Present distribution and future spread of louisiana red swamp crayfish Procambarus clarkii (Crustacea, Decapoda, Astacida, Cambaridae) in Britain : Implications for conservation of native species and habitats

摘要

The Louisiana red swamp crayfish Procambarus clarkii is highly invasive. It is now common in Europe where it is causing problems to native wildlife and structural damage to habitats. Procambarus clarkii was first recorded in Britain in 1991 and is currently found in the Hampstead Heath ponds and Regents Canal in London, as well as a small lake 15 km outside of Greater London. This paper considers how conditions in Britain affect the life cycle, breeding habits and potential range expansion of P. clarkii. Results of trapping surveys are presented in an effort to map the current distribution of P. clarkii and predict which areas it could colonise in the future. The ecological impact of potential colonisation is discussed by considering the impact P. clarkii has in mainland Europe. It is concluded that P. clarkii is likely to spread from Regents Canal into the nearby Brent, Crane, Colne, Lee and Thames catchments within 50 years. This time would be reduced significantly if further deliberate or accidental introductions by humans occur since this is deemed a far greater risk than natural expansion. P. clarkii is expected to have a negative impact on aquatic ecosystems in Britain and therefore tighter enforcement is needed to slow the spread of this species.