GREAT BARRIER REEF (Syllabus: GS Paper 3 – Env and Eco)

Context: A widespread coral bleaching event has engulfed the Great Barrier Reef (GBR), Australian authorities have confirmed. The reef is spread over an area larger than Italy.

Great Barrier Reef

• Location: Situated in the Pacific Ocean, it can be found off the northeastern coast of Queensland, Australia, within the Coral Sea.
• Largest Coral Reef Area: Indonesia
• Coral Reef Areas in India: Gulf of Mannar, the Andaman and Nicobar Islands, the Lakshadweep Islands and the Gulf of Kutch.
• UNESCO World Heritage Status: The Great Barrier Reef earned the esteemed status of a UNESCO World Heritage Site in 1981.
• Marine Protected Area: A substantial portion of this remarkable ecosystem falls under the protective umbrella of a marine protected area. 

oThis area is overseen and managed by the Great Barrier Reef Marine Park Authority of Australia.

• Biodiversity: The Great Barrier Reef boasts an incredible array of marine life. Estimates suggest it serves as the habitat for around 1,500 species of fish and over 600 diverse coral species.

Initiatives to Protect Corals

• A number of global initiatives are being taken to address the issues, like:
• International Coral Reef Initiative
• Global Coral Reef Monitoring Network (GCRMN)
• Global Coral Reef Alliance (GCRA)
• The Global Coral Reef R&D Accelerator Platform.

  Coral Bleaching

  • About: It  is a phenomenon triggered by environmental stressors affecting coral reefs.
  • Causes: Coral Bleaching occurs when corals face stress from factors such as changes in temperature, pollution, or elevated levels of ocean acidity.
  • Mechanism of Zooxanthellae: Under stress conditions, the zooxanthellae, symbiotic algae within coral polyps, produce reactive oxygen species, detrimental to the corals.
  • Expulsion of Zooxanthellae: In response to stress, corals expel the zooxanthellae from their polyps, leading to the exposure of their pale white exoskeleton and the characteristic bleached appearance.
  • Consequences: The expulsion of zooxanthellae disrupts the symbiotic relationship crucial for the survival and growth of corals.