27 Jul 2023
by Charlie Bartlett

The promise and peril of deep sea mining

The future of seafloor ecosystems hangs in the balance after regulators failed to come to an agreement on deep sea mining.

The future of seafloor ecosystems hangs in the balance after regulators failed to come to an agreement on deep sea mining.

Amidst the frustration that followed the humdrum outcome of IMO's MEPC 80, environmental groups’ greatest ire was still reserved for the International Seabed Authority (ISA), a tiny intergovernmental organisation of just 52 staff, which now holds the fate of the ocean ecosystem in its hands.

Last week, the ISA failed to come to an agreement on how deep sea mining should be regulated. It put off the beginning of deep sea mining until 2024 through a loophole called the ‘two-year rule’, which says that applications for mining rights must be “consider[ed] and provisionally approve[d]” two years after they were submitted.

The decision to proceed with seabed mining is not to be taken lightly, as it could lead to habitat destruction for thousands of species of dark-dwelling creatures, the bottom rung of many marine ecosystems.

Even electric carmakers like Renault, BMW, Volkswagen, Volvo, and Scandia, and their counterparts from tech like Rivian, Google, and Samsung SDI – deep sea mining’s potential end buyers – have expressed condemnation of the practice in its current form, which involves large tracked ROVs vacuuming up valuable nodules, along with the top layer of seabed. Silt stirred up by this interaction lingers in the water column.

The vehicles “inject water through the riser, through these pumps, into the seabed, and it vacuums up the top 10cm – modules, sediment, bacteria. All of the life,” said Oliver Gunasekara, CEO of Impossible Metals, a company developing floating submersibles aimed at improving the process. “And so, by indiscriminately destroying everything in front of it, the crawler can cause the extinction of entire species.

“Once on the support vessel, again, they separate out some of the sediment that has been collected, and discharge that in what's called a tailings plume, into the mid-water column.”

Even if this process was cleaned up, various species depend on the nodules for shelter. Their indiscriminate removal risks causing the extinction of species yet unknown to science. The biodiversity at these depths is so vast that ecosystems of corals, sponges, microorganisms and fish can be wildly different between one square kilometre and another.

“What seems crystal clear is that the majority of states feel very uneasy about a licence being granted before the regulations are in place, enough scientific research is done and the effective protection of the marine environment can be ensured,” said a campaigner for the World Wildlife Fund (WWF).

Impossible Metals’ efforts to improve the process has yielded a jellyfish-like machine that uses neutral buoyancy, rather than locomotion or perambulation, to float just above the surface of the seabed. Small reaction thrusters steer and steady the vehicle, and from there, teams of pincers reach down and snatch up the nodules, in similar fashion to the claw machine at an amusement arcade.

The mining interests, including Canada's The Metals Company (formerly DeepGreen Inc) and dredging companies like DEME, are eager to begin. The Pacific's Clarion-Clipperton Zone (CCZ) boasts vast fields of polymetallic nodules – tangerine-sized pebbles full of manganese, zinc, copper and cobalt – which could be obscenely lucrative. Their abundance makes this sort of mining easier, miners say, than the tortuous methods used to mine these metals in ever-deeper holes in the land.

These raw materials are vital for manufacturing renewable energy technologies, essential in the world's transition to decarbonisation. Inside the world’s largest wind turbines are coils containing tonnes of copper, and as renewable energy scales up, so will the need for these materials.

If the seas boil, the argument goes, there will be no seabed ecosystems for anyone. For the creatures involved, then, it might sadly be up to humans to choose between one sort of oblivion and another.