Some scientists suspect that disturbing ocean sediment could stir up long-sequestered carbon.

The electric vehicle boom is driving a surge in demand for prized metals needed for batteries and other components. Some companies say the solution lies in mining the deep oceans, but scientists say that could irreversibly damage a vast, largely pristine ecosystem.

Nauru, lying about halfway across the vast expanse of the Pacific Ocean between Australia and Hawaii, is the world’s smallest island nation. But in the emerging industry of deep-sea mining, it punches far above its weight.

This June, Nauru gave notice to the International Seabed Authority (ISA), the UN agency charged with regulating mining in international waters, that it was triggering the so-called two-year rule: The agency will have to consider any application for a deep-sea mining license two years from now, under whatever regulations are on the books at the time. This effectively forces the ISA’s hand to finalise a regulatory mining code before that deadline. With this latest development, a once-fanciful idea may soon become a global industry.

Ironically, while critics worry about deep-sea mining’s environmental impacts, proponents are offering up the urgency of climate change and the need to transition to a clean-energy economy as the reason to press ahead.

What Nauru is hoping to pull from the depths are potato-sized chunks of metals and minerals called polymetallic nodules, which contain elements vital to the clean-technology components needed for the transition away from fossil fuels, particularly lithium-ion batteries, but also solar panels and wind turbines.

The lumps are formed when something — like a shark’s tooth, perhaps — falls to the ocean floor, and minerals and metals build up slowly on its surface over millions of years. These nodules dot the ocean bottom around the world, but they are most plentiful in the Clarion-Clipperton Zone (CCZ), a 1.7 million-square-mile expanse of international waters in the Pacific Ocean. The lumps mainly contain manganese and iron, but also cobalt, nickel, copper, and traces of rare earth elements.

Demand for these metals is soaring. In a report published earlier this year, the International Energy Agency found that achieving net-zero emissions by 2050 would require six times more of certain minerals by 2040 than are being mined today. Deep-sea speculators say that ocean-floor nodules are a critical part of filling this need, with estimates that they may hold six times as much cobalt and triple the amount of nickel as there is on land — and at a higher grade. Mining nodules, they say, will help the world to shift away from the biodiversity loss, toxic pollution, and exploitive labour practices that often come with terrestrial mining.

But critics say that harvesting these nodules could put one of the world’s last pristine ecosystems at risk of irreversible damage, affect whale and tuna migration, extinguish newly discovered species, and even accelerate climate change by kicking up long-undisturbed carbon stores. They caution that two years is not nearly enough time to understand the impacts that decades of mining, spread over hundreds of thousands of square miles of ocean, would have. A handful of companies are also pushing for caution: The auto manufacturers BMW and Volvo have said they will not source minerals mined from the ocean for now, and they have encouraged a moratorium on deep-sea mining.

“Going into a new habitat to potentially destroy it and reap the metals that [supposedly] will be used to move us away from climate change … well, we’re destroying one habitat to save another and not fixing the problem,” said Diva Amon, a deep ocean biologist from Trinidad and executive at the Deep Ocean Stewardship Initiative.

Companies have been proposing mining deep sea nodules for decades, but this frontier in ocean industrialisation has been fraught with environmental, technical, and political challenges. To date, only a handful of nations have mined in their own waters. Japan, for example, has tested mining of extinct hydrothermal vents for metals such as zinc, copper and gold, and it plans to ramp up to a commercial scale. Other efforts haven’t gone so well: In 2019, a project to mine similar vents in Papua New Guinea faced environmental critics and financial hurdles, and it ground to a halt before it got up and running, losing the government hundreds of millions of dollars.

The International Seabed Authority, a relatively obscure United Nations agency based in Jamaica, was set up under the 1982 U.N. Convention on the Law of the Sea to regulate mining in international waters. The body, made up of 167 member states plus the European Union (but not the United States, which has not ratified that convention), is charged with both protecting the marine environment outside of national boundaries and drawing up a code for ocean mining.

To date, the ISA has granted at least 19 exploration contracts in the CCZ sponsored by nearly as many countries, covering about 500 square miles. This will allow operators to test technologies, perform required environmental impact assessments, and retrieve some nodules. The ISA first released a working draft of the mining code in 2016, with the most recent version in 2019. Final regulations were expected in 2020 but were stalled by the pandemic, which prevented the ISA from meeting in person. Nauru’s move adds urgency to the timeline.

Nauru’s effort is being spearheaded by Nauru Ocean Resources, Inc., a subsidiary of The Metals Company, a Vancouver-based outfit that has emerged at the forefront of deep-sea mining. The Metals Company also has exploration contracts through subsidiaries in Tonga and Kiribati, each covering about 29,000 square miles. The company is planning to go public through a merger with Sustainable Opportunities Acquisition Corporation, valued at nearly US$3 billion.

“Transitioning away from fossil fuels is essential,” said Gerard Barron, CEO of The Metals Company. Achieving that will require a lot more mining, so the world will have to weigh the impacts of increased metal production from land and sea, he argued. “We’re really heading to a period of tradeoffs because there isn’t a perfect solution. I think that’s the key thing.”

For example, cobalt, used in rechargeable batteries, including those in electric vehicles, currently comes mainly from the Democratic Republic of the Congo, where investigators have found examples of child labour and horrific stories of death and injury to workers.

