US deep-sea minerals auction near American Samoa: key points for project teams
Reviewed by Joe Ashwell

First reported on MINING.com
30 Second Briefing
The US Marine Minerals Administration will auction 31 million acres of seabed off American Samoa on 19 November for potential cobalt- and nickel-bearing deep-sea deposits, split into two tracts of roughly 16 million and 15 million acres bordering the Rose Atoll marine sanctuary. Initial leases will only permit mapping and non-invasive surveys, with any exploration drilling, pilot testing and commercial production requiring a multi-stage MMA approval process following its 19 October 2026 FONSI environmental assessment. NRDC reports over 76,000 public comments, mostly opposed, citing poorly constrained impacts on deep-sea ecosystems and local fisheries.
Technical Brief
- Auction areas sit in US federal waters outside 2024 regional deep-sea mining ban boundaries.
- Two lease blocks directly abut the protected Rose Atoll marine sanctuary, increasing edge-effect and plume-drift concerns.
- MMA’s Finding of No Significant Impact (FONSI) for commercial leasing was formally issued on 19 October 2026.
- Trump’s April 2025 executive order to accelerate deep-sea science followed a leasing request from Impossible Metals.
- NRDC reports over 76,000 public comments to MMA on the sale, with a strong majority opposed.
- Environmental NGOs warn of potential species extinctions in poorly characterised deep-sea habitats before baseline surveys are complete.
Our Take
Battery metals and critical minerals pieces in our mining database are overwhelmingly land-based; a 31-million-acre seabed auction off American Samoa signals that US supply strategy is starting to lean on frontier environments rather than just permitting reforms for onshore projects.
The presence of groups like NRDC, Greenpeace and IUCN alongside a US agency (MMA) in the same American Samoa context suggests any eventual cobalt and nickel extraction here will likely face a permitting and litigation profile closer to offshore oil and gas than to typical hard‑rock mines.
The US Department of Energy’s $42M support for a natural gas pipeline in the Northeast, referenced alongside this deep-sea push, underlines that federal critical minerals policy is being layered on top of – not instead of – continued backing for gas infrastructure, which can complicate long-term decarbonisation narratives for developers and investors.
Prepared by collating external sources, AI-assisted tools, and Geomechanics.io’s proprietary mining database, then reviewed for technical accuracy & edited by our geotechnical team.
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