Eelgrass, pictured here in Brunswick’s Maquoit Bay, mitigates erosion, removes greenhouse gases from its environment, and acts as a spawning habitat for shellfish. Photo courtesy of Dan Devereaux

In hopes of improving the health of Maine’s marine ecosystem, a new bill proposes mapping out its locations.

Though it may look unassuming, underwater meadows of eelgrass provide a habitat for shellfish to spawn, mitigate erosion and combat climate change, according to the Maine Department of Marine Resources.

Rep. Jay McCreight, D-Harpswell, sponsored a bill that would lay the groundwork for the state to resume regularly mapping eelgrass, a marine plant known for helping to maintain the health of Maine’s coast.

Mapping eelgrass, usually done through aerial photography, would help “determine if Maine is meeting its water quality standards under the Clean Water Act” and track the health of Maine’s marine life, according to a statement from McCreight released Monday.

“Mapping eelgrass would go a long way toward understanding and improving the health of Maine’s coastline, a need that has only increased with the acceleration of climate change,” McCreight wrote. “Eelgrass is a linchpin species that is connected to nearly all coastal life, and managing it well will yield major benefits for our environment and our marine economy.”

Eelgrass mapping was done in the 1990s and 2000s but ended when staff was diverted to other projects, according to McCreight’s statement.


According to the bill, the Maine Department of Marine Resources would conduct the mapping and make the information and updated maps publicly available on its website. Different sections of the coast would be studied each year, with each part of the coast being studied every five years.

It’s important to regularly track the health of eelgrass beds because they can change quickly, pointing to problems under the water’s surface, said Jeremy Gabrielson, conservation planner for the Maine Coast Heritage Trust, a nonprofit land conservation organization.

“One of the things we know about eelgrass is it’s a dynamic system,” said Gabrielson. “The coverage can change significantly year-to-year. If all we’re doing is looking at the extent of eelgrass coverage every 15 years, we’re going to miss a lot of information about how the resource is changing each year.”

Gabrielson said Mainers should be concerned with protecting the fragile resource because it absorbs greenhouse gasses that contribute to global warming, such as carbon dioxide from the air and nitrogen and phosphorus from the water, and store them in its roots as it grows.

“It also protects the silt at the bottom of the ocean from moving, preventing erosion” said Gabrielson.“When eelgrass is gone, that sand and silt gets kicked up by waves and other activity.”

Aside from its environmental benefits, Brunswick Coastal Resources Manager Dan Devereaux said Mainers can see the value of maintaining and protecting eelgrass because of its direct link to shellfish populations.


“Eelgrass provides a good habitat for baby lobster and spawning grounds for shellfish,” he said. “Whenever we see the eelgrass go, we also see the shellfish production lessen. Obviously, that hits people’s pocketbooks.”

According to a 2019 commercial landings report from the Maine Department of Marine Resources, lobster makes up 76 percent of Maine’s nearly $674 million seafood industry.

Devereaux said he’d be in favor of McCreight’s bill because it would help Brunswick track the regrowth of its eelgrass meadows after about 90% of them were “decimated” in 2012 by the “explosion” of green crabs. Green crabs are an invasive species that eat baby lobster and soft-shelled clams and destroys eelgrass as it hunts for food.

Green crabs are native to Western Europe and first came to the U.S. as stowaways in the ballasts of ships. According to a 2015 report from the Governor’s Task Force on the Invasive European Green Crab, the species was first seen on the Maine coast in 1905.

The green crab population grew exponentially in the 1950s, subsided, then reappeared with a vengeance in 2012 and have been an issue for fishermen ever since. During its three-year life cycle, a single green crab can leave behind 370,000 offspring.

“Since 2012, we’ve noticed an uptick in progression of eelgrass growing back to where it was before then,” he said. “We’re probably back up to 65% coverage. It’s coming back really well, which is incredible to me.”

Devereaux said Brunswick uses drones to monitor its over 60 miles of shallow coastline, but doesn’t regularly map eelgrass within Maquoit and Middle bays. However, he said he’d welcome the ability to have publicly accessible data, gathered by scientists, on eelgrass because “the better we can monitor that, the better off we are.”

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