Tipping the Scales

Restoring American Shad in the Delaware River Basin

An Exceptional River

The Delaware River once supported one of the largest runs of American Shad on the Atlantic coast. Each spring millions of shad migrated from the ocean to spawning grounds throughout the Delaware River Basin.

Today, American Shad populations are estimated to be at 1 to 3% of historic levels and significant efforts are needed to restore this iconic species.

As the longest undammed river east of the Mississippi, the Delaware River holds enormous potential for the recovery of American Shad and other migratory fish.


American Shad

The Fish

The American Shad is the largest of the herring family (Clupeidae), typically ranging in length from 16 to 30 inches and weighing between 4 to 7 pounds, with females (roes) often larger than males (bucks).

Sharp saw-like scales, or scutes, cover the outside of the body and internally there are over 700 bones. Despite their bony insides, the fish were traditionally eaten by the native Lenape and European colonists, with their Latin name - Alosa sapidissima - translating to "most delicious of herrings." The Lenape term for shad may be more accurate, however, roughly translating as "porcupine-fish-turned-inside-out."

Migration

American Shad are anadromous, meaning they spend most of their lives in saltwater but return to freshwater rivers to spawn and reproduce. Their native range along the Atlantic coast extends from the Sand Hill River in Labrador to the St. Johns River in Florida.

In early spring, when rivers reach around 40 degrees Fahrenheit, adult American Shad make their way upstream, sometimes ascending hundreds of miles. Female roe shad broadcast their eggs for the males to fertilize. The fertilized shad eggs float downstream for about 4-12 days before hatching.

The young shad make their way downstream, reaching the Atlantic by autumn. In the ocean, American Shad congregate in large schools and migrate along the continental shelf. It is here where they spend most of their lives, only to return to their natal, or home, river to spawn when they reach maturation. During its lifetime, an American Shad may swim over 12,000 miles!

A Keystone Species

American Shad are an important ecological link between freshwater, estuarine, and marine environments. Not only are shad a critical food source for a variety of species, ranging from sharks and black bears to osprey and striped bass, but they also help to distribute the larvae of freshwater mussels and provide beneficial marine-derive nutrients to river systems when they die after spawning.


Historic Fisheries

Shad and the Lenape

Much of the Delaware River Watershed lies within Lenapehoking, the Lenape name for Lenape land. Although the Lenape diaspora is currently dispersed throughout the United States and Canada, their records of catching shad along the Delaware River are the oldest known. Every spring, the Lenape people would congregate along the Delaware River and its tributaries to catch a bounty of shad and other fish. Driving posts into the bottom of the river in a fence-like fashion to create a fishweir, they would then use weighted nets to gather the shad in a confined location.

The Lenape traditionally cooked shad on wooden stakes or planks, allowing the fish to smoke slowly over a fire, which also caused many of the bones to disintegrate. This practice allowed the fish to be preserved so that they could be stored or eaten at a later time. Roe shad were also greatly prized for their eggs, considered a true delicacy.

The Founding Fish

The European colonists continued the Lenape tradition of fishing for shad, often using drift and seine nets. Author John McPhee, an avid shad fisherman himself, refers to American Shad as "the founding fish" owing to its importance to the colonies and a young nation. Legend has it that shad were even responsible for saving George Washington’s troops from starvation as they camped along the Schuylkill River at Valley Forge (though McPhee himself disputes this fact).

Communities in the Delaware basin and beyond relied on the abundance of shad for food and to fuel their local economies. The image to the right shows the former Dock Street Fish Market in Philadelphia, an enclosed warehouse where dozens of merchants sold fresh fish and salted river herring that would last them through the winter. By the mid-1800s, barrels of pickled shad were even being shipped as far as China.

African American Watermen

African American watermen (and women) were critically important to the fisheries and feature prominently in many historic images and illustrations from this time. Prior to the Civil War, many slaves were put to work on the Mid-Atlantic fisheries and would later play a pivotal role in the anti-slavery movement and Union efforts owing to their knowledge of the region's waterways. By the late 1800s, fishing became a major source of income for African Americans and was a well-respected profession. For a time, the Delaware River shad fisheries was the largest commercial fishery on the Atlantic coast, with annual catches numbering 3-4 million fish and employing over 3,000 people in the industry.

