Socio-economic drivers and non-indigenous freshwater crayfish species in Europe

Non-indigenous freshwater crayfish species (NICS) outnumber the indigenous ones in many European countries, representing a major threat to biodiversity via the spread of crayfish ‘plague’ and aggressive invasion andantagonismperformance.Althoughthebiologicalbasisofthissituation is well studied, the possible role of social, economic and demographic factors on this situation has been ignored. In an attempt to explore such relationships, we suggest that human population density and economic growth (measured as gross domestic product (GDP) per capita) are positivelyrelatedtotheincreasednumberofNICSintheEUarea.Moreover, this pattern is evident in countries with higher overall footprint (i.e. the human demand of biologically productive land and sea in global hectares required to provide resources and services on waste assimilation) compared to biocapacity. Within the above context, actions are urgently needed to restore/balance existing and projected metabolic rifts (i.e. rupturesinthenormalmetabolicprocessesinnaturalsystems)created by the presence of NICS.