Led by the Wildwood Trust, the Saving Devon’s Native Crayfish Project has worked over the last two years to ensure the River Culm’s surviving population of native white-clawed crayfish do not become extinct. The project has been funded through the Natural England Species Recovery Programme (with additional funding from Devon Environment Foundation and South West Water) and has included the construction of a crayfish hatchery at Wildwood Devon, crayfish rescue surveys from the Rivers Culm and Creedy Yeo, and the construction of a bespoke ‘ark site’ pond. A new crayfish display is also now open at Wildwood Devon and is home to three of the older River Culm male white-clawed crayfish rescued from the river.
During the summers of 2023 and 2024 the project team and volunteers have completed crayfish ‘rescue’ surveys on the Rivers Culm and Creedy Yeo to capture surviving white-clawed crayfish for the hatchery breeding programme. A total of 61 Culm crayfish are currently being cared for in the Wildwood Devon hatchery and demonstrated some very encouraging mating behaviour during the autumn of 2024. Females are now carrying eggs, but it is still too early to tell (and too risky to disturb the crayfish to check) if they were successfully fertilised by the males. If the process was successful, the captive bred River Culm crayfish will hatch this spring and will be cared for at the hatchery until they are old enough to be released into the ark site pond (at minimum 12 months old). Once a viable breeding population has been created in the pond, the project plans to release captive bred River Culm crayfish into safe Devon river ark sites. Work has begun to identify these (likely to be small watercourses away from the threat of American signal crayfish, with good water quality).
Sadly, it’s unlikely white-clawed crayfish will ever be released back into the River Culm, and it’s estimated that the current fragile but surviving population will become extinct within the next 10 years. This is primarily because of the rapidly expanding populations of invasive American signal crayfish but also due to reduced water quality and loss of habitat. In 2024, the survey team re-visited sites last surveyed in 2019 and found that American signal crayfish have completely taken over previous white-clawed crayfish strongholds, and in other locations are getting perilously close to the main stretch of river where white-clawed crayfish survive.
The 2024 survey team
The Wildwood Trust has submitted an application to the National Lottery Fund for the next phase of the project. If successful, this will enable the team to continue rescuing crayfish from threatened river populations, expand and improve the crayfish hatchery and captive breeding programme, and secure future safe and protected release sites. The project will train and support citizen science volunteers to take an active role in the project’s crayfish conservation objectives, and to ensure crucial monitoring continues beyond the life of the project. Through public engagement and a dedicated school outreach programme, the project will raise awareness of the fragility of white-clawed crayfish and the measures and actions needed to safeguard its future. The project will play a crucial role in species recovery and will pave the way for multiple future reintroductions to safeguard the species survival in Devon.
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