Travel thousands of metres below the surface of the ocean, and you reach the seabed. Pitch black and quiet, it is largely unexplored, untouched, unknown.
What is known is extraordinary. The landscape at the bottom of the sea is as varied as the earth surface: 4,000m (13,000ft) down, abyssal plains stretch for miles like deserts; there are trenches large enough to swallow the Earth’s largest mountains; venting chimneys rise in towers like underwater cities; seamounts climb thousands of metres. Hot thermal vents – believed by some to be the places where all life on Earth started – gush highly acidic water at temperatures of up to 400C, drawing in an array of creatures.
So little is known about what happens this far under the sea that in the 25 years following the discovery of the hydrothermal vents, an average of two new vent species are discovered every month. They include the yeti crab, a ghostly white crustacean with silky-blonde bristles on its claws that give it a resemblance to the Abominable snowman. Others discovered in the last 20 years include the beaked whale and the Greenland shark, which dives to around 1,200m and has a lifespan of close to 400 years,
making it one of the world’s longest-living organisms.
“Every time you go down into the deep, you see something incredible and often new,” says Diva Amon, a deep sea biologist and fellow at the Natural History Museum in London who has undertaken 15 deep sea expeditions.
“There’s a bone-eating worm called Osedax, which lives on the bones of dead whales in the deep … Another special one was … an anemone whose tentacles were 8ft long.”
Anna Metaxas, professor of oceanography at Dalhousie University in Nova Scotia, Canada, recalls the first time she travelled to the deep sea, in waters near the Bahamas.
“The most spectacular part of that dive was the bioluminescence. Because it gets dark at 1,000m they all light up, they all flash. I was in a submersible that had a plexiglass sphere, it was like flying through space.”
Ninety percent of the ocean – and 50% of the Earth’s surface – is considered the deep sea (areas deeper than 200m). Only 0.0001% of the deep seafloor has been investigated. Doing so is perilous, technically challenging and expensive. But despite these obstacles, companies have set their sights on the seabed as the new frontier for mining.
Since 1982, the International Seabed Authority (ISA), which is charged with regulating human activities on the deep sea floor, has issued 30 contracts for mineral exploration, taking in an area of more than 1.4m sq km. Most of these sites are in the Pacific Ocean, in the Clarion-Clipperton fracture zone (CCZ).
In particular, companies have their eyes on polymetallic nodules – bundles of ore that resemble potatoes, which litter the surface of the deep sea and are rich in manganese, nickel, cobalt and rare earth metals. The nodules are up to 10cm in diameter and are thought to form at the staggeringly slow rate of just a few centimetres every one million years.
“A battery in a rock,” is how DeepGreen, one of the big players in the nascent industry describes the polymetallic nodules. It touts deep-sea mining as a less environmentally and socially damaging alternative to terrestrial mining, and says it is crucial for affecting a transition to a greener economy, with the nodules containing the minerals needed for the batteries used in electric vehicles.
“Society has an urgent, growing need for battery metals to enable a full transition to clean energy and electric vehicles. We believe that polymetallic nodules are the cleanest source of these metals, with by far the lightest planetary touch,” says the company on its
Its proposal is to dispatch ships to the CCZ and suck up the nodules through long pipes that stretch to the seabed. The nodules would be processed on the ship, with excess sediment pumped back into the sea.
So far, licenses in international waters have only been issued for exploration and not mining, but the ISA is working on a regulatory framework for mining of the deep sea, with DeepGreen saying it will be ready to begin the work by 2024.
Our largest ecosystem
There are concerns about the environmental impact deep sea mining could have on marine ecosystems, particularly given how little is known about them and the very slow pace of reproduction and growth at those depths.
An experiment in 1978, which involved the extraction of nodules from the seabed in the CCZ, pointed to how long-lasting the damage can be. The area was revisited in 2004, and researchers found the tracks made by mining vehicles 26 years earlier were still clearly visible on the seabed. There was also a reduced diversity of organisms in the disturbed area.
“You are talking about the destruction of the habitat on the seafloor. Any area you are mining will be destroyed,” says Duncan Currie, an international lawyer who has worked in oceans law for 30 years. He represents the Deep Sea Conservation Coalition which is calling for a moratorium on deep sea mining.
Amon was part of a project that conducted baseline surveys in the area of the CCZ that the UK has a licence to explore for potential mining.
“As part of the work we were doing out there, we found that of the megafauna, the larger animals, more than half of them were completely new to science, and more than half of them relied on the nodules as a surface to attach to. Things like corals, sponges, anemones – they actually need the nodules. So potentially mining in that area could have quite a drastic impact.”
“It’s also our largest ecosystem so it provides about 96% of all habitable space on earth,” says Amon. “I think most people still assume that that space is just sort of empty or there’s not a lot happening. But actually, it couldn’t be further from the truth, the deep ocean is a vast reservoir of biodiversity.”
“The deep sea has a PR problem,” says Amon. “It’s not something that people think about. There are some cute things, but there aren’t adorable pandas, but that doesn’t mean that those species aren’t important.”
Other environmental concerns range from worries that noise pollution will interfere with deep sea species’ ability to communicate and detect food falls, increased temperature from drilling and vehicle operation, materials being discarded and heavy vehicles crushing seabed organisms and compacting the seabed.
Most concerning, Currie says, is the potential impact of sediment plumes. After the minerals are processed on ships, the proposal is to return the non-useful sediment into the ocean via long pipes, or risers, depositing them at a depth of 1,500m.
“The return sediment plume will be almost 24/7 – a continuous plume pumped into the ocean. No one has any idea what it will do: will it go up, go down? Will it interfere with the breeding of squid? We know fish migrate up and down, will it affect that? It’s incredibly important and we know almost nothing about it,” he says.
