Seagrass loss in Maine sounds like a quiet, local story, until you hear the numbers. Maine had more than 30,000 acres of seagrass meadows in the 1990s, habitat that supports fish nurseries, stabilizes coastlines, filters water, and stores carbon. But the state didn't start mapping that seagrass statewide until 2023, after decades of funding gaps left the data spotty. When better numbers finally came in, they showed steep, uneven losses: Casco Bay's islands lost more than half their seagrass between 2018 and 2022 alone, the mid-coast is down about 60% since 2005, Penobscot Bay about 35% since the mid-2000s, and the Acadia region more than half since the late 2000s. Downeast Maine still isn't fully mapped.

Here's what makes it a real mystery: scientists don't have one clean answer for why. Suspects include warming waters, worsening storms, invasive green crabs pushing north as water warms, coastal development runoff, and nutrient pollution feeding algal blooms that block sunlight and smother the meadows below. A Maine DEP biologist frames it bluntly: restoring an area without knowing why it died risks watching it die again, which is why the science and the restoration work are running side by side.

That restoration is already underway. Team Zostera, under the nonprofit COBALT, working with Bowdoin College's Schiller Coastal Studies Center and the Casco Bay Estuary Partnership, has pulled roughly 5,000 reproductive shoots from a healthy "mother meadow" between Haskell and Upper Flag Islands, with volunteers processing about 18,000 seed-bearing shoots in a single day. The University of Maine's Darling Marine Center is preparing a similar push in the Damariscotta River's Great Salt Bay. The Passamaquoddy and Peskotomuhkati Nation at Skutik bring their own thread to this story too, including Dwayne Tomah's work translating seagrass terms into the Passamaquoddy language. And there's already hope: some seagrass lost between 2018 and 2022 has started coming back on its own, helped by two years of cooler water. Catch Ocean Decoded Live for daily ocean news breakdowns like this, Monday to Thursday, 4:00–6:00 PM Eastern. Subscribe and hit the bell so you don't miss it.

Chapters:
0:00 Cold Open: Maine Lost Up to Half Its Seagrass, and No One Knows Exactly Why
3:54 The Numbers: 30,000 Acres Since the 1990s
6:01 The Suspects Behind the Loss
7:32 Meet Team Zostera: The Restoration Effort
11:43 Signs of Recovery Since 2018–2022

Takeaways:

Maine had more than 30,000 acres of seagrass in the 1990s, but statewide mapping didn't start until 2023, leaving decades of data gaps.

Casco Bay's islands lost more than half their seagrass between 2018 and 2022; mid-coast Maine is down about 60% since 2005, Penobscot Bay about 35% since the mid-2000s, and Acadia more than half since the late 2000s.

Scientists don't have one confirmed cause. Suspects include warming waters, worsening storms, invasive green crabs, coastal development runoff, and algal blooms.

A Maine DEP biologist says restoring seagrass without understanding why it died risks losing it again.

Team Zostera (COBALT), Bowdoin's Schiller Coastal Studies Center, and the Casco Bay Estuary Partnership pulled about 5,000 shoots from a healthy meadow near Haskell and Upper Flag Islands; volunteers processed roughly 18,000 seed-bearing shoots in a day.

The University of Maine's Darling Marine Center is preparing a similar restoration push in the Damariscotta River's Great Salt Bay.

The Passamaquoddy and Peskotomuhkati Nation at Skutik contribute language and cultural knowledge to the effort, including Dwayne Tomah's seagrass-terminology translation work.

Some lost seagrass has already begun recovering on its own since 2018–2022, aided by cooler water over the past two years, though near-shore beds are struggling more than outer-island beds.

#oceanconservation #MarineBiology #SaveOurOceans #ProtectTheOcean #OceanAwareness #BluePlanet #ConservationMatters #ScienceForChange #SustainableOceans

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