Case Study
White-Clawed Crayfish Survey
Location
Gloucester
Date
October 2018
Client
Mott MacDonald

Tasks
- Habitat walkover survey of two tributaries
- Identify sites for white-clawed crayfish survey
- Undertake baseline survey under protected species license (CL11)
- Manual search methodology was used where suitable refuge was present
- In addition crayfish traps were used in areas unsuitable for manual search
- Consent to trap crayfish attained from the Environment Agency
Key remarks
- Historic records were reviewed and consultation with local Wildlife Trust provided valuable catchment information.
- 4 sites were surveyed by experienced ecologists
- Survey for native crayfish is less effective in water temperatures below 8°c, water temperature was measured and recorded daily
- Following robust survey effort no native crayfish were recorded
Effects
- EcIA of infrastructure to include robust baseline data for required for impact assessment
- White-clawed crayfish were not found at any site either through trapping or through manual searches
- Data may be used to upgrade the known distribution of native crayfish and non-native crayfish species.