SOME of them look pretty nasty, but others appear pretty innocent.

But don't be fooled - these are five of Somerset's and Bristol's worst 'invaders' threatening local wildlife and the environment.

They have been outed by the Environment Agency to promote Invasive Species Week, which runs until Sunday (March 6).

 

The lobster-like Signal Crayfish has been an invader since the 1960s and are a danger to native counterparts because they carry a plague which is driving them towards extinction.

 

You may have heard of killer shrimp, but what about demon shrimp? They are less aggressive than their killer cousins, but their lack of distinction means they tend to be mistaken for our native species and might be found in Bristol Avon.

They might be small, but the zebra mussel has strength in numbers, with each capable of sucking oxygen and nutrients out of a litre of water each day in Huntspill. They also clog water pipes, filters and turbines and are a multi-million dollar menace in North America.

The aquatic Parrot’s Feather plant looks innocent, but if it grows out of control it can out-compete native plants, block essential sunlight, deplete oxygen and more. And it has been seen in West Camel.

Finally, the Creeping Water Primrose is a pond dominator and has been found in Langport.

The best way to stop these species spreading is through best practice.

The Environment Agency recommends the Check, Clean, Dry approach.

*Check your equipment and clothing for living organisms. Pay particular attention to areas that are damp or hard to inspect.

*Clean and wash all equipment, footwear and clothes thoroughly. If you do come across any organisms, leave them at the water body where you found them.

*Dry all equipment and clothing - some species can live for many days in moist conditions. Make sure you don't transfer water elsewhere.

 

Invasive Species Week, run by Defra and GB Non-native Species Secretariat, is now in its second year and sees organisations across Britain working together to raise awareness of invasive non-native species to stop them from spreading and damaging our landscapes as well as harming our native wildlife.

While the majority of animals and plants introduced to Britain are harmless, around 10 to 15% become ‘invasive’, harming our environment and costing our economy over £1.7billion a year.

 

Niall Moore, chief non-native species officer and head of the GB Non-native Species Secretariat, said: “Invasive non-native species are one of the key threats to our wildlife and natural environment, and can be extremely costly and difficult to manage if allowed to establish.

"Help to prevent this from happening by getting involved and spreading the message during Invasive Species Week."