What are invasive non-native species?

Written by Bekka Corrie-Close | 17 October 2011

Background...

Over 10,000 years ago following the Ice Age, plants and animals slowly colonised Britain coming from mainland Europe northwards. As sea levels rose, Britain was cut off from the European mainland and became an island. It is the species that had colonised Britain and established themselves during this period that we call native species.

Since then, humans have introduced many new species of animals and plants to Britain and these are called non-native species. Many of these are welcome additions to British biodiversity however, a minority do have serious negative impacts. These species spread causing damage to the environment, economy and health and are called invasive non-native species.  

How they affect you...

Whether you knew it or not, you are involved! If you are reading this, chances are you care.

Cumbrias unique freshwater environment is increasingly under threat from invasive non-native species. When they become established out of their native locations some species can cause severe and sometimes irreversable damage to the environment.

The way you live - invasive non-native species can have direct impacts on our health. Giant hogweed for example contains a photosynthetic venom which when touched caused blistering burns to the skin. Species such as Japanese knotweed and Himalayan balsam can also increase the possibility of flooding in highly infested areas.

The Economy - Invasive non-native species cost the British economy approximatley £2 billion every year! Japanese knotweed can cause huge damage to man-made structures like building foundations and tarmac roads and floating pennywort can choke watercauses, preventing recreational uses of freshwaters.

The Environment - Impacts of invasive non-native species are so significant, they are considered to be one of the greatest threats to biodiversity world wide, even more than pollution and climate change!  Invasive non-native species threaten the survival of rare native species such as the white clawed crayfish and damage sensitive ecosystems and habitats like freshwaters and wetwoodlands.

Invasive non-native species are not a one off event. The longer we wait to do something about them, the more resources, time and effort it is going to take. You play a vital role in protecting Cumbria's freshwater.