Invasive Species

Sometimes, different types of marine life have been moved from the sea or ocean that they normally live in to another sea or ocean.  Whilst this usually happens accidentally, it can cause a problem if the marine life acts like an alien in moving to a new place to invade it and do it harm. 

Different types of marine life are known as marine species, and this is why this type of marine life is called invasive species.  And if there are no natural predators in the new environment the invasive species can be almost impossible to get rid of.

Many marine species have hitched a ride across the world’s oceans on ships. Bacteria and other microbes, small invertebrates and the eggs, cysts and larvae of various species can fasten themselves to the hulls of ships.  Or they may be taken up in the ballast water that is taken on board ships in special tanks to keep the ship stable and stop it keeling over during a voyage.

To maintain their stability in the water, ships may take on or pump out ballast water, according to the amount and weight of cargo on board.  This ballast water is usually taken up by ships at the port where they begin their voyage and then emptied back into the sea on reaching the destination port.  More than 10,000 different types of species of aquatic or marine microbes, plants and animals can be carried across the globe in ballast water every day.

IMO has a regulation that says that ships’ ballast water must be specially treated before it is released into a different sea or ocean, to kill off any of these invasive species.  New methods to do this have been developed.  This includes using ultraviolet radiation, ultrasound, or special ingredients, that have been tested properly to make sure they will kill off the invasive species in ballast water but will not cause any other harm to the environment. 

Read all about it!

Have a look at a map of the world, or a globe, and find the North Sea. Now you can read all about the Underwater Alien Invasion of the North Sea.

Do we have any invasive species in our own environment?  Are there any animals or plants that you can find out about that have invaded and taken over somewhere that they shouldn’t be and caused harm in any way?