In 1896, it was recorded that 4,017,462 shad were fished out of the Delaware River in that single year! It is no wonder that shad were said to be so prolific that one could walk "over their backs drishod" (meaning to have dry shoes or feet). Unfortunately, by the early 1900s, the American Shad population in the Delaware River had largely collapsed due to massive overfishing.

Below you will find a map of prominent historical fisheries along the Delaware River and the catch totals from the 1896 fishing season. Scroll through to explore!

1

Clonmell Cove

1896 Catch Total: 25,000

At the mouth of the Clonmell Creek in Gloucester County, NJ lies a cove between Thomas Point and Bramell Point. The drawing depicts people hauling seine nets to shore from the Delaware River. This was one of the most common forms of fishing for American Shad within the Delaware.

2

Fancy Hill

1896 Catch Total: 65,000

The stretch of fisheries opposite Philadelphia were some of the most productive in the Delaware River. One of these was known as Fancy Hill operated by the Howell family. Between the years 1819 and 1822, this fishery averaged over 136,000 shad caught annually.

3

Gloucester

1896 Catch Total: 70,000

Another large and valuable fishery on the New Jersey side of the Delaware River was the famous Gloucester fishery. Thomas Eakins, a 19th century painter from Philadelphia, documented this fishery in several of his paintings such as this one, titled "Shad Fishing at Gloucester on the Delaware River" (1881).

4

Pea Shore

1896 Catch Total: 55,000

Operated within the channel between Petty's Island and the New Jersey shoreline, the Pea Shore fishery was located just north of Camden. The 1896 catch was valued at $4,125 (an amount worth approximately $135,000 in today's dollars).

5

Riverton

1896 Catch Total: 35,000

Further north on the New Jersey side, the Riverton fishery was located along the shoreline by the borough of Riverton.

6

Taylorsville

1896 Catch Total: 2,491

The Taylorsville Fishery was located just south of Titusville in the non-tidal section of the Delaware. Between 1884 and 1896, the fishery caught an average of 1,413 shad annually.

7

Lewis Family Fishery

1896 Catch Total: 9,288

Today, only one commercial shad fishery still exists along the Delaware River. Since 1888, the Lewis Family Fishery has operated out of Lambertville, NJ. The data generated by the Lewis Family Fishery on an annual basis is invaluable to our knowledge of American Shad runs in the Delaware.


The Delaware, Dammed

Barriers such as dams along a river halt the migration of shad to critical spawning and rearing habitat, which inhibits their ability to reproduce and grow their populations. As more people settled in the Delaware Valley, the building of dams became one of, if not the largest, threat to American Shad throughout the basin.

Damming the Tributaries

Beginning in the late 1600s, European settlers began building dams on Delaware River tributaries to harness water power. Water passing through a spillway would turn a water wheel that provided power to the mills, which served a variety of purposes from cutting timber to weaving cloth to making gunpowder. The image here shows a restored 19th-century gristmill - used for grinding grain into flour.

The Fairmount Dam was completed across the Schuylkill River, the Delaware’s largest tributary, in 1821. At the time, the dam was the longest in the United States at over 2,000 feet and was built to harness water power at the Fairmount Water Works (foreground) and provide a reliable water supply for the City of Philadelphia. The dam incorporated a canal and lock (opposite side of river) for the Schuylkill Navigation Company, which was the most downstream link in the system. The Fairmount Dam also put an end to the Schuylkill's historic shad runs and extirpated the species from the river for over 150 years.

Damming the Delaware

While no mainstem dams exist on the Delaware River today, that was not always the case. In 1828, the Delaware and Hudson Canal Company finished the construction of a16-foot-high slackwater dam near Lackawaxen, PA. The pool of water created by the dam allowed boats to be floated across the Delaware River, thereby linking the Pennsylvania and New York sides of the canal on either side of the river. In 1848, an aqueduct replaced the dam and, by the early 1900s, the dam had been all but destroyed by storms and ice floes on the river.

The Delaware River came under threat again following the summer of 1955, when Hurricane's Connie and Diane overflowed the banks of rivers and streams in the Delaware Water Gap region. As a flood control measure, Congress considered a one-mile-wide dam along the mainstem of the Delaware River at Tocks Island. However, the Delaware River Basin Commission ultimately voted down the project and the lands that had been acquired by the federal government for the reservoir became the  Delaware Water Gap National Recreation Area .

