British Waterways has today released a list of the 12 non-native species most likely to damage the country’s canals, rivers and towpaths, harming native wildlife. The organisation is encouraging people to think about the impact on the environment before releasing these so-called “dirty dozen” into the environment.

British Waterways spends £1million each year controlling non-native invasive species across its infrastructure, monitoring the impact of these species with the help of its ecologists. Chris John, British Waterways’ National Ecologist said: “Whilst not all non-native species are harmful, many pose real problems to our native wildlife, to boaters and to our historic channels, locks and bridges. With no natural predators to control them they can overwhelm wildlife, channels, banks and towpaths…We are therefore asking people to help us by disposing of non-native plants safely and carefully, selecting alternative plants for gardens, ponds and aquariums.”

The twelve species are: Japanese Knotweed, Australian Swamp Stonecrop, Giant Hogweed, Himalayan Balsam, Water Fern, Floating Pennywort, Chinese Mitten Crab, Red-Eared Terrapin, Mink, Zander, American Signal Crayfish and Zebra Mussels.

Access British Waterways’ guidance for the public

Access the Inasive Non-Native Species Framework Strategy for Great Britain

Access POSTnote 303 by 2008 BES POST Fellow, Fay Collier, on Non-Native Invasive Species