This website provides answers to the 15 most asked questions about deep seabed mining (see below). If you want further information, please visit Minerals in Depth or contact us using the green button above. This webpage is maintained by GSR, the deep sea exploratory division of DEME Group. 

Background to deep seabed mining

Sustainable development, the growth of urban infrastructure and clean energy transition are combining to put enormous pressure on metal supplies.

Over the next 30 years the global population is set to expand by two billion people. That’s double the current populations of North, Central and South America combined. By 2050, 66 percent of us will live in cities. To support this swelling urban population, a city the size of Dubai will need to be built every month until the end of the century. This is a staggering statistic. At the same time, there is the urgent need to decarbonise the planet’s energy and transport systems. To achieve this, the world needs millions more wind turbines, solar panels and electric vehicle batteries.

Urban infrastructure and clean energy technologies are extremely metal intensive and extracting metal from our planet comes at a cost. Often rainforests have to be cleared, mountains flattened, communities displaced and huge amounts of waste – much of it toxic – generated.

That is why we are looking at the deep sea as a potential alternative source of  metals.

Deep seabed mining is an industry in the exploration, research and development phase. Years of detailed scientific work lie ahead before there is any prospect of commercial activity. Some campaigners are calling for a moratorium on deep seabed mining until more is known about the effects on marine ecosystems.

The research that they are calling for is already required by the International Seabed Authority, a body established through the UN Convention on the Law of the Sea that governs deep seabed mining. In effect, campaigners are simply asking for the current regulatory processes to be followed and requirements applied.

GSR, the company responsible for this website, couldn’t agree more.

GSR also stands by this:  we will only apply for a mining contract if the science shows that, from an environmental and social perspective, the deep seabed has advantages over the alternative – which is to rely solely on new and current mines on land.

We hope that this site answers any questions you have about the research currently taking place, but please get in touch using the contact button above if you would like more information. We are committed to complete transparency.


Deep seabed mining (DSM) is the term applied to processes and technologies designed to collect metal-rich resources from the deep seafloor.

There are three types of deep seabed mineral resources that are of interest to mining companies:  seafloor massive sulphides, cobalt-rich ferromanganese crusts, and polymetallic nodules.

Extracting sulphides and crusts entails cutting into the seabed surface. By contrast, polymetallic nodules are rock-like accretions that lie unattached on the surface of the ocean floor and can be collected without cutting or drilling.

Most interest and investment in DSM is focused on polymetallic nodules. They were discovered almost 150 years ago during the famous HMS Challenger expedition (1872 – 1876), the voyage credited with launching modern oceanography.

There are trillions of these nodules, roughly the size of potatoes, lying at a water depth of 4,000 to 6,000 metres in the Clarion Clipperton Zone (CCZ), a six million square kilometre region of the Pacific Ocean’s seafloor between Mexico and Hawaii.

Since the early 1970s, there has been growing interest in collecting these nodules due the high-grade and multiple metals they contain – metals like nickel, cobalt, manganese, and copper.

DSM is an industry in the exploration, research and development phase. There is no commercial activity (i.e. mining) at all at present.

The metals found in polymetallic nodules are critical for clean energy technologies such as wind turbines, solar panels, electric vehicle batteries and other energy storage devices. The World Bank[1] estimates that more than three billion tons of these metals will be needed to deploy the wind, solar and energy storage technologies required to keep climate change to below +2°C.

As an example of the metal intensity associated with green technologies: electric vehicles use at least four times the amount of metals found in petrol and diesel cars. A single electric vehicle with a 75 KWh battery needs 56 kg of nickel, 12 kg of manganese, 7 kg of cobalt, and 85 kg of copper for electric wiring.

But this is just one part of the metal demand story. As with clean energy technologies, urban infrastructure is metal intensive. By 2064 the number of people living in resource-hungry urban locations is forecast to increase by 1.93 billion[2]. Remarkably, to accommodate this swelling urban population, the equivalent of 229 New York Cities will need to be built in the next 40 years, putting huge pressure on already strained resources.

