The white-clawed crayfish is the only species of freshwater crayfish which is native to the UK. It was formerly widespread in clean, calcareous to neutral, streams, rivers and lakes in Wales. However, many populations have been lost since the 1970s, and many more are critically threatened by non-native crayfish and disease.
Development on or near river banks can affect this species, especially where water flows are reduced. Information on licences for white-clawed crayfish is available on NRW’s website. White-clawed crayfish are also one of the designated features of the River Wye SAC.
You can find more information on white-clawed crayfish in The Ecology of White-clawed Crayfish from the Natural England website.