A Friend to Eelgrass: A Water Reporter Helps Look After a Vital Ecosystem in Peril • Friends of Casco Bay

Susan Woodman is eager to get to the beach during the lowest of low tides to glimpse her favorite eelgrass beds. It’s 6:47 a.m. and the tide is still way out. She can spot it in the distance. Susan began photographing the eelgrass meadows at Willard Beach about a year ago as a volunteer Water Reporter for Friends of Casco Bay. “It’s become like my garden,” she says. “It’s really quite pretty, like a field of very green grass.”

view of a relatively healthy eelgrass bed underwater — A healthy bed of eelgrass growing in clean, clear water. Photo credit: Steve Karpiak.

Eelgrass (Zostera marina) is a flowering marine plant that grows in shallow, coastal waters of Casco Bay and up and down the Atlantic seaboard. To the folks who named it, its long leaves looked like eels swimming in the water. For Casco Baykeeper Ivy Frignoca, it conjures up images of ballerinas swaying together with the waves.

Eelgrass habitats are vital ecosystems.

Beyond its lovely green locks, eelgrass habitats are dynamic ecosystems that play an essential role in the health of our fisheries, oceans, and planet. The eggs and larvae of bivalves, especially blue mussels and clams, get their start in these natural nurseries. Young fish, such as herring, striped bass, shrimp, and lobster, find safe refuge amongst the tall green eelgrasses. Its rooted blades also hold sediment in place, buffering the shoreline from storm damage and trapping carbon and excess nitrogen. Because eelgrass needs clean, clear water to thrive, it is an important indicator of water quality – meaning, if you’ve got healthy eelgrass, you’ve got healthy water for fish and shellfish.

These superheroes seagrasses have been quietly keeping our oceans healthy, our fisheries abundant, and our coastlines intact.

At Willard Beach, Susan notices chunks of the eelgrass meadows are missing. She points to a series of scattered sections that had once been an unbroken expanse, now divided into patches like an archipelago of islands. Susan is certain the January storms that ravaged so much of Maine’s coast also caused significant damage to the eelgrasses at Willard Beach.

Something is happening to Casco Bay’s eelgrass. This vital ecosystem is in peril.

In 2018, Casco Bay’s eelgrass was mapped by Maine Department of Environmental Protection, revealing an extensive network of eelgrass beds. But four years later, when mapped again in 2022, 54% of all eelgrass beds in Casco Bay had disappeared – a huge loss in a short amount of time. Ivy notes, “We know eelgrass comes and goes in cycles. But a loss this catastrophic signals that something more is going on.”

These two maps show the decline of eelgrass in Casco Bay over just four years. In 2018, Casco Bay’s eelgrass was mapped by Maine Department of Environmental Protection, revealing an extensive network of eelgrass beds. But four years later, when mapped again in 2022, 54% of all eelgrass beds in Casco Bay had disappeared – a huge loss in a short amount of time. — Maine’s Department of Environmental Protection eelgrass mapping has been invaluable and revealed a need for more frequent and regular mapping. Maine DEP had temporary funding for the 2018 and 2022 eelgrass mapping. Soon afterward, Friends of Casco Bay helped to pass a bill that now funds the mapping of eelgrass across the entire Maine coast in five year cycles.

Underwater view of an unhealthy eelgrass bed. — Without clear sunlight reaching the leaves, eelgrass struggles to thrive in cloudy waters and places where excess nitrogen feeds blooms of algae and phytoplankton. Lawn fertilizers, wastewater, stormwater, and air pollution all contribute to nitrogen pollution. Photo credit Sonny McAplin.

What’s destroying the eelgrasses of Casco Bay? The problems offer us clues…and hope for the future.

Before attempting to restore eelgrass beds, we want to understand why they are failing. Without addressing the causes of failure, planting new eelgrass will not be successful.

Friends of Casco Bay has joined a two-year collaborative pilot project. Over the summers of 2024 and 2025, Casco Bay Estuary Partnership, Manomet, Maine Department of Environmental Protection, Team Zostera, and the scientists at Friends of Casco Bay will work together on a project to study factors putting eelgrass at risk and begin testing restoration solutions.

