Deep-sea mining targets mineral deposits on the ocean floor, typically at depths of 3,000–6,000 meters. Most attention focuses on polymetallic nodules—potato-sized rocks lying on abyssal plains—and on cobalt-rich crusts that coat seamounts. These deposits are enriched in metals like nickel, cobalt, manganese, copper and molybdenum, all crucial for batteries, electronics and low-carbon technologies.
The scale is enormous. Based on decades of surveys, researchers estimate that the seafloor holds trillions of dollars’ worth of critical minerals, including nickel, cobalt, manganese and rare earth elements in nodules and crusts. One exploration company, The Metals Company, claims that the Clarion-Clipperton Zone (CCZ) in the Pacific contains the world’s largest untapped deposit of battery metals, with very high-grade nickel, cobalt, copper and manganese in nodules sitting unattached on the sediment.
To reach them, proposed mining systems would send large collector vehicles across the seabed to vacuum up nodules, pump them to surface vessels through riser pipes, and discharge waste water and sediments back into the ocean. For crusts and sulfides, mechanical cutting or drilling would physically remove parts of seamounts or vents.
Why Industry Says the World Needs Seabed Minerals
The case for deep-sea mining rests on two main arguments: resource security for the energy transition, and lower social and environmental impacts compared to some land-based mines.
As countries push to electrify transport and expand renewable energy, demand for metals like nickel, cobalt and copper has surged. Industry advocates argue that terrestrial mines alone cannot meet this demand quickly or ethically, pointing to deforestation, water pollution and human rights concerns around some existing supply chains. They present nodules as a “cleaner” alternative: very high ore grades, no need to remove forests or communities, and potentially smaller footprints per ton of metal produced.
Some governments also see strategic value. In the United States, the Deep Seabed Hard Mineral Resources Act gives NOAA responsibility for licensing exploration and commercial recovery of polymetallic nodules in areas beyond national jurisdiction, reflecting concerns about dependence on foreign suppliers for critical minerals.
However, critics note that the economic case is far from settled. A 2025 analysis in Time argued that evolving battery technologies increasingly rely on more abundant materials like iron, phosphorus and sodium, softening projected demand for cobalt and nickel and driving prices down. The article estimated that deep-sea mining might supply only a small fraction—around 3%—of global nickel and cobalt needs, while carrying heavy environmental and legal risks.
Deep-Sea Biodiversity: What’s at Risk?
The biodiversity risks of deep-sea mining are at the heart of the controversy. Deep-sea ecosystems are among the least explored on Earth, hosting species adapted over millions of years to stable, dark, low-energy environments. Many are slow-growing, long-lived and highly specialized.
Scientists warn that mining could:
- Strip the seabed of habitat for centuries or longer.
- Generate sediment plumes that smother organisms and spread over large areas.
- Create chronic noise and light pollution in naturally dark, quiet ecosystems.
A recent study presented to the International Seabed Authority (ISA) looked at a small experimental mining track created in the CCZ in 1979. Forty years later, large parts of the disturbed area still showed reduced populations of larger animals and incomplete recovery of seafloor communities.
Other researchers and conservation groups warn that mining could drive species extinctions, especially for fauna restricted to nodule fields or seamounts. The Deep Sea Conservation Coalition, for example, has compiled evidence that deep-sea mining could cause “irreversible” damage, and that current knowledge of deep-sea ecosystems is too limited to predict full impacts.
Local concerns mirror the global picture. In the Northern Mariana Islands, a deep-sea scientist recently warned that proposed seabed mineral extraction could threaten extremely high levels of endemic biodiversity, with extinction risks for species found nowhere else.
The Governance Battle: ISA Rules, National Moves and Moratorium Calls
Legally, most potential deep-sea mining areas lie in “the Area”—international seabed beyond national jurisdiction, governed under the UN Convention on the Law of the Sea (UNCLOS). The International Seabed Authority, based in Jamaica, is tasked with developing regulations for exploration and exploitation and issuing contracts to states and companies.
The ISA has already granted more than 30 exploration contracts for nodules, crusts and sulfides, allowing geological and environmental studies but not commercial extraction. It has also adopted regulations for prospecting and exploration, including language about preventing “serious harm to the marine environment.”
What it has not finalized yet are exploitation rules—the mining code that would govern full-scale operations. Negotiations have been heated. Environmental NGOs, many scientists and an increasing number of states are calling for a moratorium or “precautionary pause” on deep-sea mining until much more is known.
At the 2025 UN Ocean Conference in Nice, world leaders renewed these calls. French President Emmanuel Macron described launching industrial mining of the deep seabed as “madness” given current ignorance of its functioning, arguing for a moratorium as “a necessity.” The Director General of the International Union for Conservation of Nature (IUCN) similarly urged ISA members to uphold a moratorium in an open letter, stating that “nothing currently justifies embarking on deep-sea mining.”
At the same time, some governments and companies are pressing ahead. The Metals Company has signaled its intention to submit one of the first mining applications for the CCZ, while also seeking U.S. permits under domestic law. This raises complex questions about how national regulations interact with international rules—especially since the United States has not ratified UNCLOS, even as it develops its own deep-seabed mining framework via NOAA.
Do We Actually Need Deep-Sea Mining to Meet Mineral Demand?
One of the sharpest fault lines in the debate is whether deep-sea mining is truly necessary for the energy transition.
Proponents argue that seabed resources are essential to meet projected demand for EV batteries and grid storage, pointing to large nodule deposits and the strategic attraction of diversifying supply away from a few dominant producers.
Opponents counter that technological and policy trends are moving in a different direction. Battery chemistries are shifting toward lower-cobalt and cobalt-free designs, recycling capacity is expanding, and terrestrial mines still have significant room for improvement in both performance and social standards. The Time analysis argues that, economically and environmentally, investing in better land-based mining, recycling and processing may offer more predictable returns than opening a new industrial frontier in poorly understood ecosystems.
A recent World Resources Institute review emphasizes how many uncertainties remain: from plume behavior and cumulative impacts on biodiversity, to the true climate trade-offs once full life-cycle assessments are made.
Balancing Mineral Demand and Ocean Protection
The deep-sea mining controversy is not just a technical dispute; it’s a values question. On one side lies the push to secure metals for a low-carbon economy and geopolitical resilience. On the other lies the risk of causing long-lasting or irreversible damage to some of the planet’s most mysterious ecosystems—before scientists have even catalogued their inhabitants.
As ISA negotiations continue, pressure for a moratorium grows, and companies refine mining technologies, governments face a stark choice: race ahead into the abyss in the name of climate and industry, or slow down and prioritize precaution, innovation in material use, and better stewardship of both land and sea.
The outcome will determine whether the deep ocean becomes the next frontier of large-scale extraction—or remains one of the last great wildernesses largely left to nature.
Sources & Further Reading
- The Global Potential of Subsea Mineral Resources
- Deep Sea Mining’s Devastating Impact on Ocean Life the Hidden Cost of Mineral Extraction
- ‘Madness’: World leaders call for deep-sea mining moratorium at UN Ocean Summit
- Scientist Warns Deep Sea Mining Could Lead to Extinction of CNMI’s Biodiversity
