For a while now, a certain angst shared by both the marine science and conservation communities has instilled even greater fear for an ocean already reeling from overfishing, plastic pollution, warming and acidification. That angst is over the prospect of deep-sea mining (DSM). And when, a few weeks back, Trump signed another of his greed-and-hubris-driven executive orders for the U.S. to pursue DSM over the objections of pretty much the entire global community, well, that fear came once again to the fore.
To understand it, a primer on DSM is in order.
On its celebrated global marine-research expedition of 1872–1876 (which included discovery of the 10,984-metre-deep Mariana Trench, deepest-known point on Earth’s surface), the British ship HMS Challengerconsistently dredged up dark, fist-sized rocks from abyssal plains—the extensive, flat, sediment-laden areas that lie 4,000 to 6,000 metres below the surface. These were polymetallic nodules, concretions of iron and manganese formed over millions of years that also happen to be high in other valuable metals like nickel, copper and cobalt. A 1981 estimate put the total oceanic stash of such nodules at 500 billion tons. But occurring in largely inaccessible places and containing metals available more cheaply on land, few thought seriously about them until the past few decades. Now DSM keeners insist these deposits can meet growing demand for critical minerals—particularly those needed for digital and clean-energy tech such as EV batteries, wind turbines, and solar panels. Cobalt crusts found on the slopes of underwater seamounts and the mineral-rich sulphides of hydrothermal vents are also threatened.
DSM’s sales pitch is that extracting critical minerals from the seabed will help negate potential shortages, reduce what they describe as demonstrably worse impacts of terrestrial mining, and cut greenhouse-gas emissions. Critics, however, have a potent counterargument: an almost complete lack of scientific knowledge of seabed ecosystems means an inability to predict impacts to the biodiverse marine life reliant on nodules, seamounts and vent structures. A recent global meta-study that analyzed DNA from 1,700 ocean sediment samples revealed deep-seabed biodiversity to be up to three times that of the waters above it, with 60 per cent of organisms representing previously unknown lifeforms, some of which may function in the biological carbon pump—the life-driven sequestration of carbon from the atmosphere and land runoff to the ocean interior and seafloor that helps regulate planetary climate.
While both sides acknowledge that the direct impact of plans to use massive robotic mining vehicles to vacuum up nodules, grind down vents and strip seamounts will result in 100 per cent mortality of any organisms occupying these structures, the extent to which sediment plumes stirred by such activities may also damage habitats, interfere with nutrient cycling and cause oxygen depletion over wider areas is hotly debated.
Opponents of DSM, who include scientists, conservationists, oceanographers, nation states, Indigenous peoples and most of civil society, have called for a ban—or at least postponement—until impacts are better understood and regulations put in place by the UN-backed International Seabed Authority (ISA). Though some 22 countries called for a precautionary pause (Canada took a strong moratorium position in September 2023) this seems unlikely given the ISA’s mandate requires it be financed by royalties from exploratory mining contracts—31 of which it has already granted. Thus, the ISA’s very existence depends on DSM beginning despite the activity’s inherently damaging nature conflicting with the ISA’s other mandated obligation, protecting the marine environment.
Which brings us to the very visible campaign by Vancouver-based The Metal Company (TMC), holder of three ISA exploration permits sponsored by the tiny Pacific nations of Tonga, Nauru and Kiribati, respectively. Rhetoric populating the company’s website shills DSM as humankind’s existential saviour from the climate crisis—and economic salvation for sponsoring nations. Such shameless greenwashing isn’t new but has never been as cleverly crafted—nor so fortuitously enabled given an emerging real-world demand for EVs and renewable energy. While TMC is funding, to the tune of $100 million, a range of basic research it claims to be “objective and independent,” we have seen this before. Conducted independently or not, there’s always the danger of research designed to deliver the answer you want, echoing the policy-based sciencemaking (versus science-based policymaking) practiced by government and industries like Big Tobacco, Big Oil, Big Fish, etc.
An investigative 2022 NYT times piece—“Secret Data, Tiny Islands and a Quest for Treasure on the Ocean Floor”—was an instant cause célèbre for the anti-DSM movement, a scathing indictment of secretive dealings between the ISA and mining companies, particularly TMC, that quoted several employees on ethical breaches. Among its many transgressions, members of one of the ISA’s top policy bodies—the Legal and Technical Commission—also work for mining contractors, a five-alarm conflict of interest.
For his part, TMC’s flashy CEO, Gerard Barron—who once conjured pre-Challenger ignorance by referring to abyssal plains as barren deserts—dismisses the criticism, responding that TMC’s undertaking is of utmost importance to the planet’s future climate health (not to mention shareholders): “This could be one of those projects that could really make a difference—that could really move the needle,” he said.
No matter the outcome, the mere prospect of DSM has triggered unprecedented interest and activity in climate-related research (the deep ocean’s role is more vital than imagined), impact studies (an abyssal plain area tested in the 1980s still hadn’t recovered after 37 years), high-tech work on biodiversity (the biggest unknown), and mapping efforts (there’s a drive to map the entire seabed in high resolution by 2030).
And now, with the ISA having failed to come up with regulations first promised for 2021, the ever-predatory Trump administration, as is its wont, is willing to override even this industry toady, turbocharging legitimate angst and fear of yet another blow to planetary health.
Leslie Anthony is a biologist, writer and author of several popular books on environmental science.
