Crayfish vs crayfish: Who will win our rivers?
The American signal crayfish, introduced to Britain in the 1970s, is threatening the native white-clawed crayfish, which is now endangered. Conservationists warn that the invader’s success could harm whole river ecosystems, making the struggle important beyond the survival of one species.
The article describes Yorkshire as one of the white-clawed crayfish’s few remaining strongholds, though populations there are also at risk. Signal crayfish are larger and hardier, and can carry disease that affects native crayfish; the Yorkshire Crayfish Forum is among the groups working to protect them.
- American signal crayfish threaten Britain’s native crayfish.
- Yorkshire remains a refuge, but populations are at risk.
- Conservationists warn river ecosystems could also suffer.
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White-clawed crayfish are the only crayfish native to Britain. American signal crayfish were brought here in the 1970s and have since spread through many rivers.
Signal crayfish are larger and tougher, and can carry a disease that harms white-clawed crayfish. The native species is now endangered, with Yorkshire among its few remaining strongholds; groups such as the Yorkshire Crayfish Forum work to protect it.
The issue matters beyond the two species because changes to crayfish populations can affect river ecosystems. Protecting the native crayfish is therefore part of wider efforts to safeguard river life.