More than 20 financial institutions have publicly pledged not to finance deep-sea mining, an activity scientists warn could cause irreversible harm to ocean ecosystems. Yet a DW investigation, using company filings compiled by Greenpeace Germany and investment data from the Anti‑Corruption Data Collective (ACDC), found that some banks and investors have still put at least $684 million (€581 million) into companies linked to the sector.
Hundreds of millions flow to firms racing to extract nickel, cobalt and copper from polymetallic nodules thousands of meters below the surface — an environment where scientific knowledge is very limited. Less than 0.001% of the seafloor has been explored. Among investors identified are large global banks including Deutsche Bank, UBS, Credit Suisse, Crédit Agricole and BNP Paribas.
Some banks say their restrictions apply to financing specific mining projects rather than to buying shares in companies preparing to mine. Critics call this a loophole and accuse institutions of greenwashing — publicly rejecting project finance while still investing in companies that enable or plan seabed extraction. Greenpeace and campaigners warn that carefully worded policies and small-print exceptions let banks avoid reputational risk without changing broader investment behavior.
Storebrand, one of Norway’s largest financial groups, has divested millions from firms linked to deep-sea mining, citing the precautionary principle and saying it will not invest in companies involved in the practice until scientific knowledge improves. By contrast, Goldman Sachs, which markets itself in environmental, social and governance (ESG) investing, holds about €187 million in stakes across companies tied to deep-sea mining activities.
Taxpayer money and public pensions are also implicated. DW’s analysis found investments by funds and vehicles that draw on public pension capital. The private‑equity fund Triton IV, which pulled together money from public pension funds across Europe and Canada, managed subsea firms DeepOcean and Adepth Minerals until spring 2025 before selling the group to a new Triton‑managed entity; Triton disputed characterizations that its holdings equate to seabed‑mining investment. Campaigners say pension funds, which invest for the public’s future, should account for the environmental risks and join financiers that exclude deep‑sea mining — but so far none have made such exclusions.
Some governments draw firmer lines. Around 40 countries support moratoriums or precautionary pauses on mining in international waters, and Norway has agreed not to issue mining licences in its national waters until at least 2029. At the UN level, Special Envoy for the Ocean Peter Thomson has called for a 10‑year moratorium to let science catch up, and the UN’s finance initiative has said there is no foreseeable way financing deep‑sea mining can align with sustainable use of the ocean.
Scientists stress how little is known and how high the stakes are. Marine biologist Diva Amon says the deep sea is “home to incredible life that is fragile, yet essential to the planet” and warns that “we don’t yet understand what we’re planning to destroy, and once it’s gone, we can’t bring it back.” About 90% of deep‑sea species still lack formal names. Removing polymetallic nodules could cause damage on million‑year timescales. Early evidence from trial operations supports these concerns: a study funded by leading mining firm The Metals Company found that test mining in the Pacific reduced seafloor abundance and biodiversity by more than a third.
Risks extend beyond biodiversity loss. Deep‑sea microbes already have medical uses — enzymes used in SARS‑CoV‑2 PCR tests and compounds now being studied in cancer trials — and mining could eliminate organisms before they are discovered and studied.
Critics argue that green‑labelled investment strategies can be superficial. Former BlackRock sustainable investing chief Tariq Fancy has said it is often cheaper for firms to “paint yourself green than to actually be green,” and that lasting change requires political reform and stronger regulation rather than voluntary pledges that leave room for exceptions.
Accountability, campaigners say, is crucial: public pressure on financiers and clear policy application across all types of investment would be needed to align capital with precautionary approaches to deep‑sea ecosystems. Edited by Anke Rasper
(The investigation received a grant from the Investigative Journalism for Europe (IJ4EU) fund.)
