Far off Canada’s Pacific coast, and in oceans around the world, mining companies are exploring the bottom of the sea. There, rocky formations contain in-demand minerals like copper, nickel and cobalt. Companies see deepwater dollar signs in a potential new industry: deep-sea mining.
A Canadian deep-sea mining venture called The Metals Company recently asked the U.S. government to make its dream of an industry a reality. In the wake of the Donald Trump administration declaring deep-sea mining a priority, The Metals Company has applied for U.S. permits to explore and mine Pacific seabed minerals. If it’s successful, it could become the first company to ever commercially mine the deep. It could also undermine global co-operation on managing oceans and their resources.
Here’s what you need to know about deep-sea mining, the environmental risks, The Metals Company and a potential showdown over international ocean agreements.
Deep-sea miners plan to use remotely operated robots to remove mineral-rich seabed formations. Though it’s never been done on a commercial scale, companies and governments have explored the prospect for decades, from searching for mineral deposits to running large mining tests.
These minerals can be used to make steel, batteries, wiring and much more. With such wide-ranging applications, they’re in demand for everything from industrial manufacturing to military technology, as well as emission-free technology such as electric vehicles. The minerals found on the seabed can make powerful long-range batteries, ideal for large trucks and luxury cars.
Three types of environments could be mined. Polymetallic nodule fields are the most popular option: these deepwater plains are covered with “nodules,” or mineral-rich rocks, which lay on top of the seabed, so they’re easy to remove. Seamounts are another possibility: underwater mountains can develop mineral-rich crusts on their surfaces. Some miners are also interested in inactive hydrothermal vents: spires of minerals that formed around volcanic sea-floor fissures before cooling off.
Deep-sea nodules and seamount crusts take millions of years to form, as the minerals dissolved in seawater slowly settle into these deposits. Minerals deposits from hydrothermal vents form a bit more quickly (and can be destroyed quickly, by the volcanic activity that creates them). Still, these resources aren’t renewable on human timescales.
Canada effectively has a moratorium, or temporary ban, on domestic deep-sea mining. A 2023 statement from the ministers of natural resources and fisheries and oceans said, “Canada does not presently have a domestic legal framework that would permit seabed mining and, in the absence of a rigorous regulatory structure, will not authorize seabed mining in areas under its jurisdiction.”
While that ban could be lifted in the future, Canada also has permanent protections for all of its known hydrothermal vents and over 90 per cent of its known seamounts, so these ecosystems can never be mined. In addition, it supports a moratorium on deep-sea mining in international waters.
There are no plants in the deepest parts of the ocean, which sunlight doesn’t reach. However, there are many animals. Seamounts and hydrothermal vents are biodiversity hotspots. Stationary species, such as sponges and tubeworms, attach to them, forming communities that attract swimming species like fish. In the polymetallic nodule fields, the animals tend to be sparser and smaller, but biodiversity is still high.
The nodules offer surfaces for animals like sponges to live on, and scientists have even found octopuses laying eggs on these sponges. Tiny animals, like frilled-looking bristle worms, live in the sediments and inside nodule crevasses. Still, scientists predict the majority of deep sea life still needs to be described — or formally classified — by science: they know there are new species there, but they don’t know exactly how many there are.
One potential threat is that deep-sea mining removes rocky sea-floor formations that provide habitat for animals like sponges and corals, which need hard surfaces to grow on.
Mining machines could also bring noise and light to the dark, quiet sea-floor, while ships at the surface would add to the cacophony of industrial ocean activity. Sediment that gets kicked up by mining is another risk as it could interfere with animals’ ability to breathe, communicate with bioluminescence, or get food by filtering tiny edible things from water. After sea-floor minerals are pumped to the surface, any excess sediment that comes with them would be put back into the ocean, creating a second sediment plume.
In a recent study, U.K.-based scientists returned to a test mining site in the Pacific Ocean 44 years later to see how life there had responded. Certain species had started recolonizing the mining area, but there was lower biodiversity overall. This suggests that some life can persist after deep-sea mining, but ecosystems may not fully return to normal — at least, not on timescales we can easily measure.
