Deep Ocean Mission
21, Jul 2018
The Centre has drawn up a five-year plan to explore the deep recesses of the ocean. The mission proposes to explore the deep ocean similar to the space exploration started by ISRO.
About the mission:
- The mission is to explore and harness mineral resources beneath the ocean floor which intended to harness ocean resources in a “responsible way” and could turn out to be a transformative step for the prosperity and security of the nation.
- The focus will be on technologies for deep-sea mining, underwater vehicles, underwater robotics and ocean climate change advisory services, among other aspects.
- This will improve India’s position in ocean research field.
- The Exclusive Economic Zone allotted to India in the international waters will be covered under the Deep Ocean Mission.
- The Union Earth Sciences Ministry tasked with coordinating the exercise.
Resources from Ocean:
Energy from the Ocean:
Ocean can produce two types of energy: thermal energy from the sun’s heat, and mechanical energy from the tides and waves. The fact that the marine renewable sector is less developed than other energy sectors.
- Tidal power converts the energy from the natural rise and fall of the tides into electricity.
- Since India is surrounded by sea on three sides, its potential to harness tidal energy has been recognized by the Government of India.
The most attractive locations for tidal energy are:
- Gulf of Cambay
- Gulf of Kachchh
- Ganges Delta in the Sunder bans
Problems Faced in Exploiting Tidal Energy:
- The altering of the ecosystem at the bay
- Only provides power for around 10 hours each day, when the tide is actually moving in or out.
- Present designs do not produce a lot of electricity, and barrages across river estuaries can change the flow of water and, consequently, the habitat for birds and other wildlife
- Limited construction locations
- Barrages affect fish migration and other wildlife- many fish like salmon swim up to the barrages and are killed by the spinning turbines.
- Barrages may affect the tidal level – the change in tidal level may affect navigation, recreation, cause flooding of the shoreline and affect local marine life
- Tidal plants are expensive to build
- Wave power systems convert the motion of the waves into usable mechanical energy which in lump can be used to generate electricity.
- The potential along the 6000 Km of coast is about 40,000 MW. This energy is however less intensive than what is available in more northern and southern latitudes.
- Primary estimates indicate that the annual wave energy potential along the Indian coast is between 5 MW to 15 MW per meter, thus a theoretical potential for a coast line of nearly 6000 KW works out to 40000-60000 MW approximately. However, the realistic and economical potential is likely to be considerably less.
- Offshore desalination plants powered by renewable energies are being proposed as an alternative for a coastal desalination facility, for those locations where the lack of suitable land makes a land-based desalination plant inadequate
- The sole energy source of a reverse osmosis (RO) plant is utilised through wave or tidal energy in order to produce drinkable water, which is then transported offshore (through pipes, water tank ships, or bladders
Problems in wave energy generation:
- Depends on the waves – variable energy supply
- Needs a suitable site, where waves are consistently strong
- Must be able to withstand very rough weather
- Poses a possible threat to navigation from collisions due to the low profile of the wave energy devices above the water, making them undetectable either by direct sighting or by radar May interfere with mooring and anchorage lines with commercial and sport-fishing
- May degrade scenic ocean front views from wave energy devices located near or on the shore, and from onshore overhead electric transmission lines.
Ocean Thermal Energy:
- The main objective of ocean thermal energy or Ocean Thermal Energy Conversion (OTEC) is to turn the solar energy trapped by the ocean into useable energy.
- OTEC has a potential installed capacity of 180,000 MW in India
Barriers in OTEC:
- OTEC-produced electricity at present would cost more than electricity generated from fossil fuels at their current costs.
- OTEC plants must be located where a difference of about 40 degrees Fahrenheit occurs year round.
- Ocean depths must be available fairly close to shore-based facilities for economic operation.
- Construction of OTEC plants and laying pipes in coastal waters may cause localized damage to reefs and near-shore marine ecosystems.
- Exploration for offshore petroleum and Natural gas also has been under way in the Arabian Sea and the Bay of Bengal, both of which are believed to have large reserves.
- The sea offers a variety of minerals, many of which are considered to be alternative sources of metals in the future.
- Among these are the placer deposits, which are mechanically concentrated minerals that originate from eroded onshore rocks. The near-shore waves separate the minerals brought by rivers and glaciers into heavy and light minerals, and concentrate heavy minerals on the beaches and estuaries.
- Elements in native state (diamond, gold, and platinum) or minerals such as ilmenite, rutile, magnetite, zircon, monazite, garnet, and corundum are some examples of placer deposits.
- Oolites are the inorganic chemical precipitates of calcium carbonate that form in hyper-saline, shallow marine environment (<10 m). Oolites are found on the continental shelf off Mumbai, Visakhapatnam, and Chennai. Zeolites, Phosphorites or sedimentary phosphate, Barite are the other minerals.
- Ferro-manganese deposits form in the deep ocean basins (4-5 km depth) in areas away from the influence of terrigenous (from land) fluxes. They occur as nodules (round objects upto 10 cm in size) and encrustations (as layers on rocks exposed on the seafloor). They have copper, nickel, and cobalt (total 2.5%) content.
- Manganese nodules grow at a rate of 1-3 mm per million years and occur on the ocean floor or a few centimetres below it. Crusts with high cobalt content (0.25% – 1%) usually occur on seamounts, elevated marginal areas, and mid-ocean ridges.
- Hydrothermal deposits are formed by the interaction of seawater with submarine volcanic activity.
- Gas hydrates are compounds where gas molecules are physically trapped inside an expanded lattice of water molecules. They can be present below the ocean floor on the continental slopes and deeper areas of high rate of deposition of sediments with moderate organic content (0.5%).
- Seabed gas hydrates could be an energy source of the future.
- The Indian Ocean’s living resources represent one of the region’s most significant assets. According to the United Nations Food and Agriculture Organization (FAO), catches from Indian Ocean marine capture fisheries have soared from less than 900,000 tonnes in 1950 to 11.3 million tonnes in 2010, about 14.6 percent of the world catch.
- Aquaculture – farming fish, shellfish, and other aquatic animals in captivity – has expanded equally rapidly, growing twelve-fold globally since 1980.
- In 2010, six Indian Ocean nations – India, Indonesia, Bangladesh, Thailand, Egypt, and Myanmar – counted among the top ten producers worldwide, supplying over 11.3 million tonnes of fish between them, as much as all the region’s capture fisheries combined.