What is deep-sea mining and why is it controversial?
Trillions of dollars worth of minerals sit on the deep ocean floor, but harvesting them could devastate ecosystems we barely understand.
The answer
Deep-sea mining targets mineral-rich deposits on the ocean floor, including polymetallic nodules (potato-sized lumps rich in manganese, nickel, cobalt, and copper), seafloor massive sulfides near hydrothermal vents, and cobalt-rich crusts on seamounts. These minerals are essential for electronics and renewable energy technologies. However, mining would destroy slow-recovering deep-sea habitats, create sediment plumes that could smother filter feeders over vast areas, and disrupt ecosystems that have taken millions of years to develop. The International Seabed Authority regulates mining in international waters, but as of 2025, no commercial deep-sea mining operations have commenced, partly due to strong opposition from scientists and environmental groups.
Source: International Seabed Authority
- deep sea mining
- polymetallic nodules
- ocean conservation
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