DeepGreen disputes this saying its modelling and experiments show that the spread of the plumes is far smaller and the amount of sediment injected into the mid-water column is far less than is often cited by campaigners.
“The anti-DSM [deep-sea mining] community consistently catastrophises and misrepresents the impact assessments that don’t support their narrative,” said a spokesperson for DeepGreen, who added “we welcome and share many of the environmental concerns about the impact of nodule collection on the marine environment”.
“Our goal is to make sure that our activity does not cause any large-scale disruptions to ecosystem services and that we minimize the risk of biodiversity loss. That’s why we have partnered with the world’s leading academic and research institutions to baseline and better understand the entire water column, from seabed to surface.”
Concerns in the Pacific
Caught up at the centre of this huge push for a new extractive industry are Pacific island nations.
Nations must sponsor companies that want to explore for minerals and among the countries that have issued licences are the tiny Pacific Island countries of Tonga, Cook Islands, Nauru and Kiribati.
DeepGreen holds rights to the exploration contracts sponsored by the Pacific countries of Nauru, Tonga and Kiribati and is one of the operators making the most noise about starting commercial mining in the near future.
DeepGreen, a Canadian firm with an Australian chief executive, is in the process of being acquired by the Sustainable Opportunities Acquisition Corp. Once merged the company will be known as The Metals Company.
The relationship between DeepGreen and Nauru is of particular concern to observers of deep-sea mining. Observers have warned about an imbalance of power between the company and the tiny nation, which has a population of around 12,000.
Currie recalls an incident at the 2019 International Seabed Authority meeting in Kingston, Jamaica, when Gerard Barron, the Australian chief executive of DeepGreen (and now boss of The Metals Company) spoke for Nauru.
“[There was] surprise, some shock among some of the seasoned NGO delegates. It’s just not done,” he said.
“Everybody was taken aback,” says Metaxas of the incident. “That doesn’t happen that a contractor takes the chair of a member state.”
A spokesperson for DeepGreen said that “Mr Barron was attending the ISA meeting as a member of the Nauruan delegation and Nauru chose to offer him the opportunity to address the Council…. There is nothing uncommon about this practice.” It said that on the same day, Belgium allowed the chairman of a company that holds two exploration contracts the opportunity to address the council.
“The Pacific nations I think are particularly vulnerable,” says Metaxas. “They have vulnerable economies, this is an opportunity for an economic boom in a country if it’s done right, if it’s successful. I’m sure it’s quite tempting, but I sure hope that there’s also some advice about how much to risk and how to manage it all.”
There are still questions to be resolved about whether the company or sponsoring state would be liable in the event of environmental damage or other harm.
DeepGreen says that its subsidiary NORI has indemnified Nauru for liability under both the sponsorship agreement and its Nauru’s International Seabed Minerals Act.
However, according to an advisory opinion issued by the International Tribunal for the Law in 2011, states can still be liable if there is a “causal link between the failure of that state to meet its responsibilities and the damage caused by the sponsored contractor.”
Some have voiced concerns about the capacity of small developing nations to monitor the work done by their partner companies, which could lead to liability.
“If Nauru is the sponsoring state, they have obligations under the law of the sea convention to exercise due diligence, they have to make sure that their contractors operate appropriately and if they don’t do that work properly, international law says they are liable,” says Currie.
But Ralph Regenvanu, the opposition leader of Vanuatu, says “there’s absolutely no capacity” of states like Nauru to do this monitoring. “We’d be interested to know what are the measures they’re taking, what are the safeguards they’re taking.”
In 2014, when he was minister for lands and natural resources, Regenvanu led a months-long consultation on the subject of deep sea mining in Vanuatu.
“People thought basically it was too early to do anything, we shouldn’t do anything. There were calls even then for a moratorium,” he said.
Vanuatu’s government, along with the prime ministers of Fiji and Papua New Guinea, have called for a regional moratorium on deep-sea mining while more can be learnt about potential environmental harms and how to protect against them.
“Pacific peoples are indigenous peoples. All countries of the Pacific have some of the highest rates of indigenous people as part of population in the whole world. Pacific peoples’ views towards our Earth, our resources, are very special ones,” says Regenvanu.
Before mining can commence, the ISA needs to release a code for the exploitation of the deep sea. This was due to be released and adopted in July 2020, but was delayed due to Covid. The ISA announced this week that it aimed to resume face-to-face meetings this year.
“It is not implausible to expect that the ISA will be in position to finalise the code by 2023,” said the DeepGreen spokesperson, who added the company expects submit their environmental impact statement in 2023 for review in the hope of beginning commercial mining in 2024.
Meanwhile, others are urging caution. This month the EU parliament advised the European Union to promote a moratorium on deep seabed mining until its environmental impacts could be better understood and managed.
But DeepGreen’s boss, Gerard Barron, has suggested that if the ISA moves slowly on developing a regulatory framework, the company might invoke the so-called two-year rule, which allows a country sponsoring a mining contractor to notify the ISA that the company intends to begin mining. The ISA then has two years to finalise the regulations for deep sea mining. If it is unable to do so, the ISA is required to allow the contractor to begin work under whatever regulations are in place at the time.
“It’s something that’s consistently under review – it’s not off the table, that’s for sure,” Barron told
China Dialogue Ocean about triggering the two-year rule.
In response to the Guardian’s questions on the subject, DeepGreen said the two-year rule is “only available to sponsoring states to use, not contractors like DG, which cannot invoke it” but that it was a “a valid option available to all member states of the International Seabed Authority.”