The aim of the experiment was to investigate how induced stress can affect skin welfare of broodstock of lumpfish. From a population of approx. 300 fish of 1587 g (SEM ± 704 g), a sub-population of 20 fish were injected with 30 mg/kg fish cortisol implants 5 January 2018. The control group was not treated with implants. The stress-induced cortisol implant group showed elevated plasma cortisol over a period of approximately one month. Analyses of mucus cell area and density suggested that induced stress could produce a positive functional response (stimulus) in lumpfish early in the experiment, through a gentle increase in the barrier strength of the skin, and reduced mucus cell size and increased density of mucous cells, resulting in a strengthening of the respiratory capacity of the gills. Mucous cell density and calculated barrier strength in the skin were significantly negatively correlated with plasma cortisol, while in the gill filaments of females there was a significant negative correlation between mucous cell density and estrogen levels. The reduced volumetric density of "empty" cells (Q cells) after stress inducement indicates that these cells are important for the maintenance of homeostasis. The fish in this experiment were considered more robust compared to previous analyses on smaller lumpfish.