There is a place in the ocean where nothing lived for thirty years. The scientists called it a hypoxic zone — a region so depleted of oxygen that fish, coral, and invertebrates could not survive. It formed from agricultural runoff, accumulated year after year, until the seafloor became a desert of bare sediment stretching for miles. Then, slowly, they began to fix it upstream. Nitrogen inputs dropped. Oxygen returned. And in 2021, a research team dove into what had been the dead zone and foun
