In mining companies around the world, potato-sized seabed nodules containing metals such as cobalt, copper, manganese, and nickel have stirred intense interest, given these metals’ importance in the manufacture of batteries and other products crucial to the world’s energy transition.

Small wonder, then, that the industry pressed hard for the approval of ground rules for deep-sea mining in international waters at the 28th session of the International Seabed Authority (ISA) Assembly, held in July in Kingston, Jamaica. Had mining companies and its allied governments succeeded, the way would have been open for licensing of deep-sea projects.

Not surprising either, though, was the strong pushback from green advocates and like-minded governments that worry the risks of such mining to marine life are potentially enormous and not at all well enough understood. After much debate at its July session, the Authority adjourned with the announcement that the rules and regulations needed to guide licensing of production-mining projects would not be issued for two years.

The ISA, a Jamaica-based intergovernmental body established under the 1982 UN Convention on the Law of the Sea, is charged with protecting the seabed in international waters. In 2000, it adopted regulations governing undersea prospecting and exploration of polymetallic nodules. And in 2011 it granted the first license for such work to Nauru Ocean Resources (NORI), a subsidiary of The Metals Company (TMC) of Canada that is working in partnership with the Micronesian island-nation of Nauru.

The exploration contract is one of three TMC holds in the Clarion Clipperton Zone (CCZ), a geological submarine fracture zone between Mexico and Hawaii that contains a range of metals. In all, 17 contracts have been granted for exploration within the CCZ, an enormous seamount-studded abyssal plain that covers 4.5 million square kilometers (1.7 million sq. miles), an area approximately twice the size of Mexico.

Last year TMC extracted 3,000 tons of polymetallic nodules in an exploratory voyage to the CCZ with its sea-mining vessel, Hidden Gem. The Hidden Gem is now near Manzanillo Bay on Mexico’s Pacific coast awaiting the day it can return to the CCZ to begin commercial extraction.

TMC scientists assert the NORI exploration area contains enough battery metals for 140 million electric vehicles. They estimate its three CCZ exploration areas collectively hold metals for 280 million vehicles—roughly the number of all personal and commercial vehicles registered to drivers in the United States. And the entire CCZ, they say, contains the largest known—and, they maintain, “lowest-impact”—source of nickel on the planet.

On its website, the company says its goal is not only to mine enough nickel, cobalt, copper, and manganese to facilitate the world’s energy transition, but also to “track and recycle” the metals. Says the company: “If The Metals Company succeeds, mining virgin ores—whether in land or in the ocean—will become a marginal human activity as we meet most of our metal needs by recycling a shared common stock of metals.”

The CCZ lies 144 kilometers (90 miles) from Mexico’s Pacífico Mexicano Profundo marine protected area and 290 kilometers (180 miles) from the country’s Revillagigedo Archipelago, a four-island Unesco World Heritage site southwest of the Baja California Peninsula. Skeptics of deep-sea mining worry marine conservation areas such as these would be severely impacted by sea-bottom metals extraction in the CCZ.

Those favoring a delay in rule making for production-phase bidding, licensing, and operations argue that more time and research is needed to ensure mining plans are consistent with ISA’s mandate of protecting the seabed. This, they say, is crucial given the potentially enormous amount of mining that could occur, pointing out that the ISA has issued 19 polymetallic nodule exploration contracts covering approximately 1.28 million square kilometers (494,000 square miles), or 0.4% of the global seafloor.

Biologist Flavia Liberona, director of Terram Foundation, a Chilean sustainable-development nonprofit, argues that allowing projects to proceed to the production phase now would be recklessly premature.

“Deep-sea mining is extremely dangerous for the planet,” says Liberona, whose organization closely tracks undersea-mining issues. “We cannot calculate the impacts because they are too enormous to understand and would last thousands of years. We simply don’t have the necessary scientific knowledge to evaluate the dangers and implications.”

The positions of member states at July’s ISA meeting ranged from China’s opposition to a moratorium of any kind even being considered, to France’s contention that the environmental risks are so great that a permanent moratorium should be declared.

Ultimately, twenty-one ISA member states voted for a two-year pause in drafting production-phase bidding, licensing, and operating rules—enough for the proposal to prevail. Among these countries were Brazil, Chile, Costa Rica, Ecuador, Panama, and Canada—the home country of The Metals Company.

“With such dire environmental consequences at stake, many member states feel that creating strict standards that effectively protect the seabed would be nigh on impossible,” says Ruth Ramos, a Mexico-based member of the Greenpeace environmental group’s campaign to stop deep-sea mining.

The United States could not vote as it has yet to ratify the Law of the Sea treaty and so is not an ISA member state.

Ramos, who attended the Jamaica meeting, notes that Brazil argued a 10-year pause would be necessary to ensure adequate research of potential environmental impacts of deep-sea mining.

