Invasive Non-Native Species Management

South Cumbria Rivers Trust takes the issue of invasive non-native species (INNS) very seriously. The freshwater resources of Cumbria – its many tarns, lakes, rivers and becks – are of great ecological and economic significance. INNS have the potential to cause substantial damage to these fragile ecosystems so it is vital that we all take responsibility for protecting them.

We are relatively lucky so far with the small number of freshwater and riparian plants and animal species that have arrived in the area. Those that we do have (Japanese Knotweed, Himalayan Balsam, Giant Hogweed and American Skunk Cabbage), we run a number of control programmes for.

For those species that have not arrived to South Cumbria yet, it is incredibly important to prevent them from doing so. This is why we take biosecurity so seriously. Prevention is key – making sure that no species are introduced or spread between areas is a priority.

American Skunk Cabbage
Floating pennywort


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 and if you are reading this, chances are you care.

South Cumbria’s 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 irreversible 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 approximately £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 a watercourse, 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 wet woodlands.

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 environments.


We in Cumbria love spending our time in and on the water. Protecting our freshwaters from invasive non-native species is something that we must all address as it is all our responsibility. Invasive non-native species can hitchhike on our equipment, clothing, dogs and boats. When we move to a new pond, stream or lake, the species are released and may become established and alter our waters dramatically.

We can all help to prevent the spread of freshwater hitchhikers by following a simple three step process every time we leave any pond, stream or lake…. CHECK, CLEAN and DRY.


Our work is funded and carried out in partnership with many organisations, including the Environment AgencyNatural England, the Lake District National Park (LDNP), National Trust (NT), and a significant number of volunteers who are passionate about protecting our incredible South Lakes.


The Cumbria Freshwater Invasive Non-Native Species (CFINNS) Initiative was a collaborative project funded by the Environment Agency, Natural England and DEFRA that ended in 2020. The work on invasive non-native species was a county-wide collaborative pilot project for freshwater and riparian invasive non-native species (INNS). 

For more information about CFINNS including DOWNLOADABLE ID GUIDES and BIOSECURITY MATERIAL, click HERE.


We have recently finished working on a RAPID Life project creating a management plan for Invasive non-native species control and eradication.

Under the Animal and Plant Health Agencies (APHA) banner, RAPID life was a three-year EU Life funded project, aiming to deliver measures that will reduce the impact and spread of IAS (Invasive Alien Species) in freshwater aquatic, riparian and coastal environments across England; also known as Invasive Non-Native species (INNS). The country was split in to 5 regions and SCRT covered both the Midlands and the North. Our previous INNS officer, delivered many workshops across the region, teaching academics, volunteers and members of the public about INNS and what we can all do #stopthespread before it is too late. 

If you have a question about INNS, please get in touch with our INNS officer Sammy Graves: