Invasive non-native species

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  • Invasive non-native species (INNS) are thought to be the second largest threat to global biodiversity after habitat loss.
  • A 2010 report estimated the cost of invasive species to the UK economy at £1.7 billion and their impact is rising.
  • They reduce the biodiversity of a river by outcompeting native species and taking over.

Himalayan balsam is a textbook example – one plant can disperse its seeds for several metres causing a rapid spread which prevents the growth of other types of bankside vegetation.

Other invasive species in the Ribble Catchment include American mink, signal crayfish, Japanese knotweed and giant hogweed.  Tackling the problem is difficult and requires an organised and coordinated approach, beginning at the top of the catchment and working downstream.  Traps can be used for mink and chemical spraying can eradicate invasive weeds, but as yet there is no known way of removing signal crayfish from the Ribble’s tributaries.

If you would like to get involved or would like some information about how to go about setting up a Local Action Group to tackle invasive species in your area with the support of the Ribble Rivers Trust please contact us.