As dawn breaks over an estuary meandering past the forests and homes of Maryland’s unincorporated Beverly Beach, silver baitfish surface to gulp at oxygen-rich waters. New research shows how climate change is making the seemingly-peaceful ritual, which plays out in shallow waters the world over, more desperate and deadly.

With carbon dioxide pollution dissolving into water bodies, causing them to acidify, laboratory experiments showed silversides in the sprawling Chesapeake Bay will find it harder to breathe in low-oxygen conditions. The findings have sweeping global implications.