Biodiversity loss has been caused by global warming and the spread of invasive alien species. A long-term conservation programme has been implemented to enhance the populations of the native crayfish Austropotamobius pallipes in Italy. This also includes the control of non-native crayfish species, in order to limit their spread. Since 2022, control measures have been implemented for Procambarus clarkii populations, primarily involving volunteers trapping invasive crayfish. The first-year session by massive trapping activities resulted in the capture of over 45,000 crayfish in six ponds, with varying CPUE values per site but consistent trapping trends. Since 2023, trapping has been followed by sterilisation using the pleopod cutting technique, which has been demonstrated to be successful under controlled conditions, both in laboratory and mesocosm settings. After three-year activities by sterilisation, a total of 4,700 crayfish were captured, representing a 89% decline. The most successful outcome was achieved by the ratio of juveniles to adults, showing a 84 % decrease in juveniles and therefore indicating a population that is progressively ageing. Engaging local communities and ensuring their support is the key to achieving long-term success in eradication.

Acknowledgement: the study was financially supported by the by the European Funds through Financial Instrument for the Environment, LIFE Nature and Biodiversity (LIFE18 NAT/IT/000806).