As the International Seabed Authority meets to debate regulations for deep-sea mining, two new reports have converged to expose how unprepared the world remains for an industry racing toward commercial reality, while exposing the legal and scientific ground regulators have yet to cover.

The first, released by the Deep Sea Mining Campaign, identifies a critical and previously overlooked hazard: the mobilisation of naturally occurring radioactive material from the seafloor. 

Polymetallic nodules and seafloor massive sulphides – the very deposits targeted by mining companies – concentrate radioactive alpha particle emitters. While marine ecosystems are adapted to natural background radiation, the report warns that mining operations will disturb and mobilise these materials, exposing marine life and food chains to elevated radioactivity, potentially for significant distances from mining sites.

It has argued that the danger lies not in external exposure but in ingestion. 

“It’s well known that alpha particles are readily blocked by barriers like skin or paper. However, they become extremely dangerous when inhaled or ingested,” said Dr Helen Rosenbaum of the Deep Sea Mining Campaign. “Investigations have begun into the risks to workers handling nodules. However, our report exposes a massive blind spot: there is zero research on how radiation mobilised by DSM will impact marine ecosystems. 

“Marine life cannot escape polluted water; they will breathe it in and swallow it, and eat prey contaminated by mining operations.”

The report identifies a compounding risk, that deep-sea mining will mobilise both radioactive isotopes and heavy metals simultaneously, and the combined ecotoxicological effects of decades-long mining operations remain almost entirely unstudied. 

Marine scientist Dr Andrew D. Thaler said the implications extend well beyond the seabed itself. 

“This report highlights just how much work is left to do to understand the impacts of this industry on marine ecosystems,” he said. “The release of both heavy metals and radioactive isotopes presents a potential double threat to the ocean. Alpha emitters and heavy metals that build up within the tissue of marine organisms can multiply up the food chain. This could affect the health of top predators, including humans who eat seafood. 

“We are diving blind into an unproven industry without understanding the potential consequences of combined exposure to both heavy metals and radioactive isotopes mobilized from deep sea mining.”

For Pacific Island communities – whose governments are among those most actively engaged with the deep-sea mining debate – the findings carry particular weight. Alanna Matamaru Smith of the Te Ipukarea Society in the Cook Islands said industry messaging has consistently downplayed the radioactivity risk. 

“Being a Cook Islander whose current government supports deep-sea mining, I’ve observed that concerns about radioactive elements present in polymetallic nodules are often downplayed. It’s frequently suggested that activities such as air travel expose people to greater levels of radiation than those associated with nodules. Such comparisons divert attention away from important scientific questions about the impact of radioactive isotopes released by deep sea mining within the marine environment,” she said. 

“This report raises critical questions about the potential for ecotoxicity and biomagnification within marine food webs that are a staple food source for Pacific Island communities. It highlights exactly the type of issues that Pacific peoples and their leaders need hard data on, in order to make informed decisions about the future of our ocean resources.”

Calls for caution against deep sea mining have been echoed in a second report, a fresh legal analysis commissioned by Seas At Risk and ClientEarth, which warns that minerals from deep-sea mining could begin reaching the EU market within years, unless action is taken now. 

The pressure is mounting quickly: in April 2025, the United States opened a pathway for companies to seek deep-sea mining approval in international waters entirely outside the International Seabed Authority’s governance framework, with a commercial licence potentially issued as early as 2027. The ISA itself is under growing pressure to accelerate negotiations on a Mining Code that would open international waters to the industry.

Simon Granberg, Senior Deep-Sea Mining Policy Officer at Seas At Risk, said the industry’s framing as a solution to critical raw materials shortages does not withstand scrutiny. 

“Deep-sea mining is being marketed as a solution to the critical raw materials challenge. It is not. It is a high-risk industry seeking to industrialise one of the least understood ecosystems on earth despite mounting opposition from governments, scientists, businesses and investors. If the EU is serious about its precautionary pause position, it must not facilitate this destructive industry to capitalise on one of the largest markets in the world,” he said.

The legal analysis finds that the EU already has the authority it needs to act. The bloc has repeatedly called for a precautionary pause on deep-sea mining, a position shared by 43 countries, and its Critical Raw Materials Act effectively excludes the industry from its scope. The study concludes that the EU can lawfully prohibit deep-sea minerals from entering its market under the precautionary principle – which permits preventive action where there is risk of serious or irreversible environmental harm – and that such a measure could be compatible with World Trade Organization rules, provided it is applied in a non-discriminatory way and justified on environmental grounds.

Arthur Meeus, a lawyer at ClientEarth, said the legal tools already exist and simply need to be used. “EU law provides the legal safeguards needed to prevent products linked to harmful activities from entering the EU market. Deep-sea minerals and downstream products containing these minerals are no exception to this restriction. The EU has both the legal basis and the competence to restrict their placement on the EU market, it should therefore mobilise its legal toolkit to that end.”

Both reports converge on the shared conclusion that none of this risk is necessary. Studies cited in the legal analysis show that circular economy measures, resource efficiency and technological innovation can meet Europe’s critical raw materials needs without opening a new and poorly understood mining frontier in the deep ocean. 

Seas At Risk and ClientEarth are calling on the EU and its member states to defend a moratorium on the industry, coordinate internationally to prevent unlawful extraction, and exclude the sector from public financial support.

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