“This is a powerful statement from a country that recognizes the importance and responsibility at stake,” Ramos says. “What happens in international waters impacts all of humanity. We must think of humanity’s well-being. Whatever is decided will impact future generations and we must respect the rights of those who are yet to arrive on this planet.”

The International Seabed Authority’s July meeting attracted great attention on account of its backstory. In July 2021, Nauru, acting on behalf of NORI, executed a procedural maneuver in the ISA that effectively triggered a two-year deadline for the authority to finalize regulations governing and enabling production-phase mining in international waters. The move created the expectation among mining companies that July 2023 would mark the beginning of bidding on licenses for the extraction and commercialization of deep-sea deposits.

TMC CEO Gerard Barron was a member of Nauru’s delegation at the ISA meeting—evidence of the island nation’s and corporation’s common interest in pressing ISA to green-light metals extraction. Other countries eager to see the ISA issue mining regulations and permits also reportedly included mining company executives in their negotiating teams at the talks. Skeptics of deep-sea mining say such involvement has made it hard for the ISA to proceed with caution.

“Were it not for such intense pressure and lobbying from the mining industry, there would be no urgency for ISA to create mining regulation and science would have the time to research the possible impacts,” says Ramos. “But such pressure puts ISA in a very difficult position, and decisions taken in a rush could lead to mistakes.”

Mexico, which currently heads the ISA’s governing council, has not endorsed a moratorium and did not vote for the two-year pause. This has drawn criticism from conservationists, who point out that a national mining-law reform implemented in the country includes a ban on mining in Mexican protected areas and its national waters. (See "In Mexico, reform targets mining in protected areas" —EcoAméricas, May 2023.) Says Greenpeace’s Ramos, who is based in Mexico City: “The position of Mexico is incongruent, and it puts the country’s credibility at risk.”

Concern about plumes

Deep-sea mining involves large vessels lowering heavy machinery some two to three kilometers below the water’s surface to suction polymetallic nodules. The unselective machines also pull in ocean-bottom material and marine life, creating sediment plumes that according to the TMC settle within a few hundred meters of the suctioning site.

Experts such as marine biologist Elizabeth Soto, a researcher at the Terram Foundation, note that plumes pose risks to water-filtering benthic species.

“At great depths, the conditions in the ocean are extremely stable, which makes the ecosystem highly sensitive to the most minimal change,” Soto says. “The temperature is relatively stable, around four degrees centigrade, and there is almost no movement of water. We have no way of knowing what the effects of a high impact activity on such a fragile ecosystem would be. We are barely exploring these depths.”

Noise from the machines, Soto says, “would wreak havoc with species, such as cetaceans, that rely on sound for basic functions such as communication, mating, and navigation.” She adds: “Further, we cannot predict the impact of exposure to light from the machinery because at such depths there is next to no light.”

TMC, for its part, points to environmental-impact studies it conducted that find carbon emissions from deep-sea mining are 90% lower than those from mining the same quantity of metals on land. Further, the company argues, “Nodule exploitation means no disruption to indigenous communities, no deforestation and no child labor during the mining phase…Producing these battery metals from polymetallic nodules is the best way to ensure we can meet the challenges of the climate crisis with the lightest environmental and social impacts.”

Environmentalists argue that the push to mine vast new quantities of metal is based on a flawed, deeply counterproductive strategy.

“Replicating the existing failed model of millions of cars should hardly be the aim, but, rather, finding an entirely new transport model that is truly sustainable,” Soto says. “Those who promote deep-sea mining as the solution to transition from fossil fuels to electric vehicles are doing so at the expense of biodiversity. Reducing emissions makes no sense if in the process you destroy biodiversity. The planet’s biodiversity is already in crisis.”

Knock-on effects

Soto cites the potential toll to fisheries and those who depend on them.

“There is a common belief that you can do anything in the high seas because no one will notice, so no one complains,” she says. “But the damage to the fragile ecosystem is huge. Fish stocks, the communities who rely on fishing and food security would all certainly be impacted.”

The overriding feeling among conservationists and many scientists is that too little is known about the deep sea to assess what the impacts of mining would be, or to warrant taking decisions about how to protect it.

“Every time there are research expeditions in international waters the results are staggering,” says Ramos. “On one recent expedition to the Clarion Clipperton Zone, scientists found approximately 5,000 new species. This is a drop in the ocean compared to all that is as yet undiscovered out there. We do not even know what species are out there. How can we approve putting them at risk?”

Some corporations have publicly endorsed a cautious approach. Google, BMW, AB Volvo Group and Samsung SDI were the first global companies to publicly join a World Wildlife Fund call in March 2021 for a moratorium on deep-sea mining.

The declaration said its signers agreed “not to use deep-ocean minerals or finance deep-sea mining until comprehensive scientific research into the impact of deep-sea mining can be conducted and the consequences for the environment are clearly assessed.”