Treasures of the Deep: Tapping a Mineral-Rich Ocean Floor
How can we ensure that science provides the guide?
Thomas Peacock springs up in his sun-filled office at the Massachusetts Institute of Technology and lays a baseball-sized rock on the table. It is coal-black, pocked with bumps like those on a rash. For millennia, it lay on the bottom of the Pacific Ocean, growing less than a half-inch every million years in water now 3 miles deep.
“This,” says Peacock, an associate professor of mechanical engineering, “has the potential for being a whole new industry.”
Mineral-rich rocks like the one on Peacock’s table have certainly gotten the attention of miners and shipbuilders, diplomats, and scientists. They flocked to conference halls in London, Norway, and Jamaica this year, all drawn by the prospect of riches at the bottom of the sea.
It has the whiff, as a technical magazine put it, of a “new gold rush” in the air.
Some of these prizes are ancient lures—gold, silver, copper. Some are staples of an industrial age—nickel, manganese, cobalt, lithium. And some with sci-fi names—like dysprosium, europium, and yttrium—are rare earth elements essential to modern technology.
For eons, the minerals have been hoarded by the sea, guarded by tons of water, intense pressure, frigid temperatures, and total darkness. But now, says Lisa Levin, a professor at Scripps Institution of Oceanography in La Jolla, California, “we’re bringing new technologies to the deep waters that enable us to go in and get whatever resources we need more efficiently and economically”—tools such as submarines that can scour the depths, cameras that bring vivid arc-lit scenes from the deep onto computer screens above the surface, and crawling robots with vacuums and claws that can scoop and suck the bottom.
Companies, and countries from China to the Cook Islands, are eager to start. Last year, Japan maneuvered a robot to mine zinc a mile deep in its waters off Okinawa. A Canadian company is poised to explore the seabed off Papua New Guinea. But the big prize is in the unclaimed deep sea. The International Seabed Authority (ISA)has approved 29 exploration contracts in international waters, and more are pending. It is busily writing rules for commercial mining; miners expect to move after the rules are finished in the next two years or so.
“Many hundreds of millions of dollars are being invested around the world,” says Duncan Currie, a New Zealand lawyer and member of the Deep Sea Conservation Coalition, a group of about 70 environmental organizations. “There is no doubt companies see money that can be made.”But before mining begins on a commercial scale, Pew and other groups are urging the seabed authority to ensure that science plays a role in the guidelines for the underwater work to protect ocean life and mitigate environmental damage.
“We are extremely fortunate to have this opportunity. To write the rulebook to govern an extractive activity before it begins would be a first in human history,” says Conn Nugent, who directs Pew’s seabed mining project. But it’s important to act quickly and keep pace with the burgeoning demand.
“We’re only beginning to understand what’s on the bottom of the ocean,” says Nugent. As the would-be miners roll out seabed charts and plot mining grids, “the scientists are working hard to keep one step ahead. But time is short and the data are limited. Which is why the regulations have to be precautionary. And why setting aside large no-mining areas is the price to pay for our ignorance.”
The growth in demand for what lies at the sea bottom is fed by growth of the world’s population and rising economies, and aggravated by dwindling deposits on land.
“There’s a couple of billion people trying to get into the middle class. It’s requiring a vast amount of new metals,” says James Hein, a veteran geologist who has been studying undersea minerals for 42 years for the U.S. Geological Survey in Santa Cruz, California. “All their new homes need metals, not only in the building itself, but in all the things you put into a home.”
Many of the high-grade seams on land have been dug out, and prospectors must go deeper or to more remote places. Added to that is a surge in demand for metals for high technology, and—counterintuitively—for so-called “clean” energy.
“Green tech, moving from hydrocarbons to renewable resources, is requiring a vast amount of rare metals. For some of the green technologies, there is not enough to go around” on land, says Hein. “But there is tons of it in the oceans.”
