On April 25, 2023, three river enthusiasts offered a wealth of information about the Androscoggin River which plays such an important role – culturally, economically, and recreationally — for many Maine communities. You can watch a recording of the entire presentation here or at the end of this summary.
Charlie Spies, avid fisher, forest biologist, and resident of the Androscoggin riverbank, led with an overview of the river. The Androscoggin River drains over 3000 sq miles, joining the Kennebec River at Merrymeeting Bay. Its water quality is good and getting better. The state’s water quality classification of the lower Androscoggin was recently upgraded to Class B. This action has the effect of maintaining and improving its quality by prevent future discharges that would degrade it.
The river is an important public resource, providing food and habitat for a diverse mix of invertebrates, fish, and animals, as well as livelihoods and recreation for people. And all of that life is visible to those who live or visit near the river’s 178 miles of shore frontage.
The hydro dam between Brunswick and Topsham occupies what used to be called Great Falls. While the falls were a barrier to some fish, such as sturgeon, others were able to travel up through them. Today, the Brunswick-Topsham dam (BT dam) is one of multiple barriers to fish passage on the river, including nearby dams at Pejepscot and Worumbo. There’s a huge difference between the river’s potential fish populations and what has been counted going through the fishway at the BT dam. It’s estimated that if fish passage at the Brunswick dam were improved, hundreds of thousands of fish (alewives, shad, and others) could move upriver.
The Federal Energy Regulatory Commission (FERC) licenses hydropower projects, with re-licensing of dams occurring every 30-50 years. As part of the relicensing process, FERC has to balance many competing interests, including economic, recreational, and ecological. Existing fishways in the Androscoggin dams do not work well. The number of fish that make it upriver is a tiny fraction of historic river runs. The BT dam is up for relicensing in 2029. The relicensing process offers a once-in-a-lifetime opportunity to effect changes in hydro dams.
John Lichter, Bowdoin Professor of Biology and Environmental Studies Emeritus, continued with context on the regional ecology of the river. Indigenous people of North America understood the complexity and connectivity of the natural world.
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“ When one tugs at a single thing in nature, he finds it attached to the rest of the world.” -John Muir |
The pre-colonial ecosystem in North America was resilient. Hundreds of millions of cod lived in the Gulf of Maine, part of a rich and complex food web. The cod fishery has since collapsed, and research suggests that much of the decline occurred in the 1880s. Some of the decline was due to overfishing, but the decline of river herring as a food source for cod appears to also play a significant role.
Many dams were constructed around the Civil War, limiting the ability of anadramous fish[1] to spawn. Coastal waters are prime grounds for nurseries for young fish, as well as spawning, hatching, and feeding grounds. As dams limited access to spawning habitat for alewives, shad, salmon, and other species, the supply of nearshore food led to a decline in nearshore fish populations.
These ideas have been validated by data collected following improvement of certain dams in Maine. Since improving the fish ladder at Damariscotta Mills, one million alewives are now passing through that dam annually. The trillions of fish eggs laid by alewives and other fish in lakes, ponds, and streams are a vital food source for myriad creatures.
At the BT dam, researchers have counted 5000 shad moving toward the fish ladder during a tidal cycle, but only 79 (1.6%) made it up.
Ecological recovery is rapid in some areas and slow in other. John shared data showing the decline in dissolved oxygen (DO) in the Androscoggin River, culminating in a level of zero in 1965. Dissolved oxygen is critical to the survival of plant and animal life in rivers, so zero DO led to complete complete of the riverine ecosystem. While the Clean Water Act led to relatively rapid improvement in the river’s water quality, the recovery of submerged aquatic vegetation and the many species it supports, took much longer.
All this reinforces the reality that ecosystems are extremely complex. The food webs involving hundreds of species and spatial connections across geographic regions are not fully understood by us. We can rarely predict the consequences of altering a food web and can’t predict whether a species can adapt to some of the dramatic changes wrought by humans.
Chuck Verrill, President of Maine Rivers, followed with information about the vast number of dams across Maine — large and small. Maine has many smaller dams that don’t produce power and rarely have fish passage structures.
Maine has 109 FERC-registered hydro dams, many of which — like the B/T dam and fishway — are antiquated. Brookfield, the owner of the BT dam, is one of the largest dam owners in the world. Many dams that were originally built to power mills are no longer in use, yet continue to prevent fish passage.
The removal of the Edwards dam in Augusta in 1999 was the result of many years of persistent advocacy. Its removal became a dramatic illustration of the resilience of migratory fish which return in large numbers when barriers are removed. Even though it had been 200 years since fish had made it upstream to spawn, they returned.
While removal of the Edwards Dam was significant, four dams remain between salmon and their spawning grounds in the Sandy River. Several organizations continue to advocate before FERC to conduct an analysis of the cumulative impact of these four dams, rather than consider each dam separately.
China Lake is another example. Alewives were routinely stocked in China Lake and could move downriver, but could not return. Through many years of effort by Maine Rivers and others to remove or improve six dams, alewives can now reach China Lake. Advocates had to convince owners they wouldn’t miss the dam-created impoundments, and revegetate areas exposed by the dam removal.
In conclusion, while the FERC relicensing processing is complex, the involvement of more independent voices makes a difference. The more we can do to make people aware of the tremendous natural asset the Androscoggin (and other) river is to our community, the better chance we have of creating a brighter future for the creatures that could return and create a rich natural community that will benefit us all.
Charlie Spies is working to create a coalition of people interested in learning more about the BT dam relicensing and hopefully, getting involved. He can be contacted at .
Click here to download a copy of John Lichter’s presentation or a booklet he co-authored with Ted Ames about Maine’s fisheries and their connection to rivers. You can also watch a six-minute video exploring the connection between river spawning fish and offshore fish populations, Not Just a Fish Tale.
Here’s a link to Maine Rivers’ Alewive Migration Trail Map.
If you want to see what an effective fish ladder looks like, visit the one in Benton Falls or watch this video showing how it works.
You can watch the entire April 25th presentation, which includes much more detail than is contained in this summary, below.
[1] Anadromous fish are fish that migrate from freshwater rivers to the ocean, then return to rivers to spawn.