Dredging the depths for metal

Deep seabed mining

Marta Montojo and Ian Urbina of The Outlaw Ocean Project describe the portents of a deep sea Klondike – lucre for some; further destruction for the marine environment

Few people have ever heard of the tiny country of Nauru. Even fewer ever think about what happens at the bottom of the world’s oceans. But that may soon change. The seafloor is thought to hold trillions of dollars’ worth of metals, and this Pacific-island nation is making bold moves to get a jump on the global competition to plumb these depths.

Its target is potato-sized rocks, polymetallic nodules. Sitting on the ocean floor, these prized clusters can take more than 3 million years to form. They are valuable because they are rich in the manganese, copper, nickel and cobalt that are claimed to be essential for electrifying transport and decarbonising the economy.

The process

The process of mining the seabed for polymetallic nodules. Photo: Louis Mackay

To vacuum up these treasured chunks requires massive excavators. Typically 30 times the weight of regular bulldozers, these machines are dropped underwater where they drive along the seafloor 4,000–6,000 metres deep, suctioning up the rocks, crushing them and piping a slurry of crushed nodules and seabed sediments to the vessel above. After the minerals have been separated out, the processed water, sediment and mining ‘fines’ (small particles of the ground-up nodule ore) are piped overboard.

The concerns

But a growing number of marine biologists, ocean conservationists, government regulators and environmentally-conscious companies are sounding the alarm about a variety of environmental, food security, financial and biodiversity concerns associated with seabed mining.  They are concerned that the ships will dump back into the sea the huge amounts of toxic waste and sediments produced by the process, impacting fish and contaminating the global seafood supply chain.

They also worry that the mining may diminish the ocean floor’s distinct carbon sequestration capacity, in that by stirring up the ocean floor the mining companies will release carbon into the environment, undercutting some of the benefits intended by the switch to electric cars, wind turbines and long-life batteries.  Douglas McCauley, director of the Benioff Ocean Institute at the University of California Santa Barbara, warned against trying to counter the climate crisis with solutions that rely on a ‘paradigm of just ripping up a new part of the planet’. If the goal is to slow climate change, he said, it makes little sense to obliterate the deep sea ecosystems and marine life that presently play a role in capturing and storing more carbon than all the world’s forests.

The law

The deep seabed outside national waters is a realm subject to a unique regime under international law, which deems the international seabed area and its resources to be managed by the International Seabed Authority (ISA) on behalf of humankind as whole. ‘But who benefits and how from this new rush to seabed mining remains unclear,’ said Kristina Gjerde, high seas policy advisor for the IUCN Global Marine Programme. ’And what constitutes benefits to humankind is also unclear, as the deep seafloor is filled with untold biodiversity, much of it vitally important to the survival of our planet.’

The hopefuls

Nauru hopes nevertheless to forge ahead with seabed mining. This tiny, cash-strapped developing nation hopes to get an early edge on a potentially multi-billion-dollar market, even though Nauru itself is likely to receive only a small fraction of the financial benefits of the mining from Nauru Ocean Resources Inc. (NORI), the Canadian company it is sponsoring.  In June 2021, Nauru took the first step in launching the industry: it announced plans to submit an application for commercial extraction on behalf of its sponsored entity, as early as 2023 to the ISA. Such an application will be judged against whatever the deep sea mining rules are at that time – finalised or otherwise.

Over a dozen other countries, including Russia, the UK, India and China, have 15-year exploration contracts. The government of India has recently set aside $544 million to stoke private sector investments and technological research in this industry.

The timing

International interest in seabed mining has been stimulated partly by new advances in robotics, computer mapping and underwater drilling, combined with high commodities prices. The metals the mining companies seek are commonly found on land, but some raise concerns that these may not be enough.

‘With dwindling resources on land, with exponential growth of demand, and a shortage in circulation (recycling), there is a need to find alternative sources of critical metals needed to allow the energy transition to zero-net carbon economies,’ said Bramley Murton, a marine researcher at the UK’s National Oceanography Centre. It has been estimated that the nodules on the bottom of the ocean collectively contain six times as much cobalt, three times as much nickel, and four times as much of the rare earth metal yttrium as there is on land. Mining companies and states have set their eyes on the Clarion-Clipperton Zone, an area stretching from Hawaii to Mexico: it is estimated to contain metals valued at between $8 trillion and $16 trillion.

