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, we humans have introduced many new species of animals and plants to Britain and these are called non-native species. 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.

Natural barriers to the movement of species such as oceans and mountains have meant that unique ecosystems have developed throughout the world. Globalisation has expanded the possibilities, extent and complexity of world trade which along with the growth of tourism has expanded hugely the movements of people, commodities and products. New waterways are being built and link to river catchments across Europe and there is an increase in water-based recreation too. This has increased unintentional and intentional introductions of species outside their natural range, and establishment of FINNS away from their co-evolved competitors and predators.

How they affect you

Whether you knew it or not, you are involved! If you are reading this, chances are you care.
Cumbria’s unique freshwater environment is increasingly under threat from INNS. When they become established out of their native locations some species can cause severe and sometimes irreversible damage to the environment.

The way you live – INNS can have direct impacts on our health. Giant hogweed for example contains 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 Environment – Impacts of INNS are so significant, they are considered to be one of the greatest threats to biodiversity worldwide. They threaten the survival of rare native species such as the white clawed crayfish and damage sensitive ecosystems and habitats like freshwaters and wet woodlands.

The Economy – INNS cost the British economy approximately £1.7 billion every year! Japanese knotweed can cause huge damage to man-made structures like building foundations and tarmac roads and floating pennywort can choke water causes, preventing recreational uses of freshwaters.
INNS 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.