Tell me, if someone was to come into your home, move your furniture around and tell you what to do… how would you feel?
If you went to the market to buy your favorite food but there wasn’t any left for you to buy… how would you feel?
If a robber was to chase you down the street and try to attack you… how would you feel?
These are the type of influences that an introduced species (like carp) have on other organisms. What is an introduced species, you ask?
An introduced species is an animal or a plant that has been released in an environment other than the one they originated from. Many introductions are accidental. They may have simply extended their range or moved after a natural disaster.
Unfortunately, some introductions are a direct result of human activities and influences, and generally speaking, these are the introductions that have had the biggest impact on the environment.
So would we have introduced these species if we new the consequences? There are many reasons why an intentional introduction might occur and a few are listed below:
- some species are introduced for recreational or commercial purposes. When carp was introduced to the Murray River, South Australia, in the 1850’s to assist settlers. Now that we know how carp has affected the river systems in Australia we are trying to eliminate them from the system.
- another method of introduction could be transport on the hulls of ships, ballast water, and other storage transports. The Zebra mussel, Dreissena polymorpha, was discovered in the Great Lakes in the US in 1988, most likely introduced in ballast water. Strict rules are now in place in Australia to prevent such introductions from occurring but the damages from the past is evident.
There are many other vectors of transport, these are just a few examples.
So why is this a problem? I’m sure you are probably asking yourself why this matters. Why should you worry about something that in all honesty you cannot see and doesn’t have any impact on you personally?
Well, the presence of an introduced species can do one of two things. Most introduced species have very little impact (there are many more introductions than one might think). In most cases the organisms may survive for a short time, but they will eventually die. But in some cases, these species establish a population and disperse. And this is where the problems start.
When an introduced species establishes and disperses it will often have a serious negative impact on the organisms already populating the area and on the environment itself. Predatory organisms eat and take prey of others, they change the environment into which they are introduced, eat crops and other vegetation, and more. The presence of invasive species can be a threat to agricultural production, biodiversity, and even human safety.
So why should we care? Check out this great animation and decide for yourself 🙂
Keep your eye on this space for future posts on invasive species