OARS River Log | By Nathan Callan, OARS 2024 Environmental Intern | Published June 6, 2024

A little Massachusetts river is swarmed with salmon. Anglers, though outnumbered by the many sleek bodies that dart upriver, are in pursuit of them. I am among them, and so is my friend, who is fly fishing for them. It was at the end of this long day that my buddy—who just moved to Massachusetts from the mighty trout rivers of Colorado—exclaimed: “I’ve never seen so many big fish in my life! Makes me want to put in for a week off.”

Indeed, the river was filled with easily a hundred salmon that day. Though most of the salmon appeared to be around twenty inches in length, there were some whose size heralded a time when their much larger sea-run counterparts filled the great rivers of New England. The salmon we saw that day did not call the ocean home but the waters of Wachusett Reservoir, a drinking water supply reservoir for Boston. Though landlocked by many dams on both the Nashua and Merrimack Rivers, the salmon in Wachusett Reservoir are genuinely the last wild Atlantic Salmon left in Massachusetts.

Historically, almost every New England River north of the Hudson hosted runs of Atlantic salmon. Many of these rivers—especially major rivers such as the Connecticut, Merrimack, and Kennebec Rivers—hosted tens of thousands of sea-run Atlantic salmon (5). These fish would move upriver to the streams where they were born, often traveling hundreds of miles into what is now New Hampshire and Vermont.

Now, sea-run Atlantic salmon are functionally extirpated in the waters of Massachusetts, save for any strays that return to the Merrimack River or the rare fish that return to the Connecticut River as a result of a small legacy program. What happened to these salmon, which were once numerous in our waters (8)?

The short answer is dams—in concert with pollution, habitat degradation, and unregulated overfishing—are responsible for the disappearance of Atlantic salmon, as well as a number of other sea-run fish species (6). Though states began to pass laws in the late 18th century to mandate fish passage, and multiple restoration efforts were initiated during the 19th and early 20th centuries, these too failed to restore Atlantic salmon to our waterways (6).

The most recent and likely most robust effort to restore salmon to the Connecticut and Merrimack rivers began in the 1960s. This great effort saw the collaboration of the states of Connecticut, Massachusetts, Vermont, and New Hampshire, as well as the federal government, to restore Atlantic salmon to the Connecticut and Merrimack rivers. Armed with modern hatchery technologies, millions of dollars of funding, and seven hatcheries focused on supporting the production of Atlantic salmon for the rivers, the effort to bring Atlantic salmon back to our waters began once again (5, 6).

The result? After 50 years of the ongoing restoration program and the production of hundreds of millions of salmon for these rivers on the part of hatcheries, both the Connecticut and Merrimack River Atlantic salmon restoration programs ended due to poor salmon returns. No self-sustaining populations were established despite the documented spawning of Atlantic salmon in the Farmington River and the Souhegan River, each a tributary of these two major rivers (7, 13).

Why did this massive restoration effort fail? Though many issues have been noted to have influenced the failure of this 50-year program, a 2012 report emphasized the impact of dams on the failure of this program. In addition to acknowledging the limited efficiency of fishways and decreased survival of hatchery-produced salmon, it also referenced how dams degraded the resiliency of a salmon population by magnifying the effects of other harmful factors such as impairing habitat and climate change (5).

Indeed, dams significantly impact Atlantic salmon outside of how great of an impediment they are to their migration. With 3,000 dams spread throughout the Connecticut River watershed alone, most all habitat available to salmon was above one more dam (2). Within the Merrimack River, five mainstem dams impair or entirely prevent migratory fish, including salmon, from attempting to move upriver, resulting in only a fraction of upstream migrants reaching suitable spawning areas (8). Thus, requiring salmon to successfully pass upstream of the dam(s) and have their young pass through the hostile environment created by the dam’s impoundment where increased predation, diminished habitat quality, and risk of hydroelectric turbine strikes awaited them (5).

Despite the millions of salmon stocked into the Connecticut and Merrimack rivers, returns never exceeded more than a few hundred fish, and following the conclusion of these programs, the number of returning salmon each year has dwindled into the single digits (9, 15). It is worth noting that even after the ending of the Merrimack River salmon restoration program there have a been a few instances in recent years where as many as 14 salmon have been documented ascending the Essex Dam fish lift in Lawrence, Massachusetts (8, 14). However, even as these programs have ended, dams continue to impact the other sea-run migratory fish that inhabit these rivers, impede water quality, and exacerbate the impacts of climate change (1, 3, 10).

The Future of New England Atlantic Salmon

Despite the loss of many Atlantic salmon populations throughout New England and the many more that continue to struggle in Maine, it’s not all bad news for this sleek and majestic fish. The Penobscot River Restoration Project—an innovative partnership that saw the collaboration of a variety of stakeholders, the removal of two dams on the mainstem of the river, and the substantial improvement of fish passage at remaining dams—has significantly improved habitat access for Atlantic salmon and other fish. In addition, a new program aimed at taking advantage of underutilized salmon habitat, titled “Salmon for Maine’s Rivers,” aims to bolster the salmon population by stocking mature adults raised in net pens to colonize these reaches. The hope is that this program—based on a successful effort to restore Atlantic salmon to the Bay of Fundy—will increase the amount of naturally reared salmon returning to the Penobscot River (4).

Another success story arises from a nonprofit effort to improve dwindling salmon populations on the East Machias River. Beginning in 2012, the Downeast Salmon Federation began running a nature-based hatchery focused on reducing the domestication effects of hatchery-reared salmon and enhancing the fitness of the released salmon. Releasing the young salmon in the fall, they aimed to increase survival through critical life stages while ensuring they have time to experience the natural riverine environment before heading to sea. Ten years from the beginning of the project, the Downeast Salmon Federation has reported a much higher sea-run adult return rate than those of other Maine rivers and even counted 60 redds (rocky nests where salmon lay eggs) in 2019, the highest number observed in twenty years (9).

