Non-native species

Killer shrimpInvasive non-native species pose a severe threat to the biodiversity of the Broads but we work hard to minimise that impact.

A 12-month project to increase public awareness of the non-native species in the Broads reached more than 80% of waterways users.

The so-called 'killer shrimp' (Dikerogammarus villosus), mink, signal crayfish and fast-growing non-native plants were all targeted as part of the campaign.

The project particularly focused on the shrimp and other freshwater invaders as we promoted the Check, Clean, Dry campaign. A leaflet was produced along with signage throughout the Broads network showing people how to help stop the shrimp spreading. Information was also given out with boat and angling licences.

Some of the most concerning invasive plant species in our waterways and on our riverbanks are:

  • Australian swamp stonecropHimalayan balsam
  • Floating pennywort
  • Giant hogweed
  • Himalayan balsam
  • Japanese knotweed
  • Parrot's feather

More information and handy identification guides are available on the UK's non-native species website. Also have a look at the Norfolk non-native species initiative

Reporting sightings of invasive species

To report a sighting of an invasive species please email a photograph to

Useful links

To find out more about what is being done in Norfolk to reduce the impacts of invasive species, and about other ways you can help, please visit the Norfolk biodiversity website.