The introduction of invasive and non-native species can cause irreversible changes in the food web. Several invasive species of concern are listed below. For more information on invasive and non-native species, including a list of species prohibited from transport, visit Maryland DNR's Invasive Species page. To report the illegal transport or unauthorized introduction of invasive species, contact the Natural Resources Police—800-628-9944.
Chesapeake Channa (Northern Snakehead)
It is against Maryland, Virginia, and federal laws to possess, import, or transport live Chesapeake Channa.
The Department of Natural Resources asks anglers to report Chesapeake Channa by submitting a photo through Maryland's Invasive Fish Tracker.
Illustration of a northern snakehead (Channa argus), an invasive freshwater fish with an elongated body, mottled brown coloration, and a distinctive snake-like head. Native to Asia but introduced to North America, this species is known for its aggressive behavior, ability to breathe air, and negative impact on native ecosystems.
If you catch a Chesapeake Channa and want to eat it, you must immediately harvest the fish. Anglers are encouraged to catch and keep Chesapeake Channa year round. There is no minimum size or creel limit for Chesapeake Channa.
It is illegal to possess live Chesapeake Channa. This illegal act is punishable by a fine of up to $2,500 per fish, up to $25,000 per incident.
If you catch a Chesapeake Channa with a tag, please report the tag number and the location, date and time of day when the fish was caught to the U.S. Fish and Wildlife Service at 800-448-8322.
Blue and Flathead Catfish
The Department of Natural Resources asks anglers to report blue catfish or flathead catfish by submitting a photo through Maryland's Invasive Fish Tracker.
Chesapeake blue catfish and flathead catfish are invasive species that have spread rapidly throughout the Chesapeake Bay and its tributaries. These catfish have few natural predators, eat a wide variety of native fish and shellfish, and may cause ecological harm.
It is illegal to release live catfish into a waterbody different than where it was caught. This illegal act is punishable by a fine of up to $2,500 per fish, up to $25,000 per incident. Anglers are encouraged to keep for food or other beneficial uses year round. There is no minimum size or creel limit for these catfish.
Invasive Catfish Identification
Blue Catfish
Illustration of a blue catfish (Ictalurus furcatus), a large freshwater fish with a bluish-gray body, forked tail, and whisker-like barbels around its mouth. Native to the Mississippi River basin but introduced to other waterways, this species is known for its rapid growth, large size, and popularity among anglers. An arrow points to the fish's anal fin, distinguishing it from other catfish species.
Anal fin squared with 30 to 36 fin rays
Flathead Catfish
Flathead Catfish (Pylodictis Olivaris), an invasive freshwater fish species in Maryland. Recognizable by its broad, flat head and whisker-like barbels, this predatory fish disrupts local ecosystems by preying on native fish populations.
Projecting lower jaw and a slightly notched tail
Non-Invasive Catfish Identification
Channel Catfish
Channel catfish (Ictalurus punctatus), a popular freshwater game fish in Maryland, identified by its slender body, deeply forked tail, and whisker-like barbels.
Anal fin with rounded margin and deeply forked tail
White Catfish
White catfish (Ameiurus catus), a native freshwater species in Maryland, recognized by its stout body, broad head, and slightly forked tail.
Stocky body with large head, anal fin with rounded margin and moderately forked tail, white chin barbels
Catfish Illustrations by Duane Raver
Zebra Mussels
Zebra mussels are an aggressive invasive species and reproduce at a very prolific rate, out-competing native species for needed resources. These mussels quickly overtake and cover all available areas to such an extent that they can clog water intake structures, boats, moorings, ropes, fishing lines, traps, and even dams and power plants. Zebra mussels are established from the Susquehanna River and Flats to the upper Bay. Additionally, The Department of Natural Resources recently confirmed the presence of zebra mussels in tributaries of the upper Western Shore near Middle River in Baltimore County.
Close-up image of invasive zebra mussels (Dreissena polymorpha) attached to aquatic plant roots, posing a serious threat to Maryland's freshwater ecosystems. These small, striped mussels rapidly spread by hitchhiking on boats, fishing gear, and vegetation, disrupting native species and water quality. Learn how to identify, prevent, and report zebra mussel infestations in Maryland waters.
Help Protect our Resources and Harvest an Invasive Species
If you are interested in selling the Chesapeake Channa, blue catfish, or flathead catfish you catch, there may be a license that will let you do that. There are licenses that allow you to use hook and line or archery equipment to harvest and sell Chesapeake Channa and finfish trotlines to harvest and sell blue and flathead catfish caught from tidal waters. For more information about these licenses, contact our Licensing and Registration Service at 410-260-3220.
State Records for Invasive Species
Catfish, Blue — 84.0 lbs., Ed Jones, 8/13/2012, Near Fort Washington, Potomac River
Maryland’s Most Unwanted: A guide from the Maryland Department of Natural Resources on preventing the spread of invasive aquatic species. The flyer provides essential steps for boaters and anglers, including removing debris, draining water, and avoiding the release or transfer of fish. Scan the QR code to report invasive species and protect Maryland’s waterways.
