Maryland's Invasive Fishes
The short story of invasive fishes in Maryland
We learned a lot about invasive fishes
An invasive species can be considered by people to be bad or good. Scientists define an invasive species as an exotic or non-native species: 1) that expands its numbers and distribution from where it was introduced; and/or 2) has interactions with individuals of other species that could threaten those species' survival or reproduction.
Blue Catfish has expanded its range from original points of introduction to lower Chesapeake Bay rivers (VA) in 1970s to most subwatersheds in the tidal basin by 2020, and continues to expand its range in 2023 throughout upper Chesapeake Bay. NOTE: Areas depicted are boundaries of subwatershed and not all areas within them are inhabited by Blue Catfish. Data from angler and agency reports, including: Coastal Conservation Association (2021, 2022). Great Chesapeake Invasives Count. https://www.ccamd.org/the-great-chesapeake-invasives-count/
Northern Snakehead has expanded its range from original points of introduction to tidal Potomac River (early 2000's) and Nanticoke River (early 2010's) into most subwatersheds of the tidal basin by 2020 and continues to expand its range in 2023 to non-tidal, western waters of Maryland. NOTE: Areas depicted are boundaries of subwatershed and not all areas within them are inhabited by Northern Snakehead. Data from angler and agency reports, including: U.S. Geological Survey. 2023. Non-indigenous Aquatic Species Database.
Flathead Catfish has increased its range from orignal points of introduction at Quantico Creek (Potomac River, VA) and Susquehanna River in the 1970's to other subwatersheds of Potomac River and upper Chesapeake Bay by 2020, and continues to increase its range into 2023. NOTE: Areas depicted are boundaries of subwatershed and not all areas within them are inhabited by Flathead Catfish. Data from angler and agency reports.
MIST - Maryland Invasive Species Tracker, is a tool that the public can use to help the state track invasive species in its waterways. Data reflect public reporting and have not been verified by Maryland Department of Natural Resources.
People are asked to report invasive fishes they may see using Maryland's Invasive Species Tracker (or MIST) so that scientists can verify the species and respond as needed. Reports from the public are plotted in an online map. Click on a dot in the map for more information on what was caught, what happened, and additional information submitted in the report.
People began harvesting invasive fishes
Marylanders are working with state and federal agencies to find beneficial uses for invasive fishes while learning more about their probable impacts in the ecosystem. Beneficial uses include providing new fishing opportunities and using as food, fertilizers, and bait.
Maryland Department of Natural Resources and U.S. Fish and Wildlife Service work with charter boat captains in 2023 to learn more about the role of bowfishing in the harvest of northern snakeheads.
Maryland Department of Natural Resources harvests invasive fishes to learn more about them, their impacts, and to donate them for beneficial uses.
Maryland Department of Natural Resources worked with U.S. Geologgical Survey to learn more about abundance and movement patterns of blue catfish in Patuxent River.
Anglers and bowfishers are targeting and harvesting invasive fishes more often.
Listen to Caz Kenny talk about fishing for snakeheads.
Commercial fishing for invasive fishes has become more popular. Learn more about becoming a commercial harvester and making money on selling invasive fishes.
Blue catfish and other species are haul seined in some locations and sold to fish processors.
Fish processors cut blue catfish to sell fillets for food and skeletons can be sold to create organic fertilizer. Some blue catfish is sold as pet food. Snakeheads, though a smaller commercial fishery, is processed as food.
Eat blue catfish and flathead catfish fried or grilled.
Add nuggets of snakehead to a slider with a salad and shrimp.
Additional Links
For more information on invasive species, please visit our Invasive Species webpage .
For more information on Seafood Marketing, please visit Maryland Department of Agriculture .
For more information on consumption advisories, please visit Maryland Department of Environment .
For more information on code requirements for filleting fish for commercial sale, please visit Maryland Department of Health .
Pubished August 2023
