Prelims · Geography · 16 questions

Oceans

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Prelims 2022 · Q49

Easy

"Biorock technology" is talked about in which one of the following situations?

Answer & explanation

Answer: (a) Restoration of damaged coral reefs

Biorock technology is used to restore damaged coral reefs. A low-voltage electric current is passed through seawater between a submerged metal frame and an anode, so that minerals in the water deposit as limestone on the frame, and corals attached to it grow quickly.

✓ (a) With an anode and a cathode in sea water and a current between them, calcium and carbonate ions combine and stick to the cathode structure as calcium carbonate; corals adhere to it and grow fast. The UN has cited biorock artificial reefs as successful in certain areas.
✗ (b) Biorock is not a plant-residue building material; it is limestone grown from seawater minerals on an electrified frame.
✗ (c) Nothing in Biorock concerns locating or extracting shale gas.
✗ (d) Biorock has no link to salt licks for forest animals; it is an undersea technology.

Remember · Biorock (mineral accretion): low-voltage current in seawater grows limestone on metal frames, letting corals attach and recover. Used to restore reefs.

Sources

United Nations (CSD-15 Partnerships Fair), Biorock Technology for Coral Reef Restoration, Fisheries Restoration and Mariculture in SIDS ↗ “calcium ions combine with carbonate ions and adhere to the structure (cathode). The result is calcium carbonate. Corals adhere to CaCO3 and grow quickly.”
United Nations, Report of the Secretary-General on coral reefs and their contribution to sustainable development ↗ “(e.g. through biorock technology) has been successful in certain areas.”

Question and answer: UPSC's official GS Paper I (2022, Series A) — paper ↗ · answer key ↗. Explanation: Minimalist IAS, checked 30 Sept 2026 (how we verify). Permalink ·

Prelims 2022 · Q85

Easy

With reference to the United Nations Convention on the Law of Sea, consider the following statements:

1.A coastal state has the right to establish the breadth of its territorial sea up to a limit not exceeding 12 nautical miles, measured from baseline determined in accordance with the convention.
2.Ships of all states, whether coastal or land-locked, enjoy the right of innocent passage through the territorial sea.
3.The Exclusive Economic Zone shall not extend beyond 200 nautical miles from the baseline from which the breadth of the territorial sea is measured.

Which of the statements given above are correct?

Answer & explanation

Answer: (d) 1, 2 and 3

All three statements follow directly from the text of the UN Convention on the Law of the Sea (UNCLOS, 1982): Article 3 fixes the 12-nautical-mile limit of the territorial sea, Article 17 gives every State's ships the right of innocent passage, and Article 57 caps the Exclusive Economic Zone at 200 nautical miles.

✓ 1. Article 3 lets a State set its territorial sea up to 12 nautical miles, measured from baselines fixed under the Convention.
✓ 2. Article 17 gives ships of all States, coastal or land-locked, the right of innocent passage through the territorial sea.
✓ 3. Article 57 says the EEZ cannot go beyond 200 nautical miles from the same baselines used to measure the territorial sea.

Remember · UNCLOS 1982: territorial sea up to 12 nautical miles (Art. 3); innocent passage for all ships (Art. 17); EEZ up to 200 nautical miles from the baselines (Art. 57).