Wind turbines, for example, evoke the vision of a clean, pollution-free future. But the wind-nudged turbine blades make electricity by turning powerful magnets made of rare metals. A typical 2-megawatt turbine has about 900 pounds of neodymium and dysprosium, which make magnets hundreds of times more powerful than steel magnets. The turbine also contains 6 tons of copper.
Rare metals are used in hybrid car batteries, high-efficiency lighting, maglev trains (which float on a guideway using magnetic propulsion), electric scooters, earbud speakers, smart bombs, and super-bright LED screens. A Toyota Prius motor contains more than two pounds of neodymium, and more is scattered about the car, from its speakers to electric windows. Rare metals coat fluorescent bulbs and help MRIs see your body tissues.
The 16 or 17 rare earth elements (scientists argue over scandium and yttrium) are not really very rare, but are distributed so thinly and often in such remote conditions that they were once called “unobtaniums.” They frequently are found mixed with radioactive thorium and uranium, and must be crushed, washed, dissolved in acid and cooked multiple times to separate them from tons of ore and other metals in what Ana de Bettencourt-Dias, a chemistry professor who studies the elements at the University of Nevada, Reno, calls “a very complicated and environmentally dirty process.”
China produces most of the world’s supply of rare earth metals, and in 2010, when it reduced exports to keep more of the materials for its own manufacturing, “there was widespread panic,” de Bettencourt-Dias says.The alarm brought calls for more recycling, more mines, more study of alternative materials, but the world remains tethered to the Chinese supply.
China “supplied about 90 percent of the world’s market with [only] 23 percent of its rare earth resources,” says Liu Feng, secretary-general of the China Ocean Mineral Resources R&D Association. He says a 2012 government study showed that “China had paid a huge price for it. Serious ecological damage occurred … vegetation deterioration, soil erosion and acidification, and even crops extinction. Upgrading the mining process is urgent.”
Indeed, he noted in an email from Beijing, that is one reason China also is pursuing deep-sea mining claims, and hopes to test mining equipment at 1,000 meters in 2021.
Despite its own roaring metal mines, China needs rare-earth and basic metals to feed development for its huge population, Liu says. China’s per-capita consumption is “well below the world average,” he says. “China is now the world’s largest importer of main metals.”
Modern technology demands a wide array of metals, both rare and common. A computer contains gold, silver, and copper in hard drives and circuit boards, uses silicone for its components, aluminum for its heatsinks, and platinum for high-end graphics cards.
But many worry a rush to the seabed for these materials will present huge risks to still-unknown and fragile ecosystems, such as hydrothermal vents— fissures in the earth’s crust deep underwater that exhale superheated water boiled by the planet’s inner magma, often erupting in plumes black with dissolved minerals.
These vents were unknown until Feb. 15, 1977, when geologist Jack Corliss, aboard the submersible research vessel Alvin 1.5 miles deep in the Pacific Ocean, called to the surface. “Isn’t the deep ocean supposed to be like a desert?” he asked. “There’s all these animals down here.”
The discovery amazed scientists who had long believed that life requires energy from sunlight. Instead, clustered around the vents in the darkness of the depths were unexplored worlds of organisms. This “chemical synthesis” likely predates photosynthesis, and is perhaps the original nursery of life.
Cindy Van Dover, a deep-sea biologist from the Duke University Marine Laboratory, has seen the vents during more than 100 deep dives on the Alvin.
“It’s pretty amazing,” says Van Dover. On her first dive, in 1985 near the Galapagos Rift, she saw “thickets of giant red tubeworms, very colorful and beautiful. Giant clams, mussels, anemones. It’s like an oasis.” She later dove on the mid-Atlantic mountain ridge, where active vents called “black smokers” erupt along the tectonic borders. There, she found “just a phenomenal amount of wildlife. It was fascinating to watch. I wish I could take a holiday—no work—and just park and have a picnic and watch the black smokers. Those places are primordial, alien.”
Van Dover and other scientists have discovered galleries of new species, weird creatures with bioluminescence, translucent octopi, furry yeti crabs that farm bacterial food among the hair of their claws, shrimp with eyes on their backs.
