Deep-sea mining is the extraction of minerals from the seabed in the deep ocean. Most of the interest is in what are known as polymetallic nodules, which are potato-sized mineral deposits that have built up in layers over thousands of years. Found miles below the ocean’s surface, these nodules contain valuable metals used in batteries and electronics, but mining them could harm fragile and largely unexplored deep-sea ecosystems.
According to a new study by researchers from the University of Hawaii at Mānoa, the habitats of 30 species of sharks, rays, and chimaeras (also known as ghost sharks) overlap with areas proposed for deep-sea mining. The study, which was recently published in the journal Current Biology, warns that nearly two-thirds of these species are already at risk of extinction due to human activities. Mining the ocean floor could increase their extinction risk by disturbing seafloor habitats and releasing large plumes of sediment into the water.
Researchers overlaid global maps of shark, ray, and chimaera habitats with areas allocated for deep-sea mining by the International Seabed Authority. The researchers found that 30 species could be exposed to sediment plumes and 25 could also face direct seafloor disturbance.
Deep-sea mining is expected to occur in the Clarion-Clipperton Zone, a vast region of the Pacific Ocean about halfway between Mexico and Hawaii.
The researchers recommend improving conservation by establishing monitoring programs, incorporating species into environmental impact assessments, and creating marine protected areas to reduce the impacts of deep-sea mining.