[1] Minerals for Climate Action: The Mineral Intensity of the Clean Energy Transition, World Bank, 2020
[2] Fertility, mortality, migration, and population scenarios for 195 countries and territories from 2017 to 2100: a forecasting analysis for the Global Burden of Disease Study, Stein et al, 2020

Today all of the world’s primary metals are sourced from land-based mines. About 70 per cent of the world’s cobalt comes from the Democratic Republic of Congo (DRC), with the balance coming from Russia, Australia, Cuba, Madagascar, Papua New Guinea and Canada.

Nickel is primarily mined in Indonesia, Philippines, Russia, and New Caledonia.

Because the ore grade of land-based deposits is declining, new sources of metal supplies are being explored, often in remote and ecologically sensitive regions, including rainforests.

While many mining companies act responsibly there is no escaping the fact that land-based mining is carbon intensive, often results in deforestation, creates mountains of waste – some of it toxic – and can lead to the displacement of peoples.

Nickel, copper, manganese and cobalt never appear together in terrestrial deposits; two to three separate land-based mines are needed to extract them.

The multi-metal nature of polymetallic nodules means that a deep seabed mining area is, in effect, two or three land-based mines in one, which means there is the potential to reduce waste and CO2 emissions per tonne of metal mined and minimise a number of other negative environmental and social effects.

The world is certainly not running out of land-based metal. There are enough resources to meet demand. The problem is that mining these resources comes with a heavy environmental burden, and as exploration takes miners into ever more remote and biodiverse areas, the scale of that burden will only grow.

DSM may represent a better way of meeting future metal demand. It certainly won’t replace land-based mining entirely, but it may contribute to a less carbon intensive way of providing the metals we all need, and it may have fewer ecosystem effects overall.

Continued research will provide the evidence that all stakeholders need to draw rational conclusions about how best to proceed.

No one yet.  There are a number of marine research and engineering entities currently engaged in DSM exploration. Each is sponsored by a member State of the International Seabed Authority (ISA). They operate under a contract with the ISA that allows for exploration only, not commercial activity (i.e. mining).

Sponsoring States include but are not limited to China, Japan, Russia, France, UK, Korea, Germany, Poland, Cook Islands, Nauru and Belgium.

It is unlikely that any commercial activity will begin before 2027. That’s because, even for the most advanced ISA contractors, years of further environmental studies and testing lie ahead.

Named after the world’s fastest caterpillar, Patania II is the pre-prototype seafloor nodule collector built by Global Sea Mineral Resources (GSR). GSR is the deep-sea exploratory division of the DEME Group, a world leader in marine engineering, dredging, and environmental remediation.

GSR commenced its technical development programme in 2012. In 2017, the company tested a robot with a tracked propulsion system designed to crawl across the deep seafloor (Patania I). Using the learnings about trafficability and manoeuvrability from this test, GSR engineered Patania II, a 12 m-long, 4 m-wide, 4.5 m-high, 25-ton nodule-collecting robot, also on caterpillar tracks.

Patania II is equipped with the latest cameras and sensors, including environmental sensors. The robot is controlled from a surface vessel via a 5 km-long cable that provides power and communication capabilities.

Patania II was trialled at 4500 m water depth on the seafloor of the Pacific Ocean in April and May 2021. The trial confirmed the trafficability and manoeuvrability of Patania II and its ability to pick up nodules.  The trial followed the submission of an Environmental Impact Statement, which was made publicly available through the websites of the International Seabed Authority and Belgium government.  The results of this research will also be made public in due course.

Using the findings of this trial, GSR will design and build a full-scale nodule collector, Patania III. The future Patania III trial (scheduled for 2024) will entail a riser and lift system to bring the nodules to a surface vessel (i.e. the entire mining system will be tested).

Environmental monitoring is a key component of GSR’s development program, ensuring the effects of its activities are understood, can be accurately predicted and improved upon and so that appropriate environmental management strategies can be developed and implemented.

For the Patania II trial, GSR collaborated with the European research project Mining Impact. Scientists from 28 European institutes joined efforts with the German exploration contract holder, BGR, to independently monitor the trial to help understand the environmental effects of collecting mineral resources from the seafloor. Their research will also be made public in due course.

Never before has so much thought gone into regulating an industry before it even exists. No State or entity can commercially explore the seabed or collect nodules except under contract with the International Seabed Authority (ISA).

