Tags Current Affairs

Issue

The Zoological Survey of India (ZSI), with help from Gujarat’s forest department, is attempting for the first time a process to restore coral reefs using biorock or mineral accretion technology in the Gulf of Kachchh.

 

Background

Biorock is the name given to the substance formed by electro accumulation of minerals dissolved in seawater on steel structures that are lowered onto the sea bed and are connected to a power source, in this case solar panels that float on the surface.

 

Details

• When a positively charged anode and negatively charged cathode are placed on the sea floor, with an electric current flowing between them, calcium ions combine with carbonate ions and adhere to the structure (cathode). This results in calcium carbonate formation. Coral larvae adhere to the CaCO3 and grow quickly.

• The fragments of broken corals are tied to the biorock structure, where they are able to grow at least four to six times faster than their actual growth as they need not spend their energy in building their own calcium carbonate skeletons.

• The location for installing the biorock had been chosen keeping in mind the high tidal amplitude in the Gulf of Kachchh. The low tide depth where the biorock has been installed is four metres, and at high tide it is about eight metres.

• India has four coral reef areas, Andaman and Nicobar Islands, Lakshadweep, Gulf of Mannar and the Gulf of Kachchh.

• The ongoing initiative of coral restoration using biorock technology could potentially help to sustain the earlier successes. The technology helps corals, including the highly sensitive branching corals, to counter the threats posed by global warming.

Degradation of corals

• Water pollution

Water pollution is perhaps the most obvious cause of coral reef destruction. Reefs are harmed when oil, fertilizer, and human or animal waste are dumped in the area. These elements can end up changing the chemical makeup of the water, but the waste can also block life-giving sunlight to the reef.

• Coral bleaching

Reef bleaching occurs when extreme water conditions cause corals to expel the internal microorganisms that give them their vibrant colours.

Bleaching events are attributed to a number of factors, including pollution and extreme low tide, but the most common (and widespread) is the change in water temperature due to global warming.

• Sedimentation

When sediment enters the ocean, it can smother coral reefs, depriving them of sunlight and nutrients. Also, fish are unable to feed and coral polyps are unable to grow, leaving the area inhospitable to reef life.