A team of many talents.

Friends of Casco Bay scientists, Mike Doan and Heather Kenyon, will do what they do best – collect data on water temperature, water quality, nutrient concentrations, and light availability – to examine issues such as nitrogen loading and warming waters. While our partner organization Manomet will monitor the green crabs. Team Zostera divers will get us ready for phase two by studying the seed germination cycle of eelgrass. We are asking our volunteer Water Reporters to work with us to document eelgrass washed up on shore for signs of nutrient impairment, green crab damage, and other harm. Casco Bay Estuary Partnership is managing the project.

Next year, the project team will test methods for seeding eelgrass using seeds collected by Team Zostera. In coming years, Maine may need to consider seeding more heat-resistant varieties of eelgrass from regions to the south.

The hope behind the pilot project’s efforts is to start moving on solutions and restoration before it’s too late.

Map of the two eelgrass monitoring sites in Casco Bay: Broad Cove in Cumberland and off Mackworth Island — The pilot project will monitor two eelgrass beds in 2024 and 2025: one off Mackworth Island and a second site in Cumberland’s Broad Cove.

a closeup image f a scallop in one of Virginia's thriving eelgrass habitats — Eelgrass restoration in Casco Bay might be possible. An effort to restore eelgrass beds along Virginia’s Eastern Shore began in 2000 with a few seeds from the York River. Today, these seagrass meadows have grown to 6,195 acres—providing a home for an estimated 200,000 bay scallops reared in a hatchery. Image credit: Bob Orth, Virginia Institute of Marine Science.

Everyone can be part of the solution for Casco Bay’s eelgrass habitats.

To be a friend to the amazing eelgrasses of Casco Bay, we recommend these actions:

Become a BayScaper by limiting your use of fertilizers, or better yet, opting out of fertilizing your lawn and garden to reduce excess nitrogen entering the watershed (this applies to all locations in the watershed, from Bethel to the beach). If your property is next to water, plant a buffer of native plants to reduce nitrogen runoff.
Walk carefully at low tide to avoid stepping on fragile eelgrass beds.
Boat smart in shallow waters. Propellers, anchors, and mooring chains can all damage eelgrass.
Install high, narrow ramps and docks to avoid shading eelgrass beds.
Use sustainable harvesting practices to prevent damage from aquaculture moorings, lobster traps, and shellfish/worming rakes.

Susan Woodman holds her phone, ready to take photos of the eelgrass at Willard Beach. — Volunteer Susan Woodman was heartened to hear news of our pilot project because she recognizes eelgrass as an indicator of a healthy ecosystem, as well as a potential carbon sink. “Climate change is something I worry about. How can you not?” Eelgrass is increasingly being studied as a nature-based solution to addressing the climate crisis.

You might also consider becoming a Water Reporter, like Susan.

Before the tide inches up over the Willard Beach eelgrass meadows, Susan bends her body over to get a closer look, holding a delicate green blade like the hand of a friend. She notes the length of the blades, the interesting bumps and holes in the sand, and wonders what else is living amongst the eelgrass. Susan enjoys volunteering as a Water Reporter with Friends of Casco Bay. “It feels as though you’re contributing something and looking after the beach.”

Water Reporters make a difference.

As a Water Reporter, Susan is providing an important service to Casco Bay. By photographing evidence of algal blooms, sea level rise, pollution, eelgrass, wildlife sightings, and other notable observations with an app on their smartphones, Water Reporters help us see how the Bay is changing over time. This helps us learn how our communities can make better choices. If you are interested in becoming a Water Reporter, sign up here.

While the future of eelgrass in Casco Bay is indeed in peril, Casco Baykeeper Ivy Frignoca reminds us, “We do this work, because we’re hopeful.”

Correction: A previous version of this story stated that Maine DEP’s eelgrass mapping in 2022 was funded due to the passing of legislation that Friends of Casco Bay helped to pass. Maine DEP used temporary funds to do the mapping work for both 2018 and 2022. The bill that Friends of Casco Bay helped to pass will fund the future mapping of eelgrass across the Maine coast in five year cycles.