Why are we working with the Crayfish in Crisis?

 The Crayfish in Crisis Project was launched in 2012, with thanks to a grant of £47,000 from Heritage Lottery Funding.

The South West Crayfish Partnership was set up in 2008 in response to a dramatic 70 percent decline in numbers of  the UK’s only native crayfish species – the white-clawed crayfish (Austropotamobius pallipes) - in south west England.  White-clawed crayfish became classified as Globally Endangered in 2010 (IUCN), and are at risk of becoming extinct from Great Britain in the next 20-30 years. Working as part of the Partnership, the Crayfish in Crisis project aims to conserve endangered native crayfish through field conservation, captive breeding, research and education.

Pollution and habitat destruction are widespread pressures that affect many of our native freshwater species nationally; however white-clawed crayfish are also threatened by two new threats, non-native invasive crayfish and crayfish plague.  Invasive signal crayfish were introduced into the UK in the 1970s via crayfish farms, which were set up for the angling and restaurant trade. They are larger and more aggressive than the native species, competing for food and shelter, and displacing whole populations of white-clawed crayfish. In addition the signal crayfish carry crayfish plague, which they can withstand but is lethal to the white-claws. The disease can also be spread on items such as damp wellies, walking boots, fishing tackle and nets. Consequently, in addition to the threat from the signal crayfish, the white-clawed crayfish populations are directly threatened by the actions of humans.

The Crayfish in Crisis Project was launched in 2012, with thanks to a grant of £47,000 from Heritage Lottery Funding. The project has three aspects:

  • Captive breeding: Bristol Zoo Gardens and Bristol Zoological Society are running a successful breeding programme for the white-clawed crayfish. Since 2009, white-clawed crayfish have successfully hatched at Bristol Zoo where they are reared until they have grown to a size which increases their survival.  The juveniles have been released into a safe ‘ark’ site where American signal crayfish and crayfish plague are not known to be present. Four age classes of white-clawed crayfish are now kept at Bristol Zoo, enabling valuable research to be undertaken into this still relatively elusive species. In 2013 Bristol Zoo achieved a complete white-clawed crayfish breeding cycle for the first time.  Normally the females are brought into the zoo berried (with eggs) however this was the first time that white-clawed crayfish mated and retained their eggs to hatching within captivity.  This has important implications in the future in our quest to provide biosecure plague free brood stock.   BCSF has hosted both an international crayfish conference and a white-clawed crayfish captive breeding workshop and we are supporting Paignton Zoo Environmental Park and Slimbridge WWT to establish additional outreach and research facilities for white-clawed crayfish within South West England.
  • Increasing awareness and education activities: Schools in and around the Bristol area have benefitted from a year-long program of education sessions, which aim to inspire children, schools and families to take an active part in protecting our rivers, lakes and ponds. The roadshow which was designed and managed by Bristol Zoological Society staff includes crafts, role play, talks and games. In excess of 1600 children have been taught; with evaluation showing pupils have a 50 percent increase in conservation knowledge, post session.
  • Field conservation: The project aims to secure populations of white-clawed crayfish for the future through the largest strategic translocation of white-clawed crayfish in the UK, with over 4000 individual translocations to date. Translocations are needed in order to relocate (re-home) populations of white-clawed crayfish which are ‘at risk’ from signal crayfish or crayfish plague to safe ‘ark’ sites, 14 of which have been established in the south west. As part of the project, all crayfish populations in region have been mapped, and this has enabled The South West Crayfish Partnership to ensure that translocations have the maximum positive impact. A population is never moved in its entirety as it is important to give the opportunity for natural survival to occur.

Commenting on the HLF award acting Head of South West, Richard Bellamy, said:  “Biodiversity is the total variety of life on earth. It is crucial for the survival and wellbeing of all of us, yet this rich diversity is being lost at a fast rate. We want to encourage more people to apply to us for funding for projects that help to conserve the UK’s valuable natural heritage, and that, like the Crayfish in Crisis project, raise awareness of it, especially amongst young people, who will be its future guardians.”

The crayfish future

Since the project began there has been an estimated 50 percent increase in wild white-clawed crayfish populations within the south west. The next phase of the programme will begin in 2014 and will continue with captive breeding and research at Bristol Zoo Gardens. Within the Bristol Zoo hatchery, we are focussing primarily on River Itchen crayfish, which are from the last remaining population of white-clawed crayfish in Hampshire.  In February and March 2013 the Bristol Zoo team brought 12 crayfish females with eggs into the zoo and in June and July last year over 400 youngsters hatched.  These crayfish will be released into an ark site later in 2014, up stream of where the females were sourced. In addition new white-clawed crayfish displays and research units will be developed at other zoos and aquaria in the UK to aid wild and ark site supplementations with captive reared individuals. Established ark sites will be carefully monitored and long-term and supplementations will occur when necessary. The South West Crayfish Partnership is the largest strategic partnership project for A. pallipes conservation in Europe.  By using a single species as a flagship for conservation, several freshwater nature reserves have been established throughout the south west England, helping to conserve many other species.


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