ROUNDTABLE SESSION 1 THREATS TO INDIGENOUS CRAYFISH POPULATIONS – STUDIES ON A LANDSCAPE LEVEL

The present paper summarizes the outcome of a round-table discussion on landscape-level perspectives on threats to indigenous European crayfish populations, which took place during the CRAYNET Conference in Halden, Norway in September 2003. A comparison of threats to European indigenous crayfish indicated that land-use is considered as the second most important impact on crayfish after non-indigenous species. It became furthermore evident that the main crayfish distribution data and land-use data are readily available in many European countries. They even exist as georeferenced data in data formats usable with Geographical Information Systems (GIS). In spite of this situation, it is rather surprising that there is only one case study available that attempted to link land-use data with crayfish presence on a landscape level. As a result of this study, GIS proved a suitable tool for the assessment of land-use effects and overall human impact on crayfish distribution on a landscape level.