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The mighty American Shad once nearly disappeared from the historic Brandywine River. Thanks to a project to provide passage past 11 dams, they are coming back.
As “America’s Founding Fish,” the shad has a storied and fascinating history that is part of the very fabric of the United States.
Shad as a food source
It was an important food source for Indigenous peoples, who taught early colonists how to catch, smoke and store this bountiful member of the herring family. George Washington harvested shad in Virginia, and histories of the Revolution sometimes credit an influx of migrating shad for saving his starving army at Valley Forge. While this has proven to be a myth, there is a record of the British trying to block the fish from swimming up the Schuylkill River to the Americans’ encampment.
Shad fishing quickly became commercialized. By the 1840s, fishermen were removing more than 40,000 tons of shad a year from rivers like the Potomac, Susquehanna, and Delaware.
Healthy habitats are vital
Like salmon, the shad is an anadromous fish, meaning it lives in the ocean but migrates hundreds of miles to spawn in fresh water, adapting to different habitats as it travels. Adapting to the changing salinity of the water requires a change in their breathing and kidneys. Measuring 20 to 24 inches long, the silvery fish feed on plankton and shrimp during their incoming journey, but they swim home to areas like the Brandywine River without eating a bite, relying on fat reserves for energy.
Healthy habitat is vital to sustaining the shad population, which in turn is a fair indicator of the health of ecosystems such as the Brandywine. The river supplies drinking water to 500,000 residents of New Castle County.
Important link in the marine food chain
Shad are an important link in the marine food chain. Juveniles are a tasty treat for largemouth and striped bass and white and yellow perch. Osprey, eagles, and hawks feed on adult shad in freshwater. Even larger predators await them in the Atlantic Ocean. Meanwhile, freshwater mussel larvae attach themselves to the gills of shad to be carried upstream, where they can form colonies that filter the water.
Even after death, shad become part of the ecosystem. Most adults die after spawning, and their carcasses contribute important organic elements to the water that support many smaller life forms, including some resident fish and vegetation.
Though their commercial value has declined dramatically since the 19th century, shad provide a scrappy challenge for recreational fishermen, earning nicknames like “sliver bullet” and “the poor man’s tarpon.” Tim O’Neill, owner of O’Neill’s Fly Fishing in Hockessin, has caught (and released) 30 or more in a day during the peak of the shad run on the Brandywine River. “For their size, they fight very hard–lots of head shakes and jumping,” O’Neill says.
Local efforts to preserve and nurture the Shad
Given all this, it’s little wonder that there are concerted efforts in Delaware to preserve and nurture this magnificent fish. Among the leaders is Jim Shanahan, who lives on the Brandywine in downtown Wilmington. With Hunter Lott, Shanahan founded Brandywine Shad 2020 in 2018. The organization became Brandywine River Restoration Trust (BRRT) four years later, with Shanahan serving as president and Lott as chairman.
BRRT’s goal is to enable the environmental recovery of the Brandywine River, to increase access for all people for recreation and education, and to facilitate migration of American shad there. To accomplish this, Shanahan and Lott have assembled a coalition whose primary focus is removing 11 old industrial dams along less than 12 miles of the Brandywine in Delaware. (The first dam, at West Street, was removed in 2019). The dams, which once provided waterpower to mills along the river, are major impediments to shad migration. Shanahan says that, unlike salmon, shad are not great jumpers, so even a foot-high dam can stop their progress.
He explains that a thriving shad population is intrinsically tied to water quality: “Shad cannot survive in water with low oxygen, which is a key indicator of water quality, so removing dams improves the quality of water by lowering the temperature and increasing oxygenation.”
Impact of dam removal
The efficacy of dam removal was demonstrated in July 2020 when, in a study funded by the BRRT, professor Ed Hale, who studies fisheries at UD Sea Grant in Lewes, confirmed the presence of adult shad and hundreds of juveniles upstream of the former West Street Dam. Shanahan called the finding “a cause for celebration.”
The remaining dams are small. None is higher than 10 feet, and five are in the 2- to 4-foot range. That helps simplify design of fish passage and reduces implementation costs. The dams are numbered 2 through 11, moving upstream from downtown Wilmington north to Rockland.
