Revival of Coral Reefs

19.08.2025

Revival of Coral Reefs

Context

Coral reefs in the Gulf of Mannar, Tamil Nadu, are showing signs of recovery after nearly two decades of restoration efforts .

What are Coral Reefs?

• Coral reefs are marine ecosystems built from calcium carbonate secreted by corals.
   
• Often called the “rainforests of the sea”, they:
   
  • Support nearly 25% of marine biodiversity.
     
  • Act as natural barriers, protecting coastlines from erosion.
     
  • Provide livelihoods through fisheries and eco-tourism.
     
• The Gulf of Mannar reefs stretch across 21 islands and host species such as Acropora, Montipora, and Porites.
   

Causes of Coral Degradation

Anthropogenic Factors:

• Coral mining (1960s–1990s).
   
• Overfishing, destructive gear, and pollution.
   
• Coastal development leading to sedimentation.
   

Climate Change Factors:

• Rising sea surface temperatures → large-scale coral bleaching.
   
• Ocean acidification, reducing coral resilience.
   

Restoration Efforts

• Initiated in 2002 by the SDMRI (Suganthi Devadason Marine Research Institute) and the Tamil Nadu Forest Department.
   
• Methods:
   
  • Artificial substrates (concrete frames, clay pots, cement slabs).
     
  • Artificial Reef Modules – Triangular (TARs) and Perforated Trapezoidal (PTARs).
     
  • 20 coral species transplanted; Acropora recorded the highest survival rates.
    
     

Outcomes of Restoration

• Survival Rate: 55–79%, with some species reaching 89% survival.
   
• Biodiversity Growth: Coral recruits in TARs rose from 1.23 (2004) to 24.77 (2020).
   
• Fish Density Increase: From 14.5 (2006) to 310 (2020) per 250 m².
   

Challenges to Coral Reefs

• Repeated Bleaching: Global warming continues to stress corals.
   
• High Costs: Coral transplantation requires skilled divers, resources, and long-term monitoring.
   
• Genetic Imbalance Risk: Dependence on fast-growing species like Acropora may reduce ecosystem resilience.
   
• Ongoing Pressures: Plastic pollution, coastal projects, and unregulated tourism further threaten reef health.
   

Way Forward

• Scaling Up: Expand restoration to other sites like the Andaman, Lakshadweep, and Lakpat reefs.
   
• Community Engagement: Train fishing communities as reef guardians for monitoring and sustainable practices.
   
• Technology Integration: Use AI, drones, and remote sensing for reef mapping and bleaching alerts.
   
• Assisted Evolution: Develop heat-resistant coral strains to reduce bleaching risk.
   
• Global Cooperation: Strengthen partnerships under SDG-14 (Life Below Water) and the Paris Agreement for funding and best practices.
   

Conclusion

The revival of reefs in the Gulf of Mannar demonstrates that a blend of science, policy, and community involvement can bring degraded ecosystems back to life. As a model for climate resilience and biodiversity conservation, it shows that sustained and innovative interventions can ensure that India’s coral reefs continue to thrive as both an ecological treasure and a source of livelihood.