“These animals and microbes have evolved under an amazing array of extreme conditions, so I think there are all sorts of problems these organisms could help humans solve,” says Scripps’ Levin, who founded the Deep-Ocean Stewardship Initiative, a scientific advisory group on marine threats. These life forms could offer “almost endless benefits. New medicines, antibiotics, anti-inflammatories, bio-materials, bio-inspiration.
“We need to view the ocean as an amazing pot of genetic resources.”
And that pot of resources is abundant: When the minerals in these roiling vents hit cold water, they settle to the seabed in deposits estimated to be thicker and richer than most found on land. But scooping them from the seabed must be done carefully.
Pew and others are pushing for rules that protect these strange and alien communities, such as limiting mining to vents that have gone dormant where the surrounding life has moved on.
And there are potentially rich mining sites other than vents. The crust at the tops and sides of sea mountains also are rich in minerals, especially cobalt, a highly priced metal used in applications from jet engines to human medicine to cellphone batteries.
The ISA has issued five exploration contracts for cobalt-rich ferromanganese seamount crusts, including four contracts in the West Pacific Ocean with Japan, China, South Korea, and Russia; and one contract in the South Atlantic Ocean with Brazil. Miners envision machines that might traverse the rugged underwater mountains, scrape off the crusts—some 72 million years old—and pump the ore to ships above. The underwater terrain would be daunting, the mining techniques challenging, and excavating the large mountainsides would likely be highly destructive and devastating to the coral and deep-sea communities living on the seamounts, say observers.
Much easier to reach are rocks—technically “nodules” to geologists—like the one on Peacock’s desk at MIT. They typically contain portions of copper, cobalt, nickel, and manganese, and some have entwined traces of valuable rare earth elements. The British research vessel HMS Challenger, which explored the seas in the oceanic equivalent of the first moon walk, brought up some manganese nodules in a dredge net in 1873. But harvesting them from the ocean floor then was impossible on a large scale.
A century passed. In the 1960s and 1970s, the price of some metals skyrocketed, and big companies began to dream of ways of seizing the nodules from below. The U.S. Patent and Trademark Office became a repository of exotic plans for deep-sea mining machines.
In fact, the enthusiasm for mining provided cover for an audacious Cold War espionage scheme. When a nuclear-armed Soviet submarine mysteriously sank in the Pacific in 1968, the CIA collaborated with eccentric billionaire Howard Hughes to try to secretly recover it by building a huge hoist ship, the Glomar Explorer, under the guise of deep-sea mining. According to the CIA’s official account, the sub broke apart as it was lifted. The agency has never said if it recovered the nuclear missiles.
The mining zeal of that era largely washed away as the world price of metals dropped and new discoveries on land met demand. But now, interest is renewed.
One of the first places deep-sea mining could actually start is a swath stretching 4,500 miles from Hawaii to Mexico, as wide as the continental United States. It’s called the Clarion-Clipperton fracture zone, and on the plain between mountains created by Earth’s tectonic rifts sit billions of manganese nodules, growing at a microscopic pace as chemicals from the seawater lock onto their bumps. The rocks wouldn’t be mined so much as scooped up.
“As an engineering proposition, taking potato-sized rocks from an abyssal plain looks to be a lot less complicated than peeling off the skin of a seamount or maneuvering through hydrothermal zones,” says Pew’s Nugent. “And I think you’ll find a consensus among the scientists that the vastness of the plain provides a more comfortable margin of error than the crowded ecosystems of seamounts and vent zones. On the other hand, the nodules on the abyssal plains can only regenerate over hundreds of million years. So you have to write conservation insurance policies tailored to regional particularities. And when in doubt, rope off giant no-mining areas.”
Indeed, proponents of deep-sea mining say it may well be better for the planet to collect minerals from the seafloor rather than puncture the earth on land.
Land mining can leave “giant open pits, massive waste dumps, great big huge mounds of tailings,” says Michael Johnston, CEO of Nautilus Minerals, which from its operations headquarters in Australia hopes to mine copper and gold off Papua New Guinea.
