Eelgrass (Zostera marina) is a flowering plant that grows in dense thickets in the shallows of inlets, bays, and estuaries. Underwater, it looks like a wild meadow of graceful grasses swaying with the tides.
Eelgrass meadows have been compared to rainforests and coral reefs for many reasons – they are dynamic ecosystems that play an essential role in the health of our oceans and planet. Eelgrass beds provide vital habitat and nursery grounds for fish, lobster, shellfish, and many other marine species, benefiting Maine’s fishing industries. In this era of climate change, seagrasses around the world, including Maine’s eelgrasses, are being studied as sources of carbon capture and are known for buffering ocean acidification. Plus, they reduce wave action, stabilize sediment, and prevent erosion – something we are more keenly aware of since the destruction from this past winter’s major storms.
These superheroes of the ocean have been quietly keeping our oceans healthy, our fisheries abundant, and our coastlines intact – yet eelgrass meadows are disappearing at an alarming rate.
In just four years, from 2018 to 2022, Casco Bay’s eelgrass habitat diminished by 54 percent. Why is this happening? Warming water temperatures? Nitrogen pollution? Green crabs? We see indications all of these factors could be at work. But we like to make science-informed decisions, so we are getting in the water, gathering data, and collaborating with others to investigate.
Friends of Casco Bay is part of a two-year eelgrass pilot project, first to monitor and study why eelgrass meadows are shrinking, and second to test restoration solutions. Casco Bay Estuary Partnership is managing the project; our other collaborators include Manomet, Maine Department of Environmental Protection, and Team Zostera. This summer, Friends of Casco Bay scientists will visit seagrass sites at Broad Cove in Cumberland and Mackworth Island to collect data on water temperature, water quality, nutrient concentrations, and light availability; Manomet will monitor the green crabs; and Team Zostera divers will study the seed germination cycle. Next year, the project team will test seeding eelgrass and, hopefully, bring us one step closer to restoring Casco Bay’s seagrass habitats.
Water Reporter Spotlight: Susan Woodman and the Eelgrass Meadows at Willard Beach
Volunteer Water Reporter Susan Woodman began photographing the eelgrass meadows at Willard Beach a year ago. She times her visits for the lowest tides in hopes of seeing the eelgrass. “It’s become like my garden. It’s really quite pretty, like a field of very green grass.” She has noticed some changes since her last visit – January’s storms eroded large chunks of the eelgrass beds, leaving behind pockets of bare sandy pools.
Susan was heartened to hear news of our pilot project because she recognizes eelgrass as an indicator of a healthy ecosystem as well as an important carbon sink. “Climate change is something I worry about. How can you not?” She enjoys volunteering as a Water Reporter with Friends of Casco Bay. “It feels as though you’re contributing something and looking after the beach.”
Read more about Water Reporter Susan Woodman and the story of Casco Bay’s eelgrass.
More Eelgrass Stories
Tracking Eelgrass: The Seagrass Snapshot
Tracking eelgrass and other changes around the Bay
