The world’s corals are dying. But not on this reef | The Pacific | ABC News

Key Concepts

Coral bleaching, mass coral bleaching event, heat tolerance, selective breeding, super corals, climate change adaptation, emissions reductions, marine heatwaves, thermal tolerance, coral reef restoration, genetic diversity, Ningaloo Reef, Palao International Coral Reef Center.

Mass Coral Bleaching Event

The world has experienced the worst mass coral bleaching event on record, impacting 83 countries and 84% of the world's corals. This event is likened to an underwater bushfire, with many coral reefs turning completely white at an alarming rate.

Palao's Resilient Coral Reefs

Palao, an island nation in the western Pacific Ocean, stands out as an exception. Its coral reefs remain in remarkably good condition, attracting international scientists seeking to understand their resilience. These reefs haven't experienced a mass bleaching event since 1998, unlike the Great Barrier Reef, which has had at least seven in the same period. Research suggests that Palao's corals possess an ability to adapt to climate change.

• Cultural Significance: Coral reefs are central to Palao's culture and identity. The ocean is viewed as a living entity with a spirit, not merely a resource to exploit.
• Healthy Reefs: "I've been working in Palao for 20 years and the reefs have never looked healthier than they do now."

Selective Breeding of Heat-Tolerant Corals

The Palao International Coral Reef Center is conducting groundbreaking research to selectively breed the most heat-tolerant corals.

• Genetic Diversity: Corals, like humans, exhibit variations in resilience and immune systems. Some corals are naturally more heat-tolerant than others.
• Heritability: Studies have shown that heat tolerance can be passed down through generations via selective breeding.
• Deployment: The team has deployed devices housing 1,600 "super corals" on the outer reef. These corals were selectively bred from different species and multiple generations to maximize genetic diversity.
• Research Questions: The research team is investigating the survival and growth rates of outplanted super corals.

Lessons from Ningaloo Reef

Research in Australia is mirroring Palao's efforts to selectively breed super corals. Dr. Wigley is conducting experiments with corals from Ningaloo Reef, which was initially considered a "lucky reef" due to its seemingly buffered environmental conditions.

• Catastrophic Bleaching: Ningaloo Reef has recently experienced a catastrophic mass bleaching event, the worst on record, demonstrating that even seemingly resilient reefs are vulnerable.
• Warning: "I think Ningloo shows us this year that it's only a matter of time for even those lucky reefs."

Skepticism and Natural Adaptation

Anne, a Palaoan, expresses skepticism about relying solely on human intervention to save coral reefs. She believes that nature has its own ways of caring for itself.

• Palaoan Perspective: "For myself as a Paloan person, when I think about a super reef, I don't really think about the technical aspect of how this is a new discovery of a potential solution to addressing climate change. I think that nature has its own way of caring for itself that is beyond us humans."
• Natural Adaptation: Modeling suggests that corals can adapt naturally if global warming is limited to a maximum of 2°C. However, last year was the hottest on record, exceeding 1.5°C, and the world has already lost 30-50% of its coral reefs.

Limitations and the Need for Emissions Reductions

Selective breeding is not a silver bullet solution. It may buy some time, but it's not a guaranteed fix.

• Greenwashing Concerns: "I think that's really important that we don't greenwash these kind of methods and that we're very clear that this is going to give us a little bit more time."
• Feasibility: Selective breeding is feasible but requires significant effort and more widespread adoption.
• Long-Term Solution: The long-term solution is emissions reductions. "We really need to work on uh reduction of CO2 emission and greenhouse gases emission. So really work on this climate policy."

Synthesis/Conclusion

While selective breeding of heat-tolerant corals offers a glimmer of hope for coral reef survival, it is not a complete solution. The recent mass bleaching event and the experience at Ningaloo Reef highlight the urgency of the situation. The ultimate solution lies in addressing the root cause of the problem: reducing CO2 emissions and greenhouse gases to mitigate climate change. The work in Palao provides valuable insights and potential strategies, but these efforts must be coupled with global action to curb emissions and protect these vital ecosystems.