Water Quality Woes

Poor water quality and overfishing also contributed to the decline in shad populations. During the mid-1900s, Philadelphia sewers dumped more than 200,000 tons of solids directly into the Delaware River. This organic waste, along with industrial pollution upstream, consumed dissolved oxygen in the river leading to an anoxic (or dead) zone around Philadelphia in the summer months. Like a dam, this pollution block stopped many shad from swimming upstream to spawn.

Fortunately, regional and federal efforts to address the polluted waterways were successful. The formation of the Delaware River Basin Commission in 1961 and passage of the Clean Water Act in 1972 helped to restore water quality and, to an extent, the shad runs.

The next few slides contain accompanying audio from oral histories of residents of the Upper Delaware as documented by the National Park Service. Click play to hear more about the shad runs throughout the 1900s!

The Lewis Family Fishery in Lambertville, NJ has collected yearly shad numbers since 1888. This graph shows the number of shad caught in total and per seining haul (CPUE) for every year since 1937, when they changed their recordkeeping methods. In both 1953 and 1956, the pollution block on the Delaware was so bad that the fishery caught no shad, as described by Charley Zaimes in the below audio clip.

Despite the relative rebound in the Delaware River shad population following water quality improvements, the numbers were still far below historic levels and have since become more depressed within the basin and coastwide. "Doc" Homer recounts the differences in shad runs through the years.

While there are no mainstem dams on the Delaware River today, there are over 1,400 dams on tributaries throughout the Delaware basin. These dams, many of which no longer serve their intended purpose, fragment habitat and inhibit access to vital spawning and rearing habitat for American Shad and other migratory fish.


Reviving a Species

American Shad populations along the Atlantic coast are currently estimated to be at 1 to 3% of historic levels.

Recent dam removal efforts within the basin have demonstrated that shad will often utilize newly available habitat almost immediately following the removal of a dam.

Scroll down to explore some recent dam removal efforts throughout the basin!

Select Dam Removals in the Delaware Basin

1

Cuddebackville Dam, Neversink River, NY

Year Removed: 2004

Partners: The Nature Conservancy, U.S. Army Corps of Engineers

2

Finesville Dam, Musconetcong River, NJ

Year Removed: 2011

Partners: Musconetcong Watershed Association, U.S. Fish and Wildlife Service, Natural Resources Conservation Service, NJ Department of Environmental Protection, American Rivers

3

Darby Borough Dam, Darby Creek, PA

Year Removed: 2012

Partners: American Rivers, National Oceanic and Atmospheric Administration, Pennsylvania Fish and Boat Commission

4

Columbia Dam, Paulins Kill, NJ

Year Removed: 2018

Partners: The Nature Conservancy, American Rivers, NJ Department of Environmental Protection, U.S. Fish and Wildlife Service

5

West Street Dam (#1), Brandywine Creek, DE

Year Removed: 2019

Partners: City of Wilmington, Delaware Department of Natural Resources and Environmental Control (DNREC)

Priority Restoration Sites

In 2021, The Nature Conservancy completed a  Restoration Roadmap for American Shad and River Herring  that identifies a set of priorities for restoration in the Delaware basin. The report highlights several priority tributaries with one or more dams along them that offer significant potential to increase habitat connectivity for American Shad and river herring. The below tool highlights these priorities in addition to mapping existing dams throughout the basin and current and historic species distribution.

Click anywhere to explore!

Delaware River Basin Fish Passage Prioritization Tool (ArcGIS Web Application)

Migratory Fish of the Delaware River Basin

The American Shad (Alosa sapidissima) is one of several migratory fish species in the Delaware River and its tributaries that would benefit from dam removal and river restoration efforts. Click through for images of other migratory species and to learn some fun facts about them!

Collectively known as "river herring," Alewife (Alosa pseudoharengus; above) and Blueback Herring (Alosa aestivalis; below) are smaller than American Shad and complete similar migrations with slight variations in life history and preferred spawning habitat.

Another species of herring, Hickory Shad (Alosa mediocris) have a similar appearance to American Shad, but can be distinguished by the strongly projecting lower jaw.

