We have extensive knowledge and expertise in relation to white-clawed crayfish surveys, and their assessment and management. ECOFACT recently completed a contract on behalf of NPWS to provide monitoring baseline data for the conservation status of white-clawed crayfish in 25 Irish lakes. These lakes are located in the Bonet, Boyne, Corrib, Erne, Moy, Liffey and Shannon catchments.

Every six years, Member States of the European Union are required to report on the conservation status of all habitats and species listed on the annexes of the Habitats Directive as required under Article 17 of the Directive. The status assessments for white-clawed crayfish was submitted to the European Commission in June 2013, and ECOFACT contributed significantly to the information presented in this document.

The global decline of the white-clawed crayfish is due habitat loss, but also more importantly due impacts of non-native crayfish, such as the Signal Crayfish Pacifastacus leniusculus and associated crayfish plague Aphanomyces astaci. Other non-native crayfish species that are a risk of introduction to Ireland include the Red Swamp Crayfish Procambarus clarkii and Spiny-Checked crayfish Orconectes limosis. Both of these North American species are crayfish plague carriers and already occur in Britain.

The presence of white-clawed crayfish on a site would be a planning concern, and efforts are required to ensure that white-clawed crayfish and their habitat are retained and suitably protected within a development. Typical mitigation measures for white-clawed crayfish include the removal of individual animals from the watercourse or water-body prior to, or during, construction operations, alongside habitat reinstatement, creation or enhancement as necessary.

Further information

• White-clawed crayfish surveys 2014
• Article 17 report for White-clawed crayfish Austopotamobius pallipes [1092]
• O’Connor, W., Hayes, G., O’Keeffe, K., & Lynn, D. (2009) Monitoring of White-clawed crayfish Austropotamobius pallipes in Irish Lakes during 2007. Irish Wildlife Manuals No. 37. National Parks and Wildlife Service

For more information on ECOFACT’s experience in relation to white -clawed-crayfish and other Annex II listed aquatic species please contact info@ecofact.ie.