Recently, A study published in Nature Geoscience reveals that oxygen is released from mineral deposits located 4,000 meters (13,000 feet) below the surface in the Pacific Ocean’s Clarion-Clipperton Zone (CCZ).
What’s Dark oxygen?
- Oxygen that is being produced in complete darkness thousands of feet below the ocean surface is termed dark oxygen.
- This underwater region is called the abyssal zone.
- It receives too little sunlight for photosynthesis to be feasible. Instead, life-forms here get oxygen from water carried in by a global circulation called the ‘Great Conveyor Belt’.
The Conveyor Belt
- Question? Scientists have long understood how nutrients move from the ocean’s surface to its depths.
- As phytoplankton die, they sink and collect on the ocean floor. But if nutrients are continually sinking to the depths of the ocean, how are surface waters replenished with nutrients?
- Reason: In certain regions of the ocean, the nutrient-rich deep water was upwelling, or rising to the surface.
- Ocean was slowly turning over from top to bottom in a continuous global loop.
- Like a conveyor belt, thermohaline circulation moves nutrients from one part of the ocean to another.
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Why is the discovery important?
- Calls into question the earlier theory: It has long been recognized by scientists that photosynthetic organisms, such as plants and algae, are the main source of oxygen on Earth and provide it to both people and animals.
- The production of oxygen at such depths is thought to be impossible because there isn’t enough sunlight for plants to photosynthesize.
- However, in this case, oxygen is not being produced by plants.
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About the recent study
- Discovery of Oxygen: Scientists reported an unknown process producing oxygen in the deep ocean where photosynthesis is not feasible due to insufficient sunlight.
- Oxygen Measurement: When the scientists were conducting experiments at a depth of 4 km, researchers observed unexpected increases in oxygen levels, sometimes tripling within two days, contrary to expectations of decreasing levels due to consumption by marine life.
- They conducted follow-up studies in 2020 and 2021: In each case, they released a device from the surface that would land on the ocean floor, where it would isolate a small volume of the floor along with some sea water and measure the oxygen levels.
- Source of Oxygen: The researchers hypothesized that the oxygen could be generated by polymetallic nodules, which may create electric charges that split water molecules, releasing oxygen.
- The nodules exhibited voltages up to 0.95 V, suggesting they could function like battery cells.
- Location of Study: The study was conducted in the Clarion-Clipperton Zone, located off Mexico’s west coast, which is known for having the highest concentration of polymetallic nodules.
About Clarion-Clipperton Zone (CCZ)
- The CCZ is situated in the eastern Pacific between the Clarion and Clipperton fracture zones stretching from 5° to 20° N and 115 to 160° W and covers over 1% of the world’s surface.
- Scientific & Industrial Explorations: There has been a long history of scientific and industrial exploration of this area.
- Covering an area larger than India, the Zone is considered to have the world’s highest concentration of polymetallic nodules, including 6 billion tonnes of manganese and more than 200 million tonnes each of copper and nickel.
- ISA Role: As the CCZ is predominantly seabed beyond national jurisdiction, the mineral resources are regulated by the International Seabed Authority (ISA)
- The ISA has divided the CCZ into various mining exploration contract areas assigned to state-sponsored contractors
- About ISA: Established in 1994.
- Headquarters: Kingston, Jamaica.
- Function: To regulate mining and related activities in the international seabed beyond national jurisdiction, an area that includes most of the world’s oceans.
- The ISA came into existence upon the entry into force of the 1982 United Nations Convention on the Law of the Sea.
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About Deep Sea Mining
- About: Deep sea mining is an emerging industry that aims to extract minerals from the ocean’s surface, including manganese nodules, seafloor massive sulphides, and cobalt crusts.
- Potential: These nodules, deposits and crusts contain materials, such as nickel, rare earths, cobalt and more, that are needed for batteries and other materials used in tapping renewable energy and also for everyday technology like cellphones and computers.
- Three types of mining:
- Taking deposit-rich polymetallic nodules off the ocean floor
- Mining massive seafloor sulphide deposits
- Stripping cobalt crusts from rock.
- Regulation of Deep Sea Mining
- The International Seabed Authority (ISA) is currently accepting mining permit applications from companies and countries.
- States should apply to ISA regardless of whether or not they have signed or ratified the United Nations Convention on the Law of the Seas.
- Countries manage their own maritime territory and exclusive economic zones, while the high seas and the international ocean floor are governed by the United Nations Convention on the Law of the Seas (UNCLOS).
- Environmental Concerns
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- Threat to ecosystem: Only a small part of the deep seabed has been explored and conservationists worry that ecosystems will be damaged by mining, especially without any environmental protocols.
- Associated damages: Noise, vibration and light pollution, as well as possible leaks and spills of fuels and other chemicals used in the mining process.
- Harm to Marine Life: Once valuable materials are extracted, slurry sediment plumes are sometimes pumped back into the sea. That can harm filter feeding species like corals and sponges, etc.
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Conclusion
- This discovery challenges our knowledge of the oxygen sources on our planet. So the consequences of this discovery could drastically change our understanding of the conditions required for life to exist.
August 3, 2024
