AS WE SEE IT Reared fish, farmed escapees and wild fish stocks-a triangle of pathogen transmission of concern to Mediterranean aquaculture management

Although aquaculture in the Mediterranean is a relatively young industry, finfish diseases have been reported to cause considerable problems and mortalities among the farmed stocks. In general, the farming activity and the open design of Mediterranean aquaculture systems allow the transmission of infectious pathogens within and among farm facilities. Fish health and biosecurity programmes at farms have focused on the most obvious pathways for transmission of pathogens, i.e. through transport of infected farmed fish from hatcheries, infected equipment, staff and vessels, as well as through water currents. However, little attention has been devoted to the potential risk of pathogen and disease transmission in Mediterranean open-sea aquaculture through movements of fish. The present study focuses on the importance of considering possible pathogen transmission between reared fish, farmed escapees and farm-aggregated fish when making management decisions.