Washington, D.C. — A new global assessment has found that ocean acidification is significantly altering marine ecosystems, compromising 40% of the global surface ocean and 60% of subsurface waters to a depth of 656 feet.
According to the National Oceanic and Atmospheric Administration (NOAA), the study highlights a sharp decline in the aragonite saturation state—a key measure for shell-building marine life such as oysters, crabs, corals, and mussels. The findings were based on advanced data modeling and an extensive dataset of global ocean carbon observations.
Scientists from NOAA’s Pacific Marine Environmental Laboratory, the Cooperative Institute for Marine Ecosystem and Resources Studies, Oregon State University, and other international partners participated in the study. The analysis revealed that the aragonite saturation state has dropped by 20% in surface waters and 60% in subsurface zones since pre-industrial times, critically shrinking habitable zones for key calcifying species.
The greatest impacts were observed in polar regions and along the West Coast of North America, from Canada to Mexico. NOAA researchers also noted effects in tropical and subtropical reefs, where coral skeleton growth has slowed, as well as in cold-water fisheries like those for red king crab.
The implications of the study are wide-ranging, potentially disrupting food webs, commercial fisheries, and coastal economies. NOAA says continued monitoring and mitigation efforts are essential to protect marine ecosystems and dependent communities.
