Key CodeScientific NameCommon Name
2, 3Branta canadensisCanada Goose (non-migratory)
1, 2, 3, 4Channa argusNorthern Snakehead
* 1, 2, 3* Ctenopharyngodon idella Grass Carp
2, 3Cygnus olorMute Swan
2Gambusia affinisEastern Mosquitofish (non-tidal)
1, 2, 3Myocastor coypusNutria
2, 4Rattus norvegicusNorway Rat


* Red Alert species: Species not yet established in Maryland but considered to be of high risk.

  1. Currently Regulated by state and/or federal law
  2. Widely recognized by biologists and natural resource managers to degrade natural resources and/or negatively impact native species
  3. Known to have a negative economic impact on agricultural or natural resources
  4. Known or potential negative impacts on human (or animal) health