Distribution of Non-Indigenous Crayfish Species in Estonia and Their Impacts on Noble Crayfish (Astacus astacus L.) Populations

Invasive non-indigenous crayfish species (NICS) are a major threat to the existence of native populations in European freshwater ecosystems. The discovery signal Pacifastacus leniusculus, marbled Procambarus virginalis, and spiny-cheek Faxonius limosus Estonia has increased risk extinction Estonia’s only species, noble Astacus astacus. aim this study was give an overview status, distribution, impacts P. F. limosus, virginalis on A. astacus assess effect trapping NICS abundance. Annual monitoring been carried out since 2008 as part conservation eradication plan. In study, we present data from nine sampling locations monitored 2010 2022. spread continues increase beyond their distribution areas, two leniusculus live sympatry. Our results suggest that limited population abundance, have already caused populations. However, intensive should continue simultaneously with sensitive molecular techniques monitor NICS.