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Killing invasive species: necessary?

Hi everyone,

Today's topic is a rather controversial one: is killing invasive species necessary? We'll take it apart for you to come up with your own opinion. Enjoy!

Definition

Firstly, let's clarify what an invasive species is. An invasive species is a species that is not native and most likely causes harm to the ecosystem where it now lives. This does not include animals that migrate to another area.

Why is it a problem?

Depending on the species and the ecosystem, invasive species can cause a lot of harm to their surroundings. Often invasive species have no predators in their new habitat and reproduce in such large numbers that they massively overpopulate, causing death for other species. Or they bring sicknesses the local animals are not accustomed to, and that kills them. For example black and brown rats are an invasive species on the Galapagos Islands:
Black and brown rats were introduced to the Galapagos Islands in the 17th century. They came in the holds of pirate and trade ships and then came ashore. Because many of the birds living on the islands are endemic (only found in one place), they did not know how to deal with these new rat species. These invaders would eat the bird's eggs and chicks. This also affected many local reptile species. Because of this problem, three of the archipelago's native rat species have gone extinct and many giant tortoise species are critically endangered.
However, sometimes invasive species may have positive effects in some cases, as they may be able to cope with arising problems local species cannot deal with. This is becoming increasingly important with climate change and the problems it brings. For example, scientists are currently trying to find a way to avoid all the trees in German forests dying due to the heat in summer. One idea is to introduce different types of trees that can withstand heat. They are not native to Germany, but they could be a solution.

What is being done

Worldwide there are many projects to kill invasive species. For instance, on the Galapagos Islands of North Seymour, Rabida and Pinzon rat poison was dropped from a helicopter to kill the black and brown rats. It was successful and the giant tortoise population is now growing again.

Generally, it is hard to give a statement that applies to all cases, as with most things. But invasive species are often more harmful than helpful when they aren't introduced to a region with a specific purpose, and it is mostly necessary to kill them to save local species. Invasive species tend to threaten the local ecosystems and therefore their introduction may reduce biodiversity, which is generally to be avoided. So our take on this problem is that each case should be viewed individually and action should be taken depending on whether or not the native biodiversity is at risk.

Your Green World Team💚



Images:
This image, owned by Héctor J. Claudio (on flickr.com), is licensed under CC BY-NC-SA 2.0.

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