Bio-Invasion

Bio-Invasion- the breaching of natural barriers, when non-native organisms move into new environments where they did not exist naturally. A native organism is one, which lives in its place of origin, and where it has become established and adapted its populations over the course of thousands of years and is often referred to those plants, which were established before the arrival of the Europeans in the 1700's. These species have evolved over the past thousand years to the specific climate and interactions of the other organisms in the environment. These species have evolved in the presence of natural barriers, which are as large as mountain ranges or as small as the barrier of a tide pool. An example of how physical barriers effect the dispersal of organisms can be seen in place such as the Willapa Bay where the open mud flats are providing an exceptional habitat for the nonnative grass Spartina alterniflora but the vast land and ocean masses has prevented the natural spread of the grass from the Atlantic coast of the United States. Along with Physical Barriers several biological barriers can exist and prevent the growth of nonnative organisms, these biological barriers may be a disease or another organism which out competes the invading organism for food and nutrients. Although they help to prevent invasion of nonnative organisms physical and biological barriers are not always able to prevent introduced species form spreading throughout the ecosystem. Often species are introduced into an ecosystem where they will attempt to reproduce and sustain their gene pool, if the organism is able to establish itself in the new environment, it will have to face a new set of climatic and biological conditions, in which to survive. Often he organisms which survive do so since there is a lack of a natural predator in the new environment, or there are large open spaces ready for colonization, as is the case with Spartina grass in the Willapa, these organisms which are able to survive and rapidly reproduce soon become known as an invasive species, and without methods of control could destroy the local ecosystems which they have invaded. You may be wondering how do these foreign organisms arrive in a new ecosystem, the answer lies in humans ability to transport themselves and products around the world. New species often are introduced in agriculture, when a particular region does not naturally have a desired crop or livestock, humans will introduce it, often introducing the animals diseases and pests, into the environment where they did not previously exist. Other organisms may be transplanted into a new area to assist in erosion control, or for sport fishing and hunting. Most of these practices are strictly regulated now, but in the age of international trade and large sea going vessels the opportunity for aquatic invasion is great. According to a study funded by the Washington Sea Grant Program it has recently been discovered that the water in the ballasts of ships has led the approximately 100 introductions of nonnative species. It is obvious that humans are having a great effect on the rate at which nonnative species are able to invade an ecosystem, not only through transportation, but also in the way humans crave order, we will often replace an area such as a species rich forest or wetland with a single species of crop plant such as corn or wheat, this is just like putting out welcome mat to new nonnative species, since introduced species often are very successful in species poor environments. This is why the threat of declining biodiversity is of utmost importance to the human race.

The following is a list of things which the Washington Sea Grant Program advises people to do in order to help control and prevent the invasion of nonnative species.

1. Do not transport plants or animals when you move with out checking with local authorities.
2. Never release pets, plants, or aquarium animals or plants into the wild.
3. Look into the benefits of using native plants on you property, contact your local cooperative extension
4. Be aware of the fact that we cannot eliminate the unintentional introduction of nonnative species, we can limit them. Study the pathways of introduction and do your part to stop the accidental release or movement of non-native species.
5. Learn about and teach other about the richness of ecosystems. Explain to people that plants, animals, and microbes are all a part of a larger system and one organism cannot be affected without affecting another.
6. Be aware of legislation and governmental programs that address international and accidental introductions of non-indigenous species.
7. Participate in community groups designed to restore habitat, survey, remove and report sighting of invasive species
8. Keep in mind that eradication of established non-natives is usually impossible. Prevention is possible if we each do our part.

Specific Environmental and Economic costs of Nonindigenous species in the United States, adapted from a research paper by David Pimtel, Lori Lach, Rodolfo Zuniga, and Doug Morrison, published in BioScience January 2000. There are an estimated 50,000 introduced species in the United States many of which have been imported for agricultural practices and are considered beneficial. These organisms provide approximately $800 billion per year, to the United States economy. Many nonindigenous species are not beneficial though and take a toll on the economy each year one study by the Office of Technology assessment reports that 79 exotic species caused $97 billon to the United States economy from 1906 to 1991. Additionally 400 of the 958 threatened or endangered species in the united sates are considered to be at risk of because of competition and predation by nonnative species. The 50,000 Nonnative species are costing the United States Economy $137 billion each year in economic losses; this is an underestimated figure from Pimtel, Lach, et. Al. and does not include the loss of in environmental terms, since monetary values cannot be attached to losses in biodiversity, ecosystems, extinctions, loss of aesthetic value. As one can see Nonindigenous species are exacting a huge toll on the United States and other parts of the world, it is important that we try to prevent the continued spread of these invasive and destructive species into new areas of the world, where they do not currently exist.