Sat 30 May 2020

If we wish civilisation to keep functioning, with all the technology currently at our disposal, then we need minerals – but at what cost to the environment?

“For most of history, man has had to fight nature to survive; in this century he is beginning to realize that, in order to survive, he must protect it” – Jacques-Yves Cousteau

The Clarion–Clipperton Zone (CCZ) may sound like an uninteresting part of the commuter London underground, but its global economic and environmental importance demands that we should all become familiar with the name.

It is, in fact, the region encompassing two fractures on the seafloor of the North Pacific Ocean, approximately 5,000km in length, spanning 4.5 million square km, at a depth of 5,000m below the ocean surface.

It is home to a plethora of newly discovered deep-water species, yet this month plans are being drawn up for massive mining operations in the region, supported by a new commercial mining regulatory framework.

The endless balancing act between economic gains, technological sustainability, environmental protection and potential human food security could not be clearer or more vital than on this obscure underwater stage. 

Map of the Clarion and Clipperton fracture zones (CCZ). Base map extracted from Google Maps

Economic Gains and Technological Sustainability

Discovered in 1950, the CCZ is believed to be one of the richest sources of mineral deposits anywhere on Earth, with vast amounts of manganese (for our rubber, glass, fungicides, alloys), copper (for our electrics, motors), titanium (for our aircraft, engines, alloys), nickel (for our corrosion resistant plating), lithium (for our batteries), and many other valuable minerals.

Many of these minerals are classed as critical by the US Geological Survey and are becoming increasingly scarce and difficult to mine on land, causing price rises and supply chain concerns, which adds to the appeal of mining them from the seafloor.

Rare Earth Elements (REE) are of particular interest as they are essential for most modern technology, from phones and computers to satellites and solar panels.

In 2018, 70% of the world’s REE were produced in China, which places strict controls on their export and distribution. Society’s total dependence on these minerals in order to keep functioning, combined with distribution reliance on a single dominant country to provide them, can create obvious security risks. Mining the deep sea could break such powerful mineral monopolies, increasing national technological independence. 

Quantity estimates of selected minerals in the CCZ. Units are million metric tonnes. Data source J.R. Hein et al., Ore Geology Reviews 51, 1-14, 2013.
Value per metric tonne and total bulk potential value of selected minerals in the CCZ. Metric tonne value source data (, converted from $ using rounding to the nearest £. Background image copyright: ROV KIEL 6000, GEOMAR (CC by 4.0), Manganese Nodules on the seafloor in the Clarion-Clipperton Zone

To date, there have been only 17 mining licences granted in the CCZ, which are granted by the International Seabed Authority (ISA). However, there remains no deep-sea commercial mining regulatory code and the ISA is only now working on drafts, having convened four separate sessions this July at ISA’s headquarters in Kingston, Jamaica. The final version should be announced in 2020.

Mining techniques will involve massive machines the size of earth movers that will scour the ocean bed. Deep sea mining could benefit more than 100 companies in the UK alone, securing thousands of jobs.

Deep sea mining machines. Image via Nautilus Minerals Technology

Many mining companies have already invested millions exploring the CCZ, including Nautilus Minerals Technology (Australia) and Global Sea Mineral Resources (Belgium). UK Seabed Resources (UKSR), a subsidiary of Lockheed Martin UK, is one such company, investing more than £12 million in exploration and scientific partnership with universities. 

A positive move by the ISA, in collaboration with scientists, has been to create Areas of Particular Environmental Importance (APEIs) within the CCZ; places where mining cannot occur.

It is not known at this time whether such sanctuary zones will be sufficient to allow species to survive and ecosystems to continue unperturbed. 

Deep Sea Shrimp. Presumably Pandalus borealis. Copyright: Jan Steffen, GEOMAR (CC BY 4.0)

Environmental Protection and Human Food Security

The sea becomes classed as ‘deep’ beneath 500m. Below this depth, we have so far only described 25,709 species. However, it is estimated there may be between 0.5 to 10 million species in the deep.

The CCZ is evidently home to a hugely diverse and largely unstudied ecosystem of species, both plant and animal.

