A guest blog from the Deep Sea Conservation Coalition / Matthew Gianni & Sian Owen
The deep seabed was once believed to be a lifeless realm of mud and rock. This barren image changed dramatically, however, as technology to explore the hidden depths improved. In 2016, the United Nations First World Ocean Assessment described the deep sea as a ‘vast realm which constitutes the largest source of species and ecosystem diversity on Earth, supporting ecosystem processes necessary for our planet’s natural systems to function.’
Scientists are just beginning to discover the full richness of deep-sea life. Yet already a number of companies and countries are exploring the deep ocean for minerals and developing the technology to mine some of the last untouched areas of our planet. Much of the commercial interest is focused on deposits of cobalt, copper, nickel and manganese found in nodules that lie on the deep seabed in an area known as the Clarion-Clipperton Fracture Zone (CCZ).
Imagine what mining would look like. To collect commercially viable quantities of the metals in the CCZ, a single 30-year mining operation in the area would churn up an estimated 9,000-10,000 km2 of seabed – an area the size of Lebanon. Sediment plumes generated by the activity would fill the surrounding waters and be carried away by deep currents, reaching ecosystems far beyond the mining site. The noise and light of the subsea machinery could cause harm to marine organisms adapted to the quiet darkness, while large quantities of wastewater with residual ore and sediment would be discharged back into the sea.