It expects students to clarify with relevant facts how Ocean beds are huge repositories of critical resources. It also expects to present the scenario of distribution of such resources.
Introduction:
Oceans cover 70 percent of Earth’s surface, host a vast variety of geological processes responsible for the formation and concentration of mineral resources, and are the ultimate repository of many materials eroded or dissolved from the land surface. Hence, oceans contain vast quantities of materials that presently serve as major resources for humans.
Body:
Countries around the world need metals and minerals to satisfy burgeoning demands for technology and electronics. The ocean beds contains critical energy sources (petroleum and gas) and raw materials (sand and gravel, phosphorite, corals and other biogenic carbonates, heavy metal ores) which can fulfil this demand.
Direct extraction of resources is limited to salt; magnesium; placer gold, tin, titanium, and diamonds; and fresh water.
Ferromanganese crusts, manganese nodules, phosphorites, and hydrothermal vent deposits, which occur in many deep ocean settings from the Arctic to the Antarctic, could be important sources of these metals and minerals.
Salt, or sodium chloride, occurs in sea water at a concentration of about 3 percent and hence constitutes more than 80 percent of the dissolved chemical elements in sea water.
Potassium occurs in vast quantities in sea water, but its average concentration of about 1,300 parts per million (or 0.13 percent) is generally too low to permit direct economic extraction.
Magnesium, dissolved in sea water at a concentration of about 1,000 parts per million, is the only metal directly extracted from sea water. Presently, approximately 60 percent of the magnesium metal and many of the magnesium salts produced in the United States are extracted from sea water.
The ocean basins constitute the ultimate depositional site of sediments eroded from the land, and beaches represent the largest residual deposits of sand. Although beaches and near-shore sediments are locally extracted for use in construction, they are generally considered too valuable as recreational areas to permit removal for construction purposes.
Limestones (rocks composed of calcium carbonate) are forming extensively in the tropical to semitropical oceans of the world today as the result of precipitation by biological organisms ranging from mollusks to corals and plants. There is little exploitation of the modern limestones as they are forming in the oceans. However, the continents and tropical islands contain vast sequences of limestone’s that are extensively mined; these limestone’s commonly are interspersed with dolomites that formed through digenetic alteration of limestone.
The deep ocean floor contains extremely large quantities of nodules ranging from centimetres to decimetres in diameter (that is, from less than an inch to several inches). Although commonly called manganese nodules, they generally contain more iron than manganese, but do constitute the largest known resource of manganese.
Complex organic and inorganic processes constantly precipitate phosphate-rich crusts and granules in shallow marine environments. These are the analogs (comparative equivalents) of the onshore deposits being mined in several parts of the world, and represent future potential reserves if land-based deposits become exhausted.
Submarine investigations of oceanic rift zones have revealed that rich deposits of zinc and copper, with associated lead, silver, and gold, are forming at the sites of hot hydrothermal emanations commonly called black smokers. These metal-rich deposits, ranging from chimneyto pancake-like, form where deeply circulating sea water has dissolved metals from the underlying rocks and issue out onto the cold seafloor along major fractures.
The world’s oceans, with a total volume of more than 500 million cubic kilometres, hold more than 97 percent of all the water on Earth. However, the 3.5-percent salt content of this water makes it unusable for most human needs.
Life on the ocean beds moves at a glacial pace. Sediment accumulates at a rate of 1 millimetre every millennium.
With such a slow rate of growth, areas disturbed by deep-sea mining would be unlikely to recover on a reasonable timescale.
There could be clogging of filter feeding structures of, for example, gelatinous organisms in the water column, and burial of organisms on the sediment. There could also be some metals that get into the water column, so there are concerns about toxicology.
It is also likely possible that the extracting resources on large scale from the ocean beds may result in the disturbance in the water cycle. In turn affecting the climate of the Earth.
Species such as whales, tuna and sharks could be affected by noise, vibrations and light pollution caused by mining equipment and surface vessels, as well as potential leaks and spills of fuel and toxic products.
A better understanding of the deep sea is necessary to guide mitigation strategies and proper enforcement of regulations in order to limit the environmental impacts of mining activities.
Comprehensive baseline studies are needed to understand what species live in the deep sea, how they live, and how they could be affected by mining activities. More funds are needed for training and educational programmes focused on improving our understanding of the deep sea.
High-quality environmental assessments are needed to assess the full range, extent and duration of environmental damage from deep-sea mining operations.
The repair, recycling and reuse of products should be encouraged to help reduce the demand for raw materials from the deep sea.
The ISA is operating with the dual mandate of promoting the development of deep-sea minerals whilst ensuring that this development is not harmful to the environment. This challenging and conflicting mandate will require improved oversight by the international community – including government representatives and the general public – to ensure that marine life is adequately protected.
Conclusion:
Here, we have seen that Ocean beds contain vast amount of critical resources which appear useful for the humans, but at the same time their over-exploitation is placing a negative impact on the oceanic life cycle and life in the oceanic region. Hence, it becomes imperative to conserve the oceanic critical resources while ensuring their sustainability.
