strengthening the Reef’s ability to withstand disturbances and recover from them when they occur.
What Is Reef Resilience?
Reef resilience refers to a coral reef’s capacity to resist damage and bounce back after stress events such as bleaching, storms, or disease outbreaks. A healthy, resilient reef is far more likely to survive climate impacts than one already weakened by pollution, overfishing, or poor water quality.
The good news is that building reef resilience does not require international agreement or global consensus. It can be — and already is being — done at home. Two major strategies are being pursued together: reducing local pressures on the Reef, and actively restoring and adapting reef ecosystems.
Reducing Local Impacts on the Reef
Local stressors have long undermined the health of the Great Barrier Reef, making it more vulnerable to climate change.
One of the most damaging is poor water quality. Runoff from the land carries excess nutrients such as nitrogen and phosphorus, along with pesticides and fine sediments, into coastal waters. These pollutants largely originate from agriculture, land clearing, and coastal development. Once in the ocean, they promote harmful algal blooms and reduce the amount of light reaching corals, stifling growth and increasing disease risk.
Australia’s recently released Nature Laws have the potential to significantly reduce this decades-old problem — but only if they are properly enforced and adequately funded.
Another major threat comes from crown-of-thorns starfish (COTS). These coral-eating predators can devastate reefs, consuming vast areas of coral in a matter of weeks. Outbreaks have plagued the Reef for decades, and research suggests that poor water quality may play a role in triggering population explosions.
Today, trained dive teams are actively controlling outbreaks by injecting starfish with substances such as vinegar or cattle bile — both reef-safe but lethal to the starfish. While labour-intensive, this approach has proven effective in protecting high-value reefs from severe damage.
Fishing practices also play a critical role in reef health. Overfishing, destructive gear use, and illegal fishing can severely disrupt reef ecosystems. The removal of key herbivorous fish allows algae to overgrow and smother corals, while practices such as bottom trawling physically damage reef structures.
On the Great Barrier Reef, fishing is managed through a combination of spatial zoning, quotas, gear restrictions, and enforcement by Australian and Queensland authorities. Measures include limits on commercial access, total allowable catches, size and bag limits, and seasonal closures — all designed to maintain ecological balance and long-term sustainability.
Restoration and Adaptation: Science in Action
Alongside reducing local impacts, scientists are now working to actively restore and adapt the Reef to a warming world.
Reef restoration and adaptation is a suite of large-scale, science-driven initiatives aimed at helping corals survive climate change. The goal is to develop tools that increase coral heat tolerance, accelerate recovery after bleaching, and enhance long-term adaptation to rising temperatures.
Some of the key approaches include:
·         Coral propagation and aquaculture: Growing large numbers of heat-tolerant corals in laboratories and nurseries before transplanting them onto damaged reefs.
·         Heat tolerance acceleration: Studying coral genetics and using beneficial microbes, or “probiotics”, to enhance natural resilience to warmer waters.
·         Assisted recovery: Using robotic and semi-automated systems to distribute coral larvae and stabilise loose reef rubble, improving survival rates after disturbances.
It may sound like science fiction, but these projects are already underway — right now, on the Great Barrier Reef.

The Role of Climate Action
Despite these local and national efforts, climate change remains the Reef’s greatest existential threat. Reducing greenhouse gas emissions is essential to limiting global warming to 1.5°C — a threshold widely regarded as critical for the long-term survival of coral reefs worldwide.
Local action alone cannot save the Reef. But every step taken to reduce pollution, manage fisheries, control outbreaks, and restore damaged reefs strengthens resilience and increases the chances of survival.
Building reef resilience is not about replacing climate action — it is about buying time. And for the Great Barrier Reef, time may be the most valuable resource we have.

Contributed with thanks to Tony Fontes.

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