Posted on April 2, 2025
A NOAA-funded project on the Upper Coonamessett River in Falmouth, Massachusetts, will remove fish passage barriers and restore wetlands on a former cranberry bog. This work complements earlier NOAA-funded work on the lower part of the river.
Each autumn, a familiar sight returns to Cape Cod—acres of ruby red cranberries. They rise to the surface of flooded bogs where workers harvest them by machine or hand. However, this 200-year-old tradition is in decline due to changing weather patterns and out-of-state competition.
Today, thousands of cranberry bogs lay abandoned in Southeastern Massachusetts. Ditches and dams built to control stream flows and other habitat alterations prevent the land from returning to healthy wetland and stream habitat.
For nearly 20 years, NOAA and its partners have worked to restore former cranberry bogs to create biodiverse wetlands. These restored habitats allow migratory fish like river herring to reach their spawning grounds. This January, construction crews broke ground on a new project on Falmouth’s Upper Coonamessett River to restore a former commercial cranberry bog. NOAA’s Office of Habitat Conservation is funding this work with $1.7 million through the Infrastructure Investment and Jobs Act.
The project will:
- Remove seven barriers to fish passage
- Restore 4,000 linear feet of stream channel
- Fill in dead-end drainage ditches that entrap river herring and American eel
- Remove excess sand layers and re-expose underlying natural peat soils to allow nearly 10 acres of native wetland plants to re-establish
- Improve water quality by eliminating dead-end ditches where waters warm and lose oxygen
- Create a wheelchair-accessible stone-dust trail and boardwalk with interpretative educational signage
Project partners, including NOAA’s Jim Turek (second from the left), celebrate the start of construction at the Upper Coonamessett project site in January 2025.
NOAA and more than 30 other partners support the restoration of the Coonamessett. Major partners include:
- Town of Falmouth
- Coonamessett River Trust
- 300 Committee Land Trust
- Massachusetts Division of Ecological Restoration
- U.S. Fish and Wildlife Service
- Mass Audubon
Work on the Upper Coonamessett River builds off the success of previous NOAA-funded restoration on the lower Coonamessett River. Completed in 2020, the project opened 2.2 miles of river to fish passage, restored 4,600 feet of the river channel, and rebuilt 56 acres of wetland habitat. More than 200 species of native wetland plants returned to a landscape once dominated by a monoculture of cranberries. Native brook trout, which almost disappeared from southeastern Massachusetts rivers due to cranberry bogs, were successfully reintroduced. River herring and American eel now pass freely through this restored preserve.
A River Degraded by Industrialization and Farming
While the spring-fed Coonamessett looks more like a small creek than a river, it once hosted one of Cape Cod’s largest runs of river herring. These small silver fish are a critical part of freshwater and ocean food webs, feeding many larger species like flounder and cod. River herring and other migratory fish, like American eel, also sustained generations of indigenous Wampanoag Peoples. The name Coonamessett means “place of the long fish” in Wampanoag, in reference to the American eel.
River herring.
Historically, more than 1 million river herring returned to the Coonamessett to spawn but now only about 70,000 make the annual journey. Factors like changing ocean conditions, fishery bycatch, and increased natural predation by seals and many other predators have reduced the river herring population. Industrialization of the river and wetlands hindered their ability to reproduce.
Beginning in the 1700s, grist mills built on the river made it more difficult for fish to reach their spawning grounds. In the early 1900s, cranberry farming began, further altering the river and its wetlands. Poorly designed culverts—metal pipes redirecting water flows under roads and pathways—prevented fish from passing through the stream and bogs.
Naturally narrow and sinuous like a snake, the river was straightened and widened. This degraded the habitat and native wetland plants. Drainage ditches and other water control structures cut through and fragmented the marshland. River herring overheated and died in the warm, low-oxygen dead-end channels. The shallow water also made them easy pickings for osprey, gulls, and other predators. Over the years, layers of sand were dumped on the natural wetland peat to promote cranberry growth. Unfortunately, this kept most native plants from germinating.
Restoring the Landscape
Today, local contractors are working to undo the damage on five cranberry bogs along the upper river. They’re removing seven old culverts, artificial earthen embankments, and invasive plants. They are filling in ditches to restore native wetlands, and making the main channel narrower and more structurally complex by adding large pieces of wood.
“The project is designed to develop a mosaic of river and wetland habitats,” says Dr. Betsy Gladfelter, the Coonamessett River Restoration Project Coordinator for the Town of Falmouth. “The river itself is made longer, but it’s also made so that there are areas where it flows fast, and areas where it goes more slowly, and areas that are deep and shallow.”
Installation of a box culvert that allows fish passage on the lower Coonamessett project. Work on the Upper Bog restoration in the background
A greater diversity of plant and animal species will inhabit the varying habitat types. Contractors will remove sand, and turn the soil over to expose the underlying peat. Peat acts as a natural plant seed bank, storing native seeds that may have been dispersed more than a century or two ago. When the conditions are right, the seeds will germinate despite years of dormancy.
Restored wetland and the meandering river, after the project on the lower Coonamessett was completed.
“As we saw with the previous work on the Coonamessett, you’ll be amazed by the transformation that occurs when the peat is exposed,” says NOAA Restoration Ecologist Jim Turek, who has been involved in the project since 2006. “In a matter of months, we expect it to go from a highly disturbed site to a very green, natural wetland system.”
The peat and more natural stream and wetland habitat will help filter out pollutants and reduce instream temperatures. This will benefit fish and other aquatic organisms, as well as the townspeople of Falmouth, who use the aquifer underlying the river as a water source.
After the project is completed in July 2025, river herring will be able to reach upstream spawning areas, including the 158-acre Coonamessett Pond. Volunteers with the Coonamessett River Trust will be counting fish during the annual herring run in April. River herring spend 3 to 5 years at sea before returning to rivers to spawn. Fish born in the river after the completion of the work on the lower Coonamessett should be returning this year.
New Recreational Opportunities
Accessible boardwalks and bridges built across the Upper Coonamessett project will connect with pathways and two boardwalks along the lower river. Visitors can explore 10 miles of trails along the restored river and wetlands, and learn more about the area’s fascinating history and ecology through interpretive signage.
Betsy Gladfelter (left) and Sunny Snyder walk along a boardwalk on the lower Coonamessett River.
“We’re adding additional signage recognizing the Wampanoag Tribal culture and their contributions towards protecting river herring,” says Gladfelter. In 2023, the Mashpee Wampanoag Native Environmental Ambassadors youth group presented a “Declaration of the Rights of Herring” to their Tribal Council. It proclaimed that river herring have “the right to migrate freely, procreate abundantly, and safely make their journey back to sea.”
“This inspired the Town of Falmouth to adopt a resolution that recognizes the rights of nature,” says Gladfelter. The rights of nature give ecosystems legal standing and empower local governments to protect and restore them.
“NOAA is proud to support this work and continue our partnership with the Town of Falmouth,” says OHC Director Carrie Robinson. “The project’s long-standing partners provided the collaboration, knowledge, and commitment needed to restore the land, ensuring that natural habitats can thrive for our fisheries species and other wildlife.”
Mass Audubon is using an additional $2.8 million in NOAA funding to restore 20 acres of former cranberry bogs at nearby Marks Cove in Wareham, Massachusetts. They are working with partners to prioritize and launch five similar projects in the region. Restoring wetlands at Marks Cove is critical for allowing saltwater marsh migration. As sea levels rise, the salt water will have space to move inland, preventing the flooding of nearby infrastructure. Construction is expected to begin in 2026. Mass Audubon will also support an early-career mentoring program led by the Native Land Conservancy for Wampanoag and other Indigenous people.
“The Marks Cove Restoration Project is a wonderful example of partners protecting the future of our salt marshes, with vital support from NOAA,” said Alex Hackman, Director of Ecological Restoration at Mass Audubon. “Collaboratively identifying the best sites for marsh migration allows us to transition unproductive farmland into future salt marshes.”
Additional partners for the marsh migration work include:
