The White-clawed Crayfish

The White-clawed Crayfish

The white-clawed crayfish is the only species of crayfish that is native to Britain and although formerly widespread across Britain and Europe this species has suffered a dramatic decline since the mid to late 1900’s and is now considered to be internationally endangered. A key component of this decline is the introduction of non-native crayfish species and the disease, ‘crayfish plague’, carried by North American Signal Crayfish.

The River Alre continues to support a strong and stable but relatively small sub-population of white-clawed crayfish that remains free of the non-native signal crayfish and the associated ‘crayfish plague’. Although stable, the River Alre sub-population is fragmented and highly localised and as such is at a high risk of extinction.

Code of Conduct for visitors to the River Alre with regards to avoiding the transmission of non-native invasive species. 

Following these four simple steps can help minimise the risk of your activities:

  • Transferring invasive species (i.e. signal crayfish, killer shrimp Dikerogammarus villosus, or New Zealand pygmyweed Crassula helmsii)
  • Transmitting infectious diseases

1. Check
That you don’t have any small animals or plant fragments on your equipment before leaving a site and remove any that are present; Remember it is illegal to touch, trap, move or introduce crayfish without written permission from statutory bodies including the Environment Agency and Cefas.

2. Clean
Any mud, dirt or stones from your boots as these can increase the length of time your equipment harbours diseases; Do this before leaving site where possible but always well away from a different watercourse.

3. Disinfect
If feasible soak your equipment for an adequate length of time in an approved disinfectant. This will be made available prior to the fishing season; should you need additional supplies during the season these can be requested from the River Habitat Manager. This step is all the more important if you know you are taking wet equipment to a different site.

4. Dry
Completely drying your equipment in direct sunlight for 24 to 48hrs kills all waterborne organisms and diseases.