Frequently Asked Questions

Why do we need deep-sea mining?

While there may be technically enough metal-bearing deposits on land to meet future demand(1), those resources can only be extracted at increasingly high economic, social, and environmental cost. We believe that polymetallic nodules could contribute to supplying metal resources and alleviate some of the pressures on fragile terrerstrial ecosystems.

Access to—and development of—land-based deposits is getting harder. Falling grades mean that to get the high quality of metals needed for renewable technology, companies are forced to dig deeper and wider, creating more harm and spending more capital. Nickel, cobalt, and manganese deposits are naturally located in some of the planet’s most biodiverse places, including Indonesia, the Democratic Republic of Congo (DRC), and South Africa. Additionally, many terrestrial mining supply chains experience issues with labour rights and violations, such as child labour in cobalt mining in the DRC.(2) (3). Of all mined commodities, nickel is the most vulnerable Most battery-driven growth in nickel supply is expected to come from nickel laterites beneath the rainforests of Indonesia and the Philippines. Of all mined commodities, nickel is the most vulnerable to biodiversity risks and scaling battery-grade nickel production from laterites will likely devastate terrestrial ecosystems and human communities, with the disposal of mine waste in the deep sea putting biodiverse coral ecosystems at risk. 

Producing these metals from polymetallic nodules could reduce most of the Environmental, Social, and Corporate Governance (ESG) costs of conventional metal production. One nodule contains high grades of four key metals, meaning that four times less ore needs to be processed to obtain the same amount of metal. Nodules also contain no toxic levels of heavy elements, and the entirety of a nodule can be used, making near-zero-solid-waste production possible. Because nodules sit unattached on top of the seafloor, they will not require drilling or blasting for retrieval.

We recognise that it is unlikely that deep-sea mining will completely replace terrestrial mining. But in the face of increasing demand for metals, we feel it is important to supplement metals supplies in a way that inflicts the least impact on the planet and people. This means giving fragile rainforest ecosystems a break, and increasing the supply of high-quality metals which can be recycled and reused without breaking down.

1. Demand side: World Bank. (2020, April). The Mineral Intensity of the Clean Energy Transition; supply side: U.S. Geological Survey. | Science for a changing world. (n.d.).
2. Faber, B., Krause, B., & Sánchez de la Sierra, R. (2017). Artisanal Mining, Livelihoods, and Child Labor in the Cobalt Supply Chain of the Democratic Republic of Congo. UC Berkeley: Center for Effective Global Action. Retrieved from
3. Kelly, A. (2019, December). Apple and Google named in US lawsuit over Congolese child cobalt mining deaths. The Guardian.

Could we reduce our consumption and recycle, instead of mining more metal?

The drive to decarbonise and transition away from fossil fuels is increasing demand for mined metal. We should both reduce our consumption and recycle metal, but over the next 30 years, the impact of these measures on demand for mined metal will be marginal. The amount of spent electric vehicle (EV) batteries that are expected to reach the end of their first life is forecast to surge after 2030, but with mineral demand growing rapidly, the International Energy Agency predicts that recycled quantities of copper, lithium, nickel and cobalt from spent batteries would only reduce primary supply requirements by around 10% (4). In other words, we can’t recycle what we don’t have. As long as the transition’s projected needs exceed existing stocks, we’ll need to increase the amount of existing metals before closing the loop. 

The global light passenger vehicle fleet — currently ~ 1.2 billion cars — is projected to increase to 2 billion by mid-century(5). Demand-side reductions, such as carpooling or shared ownership, and incentivizing public transit can help reduce this projection but likely won’t negate the need to electrify the existing internal combustion engine (ICE) fleet. A conventional ICE car, on average, contains five times less selected metal mass than that required to build an EV. Even if we recycled every existing gas and diesel car, and dramatically increased ride sharing and robotic car access, we would still need a significant new injection of virgin metals to transition from ICE cars to EVs. 

We believe product redesign and circular-economy solutions should be pursued now and phased in so that they can be leveraged as growth tapers off. To achieve this, we plan to contribute to a circular battery metals supply chain to dramatically reduce—and eventually eliminate—the need to take any more metals from the planet. While this will take several decades, we expect it could be possible by the latter half of the 21st century.

