<p>Transport is an unavoidable stressor for numerous fisheries conservation and supplementation programs. We aimed to determine whether structural and diet enrichment during rearing can be used as a strategy to reduce the effects of transport-induced stress in captive-reared fish by providing them with a more complex and potentially stimulating environment compared to conventional rearing practices. First, to determine the expected changes in stress physiology during loading and transport, we shadowed an Atlantic salmon (<i>Salmo salar</i>) stocking team on two conventional reintroduction stocking efforts. Fish were blood- and gill-sampled for multiple physiological metrics (cortisol, glucose, lactate and gene expression) at key timepoints throughout conventional loading and transport procedures. Next, we conducted a follow-up transport experiment that compared probiotic diet supplementation, structural enrichment and combined probiotic and structural enrichment versus controls (barren rearing tanks) as pre-transport rearing strategies. For both parts of the study, all fish that were loaded and/or transported demonstrated significantly higher cortisol, glucose and lactate concentrations compared to fish not loaded or transported. Fish that experienced conventional loading and transport procedures also demonstrated significant increases in transcript abundance for two stress-related genes, compared to fish not loaded or transported. However, throughout transport procedures, enrichment in rearing had no significant effect on reducing cortisol, glucose and lactate concentrations. Our collaborative findings will inform management agencies and practitioners focused on monitoring and regulating physiological stress related to transport procedures with the aim of impacting the post-release success of fish that are transported as part of fisheries conservation and supplementation programs.</p>