EA releases 10 most wanted plants and animals threatening to take over Britain’s waterways

Invasive species now cost the UK economy an estimated £1.7billion every year.
The Environment Agency has the following 10 species on its hitlist:

  1. Killer Shrimp
  2. Water Primrose
  3. Floating Pennywort
  4. American Signal Crayfish
  5. Topmouth Gudgeon
  6. Giant Hogweed
  7. Japanese Knotweed
  8. Himalayan Balsam
  9. Mink
  10. Parrot’s Feather

Species such as the killer shrimp kill a huge range of native species which can cause a knock-on effects on the species which feed on them. The topmouth gudgeon and the American signal crayfish compete with our native species for food and habitat and have also introduced new diseases.

Mink often need to be controlled because of the damage that they can cause to wildlife, fisheries and property. They are a particular danger to our native water voles, which are protected in this country.

Some of these plants such as creeping water primrose, floating pennywort and parrot's feather are sold as pond and aquarium plants but they can spread rapidly and cover waterways. This starves the waterbody of light, nutrients and oxygen which kills many of the species living in it.

The Himalayan balsam, Japanese knotweed and giant hogweed  suppress the growth of native grasses and other flora. In autumn Himalayan balsam and giant hogweed die back, leaving the banks bare of vegetation, and therefore liable to erosion.

Giant hogweed also contain poisonous sap, which can cause blistering and skin irritation.

The Environment Agency advises anyone who finds these plants in their garden or pond to visit the ‘be plant wise’ website for advice on how to remove and dispose of them. The agency also urged river users to contact them immediately on 03708 506 506 if they suspect that they have seen killer shrimp in their local waterway.

For more information please visit the Environment Agency website