4. Demand side: World Bank. (2020, April). The Mineral Intensity of the Clean Energy Transition; supply side: U.S. Geological Survey. | Science for a changing world. (n.d.).
5. Future of Auto Market Runs on Batteries. Morgan Stanley. (2017).

What is the biggest threat to the oceans and won’t collecting nodules make things worse?

The biggest threat to the oceans is climate change. We believe the top priority for the entire planet—including the oceans—should be achieving net-zero emissions.

Staying dependent on fossil fuels will continue to contribute to a host of environmental and climate issues—ocean acidification, oil spills, toxic byproducts, and resource wars among them. Shifting away from carbon-based energy requires a huge amount of energy storage, in the form of batteries, for both vehicles and the grid. The bulk of those batteries will be made of yet-to-be-sourced metals that need to be sourced with the lowest impact possible.

High-grade and easy-to-access metals from land-based mining operations have already been extracted. This diminishing return of land metals means that the metals remaining are of a low grade: a huge amount of material in these ores becomes toxic pollution after mining, and ores containing nickel in particular are largely found beneath equatorial rainforests. These forests sequester carbon for the entire planet, land and oceans combined.

Peer-reviewed research shows that sourcing the metals needed for the transition to clean energy from high-grade polymetallic nodules can reduce the associated climate impacts by between 70 – 80% compared to land-based ores.

Can some deep-sea minerals be extracted more safely than others?

There are three distinct types of deep-sea resources, each of which are found in differing ecosystems and vary in their impacts. 

  1. Cobalt crusts precipitate on the flanks of submarine volcanoes (or “seamounts”) as metallic layers that form an integral part of the seafloor and require cutting hard rock to separate the ore from the substrate. At depths of between 800–2,500 meters, the local ecosystem enjoys an abundant food supply, thanks to the upwelling of nutrient-rich water, which enables a proliferation of life—including large predators such as tuna and sharks—between 10 to 100 times greater than is found on the abyssal plain. 
  2. Seafloor massive sulfides are tall, chimney-like structures that form around hydrothermal vents spewing forth metal-enriched waters from the seafloor. Similar to cobalt crusts, these formations are an integral part of the seafloor and require hard-rock cutting to separate the ore from the substrate. At depths of between 1,000–4,000 meters, bacteria, which exploit chemical compounds from the vents, supply this ecosystem with an abundance of food, supporting biomass levels 100 times greater than those on the abyssal plain. 
  3. By contrast, polymetallic nodules lie unattached atop the abyssal seafloor and can be collected using water jets directed at the nodules in parallel with the seafloor—without any digging or drilling. At depths of between 4,000–6,000 meters, the abyssal CCZ is a stable environment with little food, and one of the least productive areas of the ocean with one of the lowest biomass levels of any planetary ecosystem. 
Will deep-sea mining impact climate change by disrupting marine carbon sinks?

Collector vehicles operating in the abyssal zone at 4–6 kilometer depths will likely disrupt the top 5 centimeters of sediment, separate it from nodules inside the machine, and redeposit it at the seafloor. Recent studies and our own modeling conducted by the Danish Institute of Hydrology show that a majority of this sediment will resettle within days and hundreds of meters of origin. No known mechanism exists for carbon-bearing sediment to travel up the water column and reach the atmosphere. There are also no known methane hydrates in the Pacific Ocean’s Clarion Clipperton Zone(6), where we’re exploring with oversight and regulation by the International Seabed Authority. At the abyssal depths found in the CCZ, both inorganic carbon and methane are soluble in water, and neither forms bubbles that could rise to the surface. 

Contrary to this claim, peer-reviewed research comparing the life-cycle climate change impacts of supplying 1 billion EVs with nickel, copper, cobalt, and manganese shows that using nodules to produce these metals, rather than getting them from land-based resources, would reduce the associated climate change impacts by 90%.(7)

6. Where are gas hydrates found? (n.d.).
7. Paulikas et al. (2020). Life cycle climate change impacts of producing battery metals from land ores versus deep-sea polymetallic nodules. Journal of Cleaner Production, 275. (

Will the impacts of deep-sea mining be invisible and less well understood?

While understanding and witnessing the environmental and social damages of land-based metal production is one thing, reducing them is another(8). The theoretical potential for reducing harm on land is severely constrained: We can’t change the fact that the grades of remaining ores are low and falling, nor can we change the fact that if the rock contains only 0.5% of target metal, the other 99.5% will become a waste stream. We also can’t change the fact that remaining battery metal deposits are located in places with high biodiversity, often on Indigenous land. 

