Before revision: It seems that polymetallic nodules in the region, the target of much deep-sea mining, are crucial for fostering a high level of biodiversity on the sea floor ; they exist at overlapping depths with the species thought to be dependent on them, and in their absence, biomass decreases .
After revision: It seems that polymetallic nodules in the region, the target of much deep-sea mining, are crucial for fostering a high level of biodiversity on the sea floor .