Current ideas on methodological approaches in European crayfish conservation and restocking procedures

The present paper deals with reintroductions or restocking as a management strategy for the indigenous crayfish species (ICS) in Europe. The suitability of the target habitat, the stocking material and the stocking procedure itself are paramount during any reintroduction measure: apart from general water quality and structural parameters, a suitable habitat is ideally geographically isolated from other surface waters and human activities such as intensive fishing pressure and agricultural practices. Genetics of stocking material must be considered. However, it is first essential to make sure that the target habitat is free of crayfish plague. Analyses of experiences gathered in various European countries indicate how difficult it is to get the best information as a basis for successful restocking and consequently the discussions recently conducted among European researchers and managers were aimed at achieving consensus and common strategies.