TMC has carried out exploratory mining expeditions to the Clarion-Clipperton Zone

Professor Daniel Jones of NOC, said that to tackle the question of recovery from deep-sea mining, it is necessary to first look at available evidence and use old mining tests to help understand long-term impacts.

A new study led by Britain’s National Oceanography Centre (NOC) has revealed that the effects of a deep-sea mining experiment in the Pacific Ocean more than four decades ago are still apparent, though early signs of biological recovery have emerged.

A 2023 expedition to the mineral-rich Clarion Clipperton Zone (CCZ) by a team of scientists led by the NOC found the seafloor, a complex ecosystem hosting hundreds of species, still bears scars of a 1979 test mining operation.

The collection of small polymetallic nodules, potato-shaped rocks rich in minerals and metals, from an eight-metre strip of the seabed caused long-term sediment changes and reduced the populations of many of the larger organisms living there, the study, published in Nature, shows.

The team of researchers also found encouraging signs of recovery, with smaller and more mobile creatures returning to the area.

Lead author and expedition leader, Professor Daniel Jones of NOC, said that to tackle the question of recovery from deep-sea mining, it is necessary to first look at available evidence and use old mining tests to help understand long-term impacts. 

“Forty-four years later, the mining tracks themselves look very similar to when they were first made, with a strip of seabed cleared of nodules and two large furrows in the seafloor where the machine passed,” Jones said.

Among the first creatures to recolonize the disturbed areas were large, amoeba-like xenophyophores, commonly found throughout the CCZ — a vast area between Hawaii and Mexico.

“However, large-sized animals that are fixed to the seafloor are still very rare in the tracks, showing little signs of recovery,” he said.

The study’s release coincides with a key meeting of the UN’s International Seabed Authority (ISA) in Kingston, Jamaica, where delegates from 36 countries are reviewing hundreds of proposed amendments to a 256-page draft mining code that will rule commercial deep-sea mining. 

Environmental groups have called for a halt to such activities, a position supported by 32 governments and 63 major companies and financial institutions.

While few expect a final text to be completed by the time the latest round of talks ends on March 28, Canada’s The Metals Company (NASDAQ: TMC) plans to submit the first formal mining application in June.

TMC, which will hold fourth-quarter and full year 2024 financial results calls after market close on Thursday, has long said that deep-sea mining has a smaller environmental footprint than terrestrial mining. CEO Gerard Barron told that the new study supports this view.

Recovery likely

“For years, activists have pushed baseless claims that nodule collecting robots will dig up the seafloor and devastate ecosystems. This new study proves otherwise — showing that even with outdated, far more disruptive technology, recovery is not only possible but likely within decades,” Barron said.

“Sessile megafauna such as sponges were scarce in track areas where nodules were removed, as expected, but were observed attached to nodules left behind by the 1979 collector. This suggests a potential mitigation strategy — leaving some nodules intact to support recolonization by reliant organisms,” he said.

It was historically thought that the deep sea was fairly lifeless, but recent studies are challenging this perception.

TMC has pledged to leave at least 30% of its contract areas untouched to facilitate recovery.

“Our own nodule collector will disturb just the top 3 cm of sediment, not the 80 cm as seen in the 1970s trials,” Barron noted.

Opponents warn that the long-term consequences of deep-sea mining remain uncertain, advocating for further research before large-scale extraction begins. Supporters argue that the industry is vital for meeting growing mineral demand.

According to the International Energy Agency, demand for copper and rare earth metals is expected to rise by 40% by 2040, while the need for nickel, cobalt and lithium from clean energy technologies alone could increase by 60%, 70%, and 90%, respectively.