A previous blog informed about the disasters caused by invasive species, so now let's learn how all this happens.
Japanese Beetle (invasive to the U.S.) - Photo taken by Josesph Berger (National Invasive Species Information Center)
We know that invasive species can harm native species by outcompeting the native species, spreading rapidly, and sometimes even directly killing the native species, but how do they get to these new ecosystems in the first place?
How It Happens
An invasive species can wind up in a different ecosystem from something as simple as the release of a pet, all the way to something as big as illegal international trade.
Let's start with the release of pets. Pets either belong in their natural habitat, or with their owners, but do not belong wherever the owner would like to release them. Introduction of invasive species in this case could easily be prevented preferably by not releasing pets into the wild, or doing so very carefully (Fish & Wildlife Foundation of Florida).
A more specific cause of invasive species is ballast water in cargo ships, generally applying to marine invasive species (National Invasive Species Information Center). Here is how it works:
1) Cargo ships pump water into the ballast tanks of the ship, to make up for the weight lost after delivering the cargo.
2) Organisms in the area may wind up in the ballast tank.
3) The cargo ship goes to another place, possibly very far away in a new ecosystem.
4) The ballast water is released from the tank, along with the organisms it carried with it.
5) These organisms are likely an invasive species to this new ecosystem it is now in.
Now, moving on to illegal trade of certain species (Society for Conservation Biology). Illegal trade is very easy to avoid, as all one has to do is follow the laws when it comes to trading any kind of living organism, or just not transporting living things from place to place at all. It is, however, harder to prevent others from participating in the illegal trade of wildlife. Wildlife trade is a very broad term and even includes buying certain foods because much of them originate from plants that are imported from outside of the United States. Not all of it is illegal, of course. Just make sure to check your sources so that you know where the product you are buying is coming from, and whether it is legal or not. By not purchasing products from illegal wildlife trade, you are already helping put it to an end,
There are many more causes of invasive species, and these are just a few of them.
Famous Examples
One famous example of an invasive species invasion was the Japanese beetle, a type of Scarab beetle. It was introduced to the U.S. in the year 1911, most likely caused by Japanese beetles being in the soil of a plant import from Japan (National Invasive Species Information Center). The native plant life in the U.S. was not adapted to this invasive species, so all these newly introduced Japanese beetles destroyed a lot of lawns, golf courses, and pastures. "The Japanese beetle has become a serious plant pest and a threat to American agriculture" (US Department of Agriculture).
Another example is the English Ivy, which can now be found in western U.S. as an invasive species (Invasive.org). It originated in North Africa, Western Asia, and Europe. It was introduced to North America in 1727 by European colonists. It is a threat to native species because its vines spread across trees, blocking sunlight from reaching the trees. The vines also make trees more vulnerable to falling over during storms. It is very easy to prevent the spread of this one. Currently, this plant is still being sold in the U.S. as an ornamental plant, despite the fact that it is considered a weed, All we have to do is make sure to only buy harmless plants, especially native plants, and we should try to avoid buying and planting invasive plants such as the English Ivy.
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