Explainer: Deep seabed mining

This year a code governing the mining of the seabed in international waters is set to be finalised

deep seabed mining

A sea star 2,500 meters beneath the central Pacific turns its stomach inside out to feed on Victorgorgia coral. (Image: NOAA)

What is deep seabed mining?

It’s the process of retrieving mineral deposits from the deep sea – the area of the ocean below 200 metres. This covers around 65% of the Earth’s surface and harbours a rich diversity of species adapted to the harsh environment – many of which are still unknown to science. It also encompasses unique geological features, including mountain ranges, plateaus, volcanic peaks, canyons, vast abyssal plains and the Mariana Trench, which at almost 11,000 metres is the greatest depth registered in the ocean.

Is mining taking place now?

Shallow water mining for sand, tin and diamonds is already happening around the world, and some deep sea mining has taken place within the territorial waters of certain countries. But deep sea mining in international waters that belong to no one nation – known as The Area – is currently at the exploration stage.

To date, 29 contracts to explore for 15 years have been granted to assess the size and extent of three different types of mineral deposits in areas totalling more than 1.3 million square kilometres.

Actual mining cannot begin in The Area until the agreement of the code. This is a detailed set of regulations being debated at two key meetings this year. It’s expected to be adopted in 2020.

Who decides the code?

The International Seabed Authority (ISA), established under the UN Convention on the Law of the Sea, is an independent organisation based in Kingston, Jamaica. There are 167 member states plus the EU.

Who is exploring?

A mix of corporate enterprises, state-owned companies and several governments, including China, France, Germany, India, Japan, South Korea, Russia and the Interoceanmetal Joint Organisation (a consortium of Bulgaria, Cuba, the Czech Republic, Poland, the Russian Federation and Slovakia), as well as small island states such as the Cook Islands, Kiribati, Nauru, Singapore and Tonga.

What are they exploring for and where?

Nickel, copper, cobalt, manganese, zinc, silver, and gold are some of the targets of proposed mining activities. Current exploration is focused on three types of marine mineral deposits: polymetallic nodules found lying on the seafloor; polymetallic sulphides, or “seafloor massive sulphides”, which form around hydrothermal vents; and cobalt-rich ferromanganese crusts that cover seamounts. Exploration zones are mainly in the Pacific, mid-Atlantic and Indian oceans.

Deep sea mining
A polymetallic nodule. (Image: Nautilus Minerals)

Why do we need these minerals?

They’re used in various electronic products and energy storage – from smartphones, laptops, solar panels, wind turbines and electric vehicles. Terrestrial supplies are becoming harder and less profitable to extract while demand for minerals continues to grow. Advocates of deep seabed mining argue that it provides a source of reliable, clean and ethically sourced minerals.

How would they be extracted?

Seabed formations will be scooped, dredged, or severed by gigantic machines weighing more than a blue whale. The deposits would be piped up to a ship through several kilometres of tubing and processed at sea, where waste material would be pumped back into the water.

What possible effects could deep sea mining have on the ocean?

These processes will affect the seabed, the water column above it, and the surrounding area. The scraping of the ocean floor to extract the nodules could destroy deep sea habitats of octopuses, sponges and other species. Mining of the vents, which harbour massive animal communities at densities that make them one of the most productive ecosystems on Earth, is likely to stir up sediment that could smother some animals. Other species that are uniquely adapted to the lack of sunlight and high pressure of deep water, could be affected by the noise and pollution. Scientists are concerned that not enough is known about these species or ecosystems to establish an adequate baseline from which to protect them or monitor the impact of mining.

Who will profit from deep sea mining?

The ISA’s draft regulations state that money received from the proposed royalties or other financial regimes will be subject to a benefit-sharing regime, and distributed among members states, taking into account the interests and needs of developing states, particularly the least developed and land-locked. The payment regime is still under consideration and several different economic models are being considered.

When would mining start?

Contractors would have to conduct an environmental impact assessment in line with the rules, regulations and procedures set out by the ISA for mining rights to be granted. They will also need to demonstrate financial and technological capacity. Some industry groups say they are ready to begin as early as 2023, but most observers say that 2025 is more likely.

This article is part of our deep-sea mining series. Read more here:

The future of deep seabed mining

Species threatened by deep-sea mining

Can a ‘mining code’ make deep seabed extraction sustainable?

We need to better understand the deep ocean if mining is to go ahead 

Is China ready to mine the deep sea?