U.S. President Donald Trump signed an executive order on April 24 to expedite the process of exploring and mining for valuable minerals found on the deep ocean seafloor, in both U.S. and international waters. It’s a highly controversial move that critics say imperils an important but poorly understood ecosystem and flouts international rules on deep-sea mining.

Miners are mainly after potato-size nodules lying at the bottom of the ocean 4,000–5,500 meters (12,000–18,000 feet) deep. They contain minerals, including nickel, cobalt and magnesium, used in batteries and various other industrial applications. Trump’s tariffs will likely raise the costs of mineral imports, particularly from China, a leading exporter.

In a post on X, Secretary of State Marco Rubio said, “Today’s @POTUS executive order makes it clear: the United States – not China – will lead the world in responsibly unlocking seabed mineral resources and securing critical mineral supply chains with our partners and allies.”

However, the move is likely to anger many allies.

Mining companies have been eager to work in the Clarion Clipperton Zone (CCZ), in the central Pacific Ocean. Nodules there are estimated to contain more nickel, cobalt and magnesium than all terrestrial sources combined. However, miners have been held at bay by the U.N.- affiliated International Seabed Authority (ISA), as its 169 member states (plus the EU) slowly draft rules to govern seabed mining.

The U.S. isn’t an ISA member, and the Trump administration says it can use the 1980 Deep Seabed Hard Mineral Resources Act to grant mineral leases in international waters.

In a statement emailed to Mongabay, ISA Secretary-General Leticia Carvalho said “Any commercial exploitation carried out in the international seabed without the authorization of the Authority would, thus, constitute a violation of international law.”

Prior to the executive order, in March Canadian deep-sea mining company The Metals Company, announced it had “initiated a process” to seek U.S. approval to mine in the CCZ. “We have a boat that’s production-ready,” CEO Gerard Barron told the New York Times, “we’re just missing the permit to allow us to begin.”

The U.S. now also joins Norway, Japan and a few other nations seeking to mine their domestic waters. On April 15, U.S. company Impossible Metals announced it had submitted a leasing request to the U.S. government to mine in waters off American Samoa.

Scientists are concerned that mining will damage an ecosystem they are just beginning to explore and understand. A 2023 survey found at least 5,000 new-to-science species live in the CCZ.

“There’s so much we have yet to discover about the deepest reaches of our oceans, where wild creatures somehow eke out a living,” said Kelsey Lamp, ocean campaign director with Denver-based advocacy group Environment America, in a statement. “There’s hubris to the idea that we should permanently harm these deepwater ecosystems for minerals that can be obtained elsewhere.”

 Banner Photo:of nodules courtesy of NOAA.

Elizabeth Alberts contributed to this reporting.