Skip to Main Content Skip to Main Navigation
Join the Griffin's Guide HUNTING newsletter

Get weekly news, tips and photos from the world of hunting.
[contact-form-7 id="35884" title="GG Email"]
No Thanks!

Invasive Species

Brought to you by:

The introduction of invasive and non-native species can cause irreversible changes in the food web. They are typically long-lived, fast growing, opportunistic feeders. Invasive species can be a serious threat to our native and naturalized species. For information on invasive and non-native species and to see a list of species prohibited from transport, visit



Please Catch and Kill

Northern Snakeheads

The northern snakehead population is thriving in the Potomac River and its tributaries after being illegally introduced several years ago. It is against Maryland, Virginia, and Federal laws to possess, import, or transport live northern snakehead.

If you catch a snakehead and want to keep it, you must immediately kill the fish by removing its head, gutting it or removing its gill arches. The capture and possession of dead and dismembered snakeheads is not subject to any season, creel limit or size limit.

DNR asks anglers to report snakeheads caught outside of the Potomac River and its tributaries or upstream of Great Falls. Send catch information to or call 410-260-8325 to help DNR track the range of the species.

Federal law prohibits the importation of live snakeheads to the U.S. or transport of live snakeheads across state lines without a permit from the U.S. Fish & Wildlife Service.

If you catch a northern snakehead with a blue tag, please report the tag number and the location, date and time of day where and when the fish was caught to the U.S. Fish & Wildlife Service at 800-448-8322.


Blue & Flathead Catfish

DNR asks anglers to remove and kill any blue and flathead catfish that they catch. Catch and release of these fish is discouraged, as they are invasive top predators and pose a serious long-term threat to our native species. In Maryland, it is illegal to transport live blue and flathead catfish for the purpose of introduction into another body of water. Violators can be fined up to $1,000.

In January 2012, the Chesapeake Bay Program’s Sustainable Fisheries Goal Implementation Team adopted a Chesapeake Bay Invasive Catfish Policy to reduce blue and flathead catfish populations, stem their spread, and mitigate impacts on native fish populations and ecosystems. MD DNR policy and regulations regarding blue and flathead catfish may change in 2013. For the latest information relating to blue and flathead catfish policy or regulatory changes, please visit

To report illegal transport or unauthorized introductions of invasive species please contact the Natural Resources Police at 800-635-8124.

Blue catfish and channel catfish are similar. Please understand and recognize the difference to avoid the inadvertent spread of the invasive blue catfish.


Blue Catfish
Anal Fin Squared with 30 to 36 Fin Rays


Channel Catfish
Anal Fin Rounded with 24 to 29 Fin Rays


Chinese Mitten Crab


The first Chinese mitten crab documented in Chesapeake Bay was found in 2006 at the mouth of the Patapsco River. It migrates from nontidal rivers and tributaries to reproduce in salt water. Young crabs spend 2–5 years in nontidal tributaries and can extend up to 50 miles inland.

How to identify a mitten crab:

  • Claws equal in size with white tips and hair. A crab without hair on the claws is likely not a mitten crab.
  • Light brown to olive carapace up to four inches wide.
  • This crab has eight sharp-tipped walking legs, but no swimming legs.

If you find a mitten crab, freeze or keep it on ice and call the Smithsonian Environmental Research Center (SERC) mitten crab hotline at 443-482-2222 or contact

It is illegal to introduce any fish species into Maryland waters except bait fish on a hook for angling. This is to prevent the introduction of disease and the spread of fish that could compete with native species.

To import or stock fish in Maryland, suppliers must register with the Department and comply with Maryland fish health requirements to ensure that stocked fish do not impact resident fish.

A permit is required to stock fish into any Maryland waters, including private ponds. Contact or call 410-260-8325 for more information on registering and obtaining a permit.

Do not release aquarium fish to the wild, and never transfer fish from one area to another.


Regulations in red are new this year.

Purple text indicates an important note.

Return to the home page
Brought to you by:
Conservation Partner Advertisements: The Maryland Department of Natural Resources allows appropriate advertising in its annual regulation guides in print and online, in order to defray or eliminate expenses to the state, and support enhanced communications with Maryland Department of Natural Resources Constituents. Through a unique partnership with J.F.Griffin Publishing, LLC &, ‘Conservation Partners’ have been established that pay for advertising in support of the regulations both in print and online. The Maryland Department of Natural Resources neither endorses products or services listed or claims made; nor accepts any liability arising from the use of products or services listed. Advertisers interested in the Conservation Partners program should contact J.F.Griffin/ directly at 413-884-1001,
JF Griffin Media
J.F. Griffin Media reaches 9,000,000 sportsmen every year through our print and digital publications. We produce 30 hunting and fishing regulation guides for 15 state agencies. For advertising information, please visit: