One hundred and fifty years ago,the HMS Challenger trawled the deep seabed on a major exploration of the ocean,bringing up an exotic collection of rocks,creatures and coral that’s still treasured by museums around the world. It was just a taste of what’s down here. “Every dive looks different,” says Copley,who went on the first journey to the world’s deepest hydrothermal vents in 2013. “It’s just as diverse as the mountains and forests and deserts on land.”
What does the deep sea mean for us?
Biologists estimate we have yet to discover two-thirds of deep sea species – and some could help open new frontiers of science. Unlocking the secrets of immortal jellyfish and ancient bacteria,say,could help medicine conquer cancer and superbugs,or even reverse ageing.
Copley speaks of the scaly foot snail,which grows iron plates on its underside (“foot”) in the hydrothermal vents where it lives. “At spots like this,you can have 400 species found nowhere else on Earth somewhere half the size of Disney World,” says Copley. That snail also producesrare nanoparticles that scientists need to make to produce solar panels. “Until we saw how the snail made them we didn’t know how to do it ourselves.”
Life on this planet may have actually begun in the darkness of the deep. And the ocean makes life at the surface possible too – its rich food chain and powerful currents drive the world’s weather (and fish stocks). The weight of the sea drags things down;it’s theworld’s biggest carbon sink,compressing dead plants and animals over millennia into fossil fuels. “The deep sea is the last frontier,but it’s not an isolated box,” says ecologist Jeff Drazen at the University of Hawai’i at Manoa. “We’re still connected to it.”
If you ask some,the very key to solving climate change could lie at the bottom of the sea. Many of the rocks brought to the surface in the Challenger’s haul were actually metals – copper,zinc,cobalt and others now needed for the green energy transition. Manganese (or polymetallic) nodules are of particular interest – small,potato-shaped rocks that have formed,under intense pressure,on the ocean’s abyssal plains over millions of years. Then there are metal crusts on sea mountains. And towers of copper and gold that climb up through the deep:hydrothermal vent “chimneys” where super-hot water hissing from the Earth’s crust hits the cold ocean,igniting all kinds of chemical reactions. “We call them black smokers but they’re actually sparkly too,they glitter with crystals of iron,fool’s gold,” says Copley.
That means the profits from any riches beneath the waves are meant to be “for the benefit of all”,as decreed in the 1982 UN Convention on the Law of the Sea. The convention created the International Seabed Authority (ISA),set up in 1994,to govern deep sea mining in the Area and divvy up profits fairly among nations. Commercial mining is not yet allowed,with country delegates still negotiating a mining code. But the ISA grantsexploratory licences to countries,and to companies sponsored by governments,to prospect metal reserves,at half a million US dollars a pop.
More than 1.5 million square kilometres of international seabed,roughly the size of Mongolia,already falls under these licences,mostly in the CCZ. That zone alsohappens to beteeming with life. Drazen,who has visited the CCZ many times,describes dumbo octopuses with big,“ear-like” fins and“gummy squirrel” sea cucumbers that look like rubber sneakers.
Some small Pacific nations such as Nauru andthe Cook Islands,which sponsor companies that have licences in the CCZ,argue the billions of dollars in metals beneath the waves could help lift their countries out of poverty. But others,includingFiji,Palau and Samoa,have called for a ban,worried that mining the deep could imperil the fish and sharks in higher water that countries rely on.
Long negotiations over seabed mining are now coming to a head. In 2021,Nauru triggered an obscure rule giving the ISA a two-year deadline to finalise its mining code. That deadline expired in July,meaning the ISA’s powerful operational arm,the Legal and Technical Commission,can now consider and approve commercial mining licences,whether global rules are in place or not. TMC,which has partnered with Nauru,plans to apply next year,although the code is not expected to be adopted until at least 2025.
As ISA observer and environmental lawyer Duncan Currie puts it,a code is still “miles off”,with key principles unclear such as how profits will be shared among nations and companies,and what contamination thresholds will be set (the way companies have limits on river dumping,for example). Says Drazen:“We don’t have nearly enough research to set those limits.”
In March,UN states agreed on a new treaty to protect the high seas more broadly:two-thirds will become marine reserves. It was a big win for conservation,nearly two decades in the making. But down in the Area,deep sea mining remains under the ISA’s remit. And a growing chorus of nations including Australia,Chile,Germany and Italy (as well asthe Vatican) haveraised concerns overhow the ISA is governing mining prospectors.
One problem,Currie says,is that competing interests lie at the heart of the ISA,an agency withmore autonomy than other UN bodies. Headquartered in Jamaica,it has a legal responsibility to safeguard deep ocean ecosystems,yet its role is also to oversee mining – an inherent tension.
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Companies and governments coming to cash in on deep sea minerals are expected to pay the ISA royalties – a yet-to-be agreed share of profits for administration costs,and to divide among member states. Butthere are concernsthe ISA’s proposed models will put most of the profit in company pockets. The ISA did not respond to questions or requests for an interview,but has previously defended its integrity and independence.