Many questions remain unanswered about how deep-sea mining would impact ecosystems. The deep sea is immense and it’s not easy to sample life there. Scientists know relatively little about sea-floor biodiversity or how the ecosystems are connected. Risks depend on the environment being mined, the type of equipment used and the size of the mining area.
Despite Canada’s moratorium, some scientists are concerned that impacts from distant mining operations could reach Canadian waters. For example, planned nodule mining tests by a Chinese company near northeast Pacific seamounts could have far-reaching consequences, according to Cherisse Du Preez, a marine biologist with Fisheries and Oceans Canada.
“Even though they seem like they’re far away from Canada, they lie in one of the convention areas that we manage internationally with other countries,” she says, speaking of the North Pacific Fishery Commission convention area, which sits over the seamounts at the test mining site. The site is located in the vast open Pacific, between Hawaii and China. But because Canada is among the countries that fish there, sediment from mining could harm seafood that Canadians eat.
Seabed sediment can naturally contain metals like cadmium that become toxic at certain levels. Fish could die once exposed to these metals, or survive with dangerous levels of toxins inside them. Contaminated species may be fished from the convention area, while others could travel back to Canadian waters before being caught: some fish, like salmon, can travel incredibly far on migration routes. “We’re just a couple steps away from the deep sea with everything we do on this planet,” Du Preez says.
She notes that mining near seamounts, even at test scale, magnifies the risks of sediment plumes. These underwater mountains act like ramps, stirring up water that flows up the sides. That means plumes created by mining here can spin sediment into immense eddies that carry across long distances.
Shipping and processing deep-sea minerals would also have environmental impacts, including greenhouse gas emissions. Some U.S. deep-sea mining advocates hope to process and refine the minerals in “friendly countries,” including Canada. A 2020 assessment of predicted deep-sea mining emissions by a German university named Canada as a potential processing site for Pacific seabed minerals.
Headquartered in Vancouver, The Metals Company operates through subsidiaries across the world, including in Singapore, Indonesia, the British Virgin Islands and the United States. The publicly traded company is financed through sales of stocks and stock options, as well as loans. Just last month, it raised US$37 million from investors. More recently, it announced a US$85 million investment from a Korean metal smelting company.
The Metals Company focuses on nodule mining. The company recently poured US$250 million into researching environmental impacts and even conducted a large test mining operation that took more than 3,000 tonnes of nodules from the Pacific sea-floor. However, unless it can get a commercial mining permit, it can’t collect and sell minerals for profit. And even then, profits would be far from guaranteed: deep-sea mining is an untested industry with incredibly high expenses.
In April, the company applied for three U.S. deep sea mining permits. Two are for exploration and one is for commercial recovery — that is, actual mining. Through these permits, The Metals Company aims to explore minerals across nearly 200,000 square kilometres, and mine an area just over 25,000 square kilometres. Its proposed commercial mining site is in the Clarion-Clipperton Zone, a large patch of the Pacific between Hawaii and Mexico, with lots of nodules and some seamounts. It isn’t in U.S. waters, but rather a shared international zone.
The Metals Company’s mining system includes a remotely operated collector vehicle on the seabed, a ship at the surface and a very, very long pipe between the two.
The collector is like a “big Dyson vacuum cleaner that crawls along the seabed very slowly,” The Metals Company’s environmental manager, Michael Clarke, told The Narwhal. This vehicle uses water jets to lift the nodules off the sea-floor. It sucks them in, spins them to remove debris and sends them up the riser pipe on a four-kilometre journey to the surface vessel. That’s about the height of seven CN Towers stacked on top of each other.
The company states its mining strategy can help reduce environmental risks. Its collector vehicle is designed to be buoyant, so it doesn’t sink deep into the sea-floor, which the company says reduces the level of sediment that gets disturbed. After the minerals are collected, the company intends to put the excess sediment back in the ocean at depths of 2,000 metres, where research indicates life is more sparse than at higher levels. “We’ve put a lot of time and effort into minimizing the amount of sediment that actually goes up the pipe to the surface,” Clarke says.
Of the species The Metals Company has collected in one of its exploration zones, 80 per cent aren’t yet described by science.
