5th Mass bleaching event hits Great Barrier Reef (GBR) in 8 years | Current Affairs | Vision IAS
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    5th Mass bleaching event hits Great Barrier Reef (GBR) in 8 years

    Posted 09 Mar 2024

    Updated 25 Mar 2024

    2 min read

    • Before this event, GBR has suffered mass coral bleaching in 1998, 2002, 2016, 2017, 2020, and 2022.
    • Bleaching occurs when healthy corals become stressed by spikes in ocean temperatures, causing them to expel algae living in their tissues, which drains them of their vibrant colours.

     

    • Causes of Mass Bleaching events 
      • Climate change induced warming. Example, Current underwater heatwave is most intense in southern GBR, which is most affected by bleaching.
      • Rising frequency of El Nino increases frequency and severity of mass-bleaching events.
      • Lack of wind and currents may result in less mixing of water layers, clearer seas, and deeper penetration of solar irradiance, which can intensify bleaching.
      • Other causes: Extremely low tides, Pollution, Overexposure to sunlight, etc.

     

    • GBR stretches for more than 2,300 kilometres along the northeast coast of Australia.
      • It is the world's largest coral reef complex, located in Pacific Ocean.
      • It was declared a World Heritage Area in 1981.
      • This reef structure is composed of and built by billions of tiny organisms, known as coral polyps.

     

    Coral reefs

    • They are made up of colonies of thousands of tiny individual corals, called polyps. These marine invertebrate animals have hard exoskeletons made of calcium carbonate.
    • In India, Coral reefs are present in Gulf of Kutch, Gulf of Mannar, Andaman & Nicobar, Lakshadweep Islands and Malvan (in Maharashtra).

     

     

     

     

     

     

     

    • Tags :
    • Great Barrier Reef
    • Mass Bleaching
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