Deep-sea mining threatens sea life in a way no one is thinking about

Debris from such mining operations will have a huge impact on a unique ecosystem we barely understand.

- Alexus Cazares-Nuesser

Picture an ocean world so deep and dark it feels like another planet — where creatures glow and life survives under crushing pressure.

This is the midwater zone, a hidden ecosystem that begins 200m below the ocean surface and sustains life across our planet. It includes the twilight zone and the midnight zone, where strange and delicate animals thrive in the near absence of sunlight. Whales and commercially valuable fish such as tuna rely on animals in this zone for food. But this unique ecosystem faces an unprecedented threat.

As the demand for electric car batteries and smartphones grows, mining companies are turning their attention to the deep sea, where precious metals such as nickel and cobalt can be found in potato-size nodules sitting on the ocean floor.

Deep-sea mining research and experiments over the past 40 years have shown how the removal of nodules can put seafloor creatures at risk by disrupting their habitats. However, the process can also pose a danger to what lives above it, in the midwater ecosystem. If future deep-sea mining operations release sediment plumes into the water column, as proposed, the debris could interfere with animals' feeding, disrupt food webs and alter animals' behaviours.

As an oceanographer studying marine life in an area of the Pacific Ocean rich in these nodules, I believe that before countries and companies rush to mine, we need to understand the risks. Is humanity willing to risk collapsing parts of an ecosystem we barely understand for resources that are important for our future?

MINING THE CLARION-CLIPPERTON ZONE