Northumberland Zoo release 348 endangered crayfish in major conservation efforts
Northumberland Zoo has successfully released 348 endangered white-clawed crayfish into protected waters.
The release is a landmark moment for the zoo, whose crayfish hatchery is designed to give the young craylings a head start before being released at ark sites established to support new populations in Northumberland waters.
The journey to this release began in November 2024 when the zoo joined forces with the Environment Agency, Tyne Rivers Trust and the National Trust to rescue female white-clawed crayfish carrying eggs from the River Wansbeck.
The rescue followed the discovery of unexplained deaths and unusual symptoms within one of the world's highest-density populations of the endangered species.
While the females were cared for at the zoo, their eggs hatched safely in spring 2025 before the adults were successfully returned to the river.
Over the following year, the juvenile crayfish were carefully reared by the zoo's keeper team until they reached the minimum size required for release.
The crayfish were then released into secure, isolated water bodies where they can live away from the threats affecting wild populations.
Lucy Edwards, curator, said: “As our facility was built for a much smaller number of berried females, it was quite a jump going from three females to the 53 that were taken in during this rescue.
“I’m really proud of the amount of effort that the keeper team put into learning about the husbandry of this species, as well as the intense problem-solving required for such a sensitive species.”
Although crayfish are among the zoo's smallest residents, they are also some of its most demanding, requiring more than 1,500 hours of staff time each year.
Maxine Bradley, zoo manager, said: “White-clawed crayfish might not be the animals that people first come to a zoo to see, and they can be a challenging species to get people to love when they don't have big eyes and fur.
“They are a keystone species and an important indicator of a healthy water system, as well as an important food source for our native European otters, so the impact of protecting them goes far beyond the animals themselves.”
The release marks the completion of the first stage of a long-term conservation programme.
The zoo is now planning a conservation facility designed specifically to support the species long-term breeding, care and recovery.