We currently do not know what most of them are, how they interact with each other or with the environment around them. This wildlife diversity includes magnificent single-celled creatures called xenophyophores that can grow larger than a tennis ball and attach themselves to the valuable mineral nodules. In 2016, a new species of ‘ghost’ octopus dubbed Casper was discovered amidst the minerals. These creatures often have extensive adaptations to survive in near lightless conditions and high pressure. At 4,000m beneath the sea’s surface, the pressure is approximately 411 kg per cm2.

In a 2018 interview with London’s Natural History Museum, discussing the findings of a research mission to the CCZ using a Remotely Operated Vehicle (ROV), Professor Craig Smith recalled: “We found at least 10 species of giant sea cucumbers, a huge squid worm never seen before in the Pacific Ocean, and all kinds of sponges. We also found other animals with really neat adaptations, such as sea cucumbers with long tails that allow them to sail along the seafloor.”

Deep sea unit ROV KIEL 6000. Working on the seafloor at the Mid Atlantic Ridge between 5° and 11° S during cruise M78/2. Copyright: ROV-Team, GEOMAR (CC BY 4.0)

The mining machines are expected to kill most things in their path as they collect the valuable metallic nodules, yet their effects will be felt over a much wider scale. Noise and general vibrations from the operation may disturb the ability of organisms to communicate. Disturbed fine particle sediment is likely to form underwater sediment plumes that could reduce visibility and bury wildlife on the seafloor, potentially spilling into the upper ocean. 

The full extent of the biological consequences is difficult to quantify in advance due to the lack of studies and available data. Such plumes can be computer modelled, but currently we do not have enough data on factors such as seabed current speeds to have significant confidence in them.

The degree to which destruction and perturbation in the deep sea will affect human fishing stocks and the marine global supply chain also remain barely investigated. Approximately three billion people, out of a global population of seven-and-a-half billion, rely on marine wildlife as their primary protein source. The ISA has suggested that the best way to learn is to begin mining and observe what happens, but many scientists are cautioning against this ‘try it and see’ attitude.

A wise principle to adopt might be that, if one is scientifically unsure about the extent of harm an action may cause, assume the worst until proven otherwise.

So, what can be done? 

  • Top priority: invest heavily in deep sea scientific research so as to quantify what is down there, how it will react to varying levels of disturbance and what is the strength of the connection between the deep sea and the upper marine ecosystems that we rely on for food.
  • Ensure the protected areas are adequately large and unaffected by nearby mining. Include known biodiversity hotspots such as seamounts and hydrothermal chimneys in these protected areas.
  • When mining does occur, as seems inevitable, ensure extensive real time monitoring of impacts, observed by both industrial and independent scientific personnel. 
  • Invest in machine engineering research and development designed to minimise direct impact and sediment plumes. Involve university engineering students in the process of innovating and testing less harmful deep-sea mining extraction tools.

If we wish civilisation to keep functioning, with all the technology currently at our disposal, then we absolutely need minerals, at least for the foreseeable future.

Minerals in one form or another are often deeply interrelated with conflict and social suffering around the world, from the Maoist Naxalite insurgency in India to multi-state manipulations in the Democratic Republic of the Congo, to China recently threatening to cut off the supply of rare Earth elements to the US due to the ongoing trade war.

Alternative sources, such as deep-sea or asteroid mining offer ways to break old conflicts and dependencies. The environmental cost of deep-sea mining could be catastrophic, although at the moment, we simply don’t know. 

To learn more about the creatures in the CCZ, visit the National Oceanic and Atmospheric Administration and the Natural History Museum.

Microscope image of a sulphide. The alternating patterns can resemble the annual growth rings in trees, with sequences of zinc sulphides (darker grey) and copper sulphides (light grey). The alternations are partly caused by hot fluid changes, often at deep sea hydrothermal vents. Image is 0.03mm across. Copyright: GEOMAR (CC BY 4.0)

Main photo: The research vessel RV POLARSTERN. Copyright: Folkmar Hauff GEOMAR (CC BY 4.0).

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