American Signal Crayfish

The Problem?

Photograph by Bruce Shortland

The American Signal Crayfish (Pacifastacus leniusculus) was introduced during the 1970s for the food industry. It is now widespread up and down streams where it is destroying native White Clawed Crayfish populations by direct competition, predation and the spread of crayfish plague. American Signal Crayfish also predate on native fish eggs and invertebrates. As well as impacting on wildlife American Signal Crayfish increasing erosion and bank loss by creating large burrows in the bottom of riverbanks extending up to 3 foot.

What We Are Doing?

Photograph by David Johnson

Whilst the Tees Valley Wildlife Trust has no crayfish specific projects, trust projects operating within waterways follow bio-security measures to prevent spread of the crayfish plague. Check, Clean, Dry is adhered to for protective clothing and survey equipment used in the aquatic environment, whilst use of an aquatic friendly disinfectant is used to clean equipment to prevent the spread of crayfish plague between water bodies.