White-Clawed Crayfish

White-Clawed Crayfish

White-clawed crayfish are partially protected by the Wildlife & Countryside Act 1981 (as amended). White-clawed crayfish require specific mitigation if impacts are likely during or after development.

Implications for Development

White-clawed crayfish should be considered where development affects suitable watercourses, water-bodies and / or their banks. Impacts may be direct, such physical changes to the banks or the channel bed; or indirect, such as through pollution and run-off into the watercourse.

Survey Methods

Surveys for white-clawed crayfish are possible between July and October (inclusive) and several survey methods are available, the use of which depends on the local conditions. Survey methods include diurnal refuge search, night viewing, bait trapping, and refuge trapping.

Mitigation & Compensation

Mitigation may involve pollution control, disinfection of equipment, working downstream from an identified crayfish population, crayfish exclusion and providing alternative habitat.

Trapping, handling or moving of crayfish should be timed outside the crayfish breeding (May to July) and wintering (November to February) periods.

Other Information

White-clawed crayfish are the only native crayfish species, and are in decline due to competition from non-native invasive crayfish, disease and habitat loss / modification.