Copley notes that,for all the UN’s “utopian vision” ofusing the sea’s riches to correct inequality,in practice,the ISA’s reliance on private companies to actually do the mining could widen the gap between rich and poor. “Those companies don’t work pro bono. Maybe a little benefit trickles down. But a small group are still getting proportionately richer,the opposite of[the original] vision.”
What are the scientific concerns over mining the deep sea?
The nodules in deep plains such as the CCZ are as crucial to ecosystems as trees in a forest,Dr Helen Scales writesin her bookThe Brilliant Abyss– nurseries for octopuses,and hiding places for worms. “When we go down for our studies,about half of the large animals we see depend on them,” says Drazen,who has conducted baseline ecosystem research funded by TMC. “And they won’t grow back for millions of years.”
Mining the seafloor would dredge up storms of dust and mud that could spread up to 100 kilometres,according to Drazen and other experts.They could smother life,blinding the bioluminescent “stars” of the deep,and feed toxins into the wider food web,from whale sharks to swordfish. Excess seawater and mud sucked up from the seafloor with the nodules would then be dumped back into the ocean. “That might add in more fine particles of metal,as those nodules are broken up,” Drazen says. “Mercury already builds in animals naturally. Remember,your plate of sashimi is only ever one step in the food web removed from[the deep].”
Metallic nodules are also a little radioactive,and arecent paper inNature has raised concern that alpha emitter particles could be released by deep sea mining. “They don’t penetrate the skin,so they’re not normally a problem but they can be toxic when ingested,” explains Copley,who is running UK-funded research examining the aftermath of deep sea mining tests. (Evenafter 26 years,local biodiversity failed to recover at one site following a 1989 mining experiment in the Pacific,for example.) “It’ll be about scale,” Copley says. “Could it be managed regionally? Maybe. But we hadn’t even considered radiation before now.”
TMC and other prospective miners say they have invested millions of dollars in deep sea research and have developed technology to minimise disruption,with artificial intelligence and sensors to monitor activity down in the deep. TMC’s Australian chief executive,Gerard Barron,stresses many concerns about mining remain speculation. “People first said the sediment plume would find its way to the other side of the world,now we know it’s localised,” he says. “There will always be impact”,but compared to the destruction of land mining,he considers deep sea “harvesting” a game-changer. “We feel we have enough data” to do it responsibly,he says.
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But not everyone agrees. In 2022,more than 30 deep sea experts,including four from an ISA committee,concluded there wasn’t enough data to regulate mining in the deep. Hundreds of scientists,as well as countries such as Germany,Canada,Spain,Chile and New Zealand,have called for a moratorium until further research is done (France wants an outright ban). Tech giants including Google and Samsung,and car companies BMW,Volvo and Volkswagen alsoback a moratorium,but Australia has so far remained silent,despite the urging of some of its Pacific neighbours.
Others say the need for seabed metals has been overhyped. Some electric-battery makers,including Tesla,arealready using alternatives to cobalt and nickel. “And we have these metals on land,” says Currie. “The real issue is strategic access.” Cobalt and nickel are concentrated in places such as China and Russia,he says,and coltan (another battery metal) often involves tearing up rainforest or child labour in the Congo.
Meanwhile,China has the technology to dive into the deep sea gold rush first,says marine governance researcher Pradeep Singh,who has been on the country’s deep sea vessels. But he doubts it’s in China’s best interest to kickstart the frontier when it already has such a hold on metals on land. “If it threatens their dominance,that’s when they will jump the queue,” Singh says. Until then,he says,“they are happy to wait because whoever goes in first will have lots of technological issues,lots of legal issues.”
Renee Grogan spent a decade in the Australian mining industry before joining Impossible Metals – a start-up that promises to solve some of deep sea mining’s environmental risks through clever robotics. “We’re never going to understand all the animals that live in the sediment,” she says. “So we have to engineer in a way to protect them.” Instead of dredging and sucking up nodules,the Impossible Metals prototype hovers over the seabed and uses artificial intelligence originally developed for fruit picking to check if there is life on a nodule – Grogan says the prototype will “harvest” only those that appear uninhabited.
Impossible Metals still has plenty of tests (and critics) to wade through,but if the company can prove the technology,Grogan says it will look to sell it on to prospective miners with existing ISA licences.
“Still,it’s in no one’s interest to jump the gun and start mining before the regulation is ready,” Grogan says of the Nauru trigger. And,while all eyes are on the draft mining code,she warns little attention is devoted to how it will be enforced. She points to deep sea fishing – an industry heavily regulated on paper butnotoriously under-enforced due to the sheer difficulty of policing so much ocean. “We need to talk enforcement now.”
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Drazen worries one of the biggest decisions for our planet’s future is today being made largely in the dark. We can stare up at the night sky and wonder at the stars,he sighs,“but we don’t think about the deep sea,even though it’s our own backyard. The public need to wake up to this.”
While Copley says he has sympathies on both sides of the debate,he keeps thinking of that scaly foot snail. “If we’d just wiped it out with mining,we’d never have learnt about the solar panels particle.” Now,the snail is the first species ever to be listed as endangered because of the impending threat of deep sea mining.
“The deep is like nature’s library,” he says. “We want to read it,not burn it down.”
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