In Britain the white-clawed crayfish is our only native crayfish and is our largest freshwater invertebrate. It lives in clean, relatively hard, mineral-rich waters with a pH of between 7 and 9 and calcium concentrations above 5mgL -1. It is widespread in clean, calcareous streams, rivers and lakes in England but many populations have been lost since the 1970s.

Within the last decade the White-clawed Crayfish has been the subject of numerous site and river catchment surveys within the Yorkshire region, the results of which are being collated by the Environment Agency and resulted in the foundation of the North Yorkshire Crayfish Forum in 2019, which expanded to Yorkshire-wide in 2024.

Research paper: Gazetteer of White-clawed Crayfish in Yorkshire, by Colin Howes