Prelims 2018 · Q87
MediumConsider 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?
Answer & explanation
Answer: (d) 1, 2 and 3
All three statements are taken as correct. NCERT places coral reefs in the tropical oceans; half of all reef area is in just five countries, and Australia, Indonesia and the Philippines alone hold about 42% of it; and reefs host 32 of the 34 recognised animal phyla (UN).
- ✓ 1. NCERT describes atolls as low islands of coral reefs found in the tropical oceans, so most reefs lie in tropical waters.
- ✓ 2. Half of the world's reef surface lies in only five countries: Australia, Indonesia, the Philippines, France and Papua New Guinea. The GCRMN ranking gives Australia 16.88%, Indonesia 15.26% and the Philippines 9.74% of reef surface, a cumulative 41.88% for the three, which is more than one-third.
- ✓ 3. The UN's World Ocean Assessment says reefs host 32 of the 34 recognised phyla, nearly all of them. UPSC's official key treats this statement as correct; we could not confirm the comparison with rainforests from an official source, so we do not explain it here.
Remember · Reefs: mostly tropical, concentrated in a few countries (Australia, Indonesia, Philippines hold about 42%), and home to 32 of 34 animal phyla.
📘 Read it in NCERT: Class 11 Fundamentals of Physical Geography, Ch 12 (practise this chapter)
Sources
- NCERT Class 11 · Fundamentals of Physical Geography, Chapter 12 “These are low islands found in the tropical oceans consisting of coral reefs surrounding a central depression.”
- Status of Coral Reef Monitoring: An Assessment of Methods and Data (GCRMN, hosted by the International Coral Reef Initiative) ↗ · reference work “Half of the world’s coral reef surface is distributed between only five countries – Australia, Indonesia, Philippines, France and Papua New Guinea. … Ranking Country Coral reef surface (km²) Relative contribution (%) Cumulative coral reef surface (%) 1 Australia 44,485 16.88 16.88 2 Indonesia 40,209 15.26 32.14 3 Philippines 25,677 9.74 41.88”
- Indonesia Coral Bond project document, World Bank (March 2024) ↗ “Indonesia is home to 16 percent of the world’s coral reefs.”
- World Ocean Assessment, Chapter 43: Tropical and Sub-Tropical Coral Reefs (United Nations) ↗ “Coral reefs are the largest reservoirs of biodiversity on earth: they host 32 of 34 recognised phyla and approximately one-third of all marine biodiversity”
Question and answer: UPSC's official GS Paper I (2018, Series A) — paper ↗ · answer key ↗. Explanation: Minimalist IAS, checked 1 Oct 2026 (how we verify). Permalink ·