Improving welfare assessment in fish: behavioural stress indicators and daily rhythms for precision aquaculture

This doctoral thesis aimed to improve fish welfare assessment by developing non-invasive indicators of stress (i.e., behavioural indicators) and examining daily rhythms in stress responses. Furthermore, this research explored strategies to enhance fish welfare by refining management practices that consider the time of day, developmental stage, social interactions, and the impact of sustainable aquafeeds. Through a series of experiments, this thesis evaluated species-specific stress responses in model and farmed species, including Nile tilapia (Oreochromis niloticus), tench (Tinca tinca), koi carp (Cyprinus carpio), turbot (Scophthalmus maximus), gilthead seabream (Sparus aurata) and zebrafish (Danio rerio), offering novel insights into the distinct welfare needs and indicators of each species.