Building Reef Resilience

The Great Barrier Reef — the jewel in the crown of coral reefs worldwide — is facing an uncertain future.

The greatest threat to the Reef is climate change. Rising ocean temperatures are driving mass coral bleaching events, while ocean acidification weakens the calcium carbonate 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 it time. The key lies in building reef resilience.

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, cyclones, 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 agreements or global consensus. It can be — and already is being — done at home through two complementary strategies: reducing local pressures on the Reef and actively restoring and adapting reef ecosystems.

Reducing Local Impacts

Local stressors have long undermined the health of the Great Barrier Reef, increasing its vulnerability to climate change.

One of the most damaging is poor water quality. Runoff from the land carries excess nutrients, pesticides and fine sediments into coastal waters, largely from agriculture, land clearing and coastal development. These pollutants promote algal blooms, reduce light availability, and increase coral disease.

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, with poor water quality believed to contribute to population explosions.

Today, trained dive teams actively control outbreaks by injecting starfish with reef-safe substances such as vinegar or cattle bile. While labour-intensive, this approach has proven highly effective in protecting high-value reefs.

Fishing practices also play a critical role. Overfishing and destructive fishing methods disrupt reef ecosystems and is harmful to reef building corals.

On the Great Barrier Reef, fishing is managed through zoning, quotas, gear restrictions and enforcement — all designed to maintain ecological balance and long-term sustainability.

Restoration and Adaptation

Alongside reducing local impacts, scientists are actively restoring and adapting the Reef to a warming world.

Reef restoration and adaptation involve large-scale, science-driven initiatives aimed at improving coral heat tolerance, accelerating recovery, and enhancing long-term survival. Approaches include growing heat-tolerant corals in nurseries, boosting resilience using beneficial microbes, and using robotic systems to distribute coral larvae and stabilise damaged reef structures.

It may sound like science fiction, but these projects are already underway on the Great Barrier Reef.

Buying Time

Despite these efforts, climate change remains the Reef’s greatest existential threat. Reducing greenhouse gas emissions is essential to limiting warming to 1.5°C — a threshold widely regarded as critical for coral survival.

Local action alone cannot save the Reef. But by reducing pollution, managing fisheries, controlling outbreaks and restoring damaged reefs, we can strengthen resilience and buy time.

For the Great Barrier Reef, time may be the most valuable resource we have.

Contributed with thanks to Tony Fontes

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