"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). ·