WHITE CLAWED CRAYFISH SURVEY

White-clawed crayfish are classified as Endangered in the IUCN Red List of Endangered Species and their populations are declining throughout much of their range with predictions that the species will face extinction in much of their former range within the next few decades. White-clawed crayfish populations are under threat in Britain and Ireland from a fungal disease, crayfish plague Aphanomyces astaci, carried by a number of introduced North American species of crayfish, and competition from alien crayfish populations. Detailed survey for white-clawed crayfish torch and trapping) is seasonally constrained, with July to October being the optimal period for carrying out survey. Survey should be avoided in May and June when females are releasing young, and between December and March, when water temperatures are typically below 8°C and crayfish are less active.