Shanahan explains that four dams–7 through 10–owned by Hagley Museum, are protected historic structures. But even in these cases, there are solutions, such as putting a notch in the dam, creating a series of baffles for a fish ladder, or building channels around the dams. An example can be seen at Dam No. 2 at the bottom of Broom Street in Brandywine Park.
Enabling passage of shad past Dam No. 2, which provides the city of Wilmington with drinking water, is the responsibility of the Diamond State Port Corporation, a state entity that owns and operates the Port of Wilmington. DSPC plans to expand the port into the Delaware River at the site of the old DuPont Edge Moor plant. Shanahan explains that, as part of mitigation for resulting damage on the river, the DSPC will fund a rock ramp at No. 2. “The port has committed to a 70 percent passage rate of shad up that the ramp,” Shanahan says.
He says a dam can be removed in a matter of days once prep work–site studies and compliance with regulations–is completed. Project costs can range from $300,000 to $1 million, with $500,000 being the average, he says.
The next target is Dam No. 6, at the Experimental Station, which is owned by the City of Wilmington and the DuPont Company. Shanahan says the dam is to be removed by the end of 2023. Work should begin in spring 2024 on No. 4, at Alapocas Run State Park and is owned by the state.
Dam 5, owned by the state and the city of Wilmington, is the subject of an Alternatives Analysis by BRRT’s engineering firm, Kleinschmidt Associates. “They are looking at about a half dozen fish passage solutions,” Shanahan says, “which will be evaluated based on a number of factors, including passage rate, cost, and impact on historical structures.”
The uncertainties around each dam project make it difficult to set a schedule, but Shanahan is hoping the job will be completed within five years.
Hale, who has been conducting annual shad surveys since that initial 2020 study, says the numbers had remained fairly consistent until this year. “Out of the four years, this is the lowest that we have on record,” Hale says. “There appeared to be less frequent encounters with high concentrations or higher aggregations of the adults. I suspect the temperature–colder in late spring to early summer–and flow rate combined affected the adults’ spawning behavior and may have resulted in a lower [number].”
He adds, however, that the Brandywine is a favorable environment for high concentrations of shad. “It’s a really rocky and dynamic environment and that’s why I think adults really like it,” he says. “All of that oxygenation and riffles provide the habitat they want to spawn in.”
Hale echoes Shanahan when he says, “When you remove impediments like dams, it actually tends to improve water quality.”
Johnny Moore of the Delaware Division of Fish and Wildlife also has been doing yearly surveys on American shad in the Brandywine. Like Hale, he’s encouraged by the results. “Based on our recent surveys, I would say in general the population on the Brandywine is fairly stable,” Moore says.
Moore operates the Nanticoke Shad Hatchery, which produces about a half million tiny shad larvae (fry) a year. The fry are released into the Nanticoke River and tributaries, where they will remain for their first year of life before migrating into the Chesapeake Bay, then the ocean. They mature in four to six years.
Moore offers perspective on the precarious life cycle of the American shad when he says, “Because of predators like blue catfish, snakehead fish, and other factors, only about 10 percent of the fry survive.”
On the other hand, Hale attests to the amazing endurance of adult shad. “One of the fish we tagged in the Brandywine showed up in Nova Scotia,” he says. “It came back the next spring. That means it eluded dolphin, shark, and other predators.”
As the BRRT’s website states, “For the first time in more than 100 years, American shad are spawning in the Brandywine River at Wilmington,” thanks largely to the organization’s ongoing campaign to remove or modify dams.
Shanahan, who is not a fisherman, brings a unique perspective that helps explain his dedication to the BRRT’s mission: “When you live on a river like I do, you just get enchanted by it as you watch it every day–when it’s calm and when it’s rough, and dirty and clean, and all the wildlife on it.”
Emphasizing that his organization “is not in the business of taking down dams; we’re in the business of providing fish passage,” he adds, “It’s the right thing to do, returning this river as much as possible to its natural, free-flowing state.”
Look for the shad run to begin in spring.
About the author: Long-time Delaware journalist Bob Yearick can often be found riding his bike or angling for trout in some of our most beautiful local waterways.
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Learn more about Brandywine River Restoration Trust.
Delaware Nature Society and BRRT are among the partners in Christina Brandywine River Remediation, Restoration, Resilience(CBR4), a consortium of environmental organizations whose plan is to improve the lower Brandywine and Christina rivers. Learn more here.
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