When Karen McGlathery used to swim in the coastal bays off Virginia’s Eastern Shore, the water would quickly turn cloudy and brown as sediment swirled around her. Now, 25 years later, for as far as she can swim, the water remains clear. The sediment is anchored in place by lush green seagrass meadows, teeming with fish, scallops, and crustaceans. “It’s like this beautiful underwater prairie,” says McGlathery. “It’s just gorgeous.” 

McGlathery, an environmental sciences professor at the University of Virginia, is part of a team running the largest seagrass restoration project in the world in these coastal bays—and one of the most successful. The two-decade-long project is a “blueprint for restoring and maintaining healthy ecosystems,” according to a 2020 research paper, and proof that marine habitats can be brought back to life in a way that’s self-sustaining. 

In the 1930s, a wasting disease swept along the U.S. east coast, wiping out huge swaths of eelgrass. Where Virginia’s coastal bays used to be carpeted in this species of seagrass, […]