June 10, 2025 — The deep oceans have crossed a crucial boundary that threatens their ability to provide the surface with food and oxygen, a new study finds.
Nearly two-thirds of the ocean below 200 meters, or 656 feet, as well as nearly half of that above, have breached “safe” levels of acidity, according to findings published on Monday in Global Change Biology.
The fall in ocean pH is “a ticking time bomb for marine ecosystems and coastal economies,” Steve Widdicombe, director of science at the United Kingdom’s Plymouth Marine Laboratory (PML), said in a statement.
The study was funded in part by the National Oceanographic and Atmospheric Administration (NOAA), a federal agency that has been targeted for steep cuts by the Trump White House, in large part because of its role in investigating climate change.
Some of the biggest changes in deep water are happening off the coast of western North America, home to extensive crab and salmon fisheries, the study found.