A Startup Plans to Mine the Ocean Floor. It Could Be a Disaster.

A Startup Plans to Mine the Ocean Floor. It Could Be a Disaster.

The sea floor between Hawaii and Mexico is covered in potato-sized rocks that contain many of the metals necessary to make electric-car batteries. All that's needed is a way to lift them to the surface for processing. At least, that's the theory behind the Metals Co., a business formed earlier this year when the Canadian startup DeepGreen merged with a special-purpose acquisition company. As the company prepares to go public, it's touting seabed mining as a green alternative to land-based mineral extraction "” and potentially a hugely lucrative business.

Not everyone is quite so optimistic. Since June, 530 marine-science and policy experts from 44 countries have signed a statement warning that seabed mining would result in environmental damages "irreversible on multi-generational timescales." That should alarm not just investors, but policy makers charged with protecting the oceans.

The Pacific basin is thought to contain more than 30 billion tons of so-called polymetallic nodules, rocks that are rich with cobalt, copper, manganese, nickel, rare-earth elements and titanium. Scientists and entrepreneurs have been researching methods of extracting them since the 1960s. In 1994, the International Seabed Authority was established to regulate mining efforts and protect the seabed environment. Any of the group's 167 member-states can