Impacts of Invasive Species

Invasive species have been a major problem with natural ecosystems for millions of years. Arguably invasive species have been the most destructive and the most difficult to control. The impacts of invasive species have cost the environment and the stakeholders of the environment and immeasurable amount of money and time due to the damage.

Environmental Impacts

The environmental impacts of invasive species are immense, there has been approximately 50,000 invasive species introduced to the United States (Pimentel, 2004). Many of the invasive species in the Unites States have been introduced intentionally, for example, pets, livestock, and crops have been introduced intentionally and most species have had success.

Economical Impacts

In the United States alone the expenses associated with the damage done by invasive species is around 137 billion dollars per year (WDNR, 2005). This is an astonishing amount of money and it seems to be rising year after year.

Pathways of Invasive Species

There are many pathways for invasive species to get to a place where they are not welcome. Many aquatic species use boat hulls, fishing equipment, escapes from aquatic farming, and ballast water in ships just to name a few (EPA, 2007). There are many examples of one species being brought into an area to control another species that is causing problems, but in the end causes more problems than good. Guam was free of snakes until right after World War II when the United States Military moved equipment in that was harboring brown tree snakes. The island of Guam has lost many native birds and other reptiles directly because of this snake invading habitat (Pimentel, 2004).

Laws in place

There are many laws in the United States that try to regulate the spread of invasive species, it is however difficult to control the movement of invasive species into the country. One such law that is in place to control emerald ash borers states; “To require the Secretary of Agriculture, acting through the Deputy Chief of the State and Private Forestry organization, to provide loans to eligible units of local government to finance purchases of authorized equipment to monitor, remove, dispose of, and replace infested trees that are located on land under the jurisdiction of the eligible units of local government and within the borders of quarantine areas infested by the emerald ash borer, and for other purposes” (USDA, 2007). The laws pertaining to invasive species in the Unites States are vast and new laws come up every day to protect the natural species that still exist. Domestic Threats There area many national, state, and local threats and in Nebraska one of the main threats to the native grassland is noxious weeds. Noxious weeds in Nebraska include musk thistle, Canada thistle, and leafy spurge. In Nebraska the landowner is responsible for containing and controlling these noxious weeds so they don’t spread to other neighboring plots of land. There are many other national threats to the United States and some of the most recent species include the emerald ash borer, which arrived accidentally in a cargo ship; Africanized honeybees were imported and bred with European honeybees to increase honey production, but they are more aggressive and have had a negative impact on honey production (USDA, 2008).

== International Threats ==

A threat to one country can also be a threat to another country, so because of this many countries are joining together and finding ways to combat threats from invasive species. One example of this is the USDA and the Russian government are working together to identify the Asian gypsy moth in Russian ports to prevent its spread into the United States in international trade (USDA, 2004). Probably one of the most at risk areas in the world is South America. South America has an extremely high number of invasive species that are causing harm to the environment because of increased competition and the invasive species preying on natural wildlife.

== Methods of Prevention ==

There are several ways to prevent invasive species from coming into an area. One of these methods is the management of ballast water in cargo ships. There are several ways to do this and one is treatment of the ballast water before letting it out. Another is to remove ballast water where there is little chance for environmental harm (Buck, 2007). Other methods include heavy inspection of international cargo, restrictions on any non-native wildlife being brought in, and careful management of the land so noxious weeds cannot establish growth.

What can a single person do for prevention

The best thing that a single person can do for prevention of the introduction of invasive species is to get educated about the issues. People with unwanted pets sometimes release them into the wild and this is devastating to the environment. People that are boaters need to inspect their boat and trailer often and fishermen need to buy their bait from licensed dealers. Campers should use local firewood and inspect their items before coming and going to a camping site.

References

PNAS. 2001. Stanford. Available from http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=33232 (Accessed April 2008)

Annual Reviews. 1996. Maine. Available from http://arjournals.annualreviews.org/doi/abs/10.1146/annurev.ecolsys.27.1.83 (Accessed April 2008)

U.S. Fish and Wildlife Service. 2007. Washington D.C. Available from http://www.fws.gov/contaminants/Issues/InvasiveSpecies.cfm (Accessed April 2008)

IUCN. 2004. Available from http://www.issg.org/ (Accessed April 2008)

USDA. 2008. Available from http://www.invasivespeciesinfo.gov/ (Accessed April 2008)

Invasive Species. 2007. Georgia. Available from http://www.invasive.org/ (Accessed April 2008)

United States E.P.A. 2007. Washington D.C. Available from http://www.epa.gov/owow/invasive_species/pathways.html (Accessed April 2008)

Indiana Department of Natural Resources. 2006. Available from http://www.in.gov/dnr/invasivespecies/ (Accessed April 2008)

The Global Invasive Species Team. 2008. Available from http://tncweeds.ucdavis.edu/ (Accessed April 2008)

Wisconsin Department of Natural Resources. 2008. Available from http://dnr.wi.gov/invasives/ (Accessed April 2008)