Open access publications in the SLU publication database

Abstract

Invasive crayfish have attracted much attention by scientists and policy makers in Europe, partly due to their ability to transmit diseases to native crayfish species. In December 2012, 13 specimens of a new crayfish species were found in the River Märstaån in central Sweden. Mitochondrial DNA analyses identified them as Marmorkrebs Procambarus fallax f. virginalis. It is not known if Marmorkrebs can establish reproducing populations in Sweden, and knowledge of how different stressors negatively affect the eventual reproduction of Marmorkrebs is lacking. Since the parthenogenetic Marmorkrebs has potential to become an invasive species in Sweden and Scandinavia, it may pose a serious threat to native crayfish, fish and fisheries. Swedish authorities have produced an action plan with a national strategy in order to establish a system that manages the import, movement and release of alien species and genotypes. The River Märstaån leads to Lake Mälaren, without barriers, which enhances the risk that the crayfish will also invade the lake. Due to the potential threat of further spread, it is imperative to make an action plan with a risk assessment targeted specifically towards the Marmorkrebs in River Märstaån.