Everything you Need to Know about Deep-Sea Mining

We’re currently on the precipice of a new age of mining - deep sea mining. As the Earth’s terrestrial mineral and metal resources decline and demand for such materials continues to rise, the untapped potential of resources found within the Earth’s seabed has come into focus for mining companies looking to exploit new opportunities. 

2023 marks the deadline for the development of international regulations to govern deep sea exploitation and will potentially set the precedent for deep sea mining practices and restrictions for years to come - something that will have profound consequences for the environment. 

👉 In this article we’ll look at what deep sea mining is, the laws that govern it, and the environmental concerns and impacts. 

Deep sea mining is a subfield of experimental seabed mining that involves the process of removing mineral deposits and metals from the ocean’s seabed found at depths of over 200 metres. 

Over thousands of years, deposits of valuable minerals and metals such as manganese, nickel and cobalt have built up on the ocean’s floor. Meanwhile, depleting availability of certain metals and minerals on land have created a growing interest in the possibilities of deep sea mining.

As it stands, the majority of oceanic mining efforts have been limited to shallow coastal waters where diamonds, tin, and sand can easily be removed. However, in recent years technological advancements and exploration activities mean that deep sea mining is now more commercially viable. In particular, companies have shown an interest in deep sea mining possibilities such as:

Polymetallic nodule mining 

Also known as manganese nodules, these nodules can be found in large quantities on the bottom of the sea and contain valuable metals and deposits. In recent years, these nodules have attracted renewed commercial interest as companies try to keep up with growing demand for metals. The International Seabed Authority has granted new exploration contracts and is in the process of developing a mining code to cover the practice.

The mining of these nodules would involve the scraping of around 5 to 10 centimetres from the top of the ocean floor in order to separate the nodules from the mud.

Polymetallic sulphide mining

Polymetallic sulphide deposits can be found in areas of underwater volcanic activity, usually at depths of between 1000 and 4000 metres. The sulphides are made up of an accumulation of minerals and metals such as iron, zinc and copper, and can form heaps that sometimes exceed over 100 metres in diameter, and tens of metres in height. 

As is the case with polymetallic nodule mining, exploration contacts have been granted for polymetallic sulphide mining.

Cobalt crust mining

Valuable minerals can be found on the sides of underwater mountains, with the most valuable deposits being found at depths of between 800 and 2,500 metres. The valuable crusts form a thickness of between 10 to 25 centimetres.The mining of these minerals would involve the removal of the surface of the rock face.

As it stands, several contracts have been granted to explore cobalt rich ferromanganese crusts.

The high seas and the ocean bed are governed by the United Nations Convention on the Law of the Seas (UNCLOS). This treaty is now an integral part of international law and is even considered to apply to states regardless of whether or not they are a signatory to the treaty. 

Under the UNCLOS, the seabed and its mineral resources are what’s termed as the ‘common heritage of mankind’. This means that they must be managed in a way that protects the interests of humanity through the sharing of economic benefits, support for marine scientific research, and the protection of marine environments. 

Under the UNCLOS, a regulatory regime was established to govern deep sea minerals and metals. As per the treaty, the International Seabed Authority is charged with the regulation of deep seabed exploration and exploitation in alignment with its Mining code. The Mining Code is applicable to “the seabed and ocean floor and subsoil thereof, beyond the limits of national jurisdiction”. 

As it stands, the International Seabed Authority has only finalised the section on exploration, under which it has been able to approve contracts for exploration of the seabed for mining purposes. 

The next challenge is to create regulations on exploitation but this is by no means an easy task. The ISA is charged with protecting the deep sea and has an obligation to ensure that any mining activities benefit mankind - something that makes the development of the regulations highly complex.

The pressure is on for the International Seabed Authority to finalise the regulations. In 2021 the island nation of Nauru - in partnership with mining company Nauru Ocean Resources Inc. - submitted an application to the International Seabed Authority to exploit minerals in a specified deep sea area. 

The legally permitted application triggered a clause within the UNCLOS, requiring the International Seabed Authority to complete regulations governing deep sea exploitation within a two year period. The regulations are due for completion by July 2023, however, if no regulations are finalised, in theory Nauru can submit an application for approval of a plan of work for exploitation without any governing regulations - something that has alarmed environmentalists. 

Thankfully however, Nauru, seems to be opposed to this and has called for legal certainty and responsible development. Nauru has stated that it will not allow the partner company to apply for a licence in July unless regulations are in place. 

Nauru’s UN Ambassador has called on the ISA to provide thresholds for acceptable dust, noise and other factors, so that they are able to carry out activities responsibly.  

👉 The earliest that mining could feasibly start is 2026. The application to mine still needs to be approved and environmental impact assessments will need to be carried out.

