Deep-sea mining threatens sea life by dumping debris in midwater zone Premium

Beneath the Pacific Ocean southeast of Hawaii, a hidden treasure trove of polymetallic nodules can be found scattered across the seafloor. The nodules are rich in metals which are key ingredients for batteries, smartphones, wind turbines and military hardware.

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 650 feet (200 meters) 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’ behaviors.

As an oceanographer studying marine life in an area of the Pacific 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?

Beneath the Pacific Ocean southeast of Hawaii, a hidden treasure trove of polymetallic nodules can be found scattered across the seafloor. These nodules form as metals in seawater or sediment collect around a nucleus, such as a piece of shell or shark’s tooth. They grow at an incredibly slow rate of a few millimeters per million years. The nodules are rich in metals such as nickel, cobalt and manganese – key ingredients for batteries, smartphones, wind turbines and military hardware.

As demand for these technologies increases, mining companies are targeting this remote area, known as the Clarion-Clipperton Zone, as well as a few other zones with similar nodules around the world.