Keeping or releasing non-native crayfish and fish in England and Wales

The introduction of non-native fish and crayfish species can have far-reaching and undesirable ecological consequences for animal and plant communities in rivers and lakes.

Introduced non-natives can have direct effects on native species, for example by predation, or can upset the natural ecological balance. Also non-native species can introduce novel diseases and parasites to which our native populations may have no resistance. Zander and signal crayfish are good examples of non-native introductions that have harmed our native fish stocks.

Please choose the fish or crayfish section for more information.