crayfish - abrehartecology
Aquatic Invertebrate Surveys

Crayfish Surveys

Why are crayfish surveyed?

The UK’s only native crayfish, the white-clawed crayfish (Austropotamobius pallipes), has suffered a 70% decline in population since the 1970s following the introduction of the invasive signal crayfish (Pacifastacus leniusculus) and extensive habitat degradation and destruction. It is now classified as endangered.
It is, therefore, crucial that white-clawed crayfish are monitored and surveyed to inform mitigation to prevent further declines in their population.

A white-clawed crayfish held between fingers

When do I need to survey for crayfish?

A white-clawed crayfish survey may need to be carried out when planning on impacting watercourses in their known range and preferred habitat of shallow limestone/chalk streams with low sediment.

Alternatively, crayfish surveys may be carried out on behalf of governing bodies, charitable organisations, or landowners in order to monitor habitat improvements, conservation measures, or track populations.

Surveys are best performed between July and October as Crayfish activity decreases over the winter (November – March) and breeding in May and June prevents survey work from being carried out.

What does Abrehart Ecology offer?

At Abrehart Ecology we offer professional, skilled, and efficient aquatic invertebrate survey work. We undertake in-house fieldwork, and expert report writing.


We perform a variety of survey techniques out in the field such as, manual searching and hand netting, artificial refuge traps (ARTs), refuge searching, and baited lines/traps. These are performed under specialist crayfish licence holders in the team.

A small white-clawed crayfish held between fingers

A native white-clawed crayfish

A signal crayfish held between fingers

An invasive signal crayfish

A pair of signal crayfish claws laying on rocks

Signal crayfish remains

Call us to discuss your project: 01728 684362 / 07798 941555 or email here

Aquatic Invertebrate Surveys | Suffolk