As global demand for gold, platinum, titanium, phosphorus, and other minerals grows and terrestrial sources dwindle, industrial-scale prospectors, aided by new technology, could target the U.S. West Coast’s nearshore seafloor in search of these valuable resources. But mining in coastal waters would harm marine wildlife, commercial and recreational fisheries, and the communities that depend on them.
Marine mining can include dredging ships equipped with cutting heads to break up hard seabed, or more destructive techniques, such as bottom crawlers designed to remove up to 12 inches of rocky seafloor crust. All of these methods can remove or destroy fish, invertebrates, corals, and habitat.
Mining can generate large sediment plumes, often laced with toxins, that smother marine life, including commercially and recreationally important fish, marine mammals, and algae, such as kelp. The plumes can travel long distances on tides or currents, putting beaches and tide pools at risk.
Oregon prohibited seabed mining for hard minerals in state waters in 1991. California and Washington should act now to follow that example given the significant emerging evidence that seabed mining would harm fisheries, wildlife, and communities.