30 June 2026 | Media Release

New Report Sounds Alarm On Risks Of Unregulated Radioactivity From Deep Sea Mining

Published as the International Seabed Authority meets to debate regulations for DSM, the report reveals that mining the sea floor would expose marine ecosystems, commercial fisheries, and human seafood consumers to the risks of unregulated radioactivity.

The scientific consensus already indicates that DSM impacts will be severe, long-term, and effectively irreversible. However, this new report shines a light on an overlooked hazard: radiation eco-toxicity.

Radioactive alpha particle emitters concentrate in polymetallic nodules and seafloor massive sulphides, both of which are targeted by companies for mining. While marine ecosystems are adapted to natural background levels of radioactivity, the report warns that deep sea mining will mobilise radioactive materials and expose marine life and food chains to elevated levels, possibly for significant distances from seabed mining sites. 

Dr. Helen Rosenbaum of the Deep Sea Mining Campaign stated,

“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.  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.” 

DSM will mobilise both radioactive isotopes and heavy metals. The combined ecotoxicological impacts over decades-long mining operations remain a significant knowledge gap.

Marine scientist Dr. Andrew D. Thaler added.

“This report highlights just how much work is left to do to understand the impacts of this industry on marine ecosystems. 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.”

Alanna Matamaru Smith of the  Te Ipukarea Society in the Cook Islands states,

“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.“   

Ms Matamaru Smith continues,

“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.”

Dr. Helen Rosenbaum concludes,

“Deep Sea Mining is on the verge of exposing our ocean commons to elevated, unregulated radioactivity. We call on the global scientific community and on regulatory authorities to ensure these critical knowledge gaps are addressed before commercial mining is permitted to begin.”