The controversial search for metals beneath the world's deepest ocean

Good for microchip manufacturers, bad for the environment: the pros and cons of deep-sea mining in the Pacific

US President Donald Trump's executive order to promote deep-sea mining faces an alliance of at least 100 environmental campaign groups who are dead against the practice. Reuters

US President Donald Trump’s executive order aimed at kick-starting commercial deep-sea mining has sparked debate in environmental circles on what is the most appropriate next step.

He is keen to search for metals used in renewable energy, batteries and computer microchips such as copper, cobalt, manganese and nickel. The mining could take place at depths of thousands of metres.

The area most likely to be affected is the Clarion-Clipperton Zone − a six-million-square kilometre region of international waters in the eastern Pacific that boasts an abundance of mineral resources.

Vancouver-based firm The Metals Company has in recent years signed multiple exploration contracts from parts of the CCZ. The company, regarded as being among the most likely to begin operations, saw its stock jump in value by more than 85 per cent last month.

But if tractor-like machines moved along the seabed, what effects could there be on the unique and diverse fauna that lives in the murky depths thousands of metres below the surface?

A step into the unknown

“We don’t yet fully understand what the impacts are likely to be,” said Prof Jon Copley, professor of ocean exploration and science communication at the University of Southampton in the UK.

“It could be comparable to the lowest-impact mining on land in terms of environmental impact, or less, or it could be that there’s a risk of species extinctions. We don’t yet know. That’s why we need to do further research.”

Some organisations, such as the Deep Sea Conservation Coalition − an alliance of more than 100 international organisations working to promote biodiversity conservation in the world's seas − are against all deep-sea mining and have warned of “inevitable and permanent” damage if it took place.

Matthew Gianni, the coalition’s co-founder and political and policy adviser, said that some of the most precious minerals − called nodules − took “millions of years to form”.

“Once they’re taken out they’re not going to grow back,” he said. “[Mining] would also disturb all the animals, the ecosystem, the community of organisms living around the nodules.”

A robotic nodule collector vehicle undergoes sea trials. Photo: The Metals Company

What could happen?

Previous research on the after-effects of small-scale disturbance from the 1990s demonstrated that impacts are long-lasting, according to Dr Matthias Haeckel, of Germany’s GEOMAR Helmholtz Centre for Ocean Research Kiel.

“The oldest disturbance in the CCZ in the north-east Pacific is now almost 50 years old,” he said. This activity has left “disturbance scars, which are clearly visible at the sea floor”, added Dr Haeckel.

However, since the scale of deep-sea mining associated with Mr Trump's executive order would be significantly larger, Dr Haeckel said “larger-scale consequences can follow”.

When could it happen?

Despite the executive order, commercial deep-sea mining is not set to begin imminently and may not happen at all.

Activities are governed by the International Seabed Authority, which developed from the UN Convention on the Law of the Sea.

The US has not ratified the UN Convention on the Law of the Sea, but until recently had accepted it as what legal experts term customary international law, meaning that it would abide by it.

About a quarter of the CCZ is of potential interest and, Prof Copley said, the ISA has set up nearly two million square kilometres of protected areas in 13 blocks.

If the protected areas are, for example, representative of the wider area in terms of the species present, keeping them pristine could prevent extinctions. But Prof Copley said that significant research was needed to determine if this was the case.

“If commercial mining by The Metals Company goes ahead, I don’t think that would have immediate catastrophic impacts. The risk is from cumulative regional-scale impacts,” Prof Copley said.

This is why, he said, stepping away from the ISA framework would increase the risk of serious harm to seabed habitats, which already face pressures from climate change.

The executive order has been described as “a victory” for The Metals Company, which has been lobbying the Trump administration to allow to go-ahead for deep-sea mining.

“Ultimately, The Metals Company needs a commercial licence to be viable, that’s why it’s going to the US,” said Dr John Childs, who researches the politics of resource extraction at Lancaster University in the UK.

'Really bad idea'

Some reports have suggested that Mr Trump sees deep-sea mining – which has not yet happened on a large commercial scale – as something that could reduce the US’s dependence on China for battery metals and rare earths. Beijing has said that Mr Trump’s executive order violates international law.

Dr David Santillo, a senior scientist at the Greenpeace Research Laboratories at the University of Exeter in the UK, said that deep-sea mining would be “a really bad idea and terrible prospect”.

“If someone is saying the answer is to mine the deep sea bed, we’re asking the wrong question,” he said. “We have to take a step back and look at what we’re using minerals for.

“The minerals in question are things that could have much more closed-loop systems for their management. We’re still incredibly wasteful with minerals once we’ve finished with them. There’s some recycling, but not something we’ve in any way reached peak on,” added Dr Santillo.

More than 30 countries have declared their support for a moratorium or other restrictions that would, at least until further research is undertaken to understand the impacts, prevent operations from starting.