The ISA is mandated through the UN Convention on the Law of the Sea (UNCLOS) to organize, regulate and control all mineral-related activities in the international seabed area and for the benefit of humankind as a whole.

To date, the ISA has awarded 18 exploration contracts in the CCZ. The contractors who hold these 15-year licences represent nations including China, Japan, Russia, France, UK, Korea, Germany, Poland, Cook Islands, Nauru and Belgium. All exploration contract holders are undertaking geological and environmental studies, as part of their contractual obligations.

The ISA is in the process of developing regulations for commercial activity and any contractors wishing to undertake mining operations in the international deep seabed area will need to abide by these strict regulations.

The regulations incorporate specific provisions to ensure the effective protection of the marine environment and conservation of marine biodiversity, human health and safety, and a system of payments which aims to ensure the equitable sharing of financial and other economic benefits derived from seabed minerals. The regulations must be agreed and adopted by the ISA Council and approved by the ISA Assembly, comprised of 167 Member States and the European Union.

The majority of interest and investment in DSM is focused on polymetallic nodules in the Clarion Clipperton Zone (CCZ) of the Pacific Ocean. Nodules found in the CCZ contain 1.2 times more manganese, 1.8 times more nickel and 3.4 times more cobalt than all known land-based reserves combined.1

The CCZ represents about 1.6% of the world’s oceans. Of this, about 30% has been set aside as protected areas or APEIs (Areas of Particular Environmental Interest).

Of the remainder, about 21% has been reserved for DSM exploration but only about 30-50% of that might feasibly one day be mined, in part because each contractor must identify ‘set-aside’ areas that have similar habitats and stable biota to the mining area.

This means if all CCZ contract areas were to be developed, this would amount to an area of approximately 0.1 to 0.2% of the world’s seafloor.  By comparison, every year deep sea trawling fisheries impact 4.9 million km2, which amounts to approximately 1.3% of the global ocean.2


  1. Deep-ocean polymetallic nodules as a resource for critical materials, Hein et al, 2020
  2. Protecting the global ocean for biodiversity, food and climate, Sala et al, 2021

The research that moratorium campaigners are calling for is already required by the International Seabed Authority (ISA).

All research data and results are submitted annually to the ISA and will be incorporated into an Environmental Impact Assessment (EIA) which will culminate in an Environmental Impact Statement (EIS).  The EIS needs to be submitted as part of an application for a mining contract along with an Environmental Management and Monitoring Plan, Closure Plan and a number of other documents.

It is important to recognise that a moratorium would have the opposite of the claimed effect. Far from creating time and space for more research to be conducted, it would act as a disincentive to invest in deep sea exploration.

If the science shows the deep seabed has no advantages over the alternatives – which is to rely solely on opening up new mines on land to access new sources of metal – there will be no DSM industry.

Protesting against the current Patania II trial is like protesting against the clinical trial of a vaccine until the outcome of that trial is known. It is illogical, anti-science and irresponsible.

There is no way of extracting metals without some environmental effects. The fundamental question surrounding DSM is this: can it be counted among the more responsible ways of sourcing the metals the planet needs?

More specifically, how does the collection and processing of polymetallic nodules compare with future land-based mining with respect to carbon emissions and other environmental effects such as freshwater eutrophication and acidification? And how do the two compare from the perspective of ecosystem health and function?

There are good reasons to believe that obtaining metals from the seabed will compare well because the grades and multi-metal nature of nodules means that one mining area on the seabed produces the same volume of metals as two or three mines on land.   With DSM there is no deforestation, no need to relocate people and no mountains of often toxic waste.

The recent Patania II trial was part of a multi-year research program involving numerous scientists from some of the world’s leading research institutions and universities.  A key aspect of this research is to be able to predict, validate and monitor environmental effects. Learnings will inform future engineering design, mine planning and environmental management with the aim of reducing impacts to the fullest extent possible.

All research data, results and learnings will be incorporated into an Environmental Impact Assessment (EIA) which will culminate in an Environmental Impact Statement (EIS).  The EIS needs to be submitted to the International Seabed Authority as part of an application for a mining contract along with an Environmental Management and Monitoring Plan. This plan will be designed to ensure the conservation of ecosystems on the deep seafloor and will entail responsible environmental management strategies such as establishing representative set-aside areas and possibly remediation measures such as replacing nodules with alternative habitats (note remediation research is ongoing).

