Issue Protecting seafloor integrity from trawling and mining

Summary

The seafloor is at once a habitat, a major carbon store and a biogeochemical processor that regulates nutrient cycling. Continental shelf sediments hold about 360 billion tonnes of organic carbon in their top meter, 75 to 90 percent of marine carbon burial, yet trawling, mining, anchoring and shipping can stir them up and let stored carbon break down. In frequently trawled areas, complex seabeds once rich in life are reduced to "marine deserts" of sand or mud. Nascent deep-sea mining threatens untouched regions, and experiments show even limited disturbance there can suppress ecosystem function for decades or erase it permanently. Because many disturbed seafloor systems may not recover on human timescales, the report calls precautionary protection urgent. It recommends limiting disturbance of carbon-rich shelves, keeping slow-recovering deep-sea habitats off-limits to destructive activities and making marine spatial planning account for carbon and nutrient functions.