Chinese companies have already bought up much of the future supply of cobalt and nickel, also used for EV batteries, and that might leave auto companies in the U.S., EU, and other countries unable to hit their deadlines for a switch to electrification. Barron estimates that the cobalt and nickel from the contract areas of his company’s three sponsoring states could supply 280 million electric vehicle batteries.

One estimate found that the CCZ may hold about 226 million tons of copper, compared to more than 1,000 million tons on land, and 274 million tons of nickel, more than is available on land. Growing demand has driven up the price of these metals, making ocean mining more attractive.

But many scientists and other close observers are alarmed by what they see as the inherent risks and lack of data about possible consequences. In response to Nauru’s decision to invoke the two-year rule, more than 400 scientists signed a statement arguing that deep-sea mining will result in “loss of biodiversity and ecosystem functioning that would be irreversible on multi-generational timescales.”

Barron often portrays the deep sea as less biologically sensitive than land-based mined ecosystems: “There is just not much life” in the abyssal zone, below about 14,000 feet, he said. But others say the CCZ is incredibly biodiverse. A 2016 study of a 350-square-mile area of the CCZ found at least 170 different individuals belonging to different species, about half of which lived only on the nodules themselves. They identified 12 animal species, seven of which were new to science, and four that belonged to new genera, including sea cucumbers, brittle stars, sea anemones, and more. There was a link, they reported, between the number of nodules in any given area and the number of different kinds of larger animals.

According to Amon, a co-author of the study, these organisms are “quite important for the function of the ecosystem.”

Another study showed that nodule removal from a patch of the CCZ resulted in the disappearance of nearly 20 percent of all of the organisms from that area.

Scientists are also concerned about the sediment plumes that mining machines will inevitably create. These machines can be bigger than bulldozers; their activity will likely spread sediment, burying life nearby and possibly releasing toxic chemicals. This could have a “smothering impact” on the food web, said Douglas McCauley, a professor of ocean science at the University of California Santa Barbara.

Water and sediment sucked up by the machines will be released back into the ocean at an as-yet-unspecified depth. This plume could also spread hundreds of miles, scientists warn, possibly interfering with the mass vertical migration of animals that travel between the light-filled zone of the upper ocean and the darker depths.

Mining machines could also create a tremendous amount of noise, which travels farther in water than it does in air and can interfere with many marine animals’ ability to communicate, feed, and mate. Deep-sea mining could be “the noisiest thing we’ve ever done in the oceans,” McCauley said.

At least 25 species of whales and other cetaceans are known to pass through the CCZ, Amon said. One study found evidence that whales dive down to the seafloor in the mining region, probably to feed. Tuna also migrate through the area. A recent study showed that, depending on its size, the sediment plume could affect tuna’s ability to feed, increase the amount of toxic elements they ingest and, combined with noise, alter their migration patterns.

Some scientists also suspect that disturbing the sediment could stir up long-sequestered carbon. One study, for example, recently calculated that seafloor trawling for fish could release as much carbon dioxide per year as the entire aviation industry. While most caution that there has not been sufficient research on this question, McCauley said that the sediment dust-up could have “all sorts of uncertain impacts on climate.” There’s “all of this carbon that’s safely stored where we want it to be, on the seafloor,” he said. “What happens when you pull that back up?” The ISA’s draft regulations only mention climate change a few times, in a cursory fashion.

Barron said his company will do what it can to mitigate these concerns and said that if deep-sea mining is shown to be “more harmful than the alternative” of land-based mining, The Metals Company won’t press ahead with it. Barron said that his company plans to stop mining once they’ve gotten enough metals to shift completely to recycled materials to create their own batteries, which could take decades.

Critics argue that emerging technologies already exist that could make deep-sea mining redundant, such as cobalt-free lithium manganese oxide or lithium-iron-phosphate batteries. More investment in recycling, and cleaning up land-based mining practices, could be emphasised over ocean mining. There are “so many interesting new developments that don’t need these minerals from the seafloor at all,” said Jessica Battle, who leads the deep-sea mining initiative at the World Wildlife Fund in Geneva.

Adding more minerals into the market, she added, could perversely make recycling less attractive.

With Nauru’s move pushing the ISA to finalise its regulations sooner rather than later, critics are concerned that those regulations won’t pay heed to the scientific concerns.

“There is a real lack of confidence in the ISA’s ability to deliver … science-based standards and guidance,” said Pippa Howard, who works on mining issues for the NGO Fauna and Flora International. “They believe that their objective is to get the mining code to get deep-sea mining off the ground.”

The ISA declined to comment for this article.

Barron said that ocean mining is the only industry that is being regulated before it has even begun. The eyes of the world are on us,” he said. In the meantime, several groups have already pushed to put the brakes on the industry. In September 2019, the Pacific Islands Forum in Tuvalu called for consideration of a 10-year moratorium on deep-sea mining, given its possible impacts on livelihoods, cultural practices, and even sites of spiritual significance.

Maureen Penjueli, a coordinator at the Fiji-based Pacific Network on Globalisation, said, “It is beyond unfortunate that the Pacific would be at the forefront using the climate narrative, considering that we are one of the regions that understand what the existential threat from the climate crisis actually means. I think that the central question is who stands to benefit. It’s not Nauru, despite the fact that they think it might be good to be at the forefront. It’s [The Metals Company] and their investors.”

This story was produced by Tatiana Schlossberg, published at Yale Environment 360 Magazine on 29 July 2021, reposted via PACNEWS.

Banner: Researchers with DeepGreen Metals deploy a box core tool to capture a sample of the seafloor. Photo: The Metals Company