What We Know About Deep-Sea Mining — and What We Don’t

This guide by the World Resources Institute explains the mechanisms, current regulatory status, potential benefits, and ecological risks of deep-sea mining. It highlights the tension between the demand for critical minerals for the energy transition and the significant knowledge gaps regarding the impact on deep-ocean ecosystems and global carbon cycles.

• Deep-sea mining targets critical minerals—including copper, cobalt, nickel, zinc, silver, gold, and rare earth elements—found in polymetallic nodules, polymetallic sulfides around hydrothermal vents, and metal-rich crusts on seamounts. The primary current focus in international waters is polymetallic nodules, which would be harvested using suction devices that remove the nodules and top sediment layers, piping materials to surface vessels and pumping waste back into the water column.
• The Clarion-Clipperton Zone in the Pacific Ocean is a primary area of interest, with 17 contractors holding exploration contracts covering approximately 1 million square kilometers.
• Commercial deep-sea mining in international waters is currently stalled due to the International Seabed Authority's (ISA) inability to agree on exploitation regulations; the most recent talks ended in July 2025, with negotiations set to resume in 2026. However, the Canadian company The Metals Company, via a U.S. subsidiary, began applying for permits under the U.S. Deep Seabed Hard Mineral Resources Act of 1980 in March 2025, potentially circumventing the ISA because the U.S. has not ratified UNCLOS.
• Proponents argue deep-sea mining is necessary to meet surging demand for minerals—with nickel, cobalt, and rare earth element demand potentially doubling by 2040 in net-zero scenarios—and to avoid terrestrial mining hazards like deforestation and freshwater pollution. Conversely, critics note that shoreline processing facilities could still cause habitat loss for coastal communities and that labor abuses seen in distant-water fishing could recur.
• Mining poses severe ecological risks, including the direct killing of organisms by equipment, suffocation via sediment plumes, and disruption of species through noise and light pollution. Because many deep-sea species are slow to reproduce and nodules take millions of years to form, scientists believe some species would face extinction and ecosystems may never recover. Additionally, waste discharge could threaten international fisheries, specifically tuna stocks vital to Kiribati, Vanuatu, and the Marshall Islands.
• Deep-sea mining could impair the ocean's role as the world's largest carbon sink, which absorbs about 25% of all carbon dioxide emissions. The loss of biodiversity may disrupt microscopic organisms that sequester carbon and prevent the release of planet-warming gases like methane from seabed sediments.
• Circular economy strategies could significantly reduce the need for new mining by 2050: recycling could lower the demand for newly mined copper and nickel by 40%, and lithium and cobalt by 25%. Technological shifts, such as the move from NMC batteries to lithium iron phosphate (LFP) or sodium-ion batteries, further reduce the demand for minerals targeted by deep-sea mining.

APA

World Resources Institute (2025). What We Know About Deep-Sea Mining — and What We Don’t. https://www.wri.org/insights/deep-sea-mining-explained

Chicago

World Resources Institute. What We Know About Deep-Sea Mining — and What We Don’t. 2025. https://www.wri.org/insights/deep-sea-mining-explained.

Wikipedia

{{cite report |author=World Resources Institute |title=What We Know About Deep-Sea Mining — and What We Don’t |date=23 July 2025 |url=https://www.wri.org/insights/deep-sea-mining-explained |access-date=17 August 2026 |via=Climate Insights Directory}}

BibTeX

@techreport{worldresourcesinstitute2025what, author = {{World Resources Institute}}, title = {{What We Know About Deep-Sea Mining — and What We Don’t}}, institution = {World Resources Institute}, year = {2025}, month = jul, url = {https://www.wri.org/insights/deep-sea-mining-explained}, urldate = {2026-08-17}, note = {Indexed by Climate Insights Directory} }