Crayfish blog
Led by Wildwood Trust, the Saving Devon’s Native Crayfish project is the latest project to step up white-clawed crayfish (WCC) conservation efforts in Devon.
Thanks to funding from Natural England Species Recovery Programme, the project is developing a new crayfish hatchery, building a bespoke crayfish ark site pond, rescuing WCC from Devon rivers, and telling the story of WCC conservation through a new public display at Wildwood Trust Devon.
Following a successful trial period in early 2023 (funded by Devon Community Foundation), Natural England funding is enabling Wildwood Trust Devon to expand the crayfish hatchery facilities to accommodate native crayfish from across Devon and Somerset.
2024 highlight
The highlight in 2024 was the success of captive breeding crayfish in the hatchery.
We successfully bred 147 juvenile crayfish this year from two Somerset populations.
These will be moved to other facilities for further rearing before being released back into the wild.
This provides us with extra space for next year’s juveniles.
November 2024
Our display tank is finally ready to receive some guests!
This month saw the arrival of three adult white clawed crayfish from the hatchery. These three crayfish are larger males which we were unable to match up with females in the hatchery for the breeding season and so will stay with us in the display tank until they are released into the ark site in the Spring.
We are still awaiting the arrival of some informative signage but these small like eco engineers are visible in our park, which is open to the public.
Our education team will use these facilities to support primary school learning about river ecosystems.
August 2024
The team have been coordinating the build of an ark site specifically to house our rescued and bred crayfish in a safe place away from predators and the invasive Signal crayfish.
Working with Land Marc, an environmental engineering company, we have had dug a large pond which is fed by local spring water and aeriated by a solar panel system.
The team and volunteers from the Environment Agency and Kier have all supported the project in the building of refugees and planting trees which were donated from the Woodland Trust.
The last stage of the project is to get the pond full and circulating water until the spring which is when we will plant pond plants to provide better habitat for the crayfish before they are introduced to the area.
A huge thank you to everyone involved, we look forward to getting the animals added and monitoring the results of the ark site!
July 2024
During the survey season we aim to check traps every two weeks to maximise our chances of finding crayfish.
This year has been very successful so far, and we have managed to relocate 58 Creedy crayfish and 44 Culm crayfish to the safety of the hatchery.
The surveys, when possible, are attended by knowledgeable volunteers from the environment agency who help support us with checking traps and carrying the equipment. It’s a great learning opportunity for everyone and we’ve had some great discoveries in the river such as finding evidence of otters and catching other animals in the ARTs such as European bullheads and Lamprey.
June 2024
The team need a special Natural England survey licence to carry out these early season surveys as they are taking place outside of the normal, white-clawed crayfish survey season (Jul-Sep).
They need a separate Natural England licence to be able to take WCC from the river to the hatchery, and Environment Agency trapping permits to be able to use any kind of crayfish traps.
Landowner permission is also required.
Crayfish taken to the hatchery are transported in insulated cool boxes containing ‘floss’ material which protects them on their journey.
April 2024
The Saving Devon's Native Crayfish (SDNC) project team re-started crayfish rescue surveys in the Rivers Creedy Yeo and Culm at the beginning of April.
The aim of these early season surveys is twofold:
· To capture ‘berried’ white-clawed crayfish (females carrying fertilised eggs) to take to the Wildwood Devon hatchery. With mating complete in the wild, and the eggs already fertilised, the hatchery team can give the eggs and any surviving hatchlings the best chance of survival away from the threat of predation in the river. Click here for more information about the WCC lifecycle.
· The surviving white-clawed crayfish populations in both Devon rivers are under threat from non-native invasive American signal crayfish which are rapidly advancing into the WCC territory (and are already mixing in most places). The project team are therefore rescuing as many WCC as possible before it’s too late. Click here for more information on crayfish in Devon.
The survey team have been frustrated by bad weather over the first month of surveys with river levels too high for safe access. They have also set out traps only for these to be dislodged by high flows after recent storms.
January 2024
The hatchery team found that Creedy Yeo females bought into the hatchery in 2023 were berried (carrying fertilized eggs) and means the crayfish successfully mated in the hatchery - a major milestone for the project.
WCC are difficult to breed in captivity and so for the Wildwood Devon team to achieve this in the first year of hatchery development is exceptional, and a testament to the hours of hard work and dedication of the hatchery team!
Running the hatchery is a key part of the project and requires daily attention, 7 days a week. This includes feeding crayfish, monitoring water temperature and quality, checking equipment is working and changing the water in tanks on a weekly basis.
