An untapped abundance of minerals lies at the bottom of the deep sea. These include metals that are crucial for the production of electric vehicles and other “green technologies,” but the environmental impacts of mining these materials are largely unknown.
At the end of March, the International Seabed Authority’s (ISA) 28th Session concluded without establishing a deep sea mining code for international waters.
Companies can start filing permit applications for industrial-scale deep-sea mining in Pacific waters from July 9 this year, but without established regulations, the ISA council doesn’t know how they’re going to review applications for mining contracts. In a virtual meeting to be held before July, the governing council will debate whether permission to applications can be delayed.
The SMC asked experts to comment on the difficulties of designing and agreeing upon deep-sea mining regulations.
Professor Jonathan Gardner, Professor of Marine Biology, School of Biological Sciences, Victoria University of Wellington, comments:
What is deep sea mining and how is it done?
“Deep-sea mining, as the name suggests, is the extraction of minerals from waters greater than 200 metres deep, which roughly corresponds to the edge of the Continental Shelf.
“It is important to appreciate that commercial deep-sea mining has not yet started anywhere in the world, but a lot of incredible engineering work has been carried out over the last 10 or so years to develop ships, submersibles, and a range of autonomous mining vehicles in anticipation of commercial deep-sea mining.
“There are a range of mineral targets for deep-sea mining. Polymetallic nodules about the size of tennis balls lie on the seabed and contain many different metals in different proportions, while phosphorite nodules contain phosphate – which is commonly used as a fertiliser in agriculture.
“For nodules it is envisaged that some of these can be sucked up off the bottom using a long hose and a very powerful pumping system, whilst others may be collected by vehicles moving along the seafloor that are deployed from and returned to a mother ship.
“Seafloor massive sulfide deposits (typically the products of hydrothermal vents) and cobalt-rich crusts (at seamount sites that are or were volcanically active) also contain elevated concentrations of numerous different metals.
“For these solid rock formations, machines that look a bit like tanks – and are certainly the size/weight of tanks – have been developed. These will grind up the rock and collect it, or may be followed by other machines whose job it is to collect the crushed rock.
“Remember that all of these activities occur underwater, often at considerable depth (e.g. 4000 m) and pressure. This is an incredible engineering challenge that only makes financial sense if the abundance and value of the minerals is high.”
Why do we need these minerals?
“We need these minerals because they are valuable in their own right (e.g., some deposits are rich in gold) but mostly we need these minerals for use in a range of technologies, including new ‘green technologies’ such as electric car batteries, wind turbines and solar panels. Now that the reserves of these minerals on land are being mined out, we are turning to the sea.
“There is an important geopolitical component to deep-sea mining because most of the world’s usable land-based deposits of rare earth elements occur in China. There is therefore real concern in many countries about on-going access to these minerals and what happens if China cannot or will not export them anymore. It’s also worth noting that rare earth elements play a key role in the electronics of highly sophisticated military equipment on land, at sea and in the skies, so new sources of these minerals have been sought to help reduce world reliance on the supply from China.
“A number of less well-developed countries, including many South Pacific island states – with small land areas but very large Exclusive Economic Zones – are looking at deep-sea mining as a critical source of funding to support infrastructure development, either by mining these deep-sea areas themselves or by licensing mining within their Exclusive Economic Zones to other countries, companies or consortia of companies.”
What do we know about deep sea ecosystems? How much don’t we know?
“It may sound trite to say that we don’t know how much we don’t know about deep-sea ecosystems, but it is nonetheless true. From an environmental and/or ecological perspective we know very little about the deep sea because it is so vast and deep and difficult to explore.
“It’s worth pointing out that the deep sea is actually the world’s largest habitat type, occupying something like 90% of the marine environment, which itself occupies something like 71% of the planet. Thus, the deep sea is estimated to occupy something like 64% of planet Earth.
“We have really only recently started to catalogue life in the deep-sea, which is dominated by animals because it is so dark. We know almost nothing about small life forms such as bacteria, viruses and other single-celled life forms.
“Although research is now underway to map all of the world’s deep oceans, at most only 20% has actually been adequately mapped. This includes all of New Zealand’s Exclusive Economic Zone plus some of the extended continental shelf in our region.
“For the vast majority of species we know nothing about how long they live, reproduce, respond to disturbance or interact with their neighbours, but we can make educated cases in some cases.”
How might deep sea mining affect marine ecosystems?
“Mining is an inherently destructive process, as we have seen on land over the centuries. The mining industry is very aware of this and as far as deep-sea mining proposals are concerned, the industry is taking every reasonable and practical step to minimise disturbance.
“We know from reviews of the design of the mining gear itself, and also from some shallow water/ coastal cases, that there are going to be several different ways in which mining will affect deep-sea ecosystems.
“Most obviously, any rock extraction process is going to break up and grind the rock, thereby removing the natural surface on which organisms live. The mining machines themselves are large and heavy and will cause direct impact by crushing animals. The removal of nodules will change the seafloor by exposing sediment which previously was not exposed to water movement, and this may change the flow of water over the seafloor itself.
“This could affect the movement of oxygen and food and the removal of the animals’ waste products from the immediate deep sea environment, and reduce the amount of ‘structure’ on the seafloor. Typically areas that have more ‘structure’ tend to be characterised by greater biodiversity so loss of structure often leads to loss of biodiversity.
“The removal of sand or sediment will kill organisms associated with the surface as well as animals that live in the sand. Thus, we know that there will be considerable direct mortality of individuals and communities resulting from all forms of mining.
