Curse or Cure? [mining - marine

Abstract

Mining clumps of metal at the bottom of the ocean could address critical shortages, but the damage to the seabed may deter attempts to make this process mainstream. Last april, engineers on a ship in the middle of the Pacific Ocean held their breath as a 25-tonne mining tractor lay stranded on the silty ocean floor, more than 4km below the surface. On the 13th and final trial dive of a world-first experiment, a robot had broken free of its tether and lay in some of the darkest waters on Earth. A remote underwater vehicle helped engineers regain control within days as independent scientists watched on. But the incident galvanised public resistance to mining the deep seas. Having lain undisturbed for millennia, the murky depths of the Pacific will be busy in the coming years, as prospectors put their deep-sea mining machines - which some have compared to giant vacuum cleaners - through their paces. GSR, a subsidiary of the DEME Group, plans to test a new, larger prototype in 2024, and Canadian firm The Metals Company plans a pilot test of its entire mining system later this year. In late autumn, another independent research ship will travel the four days from San Diego, California, to the north-east Pacific - the Clarion Clipperton Zone (CCZ) - to learn more about the biology and geology of the deep, where most species are new to science. Since 2015, some euro30m of research funding has gone towards discovering the potential impact of deep-sea mining, with two major studies in the bag. Can we mine the deep seas - where a treasure trove of rare earth elements has accumulated over millions of years - without further trashing the ocean? And critically, how can such remote operations be monitored successfully?