Fact Sheet

Deep Sea Mining: The Basics

Deep Sea Mining

© NOAA Office of Ocean Exploration and Research


The deepest parts of the world’s ocean feature ecosystems found nowhere else on Earth. They provide habitats for multitudes of species, many yet to be named. In these vast, lightless regions are also found deposits of valuable minerals in concentrations richer than most on land. Deep sea extraction technologies have now developed to the point where exploration of seabed minerals can give way to active exploitation.

The International Seabed Authority (ISA) is charged with formulating and enforcing rules for all seabed mining that takes place in waters beyond national jurisdictions. These rules are now under development. Environmental regulations, liability and financial rules, oversight, and enforcement protocols—all must be written and approved within three to five years.

Deep Sea Mining

The legal foundations

  • United Nations convention. The constitutional document governing mineral exploitation on the 60 percent of the world seabed that lies beyond national jurisdictions is the U.N. Convention on the Law of the Sea (UNCLOS), also known as the Law of the Sea Treaty. UNCLOS took effect in 1994 upon passage of key enabling amendments designed to spur commercial mining. One of the distinguishing features of UNCLOS is its declaration that the international seabed must be considered “the common heritage of mankind” and that mining operations should be conducted to reflect that fact. The definition and monetization of “common heritage” present a significant challenge to the ISA and its commercial contractors.
  • The Area. The seabed beyond the exclusive economic zones (EEZs) of individual countries is known as the Area. Coastal nations can monopolize economic activity within their EEZs, which usually extend 200 nautical miles beyond national shores. EEZs can reach beyond 200 nautical miles when a coastal geological formation continues uninterrupted; they can also be confined to less than 200 miles when coastal nations lie in close proximity to each other. The ISA is solely responsible for regulating seabed mining in the Area. But UNCLOS also requires state parties to govern any seabed mining within their EEZs with national regulations that conform to the environmental standards mandated by the treaty.
  • International Seabed Authority (ISA). The ISA is the U.N. body invested by UNCLOS with broad powers to establish the conditions under which UNCLOS Member States can explore and exploit the mineral resources found at the Area’s seabed floor. The ultimate authority of the ISA is its Assembly, which elects members of the ISA Council, an executive body that considers agenda items for final disposition by the Assembly. Many of the matters under consideration by the council come as reports and recommendations by the Legal and Technical Commission (LTC), the ISA’s expert advisory body. All three bodies convene during the ISA annual meeting each summer at the organization’s headquarters in Kingston, Jamaica. Day-to-day activities of the authority are managed by the ISA Secretary-General.
  • ISA contracts. ISA Member States are eligible to apply for an ISA contract. There are two kinds: Exploration contracts govern data-gathering, sampling, and reporting. Exploitation contracts govern all aspects of actual mining. At the end of 2016, 26 exploration contracts and no exploitation contracts were in effect. It is expected that there will be no exploitation contracts until 2018 at the earliest.
  • Mining Code. The ISA uses the term Mining Code to denote “the whole of the comprehensive set of rules, regulations and procedures issued by the ISA to regulate prospecting, exploration and exploitation of marine minerals in the Area.” Currently under development, the Mining Code will cover all environmental, financial, reporting, and regulatory obligations incurred by contractors and the ISA itself. No mineral exploitation can occur until all elements of the Mining Code are finalized. One key element is the set of environmental protection regulations that will govern all exploitation contracts. A draft of those regulations is expected to be developed in 2017. International conservation organizations are planning a close review of the draft prior to its formal consideration by ISA governing bodies.

Deep sea minerals and where they are found

Hopes for the exploitation of seabed minerals rely on the fact that these valuable substances exist in greater concentrations on the ocean floor than in most terrestrial sites. These sought-after commodities include gold, copper, magnesium, nickel, lead, lithium, titanium, platinum, zinc, and the family of minerals known as rare earth elements (REEs). The ISA has signed exploration contracts for investigating three sources of these minerals:

Polymetallic nodules (16 ISA exploration contracts)

Deep Sea Mining

© Cook Islands Seabed Minerals Authority

Polymetallic nodules contain rich concentrations of manganese, nickel, copper, cobalt, and REEs. They are found in abundance in the Clarion-Clipperton Zone (CCZ), a great abyssal plain as wide as the continental United States that lies 4,000 to 6,000 meters below the surface of the eastern Pacific Ocean. There, millions of the potato-size nodules are scattered on top of or half-embedded within the muddy bottom of the CCZ. Their exploitation would probably involve scraping 5 to 10 centimeters (2 to 4 inches) off the top of the abyssal plain, pumping a mixture of the nodules and the mud in which they lie to a surface ship by means of a giant tube, separating the nodules from the mud, and returning the mud to the seabed through another tube.

Massive sulfides (six ISA exploration contracts)

Deep Sea Mining

© NOAA Office of Ocean Exploration and Research

Underwater volcanic activity exists at depths of 1,000 to 4,000 meters, usually at tectonic plate boundaries. Hydrothermal vents on the seabed release superheated solutions with high concentrations of valuable minerals that precipitate out into polymetallic sulfides. Chimneys formed by these eruptions, along with shallow subsurface deposits, could provide rich but modest-size areas for mineral exploitation. Operations would resemble those of open-pit mines on land: remove the sulfide-rich deposits, separate out commercially valuable portions, and return the unwanted remainder to the general seabed vicinity.

Cobalt crusts (four ISA exploration contracts)

Deep Sea Mining

© NOAA Office of Ocean Exploration and Research

Concentrations of valuable minerals are often found on the sides and summits of underwater mountains, generally at depths of 800 to 2,500 meters. The richest of deposits constitute the crusts of seamounts found in the western Pacific. Crust thicknesses can reach 25 centimeters (almost 10 inches), but more typical deposits run to 10 to 15 centimeters (4 to 6 inches). The basic mode of exploitation would be to remove the seamount skin without including too much of the less valuable rock beneath it. The skinning operation would require a large impact area.

Who is exploring where?

As of 2016, there are 26 ISA-approved contracts for exploration in the Area.

Deep Sea Mining
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Media Contact

Leah Weiser

Senior Associate, Communications