Deep sea mining
Deep sea mining is the extraction of minerals from the ocean floor at depths of 200 metres (660 ft) to 6,500 metres (21,300 ft).
Deep-sea mining uses hydraulic pumps or bucket systems that carry deposits to the surface for processing.
The environmental impact of deep sea mining is disputed. Environmental advocacy groups such as Greenpeace and the Deep Sea Mining Campaign claimed that seabed mining has the potential to damage deep sea ecosystems and spread pollution from heavy metal-laden plumes. Critics have called for moratoria or permanent bans. Opposition campaigns enlisted the support of some industry figures, including firms reliant on the target metals. Individual countries with significant deposits within their exclusive economic zones (EEZ's) are exploring the subject.
As of 2022, no commercial deep sea mining was underway. However, the International Seabed Authority granted 19 exploration licenses for polymetallic nodules within the Clarion Clipperton Zone. China has exclusive rights to mine 92,000 square miles (240,000 km2) or 17 percent of the area. Mining is set to begin in 2025. In 2022 the Cook Islands Seabed Minerals Authority (SBMA) granted 3 exploration licenses for polymetallic nodules within their EEZ. Papua New Guinea was the first country to approve a DSM permit, to Solwara 1, even though three independent reviews of the environmental impact statement mine alleged significant gaps and flaws in the underlying science.
Related technologies include robotic mining machines, as surface ships, and offshore and onshore metal refineries.
Wind farms, solar energy, electric cars, and battery technologies use many of the deep-sea metals.
As of 2021, the majority of marine mining used dredging operations at depths of about 200 m, where sand, silt and mud for construction purposes is abundant, along with mineral rich sands containing ilmenite and diamonds.