What is an invasive species?

An invasive species is an animal or plant that did not evolve in the Chesapeake Bay region and that has a negative effect on the Bay’s ecosystem. Invasive species arrive in Maryland through various means, including through the ballast of ships, in the packing material of imported goods, and through deliberate import.

Not all non-native species are invasive and some that initially seemed benign or beneficial - such as grass carp or European starlings - develop invasive characteristics long after their arrival.

The Maryland Department of Natural Resources has identified more than 200 non-native species that may be invasive, including nutria, a large South American rodent; mute swans; zebra mussels; water chestnut; and wavyleaf basketgrass.

Such species are able to thrive, in part, because their “new” environment lacks natural ecological controls such as predators and disease, found in native habitats. Once established, invasive species can be very difficult and costly to eradicate or control.

DNR continues to explore ways to minimize the negative impact of invasive species through regulations, public education, monitoring, and research. The public can help stop the spread of invasive species by becoming aware of the many ways they can be inadvertently transported from one habitat to another. Gardeners, pet owners and anglers can get more information on preventive measures at: /wildlife/invhelp.asp