Why in news
An unknown process is producing oxygen deep in the world’s oceans, where it is too dark for photosynthesis, scientists reported on July 22 in the journal Nature Geoscience.
The finding has important implications because oxygen helps support life and the discovery implies the existence of previously unknown ecosystems
What is dark oxygen?
Oxygen that is being produced in complete darkness thousands of feet below the ocean surface is termed dark oxygen
The oxygen comes out of Polymetallic nodules that are similar in resemblance to lumps of coal.
What is Polymetallic Nodules?
These nodules, made up of metals like manganese, iron, cobalt, nickel, copper, and lithium, can generate oxygen through electrochemical activity even in the absence of light.
They are splitting H2O molecules into hydrogen and oxygen.
If their concentration exceeds 10 kg per sq.m, mining them is considered feasible
Clarion-Clipperton Zone
The Clarion-Clipperton Zone (CCZ) is an environmental management area of the Pacific Ocean, administered by the International Seabed Authority (ISA).
It includes the Clarion Fracture Zone and the Clipperton Fracture Zone, geological submarine fracture zones.
The CCZ is regularly considered for deep-sea mining due to the abundant presence of manganese nodules.
Impact of mining polymetallic nodules on marine ecosystems
The most direct impact from deep-sea mining would be the loss of species and the fragmentation or loss of ecosystem structure and function.
The noise of the machinery would affect wildlife, the scraping off of the seabed would kill animals and plants, and the sediment plumes smother and impact marine life of all zones of the ocean.
The damage caused to the deep-sea ecosystems would most likely be permanent
India's Deep Ocean Mission
India is planning to “apply for licences to explore for deep-sea minerals in the Pacific Ocean”.
India’s Ministry of Earth Sciences is also currently building a submersible vehicle that will look for and mine similar resources in the Indian Ocean as part of its ‘Deep Ocean Mission’.
The International Seabed Authority has established 15-year contracts with at least 22 contractors — including India
to look for polymetallic nodules, polymetallic sulphides, and cobalt-rich ferromanganese crusts in the deep seabed
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