The Ohio River flows 981 miles from Pittsburgh, Pennsylvania, to the Mississippi River in Cairo, Illinois, serving as a major ecological corridor and one of the nation’s largest tributaries. This vast waterway connects six states and supports a remarkably diverse aquatic community, including over 160 species of fish. The river’s ecosystem, featuring habitats from deep navigation pools to churning tailwaters below dams, is home to a wide array of fish, ranging from sought-after sport species to forage fish that form the base of the food web.
Primary Game Fish Species
Catfish are a significant draw for recreational anglers, with three major species present: the Channel, Flathead, and Blue Catfish. Channel Catfish up to 15 pounds are commonly encountered. The Flathead Catfish is known for its size potential, with 20- to 30-pound fish being the norm and some capable of exceeding 100 pounds. Blue Catfish are also present, particularly in the lower river sections, contributing to the river’s reputation for trophy-sized fish.
The Temperate Bass group is highly abundant, consisting of the native White Bass and the stocked Hybrid Striped Bass. White Bass are the most frequently caught native game fish, typically averaging 8 to 12 inches in length. Hybrid Striped Bass, often called Wipers, are an aggressive hybrid stocked by multiple states and commonly reach sizes up to 10 pounds. Striped Bass are also stocked by states like Kentucky and can grow to weights of 20 pounds, thriving in the highly oxygenated water below the river’s dams.
The Black Bass family includes Largemouth, Smallmouth, and the less common Spotted (Kentucky) Bass. Smallmouth Bass are found near rock substrates throughout the river, thriving where crayfish, their primary food source, is abundant. Largemouth Bass prefer the calmer waters of creeks and embayments, moving there to spawn when water temperatures exceed 50 degrees. Panfish, smaller sport species, are represented by Crappie and Sauger. Sauger are a popular target, providing high catch rates, particularly in cooler months in tailwater areas.
Native Forage and Non-Sport Fish
Native species not targeted for sport fishing fulfill essential roles in the Ohio River ecosystem, forming the base of the food chain. Gizzard Shad, a member of the herring family, is one of the most numerous species encountered. These fish, which can grow over a foot long, are primary plankton feeders and drive changes in microscopic plankton populations. Due to their abundance, Gizzard Shad are a staple food source for larger predators and are routinely used as bait by anglers.
The Catostomidae family, commonly known as suckers, represents a major component of the river’s fish fauna and biomass. These native fish, including the White Sucker and various Redhorse suckers, are bottom feeders, consuming insects, mollusks, worms, and other aquatic invertebrates. Many sucker species are sensitive to pollution and sedimentation. Their increasing abundance in recent decades is a positive indicator of improved water quality following conservation efforts.
The Freshwater Drum is a common and widely distributed fish found throughout the river system. The Paddlefish is a unique native resident, recognizable by its long, paddle-shaped snout. This large filter feeder uses specialized gill rakers to strain zooplankton and small insect larvae from the water column.
Major Non-Native and Invasive Aquatic Species
The Ohio River ecosystem is home to a number of non-native species, some of which are established residents while others pose an aggressive threat. The Common Carp is a long-established fish, often found in the structural backwater areas. While not aggressively invasive like newer arrivals, its presence adds to the river’s complex mix of species.
A significant concern is the presence of several species of invasive carp, including Silver Carp, Bighead Carp, and Grass Carp. Silver and Bighead Carp are voracious filter feeders that consume microscopic organisms, directly competing with native planktivorous fish and mussels. Silver Carp are also known for their disruptive behavior of leaping out of the water when startled by boat traffic.
Other aquatic invaders, such as the Zebra Mussel, have caused widespread ecological disruption in the Ohio River basin. Transported from Europe, this mollusk has disrupted native food webs and contributed to the decline of native mussel species. Ongoing monitoring and management efforts are required to protect the river’s native biodiversity.