A popular sport fish, Striped Bass (Morone saxatilis), often called "stripers" due to the horizontal stripes on their sides, can grow up to five feet in length and weigh over 70 pounds.

Considered a living fossil, the Atlantic Sturgeon (Acipenser oxyrhynchus) has not changed much in the last 70 million years. This fish can grow up to 14 feet in length and weigh up to 800 pounds! However, overfishing and habitat degradation have led to extreme population decline and a 2012 listing under the Endangered Species Act.

Shortnose Sturgeon (Acipenser brevirostrum) are smaller than Atlantic Sturgeon and spend most of their lives in estuaries rather than the ocean. It is currently listed as endangered throughout its range along the East Coast.

Sea Lamprey (Petromyzon marinus) is a jawless parasitic fish native to the Atlantic Ocean and Delaware River Basin. Adult Sea Lamprey spawn in nests they build in streams. The larvae spend four to six years in the freshwater, growing about six inches, and can be important forage for trout.

Unlike the previous species, American Eel (Anguilla rostrata) are catadromous, meaning they are born in the ocean, mature in freshwater, and eventually return to the Sargasso Sea in the Atlantic Ocean to spawn. The Delaware River basin is considered a stronghold for American Eel.

Benefitting More Than Fish

Restoring rivers to a free-flowing state has wide-ranging ecological, social, and economic benefits. Dam removals can improve water quality by lowering ambient water temperatures and increasing dissolved oxygen levels. Additionally, they improve nutrient and sediment transport and substrate distribution, which can restore river processes and aquatic habitats.

Dam removal projects can also reduce public safety risks and remove hazardous structures that often no longer serve their original purpose. By 2025, 7 out of 10 dams in the U.S. will be over 50 years old, and many of these were not built to handle the increasing rainfall and associated flooding caused by climate change. Removing such structures can eliminate the risk of failure and drownings, associated owner liability, and costly maintenance and upgrades.

Local communities and native people can have long-standing cultural and spiritual ties connected to individual free-flowing rivers, their features and the species that they support. Restoration through dam removal can provide significant, and in some cases irreplaceable, benefits in restoring these resources and connections to communities. Local festivals celebrating the spring shad run were not uncommon in towns throughout the basin. Lambertville, NJ continues to host a shad festival and recently Wilmington, DE relaunched its ShadFest to celebrate the return of shad to the Brandywine Creek following dam removal and fish passage efforts.


The Waters Ahead

American Shad are not the only species at risk. Globally, we are facing a biodiversity crisis and freshwater species are even more threatened than their terrestrial and marine counterparts.

In the past 50 years, migratory fish populations have declined globally by 76%. In North America, the decline has been slightly less extreme (28%) demonstrating that fisheries management and restoration efforts have a critical role to play.

On top of that, nearly 1/3rd of freshwater fish species are currently threatened with extinction.

Recent reports have outlined these harrowing findings, but also serve as a call to action. The time is now to counteract the damage we have done to our rivers and further protect and restore these critical freshwater ecosystems.

Resources and Action

Delaware River Basin Resources

  •  NJdams.org  - Website hosted by the New Jersey Statewide Dam Removal Partnership (SDRP) with information about dams and dam removal.
  •  Brandywine River Restoration Trust  - Website hosted by BRRT with information about the coalition's efforts to restore the American Shad population in the Brandywine River and return the river to its free-flowing state.
  •  Upper Delaware Scenic & Recreational River  - Website hosted by the National Park Service with information about the park and this section of river, designated in the National Wild and Scenic Rivers System.

Global Status of Migratory Fish

Free-Flowing Rivers and Dam Removal

  •  World Fish Migration Day  - The next World Fish Migration Day is May 22, 2022. Organize or join an event to celebrate migratory fish!
  •  Love Flows Documentary  - This documentary directed by Francisco Campos-Lopez captures the stories of events from World Fish Migration Day 2018 and highlights the impacts of dams and the people who are working to make positive differences for rivers.
  •  Dam Removal Toolkit  - A practitioner's toolkit for dam removal.
  •  Removing Barriers to River Health  - A look at The Nature Conservancy's efforts towards restoring healthy rivers through dam removal.
  •  A Brighter Future  - A report by WWF and The Nature Conservancy highlighting how we can tackle climate change with the right renewables in the right places without sacrificing nature and free-flowing rivers.