The ocean floor, long considered a remote and largely unexplored frontier, is increasingly viewed as a potential source of critical minerals needed for the global transition to green energy. But the prospect of deep-sea mining – extracting resources like cobalt, nickel, and manganese from the seabed – is sparking intense debate, pitting the demand for sustainable technologies against concerns about irreversible environmental damage. As international regulators prepare to potentially open the deep ocean to commercial mining, scientists are racing to understand the fragile ecosystems at risk and whether responsible extraction is even possible.
The focus is largely on the Clarion-Clipperton Zone (CCZ), a vast, abyssal plain in the eastern Pacific Ocean, rich in polymetallic nodules – potato-sized concretions containing valuable minerals. These nodules lie scattered across the seabed, and companies like The Metals Company are eager to harvest them. The appeal is clear: terrestrial mining often carries significant environmental and social costs, and deep-sea nodules could offer a comparatively cleaner source of materials essential for electric vehicle batteries, renewable energy infrastructure, and other green technologies. However, the deep sea remains one of the least understood environments on Earth, and the potential consequences of disturbing it are largely unknown.
Saleem Ali, an environmental systems scientist at the University of Delaware who advises the United Nations on critical metals, argues that deep-sea mining deserves consideration within the broader context of the green transition. He coauthored a 2022 analysis comparing the environmental impacts of terrestrial mining with those anticipated from seabed resource extraction. The study, funded by The Metals Company, suggests that deep-sea mining *could* result in less waste and fewer risks to communities than traditional land-based mining. Ali emphasizes, however, that this conclusion is based on “substantial uncertainty” regarding the impacts of sediment plumes created during the mining process. “I’m not saying that we should go ahead with it,” Ali said. “I’m saying that it deserves to be considered in this broad context of very demanding choices we have to make.”
But the idea that deep-sea mining might be a less damaging alternative is fiercely contested. Critics point to the same study, noting that its initial findings of quick recovery were later revised to acknowledge potentially long-term and significant negative effects. The authors ultimately concluded that seafloor nodule mining, even on a small scale, can have “considerable negative biological effects.” The concern centers on the unique and vulnerable organisms that inhabit the abyssal plains, adapted to a world of perpetual darkness, immense pressure, and scarce resources. These creatures, scientists warn, are likely ill-equipped to cope with the noise, light, and toxic sediment stirred up by mining operations.
Credit: ROV TEAM / GEOMAR (CC-BY 4.0)
The seafloor of Clarion-Clipperton Zone is home to many creatures, some of which are shown here: anemone (top left), sea cucumber, Psychropotes longicauda (top right), sea urchin Plesiodiadema sp. (bottom right), and starfish (bottom left). The biology and ecology of these depths remain poorly understood, making it hard to know what the ecological impacts of deep-sea mining would be. Credit: ROV TEAM / GEOMAR (CC-BY 4.0)
A Race Against Time for Data Collection
Anna Metaxas, a deep-sea ecologist at Dalhousie University in Canada, emphasizes the critical need for more data before any mining can proceed. Metaxas, who participates in the Deep-Ocean Stewardship Initiative, a network dedicated to informing deep-sea policy, coauthored a 2025 overview of the potential impacts of mining on the deep-ocean ecosystem in the Annual Review of Environment and Resources. She previously led a project comparing environmental impacts of land and seabed mining, but in 2024, she and her colleagues concluded that current data are insufficient for meaningful comparison. “Our knowledge gaps are really large,” Metaxas said.
Matthias Haeckel, a marine biogeochemist at the GEOMAR Helmholtz Centre for Ocean Research in Kiel, Germany, agrees. He is part of a team of 30 experts tasked by the International Seabed Authority (ISA) to develop monitoring and assessment standards for mining impacts. The group is focusing on toxicity from heavy metals, the effects of sediment plumes, and the impact of underwater noise and light pollution. They are expected to submit draft guidelines later this year. The ISA, which has been collecting data on the deep seabed for over 30 years, is under pressure to finalize regulations and allow commercial mining to initiate.
The Metals Company is actively seeking permits, anticipating approval from the United States to begin mining in the Clarion-Clipperton Zone by the end of 2024. The company has not responded to requests for comment regarding the ongoing scientific debate. Meanwhile, researchers like Haeckel are scrambling to gather more data. His European project, MiningImpact, will return to sites previously used for mining tests conducted by Global Sea Mineral Resources, a subsidiary of the Belgian company DEME, to assess the ecosystem’s recovery five years later. “The Clarion-Clipperton Zone is a large area, and there are still many, many open questions,” Haeckel said. “We hardly know what creatures live down there, or how they interact.”
The Regulatory Landscape and Looming Decisions
The ISA Council convened in Jamaica in early March and will meet again in July to debate and potentially adopt mining regulations. The process has been fraught with delays and disagreements, with some nations advocating for a cautious approach and others pushing for rapid development. The debate highlights the complex geopolitical and economic interests at play. The ISA’s authority to regulate deep-sea mining stems from the United Nations Convention on the Law of the Sea (UNCLOS), an international treaty that governs the employ of the world’s oceans. However, the United States is not a party to UNCLOS, which complicates the regulatory process for companies seeking to operate in international waters.
The potential for deep-sea mining extends beyond the Clarion-Clipperton Zone. Other areas of interest include hydrothermal vents and seamounts, which harbor unique ecosystems and mineral deposits. The environmental risks associated with mining these areas are particularly high, and concerns are growing about the potential for irreversible damage to biodiversity. The debate over deep-sea mining is not simply an environmental issue. it likewise raises questions about equity, access to resources, and the governance of the global commons.
As the ISA moves closer to a decision, the scientific community is urging caution and emphasizing the need for a robust regulatory framework based on the best available evidence. The future of the deep ocean – and the resources it holds – hangs in the balance. The ISA Council’s July meeting will be a critical juncture, potentially paving the way for a new era of resource extraction or establishing a moratorium to allow for further research and assessment.
Disclaimer: This article provides information about a complex scientific and regulatory issue. It’s not intended to provide investment or legal advice. Readers should consult with qualified professionals for guidance on these matters.
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