White-Clawed Crayfish Surveys

Scientific Name: Austropotamobius pallipes

The white-clawed crayfish is Britain's only native species of crayfish and is primarily under threat from non-native species including the north American signal crayfish. Crayfish will occupy a variety of habitats including streams, rivers, brooks, reservoirs and water-filled quarries. Although abundant in some waterbodies, the white-clawed crayfish has seen a dramatic decline in population in recent decades. This decline has led to the white-clawed crayfish being protected under both British and European law. The white clawed crayfish is listed on Schedule 5 of the Wildlife and Countryside Act 1981 (as amended) and is also included in Appendix III of the Bern Convention and Annexes II and V of the European Habitats and Species Directive. It is also a priority species under the UK Biodiversity Action Plan (BAP).

Therefore, if development works are planned to be completed within, or in close proximity to a waterbody, it is important to determine if white-clawed crayfish are present and whether the proposed works will impact on the species.

How to Book a White-Clawed Crayfish Survey

EMEC Ecology work with many different clients from large council projects to small residential development sites. Each survey will therefore be specific to a site and the costs will change accordingly. EMEC Ecology will be happy to provide a quotation for any white clawed crayfish survey that will be both efficient and cost effective to the site specifics. Reports are produced as soon as possible however should you have a specific date for submission with a planning application we will do our utmost to accommodate this.

If you require a quotation please send an email to us at mail@emec-ecology.co.uk including any site plans that you have available (or details and photographs of the site if applicable) with details of the proposed development plans of the site, along with your name and contact details. Should you wish to contact us at the office please call 0115 9644828.

White-Clawed Crayfish Survey Methodology

Often the local record centre may be contacted to see if there are records of crayfish within the waterbody that the works will potentially impact on. Desk studies assist the findings of the survey and would be included within the report that is submitted with a planning application. A desk study is not always required however, and will be dependant on the site and its location.

Even when there are records of white-clawed crayfish in a watercourse, they are not uniformly spread along the channel and therefore a survey of crayfish presence and population must be conducted on site. All surveys are conducted by a suitably qualified ecologist with an appropriate Natural England crayfish license.

Refuge Sampling

The standard method used to search for crayfish along a watercourse includes taking samples from potential refuges and completing a habitat assessment. Several samples may be required to be able to establish a population estimate. Where appropriate, kick sampling using a pond net is also used.

Night Viewing

This method involves recording crayfish via torchlight at night. This method results in minimal disturbance to the river channel, covers a wider area and also covers inaccessible areas compared to manual searches such as refuge sampling.

Crayfish Trapping

A successful method uses baited traps that are left for no longer than 24 hours at a time. This method although successful, can harm non-target species such as otter and water vole; therefore trapping may not always be appropriate.

Survey Times

White-clawed crayfish surveys are predominantly carried out between March to September inclusively, however between April and June surveying (other than torching at night) is not advised as it is likely to cause harm to the young.

White-Clawed Crayfish Licensing and Mitigation

Should white-clawed crayfish be present within or in close proximity to a development site, where it is likely that the crayfish will be either disturbed, injured or killed, it may be necessary to translocate the crayfish (move to another location). This will require a license from Natural England that will require detailed mitigation to ensure minimal impacts on this declining species.

Should a license be required, EMEC Ecology can apply for this license on a clients behalf. EMEC Ecology has the ability to design and implement site specific mitigation that will be suitable for a planning application.

Mitigation

Translocation

Translocation involves moving the white-clawed crayfish from the area to be affected into safe areas to avoid any negative impacts form the development works. This will require the identification of a suitable receptor site. Should a suitable site not be identified EMEC Ecology can assist in the design and creation of suitable habitat. This process will ensure that both habitat management and enhancement have been considered, a prerequisite of planning applications.

Monitoring

Monitoring the impact of development works is an important part of conservation and should it be required, EMEC Ecology can monitor the site to see how effective the mitigation has been.

White-Clawed Crayfish Projects (Surveys and Mitigation)

White Clawed Crayfish Survey near Nottingham

EMEC Ecology has taken part in the production of a mitigation strategy at a site near Nottingham. This included excluding white clawed crayfish from a target area and translocation to a suitable receptor site prior to development works. In conjunction with the translocation of white clawed crayfish mitigation this project involved the creation and enhancement of suitable habitat.

Site near Derby City Centre

At a site close to Derby City centre, EMEC Ecology produced a mitigation strategy and undertook the translocation of white clawed crayfish. Timing of the works was crucial due to the need to avoid impacting mated females when they are most vulnerable to disturbance. EMEC Ecology was able to assist in applying for a license to carry out the works and was able to minimise the impact on the species. This project was monitored after the completion of the works.

White Clawed Crayfish Mitigation within Nottinghamshire

EMEC Ecology has carried out mitigation works within Nottinghamshire. The work included the potential to disturb or kill white clawed crayfish that were present at the site and the therefore a license was required form Natural England. For a licence to be granted detailed mitigation is required that needs to be designed to reduce the chances of harm. EMEC Ecology prides itself on finding solutions to development issues and was able to assist in designing site specific strategies to ensure a successful project was completed.

Annual White Clawed Crayfish Monitoring Surveys

In the East Midlands EMEC Ecology have been carrying out an on-going monitoring scheme of white clawed crayfish in the River Lin, where a strong population exists and also in Rothley Brook where there is a small local population. The monitoring programme is intended to track the health of the white clawed crayfish and also look for the presence of signal crayfish which are lethal to the white clawed native crayfish. This monitoring scheme will help assist in the awareness of the decreasing distribution of the species of conservation concern.