What is an invasive species?

Executive Order (EO) 13112 defines invasive species as species that are non-native (or alien) to the ecosystem under consideration and whose introduction causes or is likely to cause economic or environmental harm, or harm to human health. Invasive species can be plants, animals, or pathogens. The Invasive Species Advisory Committee's (ISAC) "Definitions White Paper" provides a more in-depth discussion on this topic.

Are all non-native or alien species invasive?

No, Most non-native species are not invasive and many are highly beneficial. However, even a single invasive species can cause great harm.

What are some of the ways that invasive species harm the physical environment?

Some invasive plants increase the severity and frequency of wildfires. Invasive aquatic species can alter nutrient availability and water quality. They can also interfere with the flow of water. Certain invasive plants withdraw water from deep in the soil and reduce the amount available for other uses. Others do not hold the soil well, making land more prone to erosion. Certain invasive plants alter the amount of nutrients in soils. Invasive earth worms decrease protective leaf litter cover. Nutria damage marshes that protect areas from hurricanes. Invasive crabs can dig networks of holes and weaken levees.

What are some of the ways invasive species harm other species?

Some invasive species directly feed upon or make ill fish and wildlife. Invasive plant pathogens kill forest trees and prevent their re-growth. Invasive plants shade out desired plants. Some invasive species harm other species indirectly by competing for food and space. Invasive species interfere with the growth, reproduction, and development of other species. Some invasive species produce toxins that harm other species.

What are some of the ways invasive species harm human health?

The pollen of some invasive plants can increase the severity of respiratory allergies. The sap of some other invasive plants cause skin irritation. Invasive ants cause painful stings. Invasive Brown Tree Snakes and Black Spiny-tailed iguana deliver venomous bites. The sharp spines of Yellow Starthistle cause injury to grazing livestock and interfere with military training. Invasive rodents, mosquitoes and ticks can transmit deadly pathogens. Cholera and toxic algae can be moved by the ballast of ships. Zoonotic diseases that infect both humans and animals, such as West Nile Virus, can be fatal to humans.

Where are invasive species found?

Invasive species can be found in every type of habitat. They can be found in oceans, lakes, streams, estuaries, and wetlands. On land, they can be in croplands, rangelands, back country areas, fields, and forests. Some invasive species inhabit homes and urban environments. While invasive species are in many places, there are vast resources that need our protection.

Where can I find information about invasive species in my area?

One source of information is your County's Extension Office. They are supported by the Land Grant University System and the USDA's Cooperative State Research Education and Extension Service (CSREES)

What do invasive species cost the economy?

Overall estimates are hard to determine. However, damage from just six invasive species has been estimated at $74 billion a year.

What can I do to help prevent the spread of invasive species?

You can help by learning which invasive species are in your local area, and what actions are being done to manage them. Make others aware of invasive species. Avoid unintentional movement of invasive species as hitchhikers on items such as hiking boots, boat trailers, hay, mulch, and firewood. Replace the invasive plants growing in your garden with non-invasive alternatives. Get involved in organized efforts in your area to find and remove invasive species from local parks, playgrounds and campgrounds. Learn how to care for exotic aquarium fish and other pets and plants, so that they don't become a problem. Ask your political representative to support invasive species efforts. Support non-profit organizations that work to combat invasive species.

Does NISC provide funds to control or study invasive species?

No. NISC does not provide funds directly. However, certain Federal programs within the agencies overseen by NISC members support a wide variety of invasive species actions. The USDA's National Invasive Species Information Center can provide more detailed information on grants and funding.

What is the Invasive Species Advisory Committee?

ISAC is a group of non-federal stakeholders created by the Secretary of the Interior as directed by Executive Order 13112 to provide advice to the Federal Government on invasive species issues. Chartered under the Federal Advisory Committee Act (FACA), ISAC consists of representatives from diverse subject areas such as environmental conservation, international relations, aquaculture, academics, state and tribal governments, and industry. The broad membership of ISAC provides comprehensive information across a wide spectrum of regions, habitats, species types, sectors, and constituencies.