Trend Human reach extending across the global seafloor

Summary

The seafloor, on average nearly four kilometers deep, was long shielded from human disturbance by its remoteness, but technology is eroding that protection. Bottom trawling physically scrapes 1 to 2 percent of the global seabed each year, an area about half the size of Europe, concentrated on highly productive continental shelves. As shelf stocks are depleted and gear is adapted, trawling has moved steadily deeper and now reaches from the coast to roughly 4,000 m. Future deep-sea mining could add more than 200 square kilometers of new disturbance for each polymetallic nodule operation. Offshore wind, submarine cables, ports, shipping lanes and oil and gas platforms working below 3,000 m extend infrastructure across the seabed. The report points to the Baltic Sea, where no part of the seafloor remains unaltered by people, as a guide to what wider technological access may bring.