Transdisciplinary cross-border approach to address the problem of non-native species in mollusc aquaculture

Aquaculture is one of the main vectors for the introduction of non-native species (NNS) in the Mediterranean. Poor knowledge about their presence in molluscs farms and insufficient legislative measures at both the national and European levels make it impossible to develop effective management strategies to contain their spread in the basin. Since 2019, the University of Bologna in Italy, has been applying a transdisciplinary approach to solve these problems in the cultivation of mussels and oysters in the Adriatic Sea, engaging also Croatian and Slovenian partners. We applied local ecological knowledge to gain access, through questionaries, to farmers' awareness of NNS, their observations of environmental changes in mollusc farms, and farming practices that promote the spread of NNS. An extensive sampling campaign and analysis of fauna associated with farmed molluscs along the Adriatic coast have provided updated information on the presence of NNS. Molecular methods have made it possible to detect new alien mudworms (Polychaeta: Polydora spp.) which are pests of oysters, and to trace their invasion routes in the Adriatic. The involvement of various stakeholders enabled to disseminate the results and open channels to address the problem of NNS spread in molluscs farming through further coordinated actions.