The white-clawed crayfish (Austropotamobius pallipes) is a protected species and is the only native species of crayfish in the UK. There are several non-native species including signal crayfish, red-swamp crayfish and spiny checked crayfish.
The main threats to white-clawed crayfish are habitat loss or degradation, and the “crayfish plague”, which is a fungal infection of Aphanomyces astaci which is carried by North American species such as signal crayfish. In addition, populations are increasingly being affected due to direct competition with the other non-native species, as well as predation by signal crayfish.
Legislation
White-clawed crayfish is protected under the UK Biodiversity Action Plan, the NERC Act 2006 (England and Wales) and the Nature Conservation Act in Scotland. Within UK legislation this native species is also safeguarded under the Wildlife and Countryside Act (1981) that protects white-clawed crayfish and their parts from being taken from the wild, sold or used as bait, as well as prohibiting the release of non-native species.
White-clawed crayfish are protected by European legislation as The Bern Convention, and The Habitats Directive.
Types of Survey
If direct surveys for white-clawed crayfish are required, our methodology would be based on the standard method as described in “Monitoring the White-clawed Crayfish” (S. Peay, 2003) Where the standard method is not appropriate, other methods such as trapping or night-time torch search may be undertaken instead. Rigorous biosecurity measures will be taken to prevent the transfer of crayfish diseases or non-native species between sites.
The optimal season for surveying white-clawed crayfish is between mid-July and mid-September (after the breeding season). Although valid surveys can be undertaken outside of this period in the correct weather conditions, there is a risk that females may shed their eggs or young, which would have to be managed.