Deep-Sea Mining: Is It Worth the Cost?

Deep-sea mining has been approved for testing in the Pacific Ocean by the International Seabed Authority for the first time since the 1970s. The move has drawn widespread condemnation from environmental groups, with one Greenpeace campaigner saying the activity risks destroying an ecosystem "for the remainder of human history."

The Metals Co., a deep-sea mining company, has been permitted to begin testing its deep-sea mining equipment in the Clarion-Clipperton Zone (CCZ) Exploration Area in the Pacific. This zone is around 1.7 million square miles of abyssal plain, with depths ranging between 11,500 and 21,500 feet.

The Metals Co. said deep-sea mining, especially of nickel, is the best course of action in the face of the planet's increasing population. Nickel is a key element in battery manufacturing, which is primarily harvested on land in Indonesia, a process that requires mass deforestation for access. Deep-sea mining, the company said, is a less-impactful method of accessing more nickel without producing the toxic byproducts seen in traditional ore mining.

"Of all mined commodities, nickel is the most vulnerable to biodiversity risks, and scaling battery-grade nickel production from laterites will likely devastate terrestrial ecosystems and human communities, with the disposal of mine waste in the deep sea putting biodiverse coral ecosystems at risk," the Metals Co. wrote on its website.

However, environmental groups fear that large-scale deep-sea mining in the Pacific will permanently destroy countless seabed ecosystems.

oil rig
A stock image shows an oil rig. Deep-sea mining involves harvesting minerals from the seafloor, using machinery that some say is very disruptive to deep-sea ecology. iStock / Getty Images Plus

Deep-sea mining involves harvesting minerals from the seabed, at depths below 650 feet below the surface. There are three main types of deep-sea mining, each collecting different minerals and affecting the seafloor and its biodiversity in different ways.

"In simple terms, [the concerns about deep sea mining are] about unique biodiversity and the potential for extinction, as well as major impacts generally," Gavin Mudd, an associate professor of environmental engineering at the Royal Melbourne Institute of Technology University, previously told Newsweek.

He continued: "The cause of these impacts varies, ranging from direct mining of habitats—(i.e., the nodules themselves)—to deposition of sediment across a large area due to the mining process generating plumes. Whether there is greater detriment from deep-sea or land-based mining is highly contentious."

The Metals Co. will be initially testing only polymetallic nodule collection in the CCZ, which is one of the less-damaging methods of mining deep-sea minerals. This works by directing water jets at the nodules, allowing them to be sucked up to the surface.

The other methods include the mining of cobalt crusts and seafloor massive sulfides. These methods require hard-rock cutting and affect seamounts and hydrothermal vents, both of which are areas that have larger levels of biodiversity than the abyssal plane.

Many activists and conservationists disagree with any form of deep-sea mining, however.

The net gain from the minerals acquired "absolutely will not be worth [the damage done by the process], Arlo Hemphill, a senior oceans campaigner at Greenpeace, told Newsweek.

"Proponents point to potentially fewer social injustices if we were to mine the deep sea rather than tropical forests and coasts. However, no one is volunteering to abandon land-based operations in exchange for the opportunity to deep-sea mine, and in most cases deep-sea mining companies are not the same companies that mine on land," he said.

"What we're looking at is an increased human footprint everywhere—mining on land and the ocean. The idea that it's a choice or trade-off is a false narrative," Hemphill said.

Environmental groups also say that even if seabed communities are not being destroyed directly by the mining activity, the sediment stirred up by the machinery will coat filter feeders and photosynthesizing organisms over great distances. Additionally, there is concern that connectivity between individual deep-sea communities will be broken.

"These ecosystems cannot recover in human time frames, if at all," Hemphill said. "If we destroy them, we destroy them for our lifetimes and likely the remainder of human history.... We are only beginning to understand the connectivity of these ecosystems to shallower systems and back to us. Destroying them is akin to beginning to dismantle a plane while in flight."

According to the Metals Co., recent MIT studies have shown that the vast majority of seafloor sediment kicked up during operations will settle quickly, mostly within 2.5 miles and within a few days, and then falls to natural background concentration levels.

The International Union for Conservation of Nature has said deep-sea mining should be paused until thorough assessments, effective regulation and mitigation strategies have been implemented. The Metals Co. said its testing period, in August and September, will do just that.

There is currently no information about when the company plans to begin mining.

It plans to commission deep-sea research in advance of its operations in order to study the potential impacts. Only after that data has been analyzed and shown to have acceptably low impact levels will the mining proceed.

"For a use to be sustainable, it shouldn't have permanent and irreversible effects on the environment," David Bailey, a marine ecology expert at the University of Glasgow, previously told Newsweek.

"The needs of the present shouldn't be at the expense of future generations. The evidence so far is that seabed communities don't recover from mining, or they take an enormous time to do so. On this basis, I don't think that deep-sea mining can be considered sustainable at any level," Bailey said.

Overall, while deep-sea mining is bound to affect the ecosystem to an extent, proponents of the technology argue that it would be less damaging than what is being done on land to harvest the same minerals. And demand for those minerals will increase in the coming years.

Hemphill disagrees. "Some of these ecosystems are hypothesized to have been the origin of life on earth, and organisms there could hold the cures for things like cancer, COVID and more," he said.