While humans have undoubtedly contributed to the degradation of marine ecosystems, we are also proving capable of restoring them. Just beyond the salt marshes of Virginia’s Eastern Shore, researchers and volunteers spread more than 70 million eelgrass seeds as part of a 20-plus-years project.
The eelgrass seeds initially covered just over 200 hectares but have now grown to cover an incredible 3,612 hectares—and counting. By comparison, the largest such project in Australia aims to restore 10 hectares of seagrass.
Within the first 10 years of restoration, the scientists witnessed an ecosystem rebounding rapidly across almost every indicator of ecosystem health — seagrass coverage, water quality, carbon and nitrogen storage, and invertebrate and fish biomass.
One interesting takeaway from the restoration project was that storage capacity increases for seagrass meadows the more they mature. They found that meadows in place for nine or more years stored, on average, 1.3 times more carbon and 2.2 times more nitrogen than younger plots. Within 20 years, the restored plots were accumulating carbon and nitrogen at rates similar to what natural, undisturbed seagrass beds in the same location would have stored.
Another key finding from the project was that seagrass meadows are remarkably resilient to climate change. When a sudden marine heatwave killed off a portion of the seagrass, it took just three years for the meadow to fully recover its plant density.
“It surprised us how resilient these seagrass meadows were,” says Karen McGlathery, a coastal ecologist at the University of Virginia in Charlottesville. She believes the team’s work is more than just a great case study in restoration. It “offers a blueprint for restoring and maintaining healthy seagrass ecosystems” that others can adapt elsewhere in the world, she says.
At a time where capturing carbon has never been of more importance, seagrass restoration projects such as this one are exactly what the world needs.