Polymetallic nodules and seafloor massive sulphides don’t just carry heavy metals, they concentrate naturally occurring radioactive isotopes at 10 to 20 times the levels found in surrounding sediment. 

The most dangerous of these, including polonium-210, are alpha-particle emitters capable of delivering concentrated radiation doses to organs and tissue if ingested, damaging cells, DNA  and protein. Significantly alpha radio-isotopes are known to bioaccumulate and biomagnify up marine food webs, potentially also to human consumers. DSM will undoubtedly release radioisotopes along with metals into the marine environment.

As our June 2026 report Critical Questions about the Risks of Radiation Toxicity from Deep Sea Mining sets out, the research needed to understand these risks has not been done, neither by mining proponents or the science community.

TMC’s application doesn’t address radiation ecotoxicity at all.

Earlier this year we co-published an independent technical review of TMC’s Pre-Feasibility Study, titled, Implications of The Metals Company Pre-Feasibility Study for Next Steps by the Company. Authored by mining analyst Dr Steven Emerman and commissioned by DSMC, Greenpeace International and MiningWatch Canada, its findings sit at the centre of our submission to NOAA.

The review found that the TMC study was largely prepared by TMC’s own employees.  This is allowed under the U.S. Securities and Exchange Commission (SEC) rules if disclosed, but is unusual, and not permitted under the rules of Canada where TMC is headquartered. As our submission notes, key chapters on metal pricing and capital costs were written by TMC executives rather than independent experts.

The review and our submission to NOAA also raise concerns about whether the project meets basic standards expected under securities and mining disclosure frameworks, including those associated with SEC. Those rules require a company’s economics to rest on proven, economically mineable reserves. TMC’s model added 113.1 million wet tonnes of unconverted resources on top of its 51 million tonnes of reserves. Under SEC regulations, only mineral reserves can be treated as economically viable, and inferred resources cannot be converted into reserves.

TMC’s Pre-Feasibility Study also has no plan for mine waste (let alone radiation toxicity) despite SEC rules requiring a comprehensive waste and tailings management plan in any Pre-Feasibility Study. 

TMC doesn’t consider its sediment-laden return water as waste (although it will equate to the 24/7 tailings waste discharge of a terrestrial mine) and it assumes every by-product can be sold for example as ammonium sulphate fertiliser. Yet the levels of arsenic, cadmium, chromium, lead, molybdenum and thallium would render this unsellable. 

Evaluated strictly on mineral reserves as required by law, TMC’s project would shut down after eight years with zero profit and a crushing net loss, as Dr Steven Emerman states:

“Based on the company’s own modelling, the project would exhaust its mineral reserves within eight years, and generate no profit. The economic case depends on assumptions that go beyond what regulators consider economically viable.”

Under UNCLOS, the seabed beyond national jurisdiction is the common heritage of humankind, regulated by the International Seabed Authority (ISA). The US has never ratified UNCLOS, and both the US State Department and NOAA itself have previously acknowledged that US-issued licences give no internationally recognised rights or title. TMC’s own SEC filings concede that other nations are legally bound to reject US permits, risking port access, market access and prosecution abroad.

There are consequences closer to home for Pacific states too. TMC’s application leans heavily on research from the ISA contract areas of its subsidiaries Nauru Ocean Resources Inc. (NORI) and Tonga Offshore Mining Ltd. (TOML). 

The ISA has opened formal inquiries into both, and Nauru and Tonga, as TMC sponsoring states, may now be exposed to liability if they continue to sponsor a company that has walked away from the agreed international process.

Our reports: 

The Solwara 1 Seabed Mining Project in the Bismarck Sea of Papua New Guinea, Predicting the Impacts of Mining Deep Sea Polymetallic Nodules in the Pacific Ocean and Socio-political and Regulatory Context of Deep Sea Mining in Papua New Guinea highlight how deep sea mining poses severe socio-economic and cultural threats to Pacific Island nations and coastal communities. 

For Pacific peoples, the ocean is a sacred, living space rooted in ancient lineage, cultural identity, and traditional stewardship. Deep-sea mining threatens customary rights, traditional fishing practices, and Indigenous ocean governance.

The failure of Nautilus Minerals’ Solwara 1 project in Papua New Guinea (PNG) stands as a clear warning about the dubious financial viability of deep sea mining. Solwara 1 was granted permits despite a flawed Environmental Impact Statement and lack of social consent as pointed out in our reports Socio-political and Regulatory Context of Deep Sea Mining in Papua New Guinea, Physical Oceanographic Assessment of the Nautilus EIS for the Solwara 1 Project and Out of Our Depth: Deep Sea Mining in Papua New Guinea.

The PNG government invested approximately USD 120 million into the venture –  funds badly needed for schools, healthcare and public infrastructure. When Nautilus collapsed into bankruptcy in 2019, the project left PNG with crushing public debt. Despite this financial disaster, corporate actors like Deep Sea Mining Finance (DSMF) which operates out of tax havens, are still trying to to exploit Solwara 1 permits without transparency or local consent. 

Our submission calls on NOAA to seriously consider the implications of this history for US tax payers in regard to TMC’s U.S. application. 

Our publications, Why the Rush? Seabed Mining in the Pacific Ocean, Shareholder Advisory: Critical ESG and Financial Risks in the Proposed SOAC-DeepGreen Transaction show that Gerard Barron, the co-founder, CEO and Chairman of The Metals Company (TMC), was an early investor and key promoter of Nautilus Minerals who turned an initial $226,000 investment into a $31 million payout before exiting prior to Nautilus’s bankruptcy. 

Barron subsequently founded DeepGreen (which became TMC) alongside a network of former Nautilus executives—including Anthony O’Sullivan, former Chief Operating Officer at Nautilus who now serves as TMC’s Chief Development Officer (see our infographic, The Metals Company Seeking to Clean Up on Deep Sea Mining: Corporate Ties & Executive Networks). 

This executive network reflects a troubling corporate pattern of generating speculative profits for insiders while leaving host governments, public taxpayers, and retail investors to shoulder the resulting risk.

46 countries call for a moratorium, precautionary pause or ban on deep sea mining in international waters. Four US states and two US territories, all in the Pacific on either side of the proposed mining site, have banned it in their own waters. 

More than 1,000 marine scientists from 75 countries want it paused until the science is in. 

82 financial institutions managing over €24 trillion have excluded or restricted it, and more than 77 companies, including Google, Samsung, Volkswagen and BMW, have committed not to source seabed minerals.