US opens 31.5 million acres to deep-sea mining

The United States announced that it is preparing for its first federal deep-sea mineral lease auction, marking a significant development in the global race to secure critical raw materials. Scheduled for November 19, 2026, Pacific Mineral Lease Sale 1 will offer approximately 31.5 million acres of seabed across two areas off American Samoa. The proposed leases will have a 20-year primary term, with a minimum bonus bid of US$3 million per area.

Nickel, cobalt and manganese beneath the Pacific

The targeted seabed deposits contain polymetallic nodules and ferromanganese crusts, potentially providing access to nickel, cobalt, manganese and rare earth elements used in batteries, advanced manufacturing and strategic technologies. Unlike conventional terrestrial mining, deep-sea extraction would involve specialised subsea equipment collecting mineral-bearing material from the ocean floor, followed by transportation to the surface for processing.

However, the auction represents an opportunity to acquire exploration and development rights, not an immediate authorisation to begin commercial mining.

Environmental concerns and local opposition

The proposed lease areas lie near the Rose Atoll Marine National Monument, raising concerns about potential impacts on sensitive marine ecosystems, fisheries and biodiversity. Opposition has been substantial. More than 76,000 public comments were submitted during the consultation process, with the overwhelming majority opposing the proposal. American Samoa prohibited deep-sea mining within its territorial waters in 2024, although the planned federal lease areas lie beyond that jurisdiction.Marine scientists warn that sediment plumes, habitat destruction and disturbance of slowly developing seabed ecosystems could produce long-lasting consequences.

Research into these impacts is continuing. A European scientific expedition aboard the research vessel SONNE is revisiting a Pacific test site where a prototype nodule collector operated in 2021, examining whether seabed habitats have recovered after more than five years.

The challenge of balancing mineral security and ocean protection

The US Marine Minerals Administration acknowledges the competing priorities. Acting Director Mike Olsen stated: “Its priority remains guided by science, environmental review, and meaningful engagement with the people and leadership of American Samoa.”

For the mining industry, the auction represents a potential opening of a new resource frontier. Yet important questions remain regarding commercial feasibility, environmental monitoring, regulatory oversight and the long-term effects of seabed disturbance. The central challenge is whether deep-sea mining can deliver meaningful mineral supply without causing unacceptable damage to ecosystems that science is only beginning to understand.

The November auction may establish a new chapter in US critical minerals policy, but the debate over the environmental and social consequences of extracting minerals from the deep ocean is far from settled.