The primary interest in deep sea mining is economic. Supplies of valuable minerals and metals such as nickel, copper and cobalt are finite, and their levels on land are depleting as demand for these resources continues to rise. What’s more is that these materials are often an essential component of clean technologies such as lithium-ion batteries for electric vehicles. 

These minerals and metals have been discovered to exist in deep sea environments and represent a previously untapped resource. 

Some argue that there is no getting around the fact that we need more metals, and highlight that current on-land mining is incredibly damaging for the environment. Rainforests are being destroyed and other ecosystems are depleted to harvest these materials. This has led to the argument that it is better to extract the metals from the ocean than the land - given the fact that the ocean bed is home to a smaller amount of life.

Most of the exploration contracts granted involve an area of the ocean known as the Clarion-Clipperton Zone (CCZ). Located in the Pacific Ocean between Hawaii and Mexico, the area is abundant in mineral deposits and metals. It is within this area that Nauru has announced intentions to begin deep sea mining.

👉 Mining companies interested in deep sea exploitation are partnering with counties to help them get exploration and exploitation licences. Countries are allowed to sponsor the application of a company applying for a mining licence from the International Seabed Authority. 

Notably, officials from the International Seabed Authority seem to be promoting the prospect of companies being allowed to commence deep sea exploitation, despite their responsibility to protect the Earth’s oceans.

There is a great deal of concern around the impacts of deep sea mining on ocean ecosystems and habitats. The full extent of the implications for deep sea ecosystems remain unclear however, scientists have warned that biodiversity loss is inevitable and potentially irreversible. 

Specific concerns include: 

• Removing polymetallic nodules will destroy the seabed, and since the nodules support complex ecosystems, their removal will put vulnerable species at risk. It’s estimated that each polymetallic nodule mining expedition will destroy around 8000 to 9000 square kilometres of seabed over a 30 year mining licence. 
• The mining of hydrothermal vents in polymetallic sulphide mining risks the destruction of fragile ecosystems that form around the entrances to such vents. These ecosystems have not been fully studied, and so their destruction will deprive researchers of valuable knowledge and discovery. 
• Cobalt crust mining, which involves the striping of the outer layer of rock, will destroy deep sea sponge and coral ecosystems - some of which have formed over thousands of years. Again, the mining of this environment will destroy ecosystems that have, in some cases, taken hundreds, if not thousands of years to form. 

👉 The destruction and fragmentation of these important ecosystems is highly problematic as it will lead to the loss of species, some of which cannot be found elsewhere in our oceans.

In addition to the destruction and damage of the ecosystems that are mined, there are also wider repercussions on the ocean environment more generally. For example: 

• Mining stirs up the ocean floor, spreading sediment up to thousands of square kilometres. This could potentially represent a risk to corals and sea sponges who are what's known as filter feeders. 
• As part of the mining process excess sediment from the sea bed will be picked up and then discharged back into the water by mining ships. As is the case with the sediment that is stirred up on the ocean floor, these sediment plumes can disperse over hundreds of kilometres, being suspended in the water before finally coming to settle back on the seabed. Not only does the sediment represent a risk to filter feeding species, but it could also smother animals and block visual communication. 
• Just as is the case with mining on land, mining in the ocean creates pollution. Pollution takes on a variety of different forms including noise, vibration, light pollution, as well as leaks and spills of fuels and other chemicals involved in the mining process.

As is often the case with environmentally damaging activities, those who tend to be the most vulnerable to negative impacts are coastal communities based in developing countries. 

Scientists have already warned that deep sea mining will cause permanent damage to ocean ecosystems, which will also have a knock on effect when it comes to coastal communities who rely on the ocean for their livelihoods. 

Given the geographic focus of deep sea mining activities, it is Pacific Island communities who are likely to be most affected. Mining has the potential to affect fish populations and marine ecosystems - something that these communities rely on for food and income.

Calls for a deep sea mining ban

There is significant opposition around the world to deep sea mining. A number of high profile, international companies have committed themselves to avoiding minerals that have been mined from the Earth’s oceans (Google, Samsung, BMW and Volvo to name a few). 

A growing number of governments are also calling for a ban on deep sea mining - countries such as France, Spain, Germany and New Zealand have already voiced their opposition to the practice. 

Additionally, the scientific community is generally of the opinion that the harm caused by deep sea mining outweighs any potential benefits. Over 700 scientists, hailing from over 44 different countries have signed an open call to halt deep sea mining operations. 

The clock is now ticking however for the introduction of any bans, or a moratorium on mining until certain conditions can be met. Because once a precedent has been set it will be much harder to stop the influx of exploitation applications and to prevent irreversible damage to fragile marine ecosystems.

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