The invaders that are costing us billions - Environment Agency's top 10 invasive species

08 August 2011

The invaders that are costing us billions - Environment Agency's top 10 invasive species

The Environment Agency has released its 10 most wanted list of alien invaders – the plants and animals that are threatening to take over Britain’s waterways. 

Invasive species now cost the UK economy an estimated £1.7billion every year. They cause damage to riverbanks and buildings, increase flood risk, crowd out and kill off native wildlife and become so prolific on waterways that fishermen, boaters and anglers are unable to use them.

The cost of clearing land, such as construction sites, of invasive plants can run into the millions. The rise of invasive species is also a major challenge in meeting tough new EU targets on the ecology of rivers and lakes.

The Environment Agency currently spends over £2million a year controlling invasive species, and is this year increasing its efforts with partners such as Natural England by targeting some of the £18m funding provided by Defra to help more English rivers meet the new EU targets.

While Britain’s rivers are the healthiest for over 20 years and otters, salmon and other wildlife are returning for the first time since the industrial revolution, rivers that harbour non-native species could fall short of these tough new standards.

Trevor Renals, invasive species expert at the Environment Agency said:

 “River water quality is the best its been since before the industrial revolution. But if we don’t control invasive species, we risk losing some of our precious native species and incurring even more clean up costs. We could also fall short of the strict EU targets for our rivers and lakes. 

“The Environment Agency will be working with other environment bodies as well as community and volunteer groups to manage the spread of these damaging plants and animals. We would urge everyone to help stop the spread of these species by making sure that garden and pond plants don’t end up near rivers and parkland and thoroughly cleaning any fishing, boating and canoeing equipment when moving between waterways.”

The Environment Agency has the following 10 species on its hitlist:

  1. Killer Shrimp, Dikerogammerus Villosus
  2. Water Primrose, Ludwigia grandiflora
  3. Floating Pennywort, Hydrocotyle ranunculoides
  4. American Signal Crayfish, Pacifastacus leniusculus
  5. Topmouth Gudgeon, Pseudorasbora parva
  6. Giant Hogweed, Heracleum mantegazzianum
  7. Japanese Knotweed, Fallopia japonica
  8. Himalayan Balsam, Impatiens glandulifera
  9. Mink, Mustela vison
  10. Parrot’s Feather, Myriophyllum aquaticum

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.

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