We explain what an invasive species is, what are the most invasive species in the world, where they come from and what problems they cause .
What is an invasive species?
The invasive species ( plant or animal ) is that introduced, intentionally or casually, in an ecosystem different from its origin . It becomes a plague because it does not have natural mechanisms to survive in the new ecosystem and because of the possible predators that can extinguish it.
Consequently, the invasive species develops a great capacity for adaptation and colonization of new places, and generates fertile offspring. At present, the flow of transport around the world of objects, animals, plants and humans , gives rise to invasive species that would rarely develop naturally.
Invasive species can cause minor problems or major catastrophes , for example, displacing native species , changing the appearance of an area or spreading new diseases.
The most invasive species in the world
Among the ten most invasive species in the world, of vegetables and animals, the following stand out:
- Water hyacinth ( eichhornia crassipes ). It is a native species of the Amazon basin of Brazil, in South America . It was introduced in Africa, Asia, North America, Australia and New Zealand as a decorative plant, as animal feed and as part of the aquarium trade. It also moved because its seeds adhered to the hull of the ships. It became one of the worst weeds because it causes the obstruction of rivers, hinders animal life in water and prevents sunlight and oxygen from reaching other plants.
- The kudzu ( pueraria montana var lobata ). It is native to East Asia and some islands of the Pacific Ocean . It was introduced in North America and in Europe, for orchards and as food. It is an aggressive vine that grows very fast and can suffocate other plants and even kill mature trees. It is very difficult to extract it from the ground permanently.
- The Asian carp It is a fish native to Russia and China, which was introduced in North America and Europe as food, for trade as a pet and for sport hunting. It is a problem because it reproduces quickly and because, because of its great appetite, it eats the food of other native species and the eggs of other fish species.
- The zebra mussel ( dreissena polymorpha ). It is native to the Caspian, Aral, Azov and Black Sea seas. It was introduced in Russia, Europe and North America, as a result of ballast water (the water that ships contain and that helps them maintain balance during navigation) and by adhering to the external walls of the ships. It is a problem because it eats plankton (food source of native fish) and because it reproduces rapidly.
- The cane toad ( rhinella marina ). It is native to Central America and was introduced in different warm-weather countries around the world, for example, Australia, to control crop pests. It is a problem because it has a very strong defense mechanism (a toxic substance emanates through sweat), which affects plants and animals.
- European starling or pinto ( sturnus vulgaris ). It is native to Europe, Asia and North Africa. It was introduced in North America, South Africa, Australia and New Zealand to control pests and to market as a pet. It is grouped into large flocks of birds that feed on fruits and grains, which causes serious damage to the farms. In addition, it is aggressive and away from other native bird species.
- The European rabbit ( oryctolagus cuniculus ). It is native to southern Europe and North Africa. It was introduced in all continents (except in Asia and Antarctica) to market as food. Overpopulation of the species was generated due to its high speed to reproduce. In addition, he eats so much that he has displaced many plant species and competes for food and shelter with native animals.
- The long-horned beetle ( anoplophora glabripennis ). It is native to China, Japan and Korea. It was introduced in North America and in Europe as a result of transfers (by sea) of logs and wooden packaging. It reproduces quickly and feeds on the bark, making it difficult for tree nutrients to reach their ramifications. In addition, it makes large tunnels in the wood that weaken the tree.
- The small Indian mongoose ( herpestes auropunctatus ). It is native to southern Asia and was introduced in the rest of Asia, Central and South America to control pests of rats and snakes. It is an aggressive predator and has caused various species to be in danger of extinction (such as the Jamaican petrel, the hawksbill turtle, the pink dove, the Amami rabbit and other birds, reptiles and mammals ). In addition, it transmits rage to humans.
- The North Pacific starfish (asterias amurensis). It is native to China, Japan and Korea. It was introduced in Australia as a result of ballast water and by adhering to boats and fishing boats. It is a problem because it feeds on almost anything it finds and reproduces very quickly. It has caused the spotted fish to be in danger of extinction.