The North American signal cray?sh (Pacifastacus leniusculus) has been present in Scotland since at least 1995 and the species is now known to be present in a number of catchments. Once established, few opportunities for containment exist and eradication can often be impossible to achieve. However, in small, isolated water bodies, the application of a non-cray?sh-speci?c biocide has provided the opportunity to remove this species permanently. In July 2011, signal cray?sh were discovered in a ?ooded quarry pond at Ballachulish in the Scottish Highlands.

The EU regulation 1143/2014 “On the prevention and management of the introduction and spread of invasive alien species” entered into force on 1 January 2015. On 13 July 2016, the EU list of invasive alien species that require action was adopted. The list includes ?ve di?erent cray?sh species. Member states will be required to take measures for early detection and rapid eradication of these species. Except for some eradications performed in the United Kingdom and Norway, there has not been much e?ort put into eradication of invasive cray?sh species throughout Europe.