Explained:Coral bleaching and Great Barrier Reef

News:Scientists have warned that the Great Barrier Reef will face a critical period of heat stress over the coming weeks following the widespread coral bleaching.


About Great Barrier Reef:

  • Great Barrier Reef is the world’s largest and longest coral reef system. located in Australia. 
  • It is a World Heritage Area since 1981 (the world’s first reef ecosystem to be recognised by UNESCO)
  • It is home to 400 types of coral, 1500 species of fish and 4000 types of molluscs. 

About Coral Reef:

  • Coral polyps are small (0.25-12 inches), soft-bodied marine organisms which belong to the group cnidaria.
  • They live in colonies called reefs that they build using a limestone skeleton (calicle) lying at their base.
  • In India, coral reefs are located in seven regions namely Goa coast, Kerala coast, Palk Bay, Gulf of Kutch, Gulf of Mannar, Lakshadweep islands and Andaman and Nicobar islands.

About Coral Bleaching:

  • When water is too warm, corals will expel the algae (zooxanthellae) living in their tissues causing the coral to turn completely white. This is called coral bleaching.
  • However,when a coral bleaches,it is not dead.Corals can survive a bleaching event but they are under more stress and are subject to mortality.