Coral Bleaching Devastates Western Australia’s Ningaloo Reef

Syllabus: GS3/ Environment

In News

• A severe mass coral bleaching event described as unprecedented is unfolding off Australia’s western coast, impacting the Ningaloo Reef, a UNESCO World Heritage site.

About

• The event is part of a broader fourth global coral bleaching episode, ongoing since 2023. 
• The NOAA reported that nearly 84% of the world’s reef areas have experienced bleaching-level heat stress, impacting over 80 countries and territories.
• The crisis is worsened by rising global sea surface temperatures, overfishing, and pollution—challenges that have intensified due to climate change.

Coral Reefs: Key Facts

• What are Coral Reefs?
  • Underwater ecosystems formed by reef-building corals.
  • Composed of colonies of coral polyps bound by calcium carbonate.
  • Coral polyps live in endosymbiosis with algae (zooxanthellae).
• Favorable Conditions:
  • Temperature: 20°C–35°C
  • Salinity: 27%–40%
  • Depth: Prefer shallow waters (<50 m) for sunlight access
• Major Coral Reefs:
  • Global: Great Barrier Reef, Australia (UNESCO World Heritage Site)
  • India: Gulf of Kutch, Gulf of Mannar, Andaman & Nicobar Islands, Lakshadweep, and Malvan.

Benefits of Coral Reefs

• Marine biodiversity hotspot & support oceanic food chains
• Coastal protection against storms and erosion
• Carbon sequestration aiding climate mitigation
• Livelihoods and boost to the Blue Economy
• Source of novel medicines (antivirals, anticancer agents).

Threats to Coral Reefs

• Climatic impacts: Bleaching, acidification, algal blooms
• Human Activities: Overfishing, pollution, coral mining
• Habitat Destruction: Coastal development and sedimentation

Way Ahead

• Climate Action: Keep global warming well below 2°C (Paris Agreement)
• Policy & Governance: Enforce SDGs (especially SDG 8 & 12)
• Global Collaboration: Tackle overfishing and marine pollution collectively
• Innovation: Promote R&D in climate-resilient coral species

Source: TH