The life-cycle Environmental, Social, and Corporate Governance (ESG) footprint for land-based production can be improved, but in most cases, it will be worse than the life-cycle ESG footprint of nodule-derived metals. This is because the starting point for the nodule resource is fundamentally different: rich concentrations of four metals in a single rock; an entirely usable rock mass; a barren and common environment with limited life; and no threat to Indigenous land.

Additionally, the Clarion Clipperton Zone is physically remote, but will not be “out of sight, out of mind.” Adaptive Management Systems (AMS) have been recognized as a key enabler of effective environmental management for deep-sea nodule collection, and provide a structured, iterative process of robust decision-making in the face of uncertainty, with an aim to reduce this uncertainty over time via active system monitoring. The Metals Company’s adaptive management system, a mix of deep-sea ecological data, marine sensors, and cloud-based A.I., will create a digital twin of our operating environment. This system will enable us to monitor what’s happening in real time and give eyes and ears into our offshore operations to the regulator and stakeholders. With this information, we will be able to adapt, pause, and change our operations to stay within expected ecological thresholds and inform all stakeholders of our impacts at any point, from anywhere in the world.

8. Paulikas et al. (2020). Life cycle climate change impacts of producing battery metals from land ores versus deep-sea polymetallic nodules. Journal of Cleaner Production, 275. (

Will deep-sea mining damage fragile deep-sea ecosystems?

Metal extraction—whether on land or from the deep sea—will impact ecosystems, but the extent and types of impacts are worth considering. The clean energy transition will require trade-offs. Billions of tons of metal will be extracted from the planet over the next 30 years to make this transition possible. The abyssal seafloor carries 300 to 1,500 times less life(9) and stores 15 times less carbon than ecosystems on land(10). If we source battery metals from seafloor nodules, we could reduce destruction of more biodiverse ecosystems, such as rainforests, which play a vital role in the earth’s climate cycle. Importantly, the abyssal plain is the most common environment on the planet, meaning that fauna impacted by nodule collection in license areas are likely to be well represented in areas where nodule collection does not take place. As a precautionary measure, more area within the Clarion Clipperton Zone has already been set aside for conservation than is currently under exploration(11).

9. Paulikas et al. (2020, April). Where Should Metals for the Green Transition Come From? Deep Green. Retrieved from
10. Paulikas et al. (2020, April). Where Should Metals for the Green Transition Come From? Deep Green. Retrieved from
11. Paulikas et al. (2020, April). Where Should Metals for the Green Transition Come From? Deep Green. Retrieved from

Will sourcing metals from polymetallic nodules undermine prices and incentives to scale up recycling?

Given the aggressive scale-up of demand driven by the world’s transition to clean energy, metal shortages are likely to persist for some time as metal producers make the large investments required to scale up supply. As metal supplies grow over time, metal producers will start competing on price and sustainability. At this point we expect that recycled metal will start displacing new metal supply from land-based sources due to its much better sustainability profile—even if it comes with a higher price tag. This scenario is supported by the fact that many jurisdictions around the world are making recycling of electric vehicle batteries a regulatory requirement. If done right, recycled metal is the only truly sustainable source of metal.

Metals derived from nodules will likely coexist with recycled metal for a few decades due to their lower production cost and lower ESG footprint, but will gradually be phased out as the world builds up sufficient stocks to enable a fully recycled metals commons.

Would deep-sea mining replace terrestrial mining?

We recognize that the introduction of commercial deep-sea mining would not completely replace land mining, even though the environmental benefits of doing so in the long run are clear (see “Why do we need deep-sea mining?”). What polymetallic nodules promise in the near term is an opportunity to supplement depleting terrestrial reserves to meet surging demand, and to give fragile land-based ecosystems a break and chance to recover from the damaging and intensive mining currently occurring in places such as Indonesia and Congo. In the longer term, as the nodule industry scales – and as its financial and ESG advantages over land mining become clear – competitive pressure will be placed on terrestrial mining, with those projects at the higher end of the cost curve likely becoming too uneconomical to continue.

