Q. "Biorock technology" is talked about in which one of the following situations? (UPSC Prelims 2022)
Answer: Restoration of damaged coral reefs
Notes: The correct answer is [A] Restoration of damaged coral reefs. Biorock technology, also known as Mineral Accretion Technology, is a unique method used to accelerate the growth of corals and marine organisms.

• Mechanism (Statement A – Correct): It involves passing a low-voltage electrical current through a metallic framework (usually steel) submerged in seawater. This current triggers a chemical reaction that causes minerals—primarily calcium carbonate and magnesium hydroxide—to crystallize onto the structure. Corals are then transplanted onto this "biorock," where they grow up to 3 to 4 times faster than normal due to the readily available mineral base and increased resistance to environmental stress.
• Building Materials (Statement B – Incorrect): While biorock is a "limestone" like substance, it is grown underwater for ecological restoration, not developed from plant residues for terrestrial construction.
• Shale Gas (Statement C – Incorrect): Exploration of shale gas involves techniques like hydraulic fracturing (fracking) and horizontal drilling, which have no relation to mineral accretion in oceans.
• Salt Licks (Statement D – Incorrect): Salt licks are natural or artificial deposits of salts and minerals that animals lick to supplement their nutrition; they do not involve the electrical technology or marine application described here.

In India, the Zoological Survey of India (ZSI), with support from the Gujarat Forest Department, successfully used Biorock technology to restore coral reefs in the Gulf of Kachchh.