British Waterways is highlighting 12 non-native species most likely to harm Scotland's canals, towpaths, and native wildlife. They want people to think about the environmental impact of plants and pets they buy and then dispose of.

Some invasive, non-native species have made their way into the UK's inland waterways in recent years. These can cause serious problems for native wildlife, boating, access to banks and towpaths and the maintenance of the infrastructure of the waterways. Dealing with the problem costs British Waterways £1 million each year and its ecologists, in conjunction with other organisations, monitor the impact of invasive species on native wildlife habitats.

Across Britain's 2200 mile waterway network, the 12 worst offending plants and animals 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, Zebra Mussels.

In Scotland, the worst offenders are Mink and Japanese Knotweed.
Dr Olivia Lassiere, environment and heritage manager at British Waterways Scotland 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 invest a large amount of time and money to protect our canals and rivers through identifying, monitoring and controlling damaging species, diverting resources that could be used elsewhere on the waterway network. We are therefore asking people to help us by disposing of non-native plants safely. Often, unaware of their potential to cause damage to native wildlife, people introduce non-native, invasive plants and animals intended for garden ponds and aquariums to the waterways when they dispose of them."

Invasive species cause problems for a number of reasons:

• normally bigger, faster growing or more aggressive than native species, they have no natural predators to control numbers, and are often resistant to traditional control techniques


• they compete with native species for space, water and sunlight and are the second most important threat to wildlife diversity after habitat destruction and decline


• their rapid growth can choke rivers and canal channels and they become caught on boat rudders, lock gates and canal fixtures

British Waterways Scotland is encouraging people to buy alternative native plant species for ponds and gardens, and destroy or dispose of invasive non-native plants in an appropriate and responsible way. If in doubt seek professional advice.

Do not release unwanted pets into the wild.

Prevent the spread of aquatic invasive species when using the canal – especially boaters and anglers – by cleaning equipment in warm soapy water before transporting it from one water body to another

For further information and a list of useful organisations to contact visit www.waterscape.com.