A good analogy is with power production. If a nuclear power plant or a wind farm is opened that may not mean that, say, a coal plant will be shut down. But that is not an argument against introducing more sustainable modes of power production. Over time, introducing more sustainable and cost-effective methods of power production has been shown to reduce countries’ dependence on fossil fuels such as coal, and while this has not been an automatic substitution, it has been a clear step in the right direction. The same principle is true with sourcing rare minerals: it is better to introduce more sustainable mining practices now to meet soaring demand and put pressure on costly terrestrial mining projects, than delay the green transition and cause even worse damage to the climate.

How would The Metals Company’s vision for a closed-loop system of rental and redeployment partnerships be different from current recycling programs?

While recycling practices for bulk metals are already well established, this is not yet the case for many energy-transition metals. Emerging waste streams from clean energy technologies (e.g., batteries and wind turbines) can change this picture. The amount of spent electric vehicle (EV) batteries reaching the end of their first life is expected to surge after 2030, at a time when mineral demand is set to still be growing rapidly. That’s why we’re studying how to best work with partners to recycle and redeploy the EV battery materials that we plan to source from polymetallic nodules.

While current metal recycling practices fall short and cannot immediately eliminate the need for continued investment in new supplies, it is possible that by 2040 recycled quantities of copper, lithium, nickel, and cobalt from spent batteries could reduce combined primary supply requirements for these minerals by around 10%, according to the International Energy Agency. By developing a closed-loop system of rental and redeployment partnerships around these critical metals as the EV market grows, we can ensure that the proportion of recycled battery metals continues to grow alongside it. Learn more here.


Isn’t the deep sea a pristine environment that should not be touched?

No ecosystem is immune to the impacts of industrial society, including the deepest parts of the ocean. In its upper layers (0–2,000 meters), the ocean continues to warm unabated(12). It’s likely that this surface warming impacts the deep sea. The ocean is also continuing to acidify as it absorbs more CO2 from the atmosphere(13). With this in mind, we view it as our primary focus to reduce the CO2 in our atmosphere, thereby reducing ocean warming and CO2 absorption into the oceans. This requires a massive and rapid injection of metals for batteries for electrification.  

The impacts of supplying this booming metals demand from conventional terrestrial sources will only deepen the degradation of our planet’s oceans and biodiverse ecosystems, including through an increase in atmospheric carbon and, in certain cases, the disposal of mine waste and tailings directly into the deep sea. Polymetallic nodules can provide a cleaner  path forward that can curtail these impacts and meet the needs of the clean energy transition at the same time.

12. Bindoff, N.L. et al. (2019). Changing Ocean, Marine Ecosystems, and Dependent Communities. IPCC Special Report on the Ocean and Cryosphere in a Changing Climate. Retrieved from
13. Bindoff, N.L. et al. (2019). Changing Ocean, Marine Ecosystems, and Dependent Communities. IPCC Special Report on the Ocean and Cryosphere in a Changing Climate. Retrieved from

Should we have a moratorium on deep-sea mining until the impacts of nodule collection are better understood?

To be clear, no deep-sea mining takes place today. The only activity currently underway is deep-sea research focused on baselining marine environments and characterizing the impacts of proposed operations. If this research shows that the risks outweigh the benefits, the global community, through the International Seabed Authority (ISA), can decide that our project should not go ahead. A moratorium on research will only lead to less research, and possibly a less informed approach to sourcing this critical resource. 

Contractors such as The Metals Company are commissioning the majority of current deep-sea research. From our $75 million research program, we expect hundreds of independent, peer-reviewed papers to be authored by researchers who contractually maintain their academic freedom. More on this can be found on our Research page.

If, at the end of our Environmental and Social Impact Assessment program, the research shows that producing critical battery metals from seafloor nodules will do more planetary harm than good, we will not seek to apply for an exploitation contract with the ISA and will assess other options.

Could nodule collection lead to the extinction of species in the deep sea?

All mining practices are extractive and there is no perfect or completely harmless option. Mining on land has driven species extinction and biodiversity loss for centuries. Even in countries with stringent environmental regulations, biodiversity-related impact studies typically focus only on keystone species above ground. They do not consider biodiversity comprehensively and overlook the estimated 99% of microbial species and 80% of worm species yet to be studied under the soil. (18) As mining increasingly moves into the most biodiverse ecosystems on the planet, species extinction and biodiversity loss will likely increase. Nickel production in Indonesia is of particular concern and has been described as the mined commodity most susceptible to biodiversity risks. 

Nodule collection, by contrast, would take place at 4–6 kilometers depth on the abyssal plain of the Clarion Clipperton Zone, where there are several orders of magnitude less life than on land. This is one of the least populated areas on the planet (300–1,500 less biomass than on land(19))— with no plants, no light, high pressure and few sources of food. Seventy percent of its low resident biomass is made up of microbial organisms, with the remaining biomass comprising a small population of deep-sea worms, sponges, and fish.

The abyssal plain is the most common environment on the planet, covering more than 60% of the planet’s surface20, and quite unlike the unique ecosystems that mining on land threatens. On the abyssal plain the risk of species extinction and biodiversity loss can be reduced by setting aside large areas of the abyssal plain for conservation; the ISA has already set aside more area under protection in the CCZ than is currently under exploration.

As part of our ongoing Environmental and Social Impact Assessment program, we’re studying species throughout the overlying water column and above the surface to make sure we understand how these ecosystems interact and function. This comprehensive approach goes beyond typical land-based impact studies, and includes understanding microbial populations and worms living in the seafloor mud. This will help us make better decisions about how to further mitigate our impacts, what additional areas to set aside, how to design our collector robots, at which depth to return seawater used to lift nodules from the seafloor, and what indicators to monitor during operations to keep within safe ecological boundaries. 

We believe that sourcing battery metals from loose-lying polymetallic rocks in the CCZ puts us in a better position to reduce the risk of species extinction than intensifying land-based extraction for these same metals in unique and highly biodiverse terrestrial ecosystems.

18. Guardian News and Media. (2020, December 4). Global soils underpin life but future looks “bleak,” warns UN report. The Guardian.
19. Bar-On, Phillips, & Milo. (2018). The biomass distribution on earth. Proceedings of the National Academy of Sciences of the United States of America. 115(25), 6506-6511. doi:10.1073/ pnas.1711842115.
20. Paulikas et al. (2020, April). Where Should Metals for the Green Transition Come From? Deep Green. Retrieved from

Would each nodule operation effectively strip mine vast areas of the seafloor?

Collecting deep-sea polymetallic nodules does not involve strip mining. Strip mining  is the removal of vegetation, soil, and rock (also known as “overburden”) above a layer or seam of minerals, followed by the removal of the exposed mineral. During this process, the entire surface ecosystem is removed before excavation is used for softer rocks, and drilling and blasting is used to break up and remove the subsurface hard rock.

By contrast, polymetallic nodules are loose rocks sitting exposed on top of the seafloor, with 95% of nodule mass contained in the top 5 centimeters of sediment. There is no overburden to remove. As nodule collectors move along the seafloor, they direct jets of seawater across the nodules to lift and collect them inside the machine, using the Coandă effect. While up to 5 centimeters of soft mud under the nodules will travel inside the vehicle, almost all of this will be separated and redeposited back at the seafloor. This process is engineered to minimize impact on the marine environment and involves no strip mining, drilling or blasting of the seafloor(21).

It’s also worth noting that nodule collection is projected to impact 40,000 square kilometers of the abyssal seafloor per year for 30 years. This is less than 1% of the estimated 4,900,000 square kilometers of the seafloor impacted every year by trawling, largely in much shallower and more productive waters(22).

21. E. Baker, Y. Beaudoin (Eds.), Deep Sea Minerals: manganese Nodules, a physical, biological,
environmental, and technical review, Secretariat of the Pacific Community, 1B (2013)
22. Sala, E., Mayorga, J., Bradley, D. et al. (2021). Protecting the global ocean for biodiversity, food and climate. Nature 592, 397–402.

Will sediment plumes kicked up by nodule collector vehicles travel thousands of kilometers?

Nodule collection operations will create two distinct plumes: the disturbance and suspension of seafloor sediments by nodule collector robots (‘seafloor plume’) and the reintroduction of residual sediment and nodule fines into the midwater column as seawater used for nodule transport is discharged from the riser outlet (‘mid-water plume’).

