To protect Maryland’s unique and essential native species, the Maryland Department of Natural Resources (DNR) has taken steps to help prevent invasive species from being introduced into our state’s waters and to control and contain existing populations. We work with the federal government, other Maryland state agencies, other states’ agencies and local organizations to respond to invasive species issues. The DNR is also working to educate citizens about invasive species which could affect our state. This webpage provides links to our current projects, regulations, cooperators, sources of information and other related information.
- For information on reporting and handling invasive species CLICK HERE
- For information regarding unwanted pets CLICK HERE
- Gear Cleaning, Does it Really Make a Difference? CLICK HERE
What Are invasive Species?
Invasive species can be defined as organisms that evolved in another ecosystem, and, if introduced into a new habitat, can alter or harm the new ecosystem and reduce the abundance, health and diversity of native organisms. LIST OF PROHIBITED INVASIVE SPECIES
Understanding the Terminology:
Invasives are sometimes called introduced, exotic, nuisance, or alien species. Just because a species is exotic or alien does not mean that it will become undesirable or harmful to the ecosystem. Only when a species that evolved in a different location, and then was moved purposely or accidentally to a new location by people, causes ecological, or economic damage or harm humans, is it considered invasive. We have a number of species that have adapted to life in Maryland and are seen as desirable additions. Brown trout, rainbow trout, walleye and largemouth bass are valued species for the fishing community and all are introduced. The introduced aquatic weed, hydrilla, has established dense beds in the Potomac that hinder boating but is valuable in reducing turbidity and providing cover for fish.
Although from an ecological perspective, one cannot add species without altering other species and associations within the ecosystem, several of the introduced species have “naturalized” and have developed populations that coexist with natives. On the other hand, species such as snakehead fish, grass carp, green crab, water chestnut, mitten crab, virile crayfish and zebra mussel have the capacity to radically alter habitats and reduce associated native organisms.
Alien species, introduced into new habitats, are brought in without the diseases, competitors, predators or herbivores that they faced in their native land. Without these controls on growth and reproduction, these species proliferate to the point that they outcompete and crowd out native species. These alien species may also bring in foreign diseases and parasites which harm native and naturalized species.
If alien species become established in a new habitat and become invasive, they can be very difficult to eradicate. Two common characteristics of invasive species are that they produce large amounts of seed or offspring and they are very adaptable to a range of habitat types. Zebra mussels may cover all exposed hard surfaces and leave no room for other shellfish or benthos to live. Grass carp may eat all the aquatic plants and remove cover and attachment surfaces for other water life.
Rather than continually fighting established populations of alien species, DNR prefers to prevent them from establishing, or to use early detection and rapid response measures to control new infestations. State and federal agencies have lists of prohibited species and rules against release of pets or aquaculture/agriculture organisms that may become invasive. There are numerous restrictions on international and interstate trade that may spread these pests.
Citizens can help eliminate new introductions of alien species by not moving aquatic species, either plants or animals, from one body of water to another, not emptying bait buckets and containers into the water, not releasing unwanted pets, notifying DNR of their observations of illegal releases and notifying us of observations of any specimens of the prohibited species that are listed on this website.
NEW - Zebra Mussel Meeting Annapolis 1-30-09
The following are laws and regulations that help protect Maryland’s native and naturalized species:
Fact Sheets:
If you have an exotic pet that you no longer wish to care for, the Maryland Association of Pet Industries has a program called Gold Circle Dealers which are pet stores who will re-home your unwanted pet. Please visit their website for store locations and additional information:
DO NOT release it into the wild