“…The demand for fish is increasing in Switzerland and worldwide, as indicated by the increase in fish consumption per person (FAO (Food & Agriculture Organization of the United Nations), 2012, 2018; FSO (Federal Statistical Office), 2018b; Keller et al, 2012) and increase in population growth (Eurostat, 2019; FAO (Food & Agriculture Organization of the United Nations), 2012; FSO (Federal Statistical Office), 2018a). Because of overfishing of wild fish, global fishing yields have reached their limits (Chassot et al., 2010; Worm & Branch, 2012) and aquaculture is growing rapidly as an alternative source of aquatic animals (Bostock et al., 2010; Ibrahim et al., 2020). Infectious diseases, especially bacterial infections (Defoirdt, Sorgeloos, & Bossier, 2011; Lin et al., 2016), are the leading cause of mortality in aquaculture (Aunsmo et al., 2008) and are of significant economic and welfare importance (Defoirdt et al., 2011; Lafferty et al., 2015; Subasinghe, Bondad‐Reantaso, & McGladdery, 2001).…”