Recent in-situ experiments and studies show that the vast majority of seafloor sediment kicked up during operations will settle quickly, mostly within 4 kilometers and within a few days, and dilute rapidly to natural background concentration levels—the most relevant metric for sea-life impact—within 1 kilometer. Furthermore, successful trials of the ‘Patania II’ collector vehicle by contractor Global Sea Mineral Resources (GSR) found that this sediment rarely rose more than 5 meters above the seafloor.

 These findings are supported by plume modelling for trials of our pilot collector system conducted by the Danish Hydrology Institute (DHI) as part of our ESIA program. Taken collectively, this real-world data and modelling suggests that it is highly unlikely that any direct pathway exists in which suspended carbon-bearing sediment could travel to the surface from depths of at least 4,000 meters, all but eliminating the risk that nodule collection could contribute to greenhouse gas emissions.

Will 'tailings' be discharged into the mid-water column and introduce sediment and dissolved metals over potentially large areas?

Although the sediment-seawater mixture that will be returned into the midwater column is often referred to as “tailings,” the two should not be confused. Tailings are the materials left over after the process of separating the valuable fraction from the uneconomic fraction of an ore. Tailings are distinct from “overburden,” which is the waste rock or other material that overlies an ore or mineral body and that is displaced during mining without being processed (i.e., chemically). While our processing flowsheet eliminates tailings by design, other contractors may pursue different pathways, but none are currently proposing to release tailings from nodule processing at sea. Small amounts of residual sediment and abraded nodules found in the seawater used for nodule transport are more analogous to the removal and redeposition of overburden during a terrestrial mining operation.

A recent study by researchers at MIT and plume modeling conducted by the Danish Hydrology Institute (DHI) for our Enivronmental and Social Impact Assessment (ESIA) shows that the turbulence of this plume upon re-entry into the water column limits the ability of sediment particles to stick together( 23).

Based upon emerging data, a long-term commercial mining operation can be expected to elevate sedimentation rates by as little as 1% to the impacted areas. One outstanding question that our ESIA is currently in the process of addressing is whether increased quantities of sediment falling to the seafloor are likely to be detrimental to deep-sea fauna and habitats, which have evolved in an environment naturally subjected to wide variations in sediment load. 

Ultimately, limiting the amount of sediment brought up with the nodules to the surface will play a primary role in setting the scale of the impact of midwater plumes. This is why our engineering partners, Allseas, are focused on optimizing our collector and riser system to further reduce our impacts.

Nodules are friable, and turbulence will cause some fragmentation during their rise to a collection ship, where screens and centrifuges will retain particles larger than 10 microns, with smaller particles entering the return flow. The increased bioavailability of heavy metals contained in these particles has been a historic cause for concern, however these metals are all present as compounds, which may have less toxicity than in free ion form. New research finds that, for some metal compounds, nodule collection is unlikely to exceed toxicity thresholds.  

Further research on this topic is being considered as part of our ongoing Environmental and Social Impact Assessment.

23. Muñoz-Royo, C., Peacock, T., Alford, M.H. et al. Extent of impact of deep-sea nodule mining midwater plumes is influenced by sediment loading, turbulence and thresholds. Commun Earth Environ 2, 148 (2021)., K., & Alford, M. (December 7, 2019). PLUMEX – MOD News – blog. MULTISCALE OCEAN DYNAMICS.


Will The Metals Company’s surface support vessels, seafloor equipment, and riser pipes create noise pollution?

Nodule collection will generate some noise, and our research team has collected background noise levels as well as noise from our pilot collection trials in order to study potential impacts of operating in the Clarion Clipperton Zone. However, our operation will not use sonar and is not expected to make dangerously loud noises, such as those produced by blasting during land mining. Most noise will be highly localized and similar to that of typical ship operations. Noise levels are unlikely to exceed the gross impact of military and commercial operations, which are far more widespread across the oceans, and which all use sonar. 

While whales may migrate through our contract areas in the CCZ, these areas are unlikely to be a feeding or breeding site for large marine mammals given the low productivity of their surface waters(25). Nodule-collection operations will likely be audible to various marine organisms and could interfere with communication or other processes over limited distances. At the same time, this noise may also prove useful in alerting them to our presence and avoiding contact.

The acoustic effects of nodule collection are being investigated as part of our environmental and social impact assessment  (ESIA). This data will also be used to inform engineering and design decisions to reduce noise wherever possible.

25. Paulikas et al. (2020). Life cycle climate change impacts of producing battery metals from land ores versus deep-sea polymetallic nodules. Journal of Cleaner Production, 275.

