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The resource-hungry human race is eyeing a new frontier to extract precious metals: the unexplored depths of the ocean. With metals like nickel, cobalt, and copper lying unexploited beneath the sea, a new study looked into the harm that mining operations could cause to biodiversity at such depths. It also catalogued new species in the process.
The study, the largest of its kind, focused on an area of the Pacific Ocean between Hawaii and Mexico known as the Clarion-Clipperton zone. Marine biologists from the Deep-Sea Research Lab at the Natural History Museum – co-led by the University of Gothenburg and National Oceanography Center – analyzed the effects of mining machines on the ocean floor at a depth of 4,000 meters (13,000 feet) over the course of 160 days at sea and five years of data analysis.
They collected 4,350 animals of 788 species – many new to science – and observed a 37 percent reduction of macrofaunal animals (0.3mm to two cm in size) within the tracks that a remotely operated mining machine left on the seabed. Biodiversity in the tracks declined by 32 percent.
However, the impact of the sediment plume created by the machine that clouded the water in the area was less than expected. The area impacted within 400 meters of the machine showed no evidence of a reduction in the abundance of fauna, perhaps a data point that mining companies can quote to defend the environmental impact of future operations.
“Critical metals are needed for our green transition, and they are in short supply,” said Thomas Dahlgren, marine biologist at the University of Gothenburg and one of the leaders of the research project. “Several of these metals are found in large quantities on the deep-sea floor, but until now, no one has shown how they can be extracted or what environmental impact this would have.”
Most of the new animals observed were marine bristle worms, crustaceans, and mollusks. Researchers say the new species catalogued highlight how little is known about deep ocean environments.
Adrian Glover, senior author from the Natural History Museum of London, said that such research is important to understand what biodiversity loss would occur from mining machinery and operations.
“Currently, we have no idea, for the most part, of what lives in (these areas) and thus what the risk of biodiversity loss is in the potential mined regions,” Glover said.
