The UK native, white-clawed crayfish is in danger of extinction. Its decline is due to the non-native, invasive signal crayfish, crayfish plague and habitat loss. As a result, Buglife set up the ‘Ark sites for crayfish’ project supported by the ALSF to identify and establish suitable water bodies where white-clawed crayfish could be introduced, away from the threat of signal crayfish so that they may survive in perpetuity. In 2009, Buglife approached Hanson UK to seek potential Ark sites.
Whiteball Quarry’s Town Farm pond (created through restoration in 2001) was identified and suitability surveys began in March 2010. Water pH and quality were suitable and invertebrate and amphibian surveys revealed five species of amphibians, including great crested newts (GCNs). After Buglife submitted a paper to Natural England explaining that the introduction of crayfish would not have a significant effect on the GCNs, the crayfish translocation license was granted.
Due to existing pond profiles and characteristics, habitat enhancements proved necessary in order to provide the correct foraging, refuge and breeding habitat. 60 tonnes of rock were placed in February 2011 providing holes for refuge and breeding. In September 2011, 35 crayfish were released under Environment Agency Licence into the pond having been trapped from the nearby River Culm, where the population was under serious pressure of extinction due to signal crayfish.
The project has forged a close partnership between Hanson UK and Buglife. Hanson UK has also established links with Avon Wildlife Trust and the Devon Reptile and Amphibian Group through the amphibian surveys and also with the Environment Agency who aided the capture and release of the crayfish.