While Greenpeace may not see a role for deep seabed mining in the transition to a sustainable future, it is premature to discard it as an option for delivering the metals the planet needs to realize a circular economy and a clean energy future.

At this point, DSM is in a research phase.  Contractors such as GSR are undertaking detailed multi-year environmental baseline studies and completing an environmental impact assessment.  The expedition to which Greenpeace objected is part of this scientific process and the field trial was designed to better understand environmental effects of collecting minerals from the seafloor so that informed decisions can be made, based on the best scientific information possible.

Greenpeace’s letter to DEME (parent company of GSR) and GSR’s response can be found here.

The precautionary approach is a frequently misused and misunderstood concept. Precaution operates on a spectrum and the principle cannot be used as an excuse for indefinite inertia in a world with competing challenges. Caution is in order, but indeterminate precaution is an untenable position that leads to paralysis.

With regard to DSM, the research required during the exploration phase takes years to complete and includes an environmental impact assessment, which will culminate in an Environmental Impact Statement (EIS).

The EIS, along with an Environmental Management and Monitoring Plan and a Closure Plan, must be submitted to the International Seabed Authority (ISA) as a part of the application for a mining contract, which will then be evaluated by the ISA, comprising representatives from 167 Member States plus the EU.

The recent Patania II trial was part of a long-term step-by-step technology development program that provides a good example of taking a precautionary approach (see What is the Patania II trial? Question 5 above for more details). The program was designed to test, learn and continuously improve with a specific aim of reducing the effects of seabed mineral collection.

We should all be working towards a future where most of the metals in circulation come from recycled sources, but all credible studies conclude that enormous quantities of primary resource will be required first. Current land-based sources will make a contribution, but they can’t do it all.  We will need new sources of metal.

Expanding recycling will also play a part but can only make a modest contribution. That’s because of long in-use lifetimes (an offshore wind turbine is expected to last more than 30 years for example) and also because of low efficiencies in collecting and processing end of life materials.

In one study[1], end-of life batteries are expected to contribute 7% to the overall demand for raw materials for battery production in 2030, but even this will require recycling capacities to be increased by a factor of more than 25 compared with today.

Beyond recycling, strategies such as material substitution, product re-use and product re-design may be able to place a brake on society’s thirst for metals, and future technological advances may also help to dampen demand.  However, the scale and pace of forecast demand is so high that significant new sources of metal will still be needed in the coming decades, and we have some important choices to make about where we obtain these metals from.

[1] GBA/WEF: A Vision for a Sustainable Battery Value Chain in 2030

It is entirely consistent with those commitments. The International Seabed Authority (ISA) is made up of 167 Member States, and the European Union. It is mandated through the UN Convention on the Law of the Sea (UNCLOS) to organize, regulate and control all mineral-related activities in the international seabed area and for the benefit of humankind as a whole. In so doing, ISA has the duty to ensure the effective protection of the marine environment from harmful effects that may arise from deep-seabed mineral related activities.

It is important to remember that what States are sponsoring at this stage is exploration, not commercial activity. Through exploration and research, we are able to understand the effects of DSM on the marine environment and establish responsible environmental management strategies.

Metal is one of our biggest allies in the battle against climate change, but it comes at a cost: there is no way of extracting metal without some environmental effects. If the deep seabed can help us meet future metal demand in a more responsible way than alternatives, then we all stand to benefit.

In addition, under the UN Convention of the Law of the Sea (UNCLOS), the economic advantages of DSM are to be shared for the benefit of humankind as a whole, in the form of royalty payments, with particular emphasis on the developing countries.

Entities that invest in DSM exploration and research will, of course, benefit from commercial activity but if DSM does become an established industry it will only do so because years of scientific research have demonstrated that it will deliver the metals needed for clean energy transition and sustainable development in a responsible way.

For more context about the need for new sources of metals and the role of DSM, visit Minerals in Depth.

For more information on the International Seabed Authority, visit its website here.

For more information on GSR, visit its website here.