White-Clawed Crayfish Surveys

Determining The Existence Of White-Clawed Crayfish

The White clawed-Crayfish population has dramatically declined because of pollution, competition and disease transferred by non-native species. Due to the protection afforded to them, White clawed-Crayfish Surveys may be required if distribution and historical records suggest they may be present within the watercourse in your site or on adjacent land. At JCA our surveys will determine if White clawed-Crayfish are present and whether the proposed works will adversely affect the species. For example, for informing management plans of monitoring the effectiveness of habitat management based on indicator species. Terrestrial invertebrate surveys are often needed on ecologically sensitive sites. Aquatic invertebrates are often required to monitor water quality, particularly if construction work causes runoff.

The majority of ecological surveys are seasonally constrained. Use our ecology survey calendar to plan your project timetable and factor in any seasonal constraints to project timescales as early as possible to prevent any delays.

Crayfish Surveys

An experienced ecologist will carry out a survey of the site to determine the presence of White clawed-Crayfish. A variety of methods are possible, and their use is dependent on the specific conditions of the water course. Methods used include:

  • Initial habitat appraisal
  • Manual searching and hand netting (where the water is clear and low flowing)
  • Night search by torch (where water is deep)
  • Trapping using baited plastic mesh traps (where water is too deep or cloudy for manual search)

Surveys can be carried out from April to September, but manual searches and netting must be avoided in late May and June. If it is found that white-clawed crayfish are present a Mitigation Plan may be required to prevent or reduce negative impacts.

White-Clawed Crayfish Surveys and the Law

White clawed-Crayfish are protected under Schedule 5 of the Wildlife and Countryside Act 1981. Under these legislations, it is an offense to:

Intentionally take (capture) White clawed-Crayfish from the wild.

Sell, offer for sale or advertise for sale live or dead White clawed-Crayfish.

It is also listed until Annex II of the EU Conservation (Natural Habitats, andc.) Regulations 1994, allowing areas where White clawed-Crayfish occur to be designated as Special Areas of Conservation (SAC). This designation brings legal restrictions to the management and developments that can occur in such sites, to help conserve the White clawed-Crayfish and the specific habitat it requires.