Hudson River fish species
A guide to the river's most iconic wildlife
May 18, 2026
David Stormer, Ph.D.
Habitat Restoration Director
Matthew Best
Habitat Restoration Manager
Every year, the Hudson River supports the epic migration of iconic fishes including the Atlantic sturgeon, American eel, striped bass, American shad and shimmering schools of river herring – all on their journey to spawn, just as they have for centuries.
Who are these marvelous aquatic neighbors who call the Hudson home?
American eel
Eels have a unique and extraordinary life cycle. Eels are catadromous, meaning they live in both fresh and salt water. They spawn in the Sargasso Sea near Bermuda, then travel thousands of miles to tributaries of the Hudson River to grow and mature.
Beginning as nearly transparent “glass eels,” they live their lives in the freshwater portions of the river and its tributaries for up to 20 years (growing up to five feet long!) before returning to sea to spawn.
Eels can absorb oxygen through their skin to survive for a brief period on land. This is also why they are such strong climbers, and can scale steep surfaces, a very useful skill when migrating upstream. They eat worms, crustaceans, and small fish, and are eaten by birds, mammals like racoons, and larger fish (as well as humans).
Riverkeeper supports various efforts to improve and protect eel populations, including bringing down barriers that block eels from their natural habitat, and modifying existing hydroelectric dams to have ladders and properly sized intake screens that can ensure eels' safe passage.
Shad
American shad have a long and rich history in the Hudson River. The migratory fish is known as the world’s largest herring species and is found along the Atlantic Coast from Newfoundland to Florida. American shad was one of the most significant and popular commercially caught fish in the Hudson River. Their spring migration was such a massive event in the Hudson Valley that it was celebrated in the form of "shad festivals" where thousands turned out along the river to honor and eat traditional smoked shad and shad roe (eggs).
400
shad-fishing operations functioned on the Hudson before they were banned
Due to fine hairs in shad’s ear structures, they have extremely sensitive hearing that helps them pick up echolocation from dolphins, a common shad predator. Their scientific name, Alosa sapidissima, translates to “most delicious” shad, as the fish and its eggs were considered a delicacy by Indigenous peoples and colonial communities (George Washington relied on shad to feed his troops during the Revolutionary War).
Shad populations have diminished in the 20th and 21st centuries, and commercial and recreational fishing for shad has been banned in the Hudson River since 2010. American shad would swim 600 miles to spawn before the Susquehanna River was dammed.
Thanks to Riverkeeper’s dam removal efforts, shad and river herring are returning to critical habitat where they have not been in decades. Riverkeeper is petitioning the New York State Department of Environmental Conservation (NYS DEC) to increase protections on American shad by making them a “species of concern.”
Striped bass
Striped bass are the East Coast’s premier saltwater gamefish, and these fish represent another iconic Hudson River species that is struggling to recover.
When striped bass, known as “stripers, or rockfish” enter the river to spawn and as they mature, they utilize Atlantic menhaden, river herring, and shad as a food source. The world record for a striped bass is 81 pounds and 14 ounces. Mature, large female striped bass are called "cows,” and because they have no eyelids, they prefer feeding in lower light conditions (dawn and dusk) and move to deeper water when the sun is high.
Recovery of the Hudson’s striped bass population is dependent on reducing fishing mortality, while also protecting the forage fish that striped bass need to sustain themselves. Riverkeeper works alongside managing agencies to advocate for striped bass and other fisheries to ensure the sustainability and future health of the species.
Our Save a Million Bass program educates anglers about changes in regulations and gives recommendations that help ensure striped bass survive recreational catch and release fishing. Generally, an estimated 9 percent of stripers don’t survive being caught and released.
River herring
River herring in the Hudson River include two distinct species: alewife and blueback herring. Both are extremely important for the ecosystem — when herring numbers are healthy, other animals benefit because of their role as a preferred prey for a number of species.
River herring are “planktivorous,” meaning they mostly consume zooplankton, tiny, often microscopic animals, by swimming with their mouths open, filtering out the plankton to eat from the river.
River herring are also “anadromous,” meaning they spend their adult life in the ocean before returning to the river and tributaries where they were born to reproduce in the springtime (March through May). They stay for about three years before returning to the ocean.
River herring are often referred to as “sawbellies” because they have hard, sharp, bony plates called “scutes,” along their belly. These scutes offer protection from predators and help navigate rough terrain when migrating into rivers and streams with hard bottoms.
How can you tell the difference between alewife and blueback herring?
Alewife
Alewife have a slightly larger eye, deeper body shape and the inner lining of their body cavity is gray to white. Alewife prefer to spawn in slower moving water and pools over softer surfaces (e.g. sands, gravel, or vegetated surfaces) in both tributaries and the main Hudson River.
Blueback
Blueback herring have a slightly smaller eye, more slender body shape and the inner lining of their body cavity is black. Blueback herring prefer to spawn in faster moving water over hard surfaces (e.g. stones and cobbles) in tributaries.
Both species populations are considered depleted by the Atlantic States Marine Fisheries Commission (ASMFC), and face threats from pollution, invasive species, and loss of habitat from dams.
By removing obsolete dams, restoring spawning habitat in Hudson River tributaries, and advocating for policies that reduce bycatch, Riverkeeper is reconnecting fish to historical spawning grounds, allowing alewife and blueback herring populations to recover.
Atlantic sturgeon
The endangered Atlantic sturgeon has been on earth since the time of the dinosaurs — at least 120 million years ago.
Unlike most fish, sturgeon don’t have scales. Instead, similar to the bellies of river herring, they have large bony plates running down their body called “scutes.” They are slow-growing fish that can live up to 80 years. Female sturgeon spawn in the Hudson River estuary in May and June every two to six years and produce up to 2 million eggs in a single season.
Despite their size, Atlantic sturgeon are known to travel long distances. One individual was found to have swum 900 miles in a single summer!
In the past, the Atlantic sturgeon were part of a huge commercial fishing industry and were such a common source of protein for people living along the Hudson that they earned the nickname “Albany beef.”
Atlantic sturgeon numbers have declined precipitously since the 1900s due to overfishing and impacts from human activity. Fishing for sturgeon was outlawed in 1998, and the species was declared endangered in 2012. Despite federal protections, monitoring efforts, and legal actions, these endangered fish are not showing signs of recovery. Riverkeeper is working to reverse this trend by holding states and managing agencies accountable for keeping this iconic species safe.
Related campaigns
Saving Hudson River fish
Protecting iconic species vital to our local ecosystems
Protecting and restoring habitats
The Hudson River watershed is home to a breathtaking diversity of life. Protecting and restoring our aquatic habitats is critical for their renewal and for a healthy future for all life in the watershed
Dam removal
By removing old, obsolete dams, we are healing the ecosystem and restoring life to the Hudson and its tributaries
Related news
May 28, 2025
Riverkeeper announces first annual Fish Migration Celebration
Press release
April 13, 2020
Hudson River fish: The springtime procession
George Jackman
Blog
April 10, 2026
Can you eat fish from the Hudson River?
Update
October 21, 2021
What happens when you remove a dam? One year later, life returns to a Hudson River tributary
Leah Rae
Blog