He says as the world moves from fossil fuels to technologies like electric cars, “some of the key elements—nickel and cobalt in particular—are more common on the seafloor than the land.
“If for whatever reason we don’t get it up, somebody else will,” Johnston says. “It’s going to happen. There’s no doubt about it.”
Undersea mining “might have a smaller ecological footprint than, say, a copper mine in the Democratic Republic of Congo,” Nugent acknowledges. But, he notes, we don’t know for sure. “It’s not proven at all, and the more the scientists examine the abyss, they find the abyss is not so abysmal. It teems with life.”
Machines built for Nautilus and other companies are giants, much like big construction land movers. Nautilus has magnetically mapped copper seams, and its machines would chew into the ore with whirling blades fitted with steel shark-like teeth. The material would be sucked up a 12-inch pipe to a surface vessel, then dumped into barges to be processed ashore. The cold sea water would be returned to the bottom by smaller pipes.
UK Seabed Resources Ltd., a subsidiary of Lockheed Martin UK, has rights to explore two plots in the Pacific for nodules, and would pluck them from the seabed floor with a machine that operates like a farm combine, sending the rocks up a conveyer to the surface.
“I think there is a broad misapprehension of the scale of actual seabed mining,” says Christopher Williams, managing director of UK Seabed Resources. Although the company’s undersea plots are nearly 29,000 square miles each, he says the actual mining will be done on a comparatively small patch of the huge ocean floor.
“We do want to find an environmentally responsible way to do it,” Williams says. “Reputationally, ethically, morally, it’s important to get it right.”
Still, the heavy machinery, crisscrossing its areas in grids directed from robotic submersibles, would compact the seafloor and likely kill much that is under its treads. German researchers dragged a sled over the seabed 3 miles down nearly 30 years ago, and when rechecked in 2015, the tracks looked perfectly fresh.
Pew is pushing for “precautionary” rules from the ISA that would be based on good science, good monitoring, and tough enforcement of the rules. Pew also is pushing for set-asides, by having the International Seabed Authority designate large areas that would be off-limits to mining to protect ocean life.“The larger the better,” Nugent says. “We want really big ecologically important areas roped off from mining forever.”
The ISA was formed in 1994 under the United Nations Convention on the Law of the Sea, which requires the agency to both manage the international seabed for the benefit of humanity and to avoid significant damage of the marine environment. (As one of the few countries that has not ratified the 1982 U.N. Convention on the Law of the Sea, the United States has only observer status at the ISA.)
And, at least until the shovels hit the ocean floor, many of the 168 members of the ISA say they agree with that balance. “Right now,” says Nugent, “the atmosphere seems auspicious.”
The small staff of the ISA—about three dozen employees based in Jamaica—is credited by environmental groups and mining companies alike with having good intentions, but the Legal and Technical Commission that reviews each contract meets in secret to protect contractors’ proprietary plans.
Last year, a contract allowing Poland to explore 3,900 square miles in the mid-Atlantic was approved before the ISA membership realized the area was adjacent to an active area of stunning 200-foot chimney vents called “Lost City,” on the list of possible United Nations World Heritage Sites.
Pew is urging more transparency, with full disclosure of the facts and plans before mining contracts are approved. The information released to the ISA members on each contract “is simply inadequate,” says Winnie Roberts, who works with Nugent on Pew’s seabed mining project. “As these contracts start ramping up and move toward actual mining, that has got to change.”
Transparency is not easy when it comes to the deep sea, says Currie of the Deep Sea Conservation Coalition. That’s true in the regulatory scheme—and in monitoring the mining itself: “We’re talking about areas [3,000] to 4,000 meters deep. A good deal of damage could be caused, and nobody would know.”
Van Dover, the veteran of more than 100 deep-sea dives in the Alvin, says caution is needed.
“I’m not trying to say we should have no mining in the sea,” she says. But “if we break it, I don’t know how we fix it.”