While the sea-floor collector vehicle is fairly quiet, noise from the surface ship could impact the behaviour of marine mammals, like whales, in a radius of nearly four kilometres. “This is really no different from any other vessel that’s out there that’s using dynamic positioning,” Clarke says, referring to the use of thrusters to keep ships in place, which is common in the oil and gas industry.
On the sea-floor, it’s not fully clear which species stand to be impacted. Of the species The Metals Company has collected in one of its exploration zones, 80 per cent aren’t yet described by science. The company states its operations would transform a seabed nodule habitat into a “nodule free habitat,” which would likely change what’s able to live there, since some species appear to depend on the nodules for survival. “We don’t need to know the name of every species that’s out there. We don’t need to know the distribution of every species,” Clarke says. “What we do need to know is the magnitude of the impacts that we’re creating.”
In 2021, The Metals Company emerged in its present iteration, out of an earlier brand called DeepGreen Metals. Every year since 2021, it has invested in lobbying U.S. government agencies to support deep-sea mining. That investment seems to have finally paid off, as the Trump administration issued a pro-deep-sea mining executive order in April, just before The Metals Company applied for permits.
U.S. executive orders don’t create laws, but lay out policy intentions — and this one contains a lot of intentions. One highlight is that it calls for fast-tracking the deep-sea mining permitting process. It also orders a report on adding seabed minerals to the U.S. National Defense Stockpile — a strategic inventory of raw materials for wartime use — and calls for revised regulations to support U.S. mineral processing.
The U.S. government has invited deep-sea miners and supporters to speak to policymakers, including at a recent Committee on Natural Resources hearing, where the possibility of Canadian mineral processing was mentioned. Several deep-sea mining supporters are members of the Trump administration.
The Metals Company’s plan to get a go-ahead from the U.S. has been criticized by a number of countries and organizations, including the International Seabed Authority. The United Nations-affiliated authority oversees deep-sea mining in international waters. Most countries are International Seabed Authority members, including Canada, but the U.S. is not. The authority has issued many exploration permits, including to The Metals Company subsidiaries. However, it’s never issued a commercial mining permit. Its mining regulations are still under debate.
Since 1984, the U.S. has also issued and renewed exploration permits for minerals on the international seabed, ignoring international agreements in favour of its own legal framework. But, like the International Seabed Authority, it has never issued a commercial mining permit.
The Metals Company hopes to get U.S. permits and start mining the high seas quickly. But if it bypasses the slow and unwieldy International Seabed Authority, the Canada-headquartered multinational would break the international rules Canada has agreed to. According to international law, resources of the high seas are the “common heritage” of everyone on Earth, which means choosing what to do with them should be a global decision. If they’re claimed by the U.S., that law is upended. Legal disputes could be on the horizon.
These are uncharted waters, so to speak. Experts disagree on whether the U.S. is within its rights. Because the U.S. never joined the authority, some argue it’s not bound by the authority’s rules. The essential question is: if most of the world has agreed to a set of rules, what does that mean for a country that hasn’t?
In March, The Metals Company posted a statement from CEO and chairman Gerard Barron on its site, stating that “After 16 years of engaging with the [International Seabed Authority] in good faith, we are increasingly concerned” its eventual regulations will not allow commercial mining at all. The statement also noted that “more than two dozen nations” do not recognize the authority’s jurisdiction as binding.
“The freedom to mine the deep seabed, like the freedom of navigation, is a high seas freedom enjoyed by all nations,” Barron’s statement said.
Still, The Metals Company has a long way to go before it can put U.S. regulations to the test. The company will need to scale up its mining equipment for commercial operations. And the U.S. agency in charge of approving or denying the company’s permits has faced significant staff cuts under Trump, which could slow things down.
At this stage, it’s not clear where The Metals Company’s deep-sea minerals might be processed and refined, or who might buy them. In a 2024 report, the company said it intends to use “processing operations in locations like Japan and Indonesia and refineries in locations like South Korea and Canada.” With its recent pivot, The Metals Company is considering shifting its plans toward the U.S. — but because the U.S. has long outsourced mineral processing, this would require new onshore infrastructure.
Given the reach of the industry, from sea-floor to surface and from open ocean to global ports, Du Preez believes “deep-sea mining” is a bit of a misnomer. “It’s ocean mining,” she says, “where some of the activity is going to happen on the sea-floor.”
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