Q. Consider the following statements:

  1. Most of the world’s coral reefs are in tropical waters.
  2. More than one-third of the world’s coral reefs are located in the territories of Australia, Indonesia and Philippines.
  3. Coral reefs host far more number of animal phyla than those hosted by tropical rainforests.

Which of the statements given above is/are correct?

  • 1 and 2 only
  • 3 only
  • 1 and 3 only
  • 1, 2 and 3

Answer: (d) 1, 2 and 3

Notes:

  • Most of the world’s coral reefs are located within the tropical zone between 30º N and 30º S latitude.
  • Conditions for the growth of Coral Reefs:
    • It required a preferred temperature range of approximately 22º to 30º C. 
    • ​For the growth of coral, the depth of the water should not exceed 200m.
    • Corals can live only in saline waters, and the average salinity should be between 27 to 40% for their proper growth.
  • More than one-third of the world’s coral reefs are located in territories of Australia, Indonesia, and the Philippines.
  • The coral reefs are most commonly grown in the Pacific and the Indian Ocean, due to their shallow, warm, and clean water.
  • Some scientists estimate that more than 25,000 described species from thirty-two of the world’s thirty-three animal phyla live in reef habitats – four times the number of animal phyla found in tropical rain forests.