World’s Largest Seagrass Project Proves “You Can Actually Restore the Oceans”

World’s Largest Seagrass Project Proves “You Can Actually Restore the Oceans”

A “game changing” 20-year effort suggests that even severely depleted marine ecosystems can be brought back to life.

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, suddenly they were barren. “Everyone thought that eelgrass could never, ever get back,” says Robert Orth, who was a marine biologist at the Virginia Institute of Marine Sciences (VIMS) until his retirement this year, “but nobody really started doing any kind of experiments to see.” 

That changed in the late 1990s with the discovery of some small patches of seagrass in the bay, the existence of which proved that conditions could once again support the plants. 

Orth started with small-scale experiments, digging up adult seagrass from other areas and transplanting it into the bay. The seagrass survived, but the process wasn’t scalable — restoring thousands of acres through transplanting would have been a huge logistical challenge. So, says Orth, “We said, well, why not try to launch a restoration program using seeds?”

In 2001, he started an effort to physically rebuild the ocean ecosystem, seed by seed. From a moving boat, he and his team scattered seeds across four bays: South, Cobb, Spider Crab and Hog Island. The seeds survived, growing into plants which, in turn, produced their own seeds. “Nature kind of took over,” says Orth. “While we continue to put seeds in areas that don’t have eelgrass, nature has been spreading eelgrass naturally.” 

Over the last 20 years, supported by an army of volunteers, the project team has sown nearly 75 million seeds. Around 9,000 acres of coastal bays are now blanketed with eelgrass, which has improved water quality, increased marine biodiversity and helped mitigate climate change by capturing and storing carbon.

The project is “game changing,” says Carlos Duarte, a seagrass expert and marine science professor at King Abdullah University of Science and Technology in Saudi Arabia, both in its sheer scale and the raft of long-term data it provides on the climate benefits of seagrass. 

A decade ago, Duarte and Orth nicknamed seagrass “the ugly duckling” of environmental conservation, because so few cared about it. That’s slowly changing as the huge benefits it offers are recognized. Despite covering less than 0.2 percent of the ocean, it is responsible for about 10 percent of the ocean’s ability to store carbon. It provides a vital habitat for marine life, boosts commercial fishing, helps purify water, protects coastlines and even traps and stores microplastics

Full story by Laura Paddison at Reasons To Be Cheerful