Thousands of young alewives school in a Maine pond.
Alewives in Maine Thousands of alewives school in a Maine pond. © Mark Berry/TNC

Stories in Maine

The Comeback: Restoring Free-Flowing Rivers in Maine

Completing five barrier removal projects in the Bagaduce River watershed is the latest example of partnerships that work to restore our rivers.

Maine is one of the last places along the East Coast where sea-run fish migrations can still be restored on a grand scale, and thanks to the efforts of The Nature Conservancy and our many partners and supporters, Maine’s rivers are experiencing an incredible comeback. Below, you’ll learn about some of our projects and how and why we do this critical work.

Bringing Back the Bagaduce

Two large yellow backhoes slowly descend an embankment along Route 15 in Sedgwick, Maine. Workers in safety vests and hard hats reach out for the chains hanging from buckets extending from the big machines. At Snow Brook, water that was held back by giant sandbags begins to flow under the road again. Only this time, there are no old bent metal pipes constricting the flow and no crumbling stone walls holding back the earth. A natural, rocky bottom carries the stream through a wide concrete opening, allowing the water, and the creatures that live in it, to pass without obstruction. Another road-stream crossing project is complete, and another stream fully restored.

The Nature Conservancy in Maine has taken part in many restoration projects over the decades, opening hundreds of miles of river, stream, and pond habitat to native fish. This one at Snow Brook is the last of five separate projects to restore the Bagaduce watershed, which TNC has been working with partners to accomplish since 2015.

Each spring, thousands of river herring, a collective name for both alewives and blueback herring, enter the mouth of the 12-mile-long Bagaduce River, to swim up tributary streams to spawn in ponds in the towns of Penobscot, Brooksville, and Sedgwick. These bodies of water together make up the Bagaduce watershed, which encompasses more than 42,000 acres of water habitat. With the advent of dams over the past few hundred years, river herring became largely cut off from their spawning habitat.

two backhoe tractors list white bags out of a stream
Let it Flow Workers remove a temporary barrier at the completion of a road-stream crossing project at Snow Brook in Sedgwick, Maine. © Ben Matthews

“This project is critical in the effort to restore sea-run fish in the Bagaduce river watershed,” says Molly Payne Wynne, freshwater program director for TNC in Maine. “These five restoration projects have provided these fish, as well as other species like brook trout, access to over thirty miles of streams, seven ponds, and many additional wetlands and flowages.”

“It is thrilling to have completed this set of projects in under five years, and it has been a big learning experience,” notes Senior Project Manager Ciona Ulbrich of Maine Coast Heritage Trust (MCHT), a TNC partner who led coordination on the five projects. “Thanks to a key community member showing us the need and the possibilities, a lot of individuals and organizations were able to come together to make it happen.” 

That community leader is Bailey Bowden. A lifelong resident of Penobscot, Bowden spent his childhood on the shore and in the waters of the Bagaduce River. Since 2015, Bowden has led community members from Sedgwick, Brooksville, and Penobscot to form a Three Town Alewife Committee charged with, among other things, identifying and prioritizing streams and ponds that have barriers to fish species that migrate between the ocean and fresh water to spawn.

Quote: Molly Payne Wynne

It’s exciting to complete projects like this, with so much potential upside for people and nature.

Freshwater Program Director

To aid in the effort, the committee called on multiple agencies and non-profits, including the Maine Center for Coastal Fisheries, the National Oceanic and Atmospheric Administration, National Fish and Wildlife Foundation, MCHT, and TNC, to help restore free-flowing streams connected to the Bagaduce.

One of Bowden’s goals with reopening waterways was alewife harvesting, both for consumption and lobster bait. This is a common and longstanding practice in Maine that goes back thousands of years. Many Maine rivers with continuous passage from the ocean to ponds and lakes see millions of these small river herring returning from the ocean every spring to spawn in ponds. That migration supports the vital lobster industry at a time of year when bait can be scarce and provides local communities with an economic boost.

