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UPSC Prelims 2012 · World Geography · Oceans, Seas and Straits
The acidification of oceans is increasing. Why is this phenomenon a cause of concern? Which of the statements given above is/are correct?
- The growth and survival of calcareous phytoplankton will be adversely affected.
- The growth and survival of coral reefs will be adversely affected.
- The survival of some animals that have phytoplanktonic larvae will be adversely affected.
- The cloud seeding and formation of clouds will be adversely affected.
- (a) 1, 2 and 3 only
- (b) 2 only
- (c) 1 and 3 only
- (d) 1, 2, 3 and 4
Show the answer and explanation
Answer: (d) 1, 2, 3 and 4
All four effects are concerns.
Statement by statement
1. ✓ YES Calcareous plankton (coccolithophores) struggle to build shells.
2. ✓ YES Corals struggle to build skeletons.
3. ✓ YES Animals with planktonic larvae (oysters, sea urchins) suffer.
4. ✓ YES Phytoplankton release DMS that helps clouds form; fewer plankton, fewer cloud seeds.
Why the others are wrong
(a) Drops the cloud link.
(b) Keeps only corals.
(c) Drops corals.
The trap
The cloud link sounds far-fetched — it works through DMS from plankton.
🔒 Ocean pH ~8.2 → ~8.1 since industrialisation (~30% more acidic).
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