The problem

Scientists have conservatively estimated that each mining licence will permit direct strip mining of some 8,000 square kilometres of seabed over the course of a 20-year mining licence from the ISA, and that the sediment plumes generated by the mining the ocean floor will ‘easily’ impact a further 8,000–24,000 square kilometres of surrounding seabed life. They estimate that the ‘nodule obligate species’ – the animals living on the nodules or which, like deep sea octopuses, need the nodules to survive – will take millions of years to recover, and even the animals living in the surrounding sediment may take hundreds to thousands of years to recover from the impact of mining.

The scepticism

Massive subsea mining machines from Nautilus Minerals. The Toronto-based company is the first to explore the seafloor for massive sulfide systems, a potential source of high grade copper, gold, zinc and silver. Photo: Nautilus Minerals / PD

In March, BMW and Volvo Group, along with Samsung and Google, pledged to abstain from sourcing deep sea minerals. In its most recent global report, the International Energy Agency, a global body that advises countries on policy, concluded that seabed mining machines, ‘often cause seafloor disturbance, which could alter deep sea habitats and release pollutants … stirring up fine sediments, [and] could also affect ecosystems, which take a long time to recover.’ In June, the European Parliament also asked the executive branch of the European Union to stop financing deep sea mining technology, and called for a delay in more exploration operations.

The UK House of Commons Environment Audit Committee in 2019 concluded that: deep sea mining would have ‘catastrophic impacts on the seafloor’; the ISA benefiting from revenues from issuing mining licences is ‘a clear conflict of interest’; and that ‘the case for deep sea mining has not yet been made’.

‘We need much more time for research to be carried out, not by mining companies, but by independent seabed ecologists,’ said Kelvin Passfield, who runs the Te Ipukarea Society in the Cook Islands and is part of a group of non-profit organisations in Fiji, Vanuatu and other Pacific islands concerned about the impacts of mining’s residue plumes on local fishermen and food security.

Other critics see the mining as a Ponzi scheme of sorts intended to attract venture capital investment but which has little real chance to make money in the long term. Matthew Gianni, co-founder of the Deep Sea Conservation Coalition, said that when sea-bed mining companies claim we need 100s of millions of tons of these metals to build batteries for electric vehicles and other renewable energy storage technologies they are trying to peddle a false choice between having to mine cobalt and nickel on land or in the deep sea. ‘We don’t need to build batteries with either nickel or cobalt. Tesla and BYD, the world’s second-largest EV manufacturer, are making cars with Lithium Iron Phosphate (LFP) batteries, with little to no nickel or cobalt, which are selling unexpectedly well,’ he said. ‘There is massive investment now being put into developing batteries that don’t use these metals at all. Better product design, recycling and reuse of metals already in circulation, urban mining, and other “circular” economy initiatives can vastly reduce the need for new sources of metals.’

The sealife

A deep sea octopus. The destructive effects of ocean floor mining operations pose a threat to marine biodiversity, as well as to the livelihoods and the food security of vulnerable fishing communities. Photo: NOAA / PD

Once thought to be relatively lifeless, the deep sea is now seen by most scientists as a species-rich environment populated by creatures that thrive under conditions that seem impossibly extreme. And yet, much of its biodiversity on the seafloor is distinctly vulnerable to change because their habitat is so far removed and thus rarely disturbed. The oceans already face a daunting list of threats ranging from overfishing, sonar testing, oil dumping and plastic pollution, to sea level and temperature rise, acidification, oxygen depletion, algal blooms and ghost nets. Add to those the additional strains faced by deep sea marine life on the seafloor: internet cables, bottom trawling, treasure hunting, oil and gas drilling, coral bleaching, the sinking of retired drilling rigs. In 2019 the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services (IPBES) issued its Global Assessment report which estimated that unless we reverse the drivers of biodiversity loss a million species are at risk of extinction, many within the next several decades.

The invisibility

One of the biggest challenges in stoking concern about this type of mining is that the seabed is so far removed – geographically, emotionally and intellectually – from the public that benefits from it. Most of the world’s seafloor is not even mapped, let alone properly or fully understood or robustly governed. Deep below the waterline it is always dark, and many of its inhabitants defy categorisation into the traditional animal–plant–mineral taxonomy.

No solution to a problem as complex as the climate crisis will come without difficult decisions and heavy costs, especially as the global public tries to wean itself from fossil fuels. The hard part, though, is figuring out how to take one step forward without also moving three steps back.

The Outlaw Ocean Project is a journalistic non-profit organisation based in Washington DC that focuses on environmental and human rights concerns at sea. Marta Montojo is the project’s foreign editor, Ian Urbina its executive editor. For more information see: www.theoutlawocean.com