Despite these successes, much work is still needed to restore salmon to New England rivers. This endangered species faces threats not only in the rivers they inhabit but also in the ocean, where the survival of young salmon has plummeted despite the closing of the ocean fishery off the coast of Greenland (4, 9). Along with this, certain populations remain under threat of extinction, such as the Kennebec River Atlantic salmon, where four hydroelectric dams block fish from accessing prime salmon habitat on the Sandy River (12).

For some salmon populations, the future holds more promise than others. However, hope remains that through these many efforts, dam removals, and innovative solutions, Salmon might resurge and reclaim the waters of Maine. But what about our waters? What about the Merrimack, Connecticut, Housatonic, and the many other New England rivers that once hosted bountiful runs of Atlantic salmon? Though the rivers remain fragmented by many dams on the mainstem and tributaries, in some, the prime habitat for spawning and rearing young Salmon remains. There may yet be hope for a resurgence of these fish, as in the words of Henry David Thoreau, “Salmon, shad, and Alewives were formerly abundant here… until the dam,… and the factories at Lowell put an end to their migrations hitherward… Perchance, after a few thousand years, if the fishes will be patient, and pass their summers elsewhere… nature will have leveled… the Lowell factories and the Grass-ground River [will] run clear again” (11).

References

1. Abbott, K., Roy, A., & Nislow, K. (2022). Restoring Aquatic Habitats Through Dam Removal. U.S. Fish & Wildlife Service. Retrieved January 3, 2024, from https://doi.org/10.3996/css92498424
2. American Rivers. (n.d.). Connecticut River. Retrieved June 17, 2024, from https://www.americanrivers.org/river/connecticut-river/
3. American Rivers. (2022, February). Free Rivers: The State of Dam Removal in the United States. Retrieved January 3, 2024, from https://www.americanrivers.org/wp-content/uploads/2023/02/DamList2021_Report_02172022_FINAL3.pdf
4. Belfast Free Library. (2021, March 19). What’s New in the Penobscot River? with Danielle Frechette, fish biologist. [Video]. YouTube. Retrieved June 17, 2024, from https://www.youtube.com/watch?v=vrRqxvfr_7U
5. Brown, J. S., Limburg, K. E., Waldman, J. R., Stephenson, K. S., Glenn, E. P., Juanes, F., & Jordaan, A. (2013). Fish and hydropower on the U.S. Atlantic coast: failed fisheries policies from half-way technologies. Conservation Letters, 6(4), 280–286. https://doi.org/10.1111/conl.12000
6. Department of Energy & Environmental Protection [DEEP]. (2024, March). Atlantic Salmon Management Areas. CT.gov. Retrieved June 12, 2024, from https://portal.ct.gov/deep/fishing/fisheries-management/atlantic-salmon-management-areas
7. Freeland, A. (2016, March 23). Salmon Spawning Again in CT: An Ecological Cautionary Tale. WSHU. https://www.wshu.org/news/2016-03-23/salmon-spawning-again-in-ct-an-ecological-cautionary-tale
8. German, Benjamin. (2024). Notes from phone call with Nathan Callan, Ecological Restoration Intern, OARS.
9. Greater Boston Trout Unlimited. (2022, March 20). The Peter Gray Parr Project Presented by Dwayne Shaw [Video]. YouTube. Retrieved June 17, 2024, from https://www.youtube.com/watch?v=Q-e0ImOGfE4
10. Mansfield, M., Mansfield, M., Mecklenburg, C., & Groff, M. (2022). Massachusetts Climate Change Assessment: Volume II – Statewide Report. In Mass.gov. Executive Office of Energy and Environmental Affairs. Retrieved May 30, 2024, from https://www.mass.gov/info-details/massachusetts-climate-change-assessment
11. National Park Service [Lowell National Historical Park]. (2018, November 9). The Merrimack River. NPS.gov. Retrieved June 17, 2024, from https://www.nps.gov/lowe/learn/historyculture/the-merrimack-river.htm
12. Natural Resources Council of Maine [NRCM]. (2023, March 20). NOAA Ignores Science Showing Extinction Threat for Atlantic Salmon. Natural Resources Council of Maine. Retrieved June 17, 2024, from https://www.nrcm.org/news/noaa-ignores-science-showing-extinction-threat-atlantic-salmon
13. New Hampshire Fish and Game Department. (n.d.). Atlantic Salmon. State of New Hampshire Fish and Game. Retrieved June 17, 2024, from https://www.wildlife.nh.gov/fishing-new-hampshire/fish-species-nh/atlantic-salmon
14. The Technical Committee for Anadromous Fishery Management of the Merrimack River Basin. (2021). Merrimack River Watershed Comprehensive Plan for Diadromous Fishes. In Federal Energy Regulatory Commission. Retrieved June 20, 2024, from https://elibrary.ferc.gov/eLibrary/filelist?accession_number=20210617-5016&optimized=false
15. U.S. Fish & Wildlife Service [CT River Fish and Wildlife Conservation Office]. (2024, February 22). Connecticut River Migratory Fish Counts. U.S. Fish & Wildlife Service. Retrieved June 17, 2024, from https://www.fws.gov/office/connecticut-river-fish-and-wildlife-conservation/connecticut-river-migratory-fish-counts

Nathan is curerntly a student at UMass Lowell studying Environmental Engineering