“All of these extraction processes are going to create sediment plumes, either directly at the bottom where the point of extraction occurs, or in the water column when the spoil is returned to the marine environment. Sediment plumes may be short-lived or long-lived, depending on the local conditions and currents, but generally these sediment plumes will smother animals and/or clog their delicate feeding and respiration surfaces.
“In some cases, the sediment itself may be toxic because it contains resuspended particles that are associated with naturally occurring heavy metals, which are toxic to many forms of life. There is therefore expected to be considerable indirect forms of mortality of individuals and communities resulting from all forms of mining.”
How are researchers and decision makers weighing up the need for these minerals against these environmental impacts?
“This is the big question. Everyone wants a ‘first world’ standard of living, and as much of the world continues to develop and more and more people move into ‘the affluent middle class’, there is ever increasing need for minerals to support this sort of lifestyle. There is also, of course, a real global effort to move towards ‘green technologies.’
“Trying to find the balance between the need to permit further global development and sustain living standards versus protecting the deep-sea environment is the challenge.
“The International Seabed Authority (ISA), which is based in Jamaica, is the body tasked with trying to develop rules and regulations for mineral extraction, plus how the wealth from mining will be shared equitably amongst countries large and small, with and without national access to deep-sea mineral resources.
“They have a panel of multi-disciplinary experts trying to develop guidelines that countries will adhere to before deep-sea mining commences. It is interesting to note that this is possibly the first time in human history that a new industry – deep-sea mining – could be regulated from the outside before any mining activity has actually taken place.
“There is no consensus about how/where/when commercial mining will commence at the moment, and because the deep-sea is unknown and unknowable to most of us, there is real concern in some quarters that environmental impacts will be down-played or understated by regulators in the hunt for mineral wealth from the deep sea.
“Scientists, and a number of governments, including the European Parliament and New Zealand government, and large companies such as BMW, Volvo, Google and Samsung have already put in place either embargoes on deep-sea mining or made calls for the start of deep-sea mining to be delayed until we have a better understanding of the deep-sea environment and the impact that mining may have on it.
“As is always the way, the decision-making path that the ISA takes will be influenced by people from many different interest groups, including the countries themselves, the mining industry, environmentalists, scientists, etc.
“Not surprisingly, trying to find a path through these competing interests has been difficult and time consuming and is why the ISA has not yet been able to arrive at a definitive decision.”
What research is being done to help inform rules and regulations for deep sea mining?
“There certainly is some research that has happened and is ongoing right now trying to better understand the impact of deep-sea mining so that rules and regulations can be informed by science.
“The biggest problem with this small body of international work is that it’s based on small-scale studies, and most mining activities are going to be much bigger in scale, so the direct applicability and relevance of the research to the actual mining problem can be called into question.
“In addition, from a scientific perspective, this work, as good as it is, is very limited because the researchers do not have access to the kinds of deep-sea mining equipment and machines that will actually be used by the mining companies. So simulating mining activity in real-world circumstances is impossible. This means that the researchers are often looking at one component only, not all aspects, of deep-sea mining.
“For example, recent NIWA work focussed on the impact of sediment plumes, but the spatial extent of mining will be much greater in most cases than the researchers can simulate.
“Beyond this, there is the problem of time. How long will it take for deep-sea communities to (partially or fully) recover from mining activities? If recovery takes decades or even centuries (and a timeline of centuries is realistic in some cases) then how long do we run scientific testing before we commence deep-sea mining? Are we prepared to wait to find out that recovery takes centuries or that, in some cases, there is no actual recovery? And if this is the case then do we not commence mining at all?
“These are really big and important questions and unfortunately research looking into impacts of mining and the recovery of deep-sea systems has been largely overlooked until recently, and as a consequence has been grossly under-funded.
“Not having the research means we don’t have answers to many of the obvious and important questions, which means that making a truly science-based informed decision is going to be very hard for ISA.”
Conflict of interest statement: ” I am a Professor of Marine Biology at Victoria University of Wellington, working on (among other things) deep-sea genetic connectivity. I work very closely with NIWA and my research has been jointly funded with NIWA. I have received funding for deep-sea genetic connectivity work from MPI and MBIE. I am on the Technical Advisory Board of CIC Ltd – a deep-sea mining company. I am a Trustee of The Guardians of Kapiti Marine Reserve.”
Dr Malcolm Clark, Principal Scientist – Fisheries, NIWA, comments:
“NIWA’s research on deep-sea mining impacts and their potential management has identified that the resource setting, likely type of operations, nature of the habitats, faunal communities, and nature and extent of environmental impacts are highly variable. It is therefore difficult, if not impossible, to generalise across all deep-sea mining ‘types’.
“Mining will have an impact, but the nature and extent of impacts, and how these risks and impacts are assessed, mitigated, and managed is where scientific research can inform potential policy and management. There will be a complex array of impacts, both direct and indirect, that require extensive multidisciplinary research and assessment.
“Three key processes are needed for effective management of deep seabed mining and reduction of the risks of major harmful effects:
- An effective Environmental Impact Assessment (EIA) process: this requires a strong Environmental Risk Assessment (ERA) component to focus research and resources on the main impacts and a strong link with Environmental Monitoring Management Plan (EMMP) to mitigate residual impacts.
- Conservation management: spatial management is a key component, which may need to operate at various spatial scales (regional to local).
- Reducing uncertainty to an acceptable level: there may remain many gaps in knowledge, but these can potentially be managed by adaptive management and strong monitoring systems. Precaution will be important.”
Conflict of interest statement: “Dr Malcolm Clark is an independent expert member of the International Seabed Authority’s Legal and Technical Commission. NIWA is an independent sub-contractor for a CSIRO project for The Metals Company, providing scientific advice for developing an assessment of environmental impacts for a potential seabed mining application in the eastern Pacific Ocean.”