Will deep-sea mining destroy marine genetic resources that could provide new medicines and breakthrough treatments?

We believe our exploration activities can be a primary driver of research and discovery when it comes to marine genetic resources. The Metals Company has already compiled an extensive library containing more than 20,000 preserved biological samples collected at 7-kilometre intervals. Sample collection and preservation is an integral part of our exploration program and we expect to collect many more samples as we explore new parts of our contract areas. We’re actively seeking academic partnerships to understand the genetic resource potential of this ever-expanding library.

In addition, a larger area in the Clarion Clipperton Zone has already been set aside for conservation than is currently under exploration. These protected areas will remain protected from any future nodule collection operations and will be available for continued research on marine genetic resources, new genes, antibiotics and pharmaceuticals.

Will deep-sea ecosystems recover from deep-sea mining?

Our collectors are being engineered to only remove most nodule cover around the top 5 centimeters of sediment. Recovery can start naturally and immediately after the collector moves on. 

Between the 1970s and present, scientists have conducted 11 seafloor disturbance and commercial mining studies. They repeatedly revisited these sites over a 26-year time period to measure each area’s recovery. Review studies of research to date show that mobile and pelagic fauna density and diversity recovers within one year(26) , and that microbial density, diversity, and function (70–80% of the total biomass impacted by nodule operations) are expected to recover within 50 years(27). New nodules will continue forming on the impacted site, but it will take up to 5 million years to regenerate nodule cover comparable to pre-disturbance state. Recovery of species that need the hard substrate of nodules (less than 10% of the total biomass impacted) is currently not known and depends on habitat connectivity, recruitment, and the extent of remaining nodule coverage.   

Compare this rate of recovery to the default driving nickel supply growth today: mining nickel laterites in Indonesia(28) (29).  The entire overlying rainforest ecosystem is removed (trees, plants, soil, rock, and all animals and microbes living therein). As the rainforest is cleared, the organic carbon it contains is released, and the below-ground microbial and worm populations are impacted. Recovery often only begins when mine operations cease in the area (this can take many years) and requires active restoration efforts and funding by the mine operator or local government. 

It can take hundreds or thousands of years to regenerate new soil and forests that can support previous levels of biodiversity(30). Nickel laterites that are removed can reform through continued weathering and wet leaching of unweathered rock, but—like nodules—will take millions of years. 

26. Jones, D. O., Kaiser, S., Sweetman, A. K., Smith, C. R., Menot, L., Vink, A.,Clark, M. R. (2017). Biological responses to disturbance from simulated deep-sea polymetallic nodule mining. PLoS ONE, 12(2), e0171750. doi:10.1371/journal.pone.0171750.
27. Vonnahme, T. R., Molari, M., Janssen, F., Wenzhofer, F., Haeckel, M., Titschack, J., & Boetius, A. (2010). Effects of a deep-sea mining experiment on seafloor microbial communities and functions after 26 years. Science Advances, 6(18). doi:10.1126/sciadv.aaz5922.
28. Ghose, M. (2001). Management of topsoil for geo-environmental reclamation of coal mining areas. Environmental Geology, 40, 1405–1410. doi:10.1007/s002540100321.
29. Block, P. R., Gasch, C. K., & Limb, R. F. (2020). Biological integrity of mixed-grass prairie topsoils subjected to long-term stockpiling. Applied Soil Ecology, 103347, doi:10.1016/j.apsoil.2019.08.009.
30. Haynes, R.J. (2014). Nature of the belowground ecosystem and Its development during pedogenesis. Advances in Agronomy, 127: 43–109.


Is The Metals Company’s research biased or subject to influence?

The Metals Company is committed to commissioning independent, peer-reviewed and reproducible research before any commercial mining takes place. This research will study the potential impacts of deep-sea mining and we will share that information with the international community once investigations have concluded.

We commission research so that the international community can come to a fair, science-based conclusion on the effects of polymetallic nodule collection. The blind peer review process means that no outside group, including The Metals Company, can influence the research or publication process. No commercial collection can or will take place until rigorous, multiyear Environmental and Social Impact Assessments are conducted, vetted, reviewed and evaluated by the International Seabed Authority.

We invite curious readers to consult our LCAs for some science showing some of the benefits of nodules.