2. American minkMustela vison Main cause of catastrophic decline in water vole population in Britain. © John McAvoy Invasive non-native species

3. Floating Water PennywortHydrocotyle ranunculoides Chokes waterways, impacting upon fish, plants and invertebrates. © GBNNSS Invasive non-native species

4. Water FernAzolla filiculoides Reduces light beneath water surface, killing native plants and causing de-oxygenation. © GBNNSS Invasive non-native species

5. Rhododendron ponticum in Snowdonia. Taking over native ecosystems. © Mike McCabe Invasive non-native species

6. Topmouth GudgeonPseudorasbora parva Can achieve high densities and dominate waterways in which they become established. © Matt Brazier Invasive non-native species

7. Environment Agency Rotenone piscicide application. © Matt Brazier

8. Heath Star Moss Campylopus introflexus Invasive moss from the southern hemisphere, now carpeting areas of British moors and heaths. © GBNNSS Invasive non-native species

9. Japweed Sargassum muticum Fast growing, reduces light availability & increases sedimentation rates. Clogs harbours & beaches. © Chris Wood Invasive non-native species

10. Oxford RagwortSenecio squalidus Oxford Botanic Gardens escapee (late 18 th century). Spread via railway lines across Britain. © GBNNSS Invasive non-native species

11. Chinese Mitten CrabEriocheir sinensis Causes erosion of river banks, impacting upon flood defences. © Fera Invasive non-native species

12. ShallonGaultheria shallon An invasive shrub of heath and woodland, originally used for game cover. © GBNNSS Invasive non-native species

13. ShallonGaultheria shallon An invasive shrub of heath and woodland, originally used for game cover. Invasive non-native species © GBNNSS

14. Signal CrayfishPacifastacus leniusculus Rapid spread since introduction in 1970’s. Carrier of ‘crayfish plague’ which kills infected native crayfish. © GBNNSS Invasive non-native species

15. Goat’s RueGalega officinalis Widely naturalised on waste ground and railway embankments, especially in the south-east. Invasive non-native species © GBNNSS

16. Australian Swamp StonecropCrassula helmsii Forms dense mats, out-competing native species, and choking ponds and drainage ditches. Invasive non-native species © GBNNSS

17. Australian Swamp StonecropCrassula helmsii Forms dense mats, out-competing native species, and choking ponds and drainage ditches. Invasive non-native species © GBNNSS

18. Michaelmas DaisyAster novi-belgii Widely spread throughout road and rail embankments. Invasive non-native species © GBNNSS

19. Butterfly BushBuddleia davidii Huge cost for railway industry, and damages historic buildings. Invasive non-native species © GBNNSS

20. Harlequin LadybirdHarmonia axyridis Preys on native invertebrates, causing declines in our native ladybirds.. Invasive non-native species © Mike Majerus

21. Himalayan HoneysuckleLeycesteria formosa Invasive in native woodlands Invasive non-native species © GBNNSS

22. Japanese RoseRosa rugosa Invasive non-native species © GBNNSS Forms large thickets causing damage to natural habitat, and out-competing native species.

23. MontbretiaCrocosmia crocosmifolia A garden escape that has spread rapidly along roadside verges and woodland throughout Britain. Invasive non-native species © Trevor Renals

24. MontbretiaCrocosmia crocosmifolia A garden escape that has spread rapidly along roadside verges and woodland throughout Britain. Invasive non-native species © GBNNSS

25. African Clawed FrogXenopus laevis Invasive non-native species © GBNNSS A vector for the chytrid fungus, implicated in serious amphibian population declines.

26. Slipper LimpetCrepidula fornicata Can reach densities of up to 1,700 per m, a pest on commercial oyster beds. Invasive non-native species © GBNNSS

27. Red-eared TerrapinTrachemys scripta Long-lived species, basks on nests of waterfowl causing desertion. Carries Salmonella. © GBNNSS Invasive non-native species

28. RaccoonProcyon lotor Escape from captivity has resulted in well-established populations in mainland Europe. © Niall Moore Invasive non-native species

29. Pacific OysterCrassostrea gigas Form reefs of razor sharp shells, impacting upon native species and making beaches inaccessible to the public. © GBNNSS Invasive non-native species

30. Monk ParakeetMyiopsitta monachus An agricultural pest, causes huge problems in U.S. by causing power black-outs.. © GBNNSS Invasive non-native species

31. Ring-necked ParakeetPsittacula krameri Competes for nesting sites with native hole-nesting bird species (e.g. nuthatch). © GBNNSS Invasive non-native species

32. Himalayan BalsamImpatiens glandulifera Germinates earlier and faster than native species, forming tall dense stands, causing a reduction in biodiversity. © GBNNSS Invasive non-native species

33. Parrot’s FeatherMyriophyllum aquaticum A common escapee from garden ponds, spreading by growth from small stem fragments. © GBNNSS Invasive non-native species

34. Water PrimroseLudwigia peploides Highly invasive; can cover large areas rapidly (e.g. 500ha. in 5 years in one area of France). © Trevor Renals Invasive non-native species

35. Water PrimroseLudwigia peploides Highly invasive; can cover large areas rapidly (e.g. 500ha. in 5 years in one area of France). © GBNNSS Invasive non-native species

36. Water PrimroseLudwigia peploides Highly invasive; can cover large areas rapidly (e.g. 500ha. in 5 years in one area of France). © GBNNSS Invasive non-native species