Invasive Species

Introduction | Species Info | Teacher Materials | Resources

Unique Physiological Advantages of NIS

NIS have biological advantages that help them to succeed.

• High rate of reproduction: Some NIS, especially plants, can reproduce both sexually and asexually. Most have high genetic variability, as well as early and rapid physiological development.
• Long-lived: Most NIS can subsist on available foodstuffs. Many have advanced systems to utilize nutritional value of food and/or advanced defense-offense mechanisms.
• Adaptable: Most NIS have a broad native range and can tolerate a wide range of climatic conditions.

When NIS seek residence in a new environment, their biological advantages are often enhanced by a lack of natural predators, diseases, or parasites that controlled their populations in their native ranges.

Because the harmful effects of NIS may differ, those trying to control the spread of these species need information on their physical descriptions, native and invaded habitats, and population densities. Several federal, state, and regional agencies maintain such information, including fact sheets, brochures, and maps of infestation locations. Some of the most comprehensive information resources are accessible online.

• List of aquatic NIS in the Gulf of Mexico and south Atlantic regions
• Database of invasive species throughout the U.S.

Bibliographical resources about NIS are available online.

• The Sea Grant National Aquatic Nuisance Species Clearinghouse is a library of research, public policy, and outreach education resources pertaining to NIS in North America. It contains publications on invasive fish, mollusks, crustaceans, other invertebrates, and birds.
• The Aquatic Invasions Research directory is a database of current information on people, research, technology, policy, and management issues relevant to aquatic invasions.

Although a small number of the many NIS that are transported throughout the world actually cause economic or ecological harm, their effects are multiple and costly. An estimated annual cost of about $137 billion for controlling and monitoring about 30,000 plants and animals in the U.S. is only the beginning. At least that much is lost due to costs in world trade and travel, as well as production, when agricultural products are affected. Information on national, regional and state scales is available from the National Invasive Species Information Center.