Hearing the word "invasive species", a lot of people might think that only specific flora and fauna have the power to turn "invasive". In fact, this is a common misunderstanding of the invasive species.
What are invasive species?
Technically, any species could be an invasive species, as long as it is not native to an ecosystem. When species are relocated in a new environment, it either dies out or overgrows because no natural enemy exists. Invasive species are labeled "invasive" because the species will grow and reproduce rapidly and aggressively, and can harm the ecological balance, biodiversity, or even human health.
The African giant snail is an invasive species in China. /VCG Photo
How severe are the impacts of invasive species?
Invasive species' impact on native species can be terrible, even lead to extinction. One of the most famous examples of extinction led by invasive species happened in the 16th Century.
The dodos, flightless birds endemic to the island of Mauritius, went extinct because of the introduced animals, including pigs and macaques, brought by sailors.
A three-dimensional reduction picture of dodos. /VCG Photo
Scientists believe that the invasive animals had disturbed the ecological balance, and caused the dodos to die out in the competition for habitat and limited food resources.
Examples of invasive species
Many invasive species have already caused trouble. For example, the famous Asian carps that almost occupy the Mississippi River in the United States, the Eastern gray squirrels in Great Britain, and European rabbits in Australia. They had driven the government to establish policies and spend a lot of money, killing them to prevent them from threatening local species.
Asian carps in the United States. /VCG Photo
Things are little different in China, as one of the most famous invasive species, the Louisiana crawfish, got controlled in a creative way.
The Chinese dish "Spicy Crawfish" is one of the most popular ways to cook Louisiana crawfish. /VCG Photo
The Louisiana crawfish was first introduced to Japan in 1927 and soon grew invasively. It was then discovered in Nanjing City of east China's Jiangsu Province. However, Chinese people soon found many flavorful ways to cook it. Hence the joke "Louisiana crawfish may feel regret to have invaded China."
(All images via VCG)
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