Bowden also noted that this demanding work creates an invaluable opportunity to educate young people. “The newest generation of kids, they’ve lost their connection with these river herring runs,” Bowden says. “The best way to reconnect the kids with the fish was to put them in the brook and let them see the fish over what was once the obstruction.”

side view of bridge over a stream and surrounded by trees.
Completed The new road crossing over Snow Brook marks the last restoration project in the Bagaduce watershed. © Ken Woisard Photography and MCHT

Restoring fish passage also means new road-stream crossings, which protect roads from washing out during the more frequent flood events brought on by climate change. In fact, the Maine Department of Transportation was a partner in the Snow Brook project through their Municipal Partnership Initiative program, which provides funding to towns for projects on the basis of need, benefits, and safety.

Back at Snow Brook, the big machines are loaded up and moved out. Construction cones are removed. A pickup truck rumbles over the short section of fresh asphalt, delivering lobsters from Deer Isle to markets on the mainland. Next spring, thousands of alewives will make their way through the free-flowing stream below to spawn in Frost Pond. Three years after that, following their natural cycle, tens of thousands more adult fish will follow the same journey, bringing nutrients from the ocean to the rivers, lakes, and ponds.

“It’s exciting to complete projects like this, with so much potential upside for people and nature,” says Payne Wynne. “Pulling these partners together to make it happen demonstrates how we all do our work—together.”

Sea-Run Fish Feed River Ecosystems

Uniquely among east coast states, Maine waters support 12 native species of sea-run fish—species that live in the ocean and travel to fresh water rivers or ponds to lay their eggs, or, like the American eel, spend their lives in fresh water and migrate to the ocean to spawn.

Alewives, Atlantic salmon, American shad, Atlantic sturgeon, Atlantic tomcod, blueback herring, rainbow smelt, sea lamprey, sea-run brook trout, shortnose sturgeon and striped bass live most of their lives in the ocean, only migrating to fresh water during the spring to spawn. American eels do the opposite—they live in our freshwaters and migrate to the Sargasso Sea to mate, far off the coast of the southern United States. Many of these species may make the trip multiple times during their lives.

The Comeback See how millions of alewives are returning to Maine's rivers.

These amazing fish bring important ocean nutrients to freshwater ecosystems and provide food for eagles, osprey, kingfishers, otters, seals and other animals that rely on the river for some or all of their life cycle. Schools of alewives, blueback herring, and shad also provide food for larger marine fish like cod. Many coastal communities enjoy annual alewife and herring harvests for eating and for use as lobster bait. Entire festivals are celebrated each spring in Maine to welcome these fish back to their spawning grounds.

Dams and Culverts Block Fish Migration

Our rivers were once filled with millions of fish swimming upstream from the ocean every year on their spawning migrations, providing food for people and wildlife. Then, during a long and productive history of industry in Maine, dams were built to harness the river’s power and roads were cut to bring goods and people together. In many places this construction cut off sea-run and other native fish from the types of habitat they need to reproduce and thrive. 

This, among other challenges like water pollution and overfishing, have resulted in drastic population declines. Atlantic salmon and shortnose sturgeon are now endangered, Atlantic sturgeon are listed as threatened, and rainbow smelt, blueback herring, and alewives are considered species of special concern. These blocked waterways don’t only effect migratory fish—dams and poor culverts also impact other wildlife that depend on streams, like native brook trout and turtles.

A large, corrugated metal half-pipe suspended over a ditch full of water.
Installing an arch culvert An open-bottom culvert is installed over a Maine stream. © Robert Bukaty

Better Road-Crossings Are Good for People Too

Dams and undersized culverts that block water flow can degrade water quality, increase water temperatures, and deplete oxygen. Culverts that are too small and aging dams are vulnerable to storms and flooding that can cause erosion and structural damage. Precipitation has increased across Maine, with more frequent intense storms. Properly designed fish-friendly road crossings reduce flood risk, improve transportation safety, and help minimize short-term repairs cost.

TNC's Strategy for River Restoration

The Nature Conservancy in Maine is working with partners to remove barriers to sea-run fish and promote healthy, free-flowing rivers all around the state. This work also enhances and protects riverside communities by offering new economic opportunities, improving state and town road safety, and generally increasing people’s quality of life.

We’re working with partners to:

  • Remove or find ways around dams so that the needs of both fish and people are considered.
  • Upgrade public and private road-stream crossings to be fish-friendly and storm-resistant.
  • Promote policies and regulations that encourage habitat protection and access for fish and wildlife while supporting the communities that depend on clean water and safe roadways.