Seagrass Snapshot Map
During the 2025 Seagrass Snapshot, 45 Water Reporters braved extreme low tides in April, May, and June to document eelgrass. With the Bay’s eelgrass beds fully exposed, volunteers explored mudflats and shallow waters to document where eelgrass thrives, and where it is missing. This was our third snapshot since September 2024, and each one is helping scientists piece together the story of Casco Bay’s changing eelgrass habitats.
Below is a map of all the photos submitted by Water Reporters during the Seagrass Snapshot. We recommend viewing it on an iPad, desktop computer, or laptop. The map is interactive—feel free to explore!
Volunteer Water Reporters Catherine Tarpy, Rick Frantz, John Contas, and Harry Nelson, uploaded these images of eelgrass to our Water Reporter App.
Read our story about the 2025 Seagrass Snapshot.
How to use the map:
- Each dot is clickable: Click a dot to see information about the site. The photo will be at the bottom of the popup and may take a moment to load. Scroll down if needed.
- View larger photos: Clicking the photo will open a larger version in a new tab.
- Multiple reports in one dot: If a dot contains more than one report, use the arrows (< >) at the bottom left of the popup to see each report.
- Exit a popup: Click the “x” at the top right to close the popup and explore another site.
- Zoom in/out: Scroll or use the “+” and “-” buttons in the top left corner of the map.
- Click and drag: Navigate around the map by clicking and dragging to move the view.
- Return to default mode: Click the home icon in the top left corner of the map to reset the view.
- Search locations: Use the search function in the top right corner of the map to explore specific locations.
- Explore DEP-mapped eelgrass beds: The dark green and light green patches represent eelgrass beds mapped by the DEP. You can click these areas for more data.
- Explore eelgrass data from different snapshots: There is a square icon on the bottom right of the map. If you click that, you can select or deselect data from different months.
- Explore presence and absence: On the left toolbar click “Yes”, “No”, or “Unsure” to view different data points.
What the colors mean:
- Green circles: Eelgrass was visible.
- Orange circles: No eelgrass was seen.
- Yellow circles: Inconclusive. It was unclear whether eelgrass was present.
Why Photograph Eelgrass?
The Maine Department of Environmental Protection (DEP) last mapped eelgrass beds in Casco Bay in 2022, revealing a 54% decline since 2018. This loss spurred action from government agencies, scientists, advocates, and the community.
Friends of Casco Bay is in year one of a two-year pilot project, led by the Casco Bay Estuary Partnership, to study eelgrass. We’re focusing on three key beds, examining water quality, green crabs, and other factors to understand why eelgrass is disappearing and how we can restore it. Water Reporters are helping this effort by providing on-the-ground documentation of eelgrass, giving us an up-to-date snapshot of the health of these critical ecosystems.
Learn more about eelgrass.
Thank you to our Water Reporter supporters for making these events possible, including our members and donors, Allagash Brewing Company, L.L.Bean, Morton-Kelly Charitable